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apache / hawq / 91c45cab0e5844abfe0f398f2378637f4028fe45 / . / src / backend / postmaster / postmaster.c
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*-------------------------------------------------------------------------
*
* postmaster.c
* This program acts as a clearing house for requests to the
* POSTGRES system. Frontend programs send a startup message
* to the Postmaster and the postmaster uses the info in the
* message to setup a backend process.
*
* The postmaster also manages system-wide operations such as
* startup and shutdown. The postmaster itself doesn't do those
* operations, mind you --- it just forks off a subprocess to do them
* at the right times. It also takes care of resetting the system
* if a backend crashes.
*
* The postmaster process creates the shared memory and semaphore
* pools during startup, but as a rule does not touch them itself.
* In particular, it is not a member of the PGPROC array of backends
* and so it cannot participate in lock-manager operations. Keeping
* the postmaster away from shared memory operations makes it simpler
* and more reliable. The postmaster is almost always able to recover
* from crashes of individual backends by resetting shared memory;
* if it did much with shared memory then it would be prone to crashing
* along with the backends.
*
* When a request message is received, we now fork() immediately.
* The child process performs authentication of the request, and
* then becomes a backend if successful. This allows the auth code
* to be written in a simple single-threaded style (as opposed to the
* crufty "poor man's multitasking" code that used to be needed).
* More importantly, it ensures that blockages in non-multithreaded
* libraries like SSL or PAM cannot cause denial of service to other
* clients.
*
*
* Portions Copyright (c) 2005-2009, Greenplum inc
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.505.2.3 2007/02/11 15:12:21 mha Exp $
*
*
* NOTES
*
* Initialization:
* The Postmaster sets up shared memory data structures
* for the backends.
*
* Synchronization:
* The Postmaster shares memory with the backends but should avoid
* touching shared memory, so as not to become stuck if a crashing
* backend screws up locks or shared memory. Likewise, the Postmaster
* should never block on messages from frontend clients.
*
* Garbage Collection:
* The Postmaster cleans up after backends if they have an emergency
* exit and/or core dump.
*
* Error Reporting:
* Use write_stderr() only for reporting "interactive" errors
* (essentially, bogus arguments on the command line). Once the
* postmaster is launched, use ereport(). In particular, don't use
* write_stderr() for anything that occurs after pmdaemonize.
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <sys/wait.h>
#include <ctype.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <limits.h>
/* headers required for process affinity bindings */
#if defined(pg_on_solaris)
#include <sys/types.h>
#include <sys/processor.h>
#include <sys/procset.h>
#endif
#ifdef HAVE_NUMA_H
#define NUMA_VERSION1_COMPATIBILITY 1
#include <numa.h>
#endif
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#ifdef USE_BONJOUR
#include <DNSServiceDiscovery/DNSServiceDiscovery.h>
#endif
#include "access/transam.h"
#include "access/xlog.h"
#include "bootstrap/bootstrap.h"
#include "catalog/pg_control.h"
#include "catalog/pg_database.h"
#include "cdb/cdbutil.h"
#include "commands/async.h"
#include "lib/dllist.h"
#include "libpq/auth.h"
#include "libpq/ip.h"
#include "libpq/libpq.h"
#include "libpq/pqsignal.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "postmaster/fork_process.h"
#include "postmaster/pgarch.h"
#include "postmaster/postmaster.h"
#include "postmaster/seqserver.h"
#include "postmaster/checkpoint.h"
#include "postmaster/fts.h"
#include "postmaster/perfmon.h"
#include "postmaster/primary_mirror_mode.h"
#include "postmaster/walsendserver.h"
#include "postmaster/walredoserver.h"
#include "postmaster/ddaserver.h"
#include "postmaster/syslogger.h"
#include "postmaster/perfmon_segmentinfo.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "tcop/tcopprot.h"
#include "utils/builtins.h"
#include "utils/datetime.h"
#include "utils/faultinjector.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/resscheduler.h"
#include "cdb/cdbgang.h" /* cdbgang_parse_gpqeid_params */
#include "cdb/cdblogsync.h"
#include "cdb/cdbvars.h"
#include "cdb/cdbfilerep.h"
#include "cdb/cdbmetadatacache.h"
#include "resourcemanager/envswitch.h"
#include "resourcemanager/communication/rmcomm_QD2RM.h"
#include "resourcemanager/resourcemanager.h"
#include "resourcemanager/errorcode.h"
#ifdef EXEC_BACKEND
#include "storage/spin.h"
void SeqServerMain(int argc, char *argv[]);
void FtsProbeMain(int argc, char *argv[]);
#endif
/*
* List of active backends (or child processes anyway; we don't actually
* know whether a given child has become a backend or is still in the
* authorization phase). This is used mainly to keep track of how many
* children we have and send them appropriate signals when necessary.
*
* "Special" children such as the startup, bgwriter and autovacuum launcher
* tasks are not in this list. Autovacuum worker processes are in it.
* Also, "dead_end" children are in it: these are children launched just
* for the purpose of sending a friendly rejection message to a would-be
* client. We must track them because they are attached to shared memory,
* but we know they will never become live backends. dead_end children are
* not assigned a PMChildSlot.
*/
typedef struct bkend
{
pid_t pid; /* process id of backend */
long cancel_key; /* cancel key for cancels for this backend */
int child_slot; /* PMChildSlot for this backend, if any */
bool is_autovacuum; /* is it an autovacuum process? */
bool dead_end; /* is it going to send an error and quit? */
Dlelem elem; /* list link in BackendList */
} Backend;
static Dllist *BackendList;
/* #define DO_DDA_SERV 1 */
/* CDB */
typedef enum pmsub_type
{
SeqServerProc = 0,
WalSendServerProc,
WalRedoServerProc,
#ifdef DO_DDA_SERV
DdaServerProc,
#endif
PerfmonProc,
PerfmonSegmentInfoProc,
MetadataCacheProc,
ResouceManagerProc,
MaxPMSubType
} PMSubType;
#ifdef EXEC_BACKEND
static Backend *ShmemBackendArray;
#endif
/* The socket number we are listening for connections on */
int PostPortNumber;
char *UnixSocketDir;
char *ListenAddresses;
/*
* ReservedBackends is the number of backends reserved for superuser use.
* This number is taken out of the pool size given by MaxBackends so
* number of backend slots available to non-superusers is
* (MaxBackends - ReservedBackends). Note what this really means is
* "if there are <= ReservedBackends connections available, only superusers
* can make new connections" --- pre-existing superuser connections don't
* count against the limit.
*/
int ReservedBackends;
/* The socket(s) we're listening to. */
#define MAXLISTEN 64
static int ListenSocket[MAXLISTEN];
/*
* Set by the -o option
*/
static char ExtraOptions[MAXPGPATH];
/*
* These globals control the behavior of the postmaster in case some
* backend dumps core. Normally, it kills all peers of the dead backend
* and reinitializes shared memory. By specifying -s or -n, we can have
* the postmaster stop (rather than kill) peers and not reinitialize
* shared data structures. (Reinit is currently dead code, though.)
*/
static bool Reinit = true;
static int SendStop = false;
/* still more option variables */
bool EnableSSL = false;
bool SilentMode = false; /* silent_mode */
int PreAuthDelay = 0;
int AuthenticationTimeout = 60;
bool log_hostname; /* for ps display and logging */
bool Log_connections = false;
bool Db_user_namespace = false;
char *bonjour_name;
static PrimaryMirrorMode gInitialMode = PMModeMirrorlessSegment;
/* PIDs of special child processes; 0 when not running */
static pid_t StartupPID = 0,
StartupPass2PID = 0,
StartupPass3PID = 0,
StartupPass4PID = 0,
BgWriterPID = 0,
CheckpointPID = 0,
AutoVacPID = 0,
PgArchPID = 0,
PgStatPID = 0,
SysLoggerPID = 0;
#define StartupPidsAllZero() (StartupPID == 0 || StartupPass2PID == 0 || StartupPass3PID == 0 || StartupPass4PID == 0)
static volatile sig_atomic_t filerep_has_signaled_state_change = false;
static volatile sig_atomic_t filerep_requires_postmaster_reset = false;
static volatile sig_atomic_t filerep_has_signaled_backends_shutdown = false;
/* Startup/shutdown state */
#define NoShutdown 0
#define SmartShutdown 1
#define FastShutdown 2
#define ImmediateShutdown 3
static int Shutdown = NoShutdown;
/* T if recovering from a backend crash, up to the point of resetting shared memory and starting up again
* (or going into quiescent mode if it's a primary/mirror that has reset) */
static bool FatalError = false;
static bool RecoveryError = false; /* T if WAL recovery failed */
static int pmResetCounter = 0;
static bool gHaveCalledOnetimeInitFunctions = false;
/*
* We use a simple state machine to control startup, shutdown, and
* crash recovery (which is rather like shutdown followed by startup).
*
* After doing all the postmaster initialization work, we enter PM_STARTUP
* state and the startup process is launched. The startup process begins by
* reading the control file and other preliminary initialization steps.
* In a normal startup, or after crash recovery, the startup process exits
* with exit code 0 and we switch to PM_RUN state. However, archive recovery
* is handled specially since it takes much longer and we would like to support
* hot standby during archive recovery.
*
* When the startup process is ready to start archive recovery, it signals the
* postmaster, and we switch to PM_RECOVERY state. The background writer is
* launched, while the startup process continues applying WAL.
* After reaching a consistent point in WAL redo, startup process signals
* us again, and we switch to PM_RECOVERY_CONSISTENT state. There's currently
* no difference between PM_RECOVERY and PM_RECOVERY_CONSISTENT, but we
* could start accepting connections to perform read-only queries at this
* point, if we had the infrastructure to do that.
* When archive recovery is finished, the startup process exits with exit
* code 0 and we switch to PM_RUN state.
*
* Normal child backends can only be launched when we are in PM_RUN state.
* (We also allow it in PM_WAIT_BACKUP state, but only for superusers.)
* In other states we handle connection requests by launching "dead_end"
* child processes, which will simply send the client an error message and
* quit. (We track these in the BackendList so that we can know when they
* are all gone; this is important because they're still connected to shared
* memory, and would interfere with an attempt to destroy the shmem segment,
* possibly leading to SHMALL failure when we try to make a new one.)
* In PM_WAIT_DEAD_END state we are waiting for all the dead_end children
* to drain out of the system, and therefore stop accepting connection
* requests at all until the last existing child has quit (which hopefully
* will not be very long).
*
* Notice that this state variable does not distinguish *why* we entered
* states later than PM_RUN --- Shutdown and FatalError must be consulted
* to find that out. FatalError is never true in PM_INIT through PM_RUN
* states, nor in PM_SHUTDOWN states (because we don't enter those states
* when trying to recover from a crash).
*
* RecoveryError means that we have crashed during recovery, and
* should not try to restart.
*/
typedef enum
{
PM_INIT, /* postmaster starting */
PM_STARTUP, /* waiting for startup subprocess */
PM_STARTUP_PASS2, /* waiting for startup pass 2 subprocess */
PM_STARTUP_PASS3, /* waiting for startup pass 3 subprocess */
PM_STARTUP_PASS4, /* waiting for startup pass 4 subprocess */
PM_RECOVERY, /* in archive recovery mode */
PM_RECOVERY_CONSISTENT, /* consistent recovery mode */
PM_RUN, /* normal "database is alive" state */
//PM_WAIT_BACKUP, /* waiting for online backup mode to end */
/** ORDER OF SHUTDOWN ENUMS MATTERS: we move through the states by adding 1 to the current state */
/* shutdown has begun. */
PM_CHILD_STOP_BEGIN,
/* check to make sure startup processes are done */
PM_CHILD_STOP_WAIT_STARTUP_PROCESSES,
/* waiting for live backends to exit */
PM_CHILD_STOP_WAIT_BACKENDS,
/* waiting for pre-bgwriter services to exit */
PM_CHILD_STOP_WAIT_PREBGWRITER,
/* waiting for bgwriter to do shutdown ckpt */
PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT,
/* waiting for post-bgwriter services */
PM_CHILD_STOP_WAIT_POSTBGWRITER,
/* waiting for dead_end children to exit */
PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN,
/* all important children have exited */
PM_CHILD_STOP_WAIT_NO_CHILDREN,
/* this is NOT a stopping state; this state is used after everything has been stopped for postmaster reset
* during mirroring -- if we should reset the peer as well and start the system back up, we enter this
* state */
PM_POSTMASTER_RESET_FILEREP_PEER,
PM__ENUMERATION_COUNT
} PMState;
/**
* WARNING: some of these labels are used in management scripts -- so don't
* change them here without checking the management scripts (check for starting with child_stop_
* as well -- management scripts use startWith in some cases)
*/
static const char *const gPmStateLabels[] =
{
"init",
"startup",
"startup_pass2",
"startup_pass3",
"startup_pass4",
"recovery",
"recovery_consistent",
"run",
"child_stop_begin",
"child_stop_wait_startup_processes",
"child_stop_wait_backends",
"child_stop_wait_pre_bgwriter",
"child_stop_bgwriter_checkpoint",
"child_stop_post_bgwriter",
"child_stop_dead_end_children",
"child_stop_no_children",
"reset_filerep_peer"
};
typedef enum
{
PEER_RESET_NONE,
PEER_RESET_FAILED,
PEER_RESET_SUCCEEDED,
} PeerResetResult;
static PeerResetResult peerResetResult = PEER_RESET_NONE;
static PMState pmState = PM_INIT;
/**
* We set this to true to force the state machine to run the actions for transitioning to its current state,
* even if the state is not changed
*/
static bool pmStateMachineMustRunActions = false;
/* CDB */
typedef enum PMSUBPROC_FLAGS
{
PMSUBPROC_FLAG_QD = 0x1,
PMSUBPROC_FLAG_STANDBY = 0x2,
PMSUBPROC_FLAG_QE = 0x4,
PMSUBPROC_FLAG_QD_AND_QE = (PMSUBPROC_FLAG_QD|PMSUBPROC_FLAG_QE),
PMSUBPROC_FLAG_STOP_AFTER_BGWRITER = 0x8,
} PMSUBPROC_FLAGS;
typedef struct pmsubproc
{
pid_t pid; /* process id (0 when not running) */
PMSubType procType; /* process type */
PMSubStartCallback *serverStart; /* server start function */
char *procName;
int flags; /* flags indicating in which kind
* of instance to start the process */
bool cleanupBackend; /* flag if process failure should
* cause cleanup of backend processes
* false = do not cleanup (eg. for gpperfmon) */
} PMSubProc;
static PMSubProc PMSubProcList[MaxPMSubType] =
{
{0, SeqServerProc,
(PMSubStartCallback*)&seqserver_start,
"seqserver process", PMSUBPROC_FLAG_QD, true},
{0, WalSendServerProc,
(PMSubStartCallback*)&walsendserver_start,
"walsendserver process",(PMSUBPROC_FLAG_QD|PMSUBPROC_FLAG_STOP_AFTER_BGWRITER), true},
{0, WalRedoServerProc,
(PMSubStartCallback*)&walredoserver_start,
"walredoserver process", PMSUBPROC_FLAG_STANDBY, true},
{0, PerfmonProc,
(PMSubStartCallback*)&perfmon_start,
"perfmon process", PMSUBPROC_FLAG_QD, false},
{0, PerfmonSegmentInfoProc,
(PMSubStartCallback*)&perfmon_segmentinfo_start,
"stats sender process", PMSUBPROC_FLAG_QD_AND_QE, true},
{0, MetadataCacheProc,
(PMSubStartCallback*)&metadatacache_start,
"metadatacache process", PMSUBPROC_FLAG_QD, true},
{0, ResouceManagerProc,
(PMSubStartCallback*)&ResManagerProcessStartup,
"resourcemanager process", PMSUBPROC_FLAG_QD_AND_QE, true},
#ifdef DO_DDA_SERV
{0, DdaServerProc,
(PMSubStartCallback*)&ddaserver_start,
"ddaserver process", PMSUBPROC_FLAG_QD_AND_QE, true},
#endif
};
bool ClientAuthInProgress = false; /* T during new-client
* authentication */
bool redirection_done = false; /* stderr redirected for syslogger? */
static volatile bool force_autovac = false; /* received START_AUTOVAC signal */
/*
* State for assigning random salts and cancel keys.
* Also, the global MyCancelKey passes the cancel key assigned to a given
* backend from the postmaster to that backend (via fork).
*/
static unsigned int random_seed = 0;
static struct timeval random_start_time;
extern char *optarg;
extern int optind,
opterr;
#ifdef HAVE_INT_OPTRESET
extern int optreset; /* might not be declared by system headers */
#endif
/* some GUC values used in fetching status from status transition */
extern char *locale_monetary;
extern char *locale_numeric;
extern char *locale_collate;
/*
* postmaster.c - function prototypes
*/
static void getInstallationPaths(const char *argv0);
static void checkDataDir(void);
static void checkPgDir(const char *dir);
static void checkPgDir2(const char *dir);
#ifdef USE_TEST_UTILS
static void SimExProcExit(void);
#endif /* USE_TEST_UTILS */
#ifdef USE_BONJOUR
static void reg_reply(DNSServiceRegistrationReplyErrorType errorCode,
void *context);
#endif
static void pmdaemonize(void);
static Port *ConnCreate(int serverFd);
static void ConnFree(Port *port);
/**
* @param isReset if true, then this is a reset (as opposed to the initial creation of shared memory on startup)
*/
static void reset_shared(int port, bool isReset);
static void SIGHUP_handler(SIGNAL_ARGS);
static void pmdie(SIGNAL_ARGS);
static volatile int need_call_reaper = 0;
static void reaper(SIGNAL_ARGS);
static void do_reaper(void);
static void do_immediate_shutdown_reaper(void);
static bool ServiceProcessesExist(int excludeFlags);
static bool StopServices(int excludeFlags, int signal);
static char *GetServerProcessTitle(int pid);
static void sigusr1_handler(SIGNAL_ARGS);
static void dummy_handler(SIGNAL_ARGS);
static void CleanupBackend(int pid, int exitstatus, bool resetRequired);
static void HandleChildCrash(int pid, int exitstatus, const char *procname);
static void LogChildExit(int lev, const char *procname,
int pid, int exitstatus);
static void PostmasterStateMachine(void);
static void BackendInitialize(Port *port);
static int BackendRun(Port *port);
static void ExitPostmaster(int status);
static bool ServiceStartable(PMSubProc *subProc);
static int ServerLoop(void);
static int BackendStartup(Port *port);
static int ProcessStartupPacket(Port *port, bool SSLdone);
static void processCancelRequest(Port *port, void *pkt);
static void processPrimaryMirrorTransitionRequest(Port *port, void *pkt);
static void processPrimaryMirrorTransitionQuery(Port *port, void *pkt);
static int initMasks(fd_set *rmask);
static void report_fork_failure_to_client(Port *port, int errnum);
static enum CAC_state canAcceptConnections(void);
static long PostmasterRandom(void);
static void RandomSalt(char *md5Salt);
static void signal_child(pid_t pid, int signal);
static void SignalSomeChildren(int signal, bool only_autovac);
#define SignalChildren(sig) SignalSomeChildren(sig, false)
#define SignalAutovacWorkers(sig) SignalSomeChildren(sig, true)
static int CountChildren(void);
static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
static pid_t StartChildProcess(AuxProcType type);
static void setProcAffinity(int id);
#ifdef EXEC_BACKEND
#ifdef WIN32
static pid_t win32_waitpid(int *exitstatus);
static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired);
static HANDLE win32ChildQueue;
typedef struct
{
HANDLE waitHandle;
HANDLE procHandle;
DWORD procId;
} win32_deadchild_waitinfo;
HANDLE PostmasterHandle;
#endif
static pid_t backend_forkexec(Port *port);
static pid_t internal_forkexec(int argc, char *argv[], Port *port);
/* Type for a socket that can be inherited to a client process */
#ifdef WIN32
typedef struct
{
SOCKET origsocket; /* Original socket value, or -1 if not a
* socket */
WSAPROTOCOL_INFO wsainfo;
} InheritableSocket;
#else
typedef int InheritableSocket;
#endif
typedef struct LWLock LWLock; /* ugly kluge */
/*
* Structure contains all variables passed to exec:ed backends
*/
typedef struct
{
Port port;
InheritableSocket portsocket;
char DataDir[MAXPGPATH];
int ListenSocket[MAXLISTEN];
long MyCancelKey;
int MyPMChildSlot;
unsigned long UsedShmemSegID;
void *UsedShmemSegAddr;
slock_t *ShmemLock;
VariableCache ShmemVariableCache;
Backend *ShmemBackendArray;
LWLock *LWLockArray;
PROC_HDR *ProcGlobal;
PGPROC *AuxiliaryProcs;
PMSignalData *PMSignalState;
InheritableSocket pgStatSock;
pid_t PostmasterPid;
TimestampTz PgStartTime;
TimestampTz PgReloadTime;
bool redirection_done;
#ifdef WIN32
HANDLE PostmasterHandle;
HANDLE initial_signal_pipe;
HANDLE syslogPipe[2];
#else
int syslogPipe[2];
#endif
char my_exec_path[MAXPGPATH];
char pkglib_path[MAXPGPATH];
char ExtraOptions[MAXPGPATH];
char lc_collate[NAMEDATALEN];
char lc_ctype[NAMEDATALEN];
} BackendParameters;
static void read_backend_variables(char *id, Port *port);
static void restore_backend_variables(BackendParameters *param, Port *port);
#ifndef WIN32
static bool save_backend_variables(BackendParameters *param, Port *port);
#else
static bool save_backend_variables(BackendParameters *param, Port *port,
HANDLE childProcess, pid_t childPid);
#endif
static void ShmemBackendArrayAdd(Backend *bn);
static void ShmemBackendArrayRemove(Backend *bn);
#endif /* EXEC_BACKEND */
#define StartupDataBase() StartChildProcess(StartupProcess)
#define StartupPass2DataBase() StartChildProcess(StartupPass2Process)
#define StartupPass3DataBase() StartChildProcess(StartupPass3Process)
#define StartupPass4DataBase() StartChildProcess(StartupPass4Process)
#define StartBackgroundWriter() StartChildProcess(BgWriterProcess)
#define StartCheckpointServer() StartChildProcess(CheckpointProcess)
static bool SyncMaster = false;
/* Macros to check exit status of a child process */
#define EXIT_STATUS_0(st) ((st) == 0)
#define EXIT_STATUS_1(st) (WIFEXITED(st) && WEXITSTATUS(st) == 1)
#define EXIT_STATUS_2(st) (WIFEXITED(st) && WEXITSTATUS(st) == 2)
static int Save_MppLocalProcessCounter = 0;
bool GPStandby()
{
return (SyncMaster);
}
/**
* filerep process is interested in the bg writer's pid, so
* all sets of bgwriter pid should go through this function
* so that we update shared memory
*/
static void SetBGWriterPID(pid_t pid)
{
BgWriterPID = pid;
}
/**
* return true if we are allowed to start actual database processes in this state.
*
* Note that this checks whether we are in fault from postmaster reset, so should not be used for
* assertions in do_reaper -- because it may have faulted from the time we started the process
* to the time the reaper is called
*/
static bool
isFullPostmasterAndDatabaseIsAllowed(void)
{
return isPrimaryMirrorModeAFullPostmaster(false) && ! isInFaultFromPostmasterReset();
}
/*
* gpsyncMaster main entry point
*/
int
gpsyncMain(int argc, char *argv[])
{
SyncMaster = true;
return PostmasterMain( argc, argv );
}
int
PostmasterGetMppLocalProcessCounter(void)
{
return Save_MppLocalProcessCounter;
}
static void
signal_child_if_up(int pid, int signal)
{
if ( pid != 0)
{
signal_child(pid, signal);
}
}
/*
* Postmaster main entry point
*/
int
PostmasterMain(int argc, char *argv[])
{
int opt;
int status;
char *userDoption = NULL;
int i;
char stack_base;
COMPILE_ASSERT(ARRAY_SIZE(gPmStateLabels) == PM__ENUMERATION_COUNT);
MyProcPid = PostmasterPid = getpid();
MyStartTime = time(NULL);
IsPostmasterEnvironment = true;
/* Set up reference point for stack depth checking */
stack_base_ptr = &stack_base;
/*
* for security, no dir or file created can be group or other accessible
*/
umask((mode_t) 0077);
/*
* Fire up essential subsystems: memory management
*/
MemoryContextInit();
/*
* By default, palloc() requests in the postmaster will be allocated in
* the PostmasterContext, which is space that can be recycled by backends.
* Allocated data that needs to be available to backends should be
* allocated in TopMemoryContext.
*/
PostmasterContext = AllocSetContextCreate(TopMemoryContext,
"Postmaster",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
MemoryContextSwitchTo(PostmasterContext);
/* Initialize paths to installation files */
getInstallationPaths(argv[0]);
/*
* Options setup
*/
InitializeGUCOptions();
opterr = 1;
/*
* Parse command-line options. CAUTION: keep this in sync with
* tcop/postgres.c (the option sets should not conflict) and with the
* common help() function in main/main.c.
*/
while ((opt = getopt(argc, argv, "A:b:B:C:c:D:d:EeFf:h:ijk:lN:mM:nOo:Pp:r:S:sTt:UW:y:x:z:-:")) != -1)
{
switch (opt)
{
case 'A':
SetConfigOption("debug_assertions", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'B':
SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'D':
userDoption = optarg;
break;
case 'd':
set_debug_options(atoi(optarg), PGC_POSTMASTER, PGC_S_ARGV);
break;
/*
* Normal PostgreSQL used 'E' flag to mean "log_statement='all'",
* but we co-opted this letter for this... I'm afraid to change it,
* because I don't know where this is used.
* ... it's used only here in postmaster.c; it causes the postmaster to
* fork a seqserver process.
*/
case 'E':
/*
* SetConfigOption("log_statement", "all", PGC_POSTMASTER, PGC_S_ARGV);
*/
break;
case 'e':
SetConfigOption("datestyle", "euro", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'F':
SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'f':
if (!set_plan_disabling_options(optarg, PGC_POSTMASTER, PGC_S_ARGV))
{
write_stderr("%s: invalid argument for option -f: \"%s\"\n",
progname, optarg);
ExitPostmaster(1);
}
break;
case 'h':
SetConfigOption("listen_addresses", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'i':
SetConfigOption("listen_addresses", "*", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'j':
/* only used by interactive backend */
break;
case 'k':
SetConfigOption("unix_socket_directory", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'l':
SetConfigOption("ssl", "true", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'm':
/*
* In maintenance mode:
* 1. allow DML on catalog table
* 2. allow DML on segments
*/
SetConfigOption("maintenance_mode", "true", PGC_POSTMASTER, PGC_S_ARGV);
SetConfigOption("allow_segment_DML", "true", PGC_POSTMASTER, PGC_S_ARGV);
SetConfigOption("allow_system_table_mods", "dml", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'M':
/* note that M is a postmaster-only option */
gInitialMode = decipherPrimaryMirrorModeArgument(optarg);
if (gInitialMode == PMModeUninitialized)
{
write_stderr("%s: invalid argument for option -M: \"%s\"\n", progname, optarg);
ExitPostmaster(1);
}
/*
* M defines the role of this instance,
* it can be master, standby or segment
*/
SetSegmentIdentity(optarg);
break;
case 'N':
SetConfigOption("max_connections", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'n':
/* Don't reinit shared mem after abnormal exit */
Reinit = false;
break;
case 'O':
/* Only use in single user mode */
SetConfigOption("allow_system_table_mods", "all", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'o':
/* Other options to pass to the backend on the command line */
snprintf(ExtraOptions + strlen(ExtraOptions),
sizeof(ExtraOptions) - strlen(ExtraOptions),
" %s", optarg);
break;
case 'P':
SetConfigOption("ignore_system_indexes", "true", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'p':
SetConfigOption("port", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'r':
/* only used by single-user backend */
break;
case 'S':
SetConfigOption("work_mem", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 's':
SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'T':
/*
* In the event that some backend dumps core, send SIGSTOP,
* rather than SIGQUIT, to all its peers. This lets the wily
* post_hacker collect core dumps from everyone.
*/
SendStop = true;
break;
case 't':
{
const char *tmp = get_stats_option_name(optarg);
if (tmp)
{
SetConfigOption(tmp, "true", PGC_POSTMASTER, PGC_S_ARGV);
}
else
{
write_stderr("%s: invalid argument for option -t: \"%s\"\n",
progname, optarg);
ExitPostmaster(1);
}
break;
}
case 'U':
/*
* In upgrade mode, we indicate we're in upgrade mode and
* 1. allow DML on persistent table & catalog table
* 2. alter DDL on catalog table (NOTE: upgrade_mode must set beforehand)
* 3. TODO: disable the 4.1 xlog format (stick with the old)
*/
SetConfigOption("upgrade_mode", "true", PGC_POSTMASTER, PGC_S_ARGV);
SetConfigOption("gp_permit_persistent_metadata_update", "true", PGC_POSTMASTER, PGC_S_ARGV);
SetConfigOption("allow_segment_DML", "true", PGC_POSTMASTER, PGC_S_ARGV);
SetConfigOption("allow_system_table_mods", "all", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'W':
SetConfigOption("post_auth_delay", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'c':
case '-':
{
char *name,
*value;
ParseLongOption(optarg, &name, &value);
if (!value)
{
if (opt == '-')
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("--%s requires a value",
optarg)));
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("-c %s requires a value",
optarg)));
}
SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
free(name);
if (value)
free(value);
break;
}
case 'y':
// Indicate that gpstart did not start the standby master.
SetConfigOption("master_mirroring_administrator_disable", "true", PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'x': /* standby master dbid */
SetConfigOption("gp_standby_dbid", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
case 'z':
SetConfigOption("gp_num_contents_in_cluster", optarg, PGC_POSTMASTER, PGC_S_ARGV);
break;
default:
write_stderr("Try \"%s --help\" for more information.\n",
progname);
ExitPostmaster(1);
}
}
/*
* Postmaster accepts no non-option switch arguments.
*/
if (optind < argc)
{
write_stderr("%s: invalid argument: \"%s\"\n",
progname, argv[optind]);
write_stderr("Try \"%s --help\" for more information.\n",
progname);
ExitPostmaster(1);
}
/*
* Locate the proper configuration files and data directory, and read
* postgresql.conf for the first time.
*/
if (!SelectConfigFiles(userDoption, progname))
ExitPostmaster(2);
/*
* CDB/MPP/GPDB: Set the processor affinity (may be a no-op on
* some platforms). The port number is nice to use because we know
* that different segments on a single host will not have the same
* port numbers.
*
* We want to do this as early as we can -- so that the OS knows
* about our binding, and all of our child processes will inherit
* the same binding.
*/
if (gp_set_proc_affinity)
setProcAffinity(PostPortNumber);
/* Verify that DataDir looks reasonable */
checkDataDir();
/* And switch working directory into it */
ChangeToDataDir();
/*
* CDB: Decouple NBuffers from MaxBackends. The entry db doesn't benefit
* from buffers in excess of the global catalog size; this is typically
* small and unrelated to the number of clients. Segment dbs need enough
* buffers to accommodate the QEs concurrently accessing the database; but
* non-leaf QEs don't necessarily access the database (some are used only
* for sorting, hashing, etc); so again the number of buffers need not be
* in proportion to the number of connections.
*/
if (NBuffers < 16)
{
/*
* Do not accept -B so small that backends are likely to starve for
* lack of buffers. The specific choices here are somewhat arbitrary.
*/
write_stderr("%s: the number of buffers (-B) must be at least 16\n", progname);
ExitPostmaster(1);
}
/*
* Check for invalid combinations of GUC settings.
*/
if (ReservedBackends > MaxBackends)
{
write_stderr("%s: superuser_reserved_connections must be less than max_connections\n", progname);
ExitPostmaster(1);
}
/*
* Other one-time internal sanity checks can go here, if they are fast.
* (Put any slow processing further down, after postmaster.pid creation.)
*/
if (!CheckDateTokenTables())
{
write_stderr("%s: invalid datetoken tables, please fix\n", progname);
ExitPostmaster(1);
}
/*
* Now that we are done processing the postmaster arguments, reset
* getopt(3) library so that it will work correctly in subprocesses.
*/
optind = 1;
#ifdef HAVE_INT_OPTRESET
optreset = 1; /* some systems need this too */
#endif
/* For debugging: display postmaster environment */
{
extern char **environ;
char **p;
ereport(DEBUG3,
(errmsg_internal("%s: PostmasterMain: initial environ dump:",
progname)));
ereport(DEBUG3,
(errmsg_internal("-----------------------------------------")));
for (p = environ; *p; ++p)
ereport(DEBUG3,
(errmsg_internal("\t%s", *p)));
ereport(DEBUG3,
(errmsg_internal("-----------------------------------------")));
}
/*
* Fork away from controlling terminal, if silent_mode specified.
*
* Must do this before we grab any interlock files, else the interlocks
* will show the wrong PID.
*/
if (SilentMode)
pmdaemonize();
/*
* Create lockfile for data directory.
*
* We want to do this before we try to grab the input sockets, because the
* data directory interlock is more reliable than the socket-file
* interlock (thanks to whoever decided to put socket files in /tmp :-().
* For the same reason, it's best to grab the TCP socket(s) before the
* Unix socket.
*/
CreateDataDirLockFile(true);
/*
* If timezone is not set, determine what the OS uses. (In theory this
* should be done during GUC initialization, but because it can take as
* much as several seconds, we delay it until after we've created the
* postmaster.pid file. This prevents problems with boot scripts that
* expect the pidfile to appear quickly. Also, we avoid problems with
* trying to locate the timezone files too early in initialization.)
*/
pg_timezone_initialize();
/*
* Likewise, init timezone_abbreviations if not already set.
*/
pg_timezone_abbrev_initialize();
/*
* Remember postmaster startup time
* CDB: Moved this code up from below for use in error message headers.
*/
PgStartTime = GetCurrentTimestamp();
/*
* Initialize SSL library, if specified.
*/
#ifdef USE_SSL
if (EnableSSL)
secure_initialize();
#endif
/*
* process any libraries that should be preloaded at postmaster start
*/
process_shared_preload_libraries();
/*
* Remove old temporary files. At this point there can be no other
* Postgres processes running in this directory, so this should be safe.
*/
RemovePgTempFiles();
/*
* Establish input sockets.
*/
for (i = 0; i < MAXLISTEN; i++)
ListenSocket[i] = -1;
if (ListenAddresses)
{
char *rawstring;
List *elemlist;
ListCell *l;
int success = 0;
/* Need a modifiable copy of ListenAddresses */
rawstring = pstrdup(ListenAddresses);
/* Parse string into list of identifiers */
if (!SplitIdentifierString(rawstring, ',', &elemlist))
{
/* syntax error in list */
ereport(FATAL,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid list syntax for \"listen_addresses\"")));
}
foreach(l, elemlist)
{
char *curhost = (char *) lfirst(l);
if (strcmp(curhost, "*") == 0)
status = StreamServerPort(AF_UNSPEC, NULL,
(unsigned short) PostPortNumber,
UnixSocketDir,
ListenSocket, MAXLISTEN);
else
status = StreamServerPort(AF_UNSPEC, curhost,
(unsigned short) PostPortNumber,
UnixSocketDir,
ListenSocket, MAXLISTEN);
if (status == STATUS_OK)
success++;
else
ereport(WARNING,
(errmsg("could not create listen socket for \"%s\"",
curhost)));
}
if (!success && list_length(elemlist))
ereport(FATAL,
(errmsg("could not create any TCP/IP sockets")));
list_free(elemlist);
pfree(rawstring);
}
#ifdef USE_BONJOUR
/* Register for Bonjour only if we opened TCP socket(s) */
if (ListenSocket[0] != -1 && bonjour_name != NULL)
{
DNSServiceRegistrationCreate(bonjour_name,
"_postgresql._tcp.",
"",
htons(PostPortNumber),
"",
(DNSServiceRegistrationReply) reg_reply,
NULL);
}
#endif
#ifdef HAVE_UNIX_SOCKETS
status = StreamServerPort(AF_UNIX, NULL,
(unsigned short) PostPortNumber,
UnixSocketDir,
ListenSocket, MAXLISTEN);
if (status != STATUS_OK)
ereport(WARNING,
(errmsg("could not create Unix-domain socket")));
#endif
/*
* check that we have some socket to listen on
*/
if (ListenSocket[0] == -1)
ereport(FATAL,
(errmsg("no socket created for listening")));
/*
* Set up shared memory and semaphores.
*/
reset_shared(PostPortNumber, false);
/*
* Estimate number of openable files. This must happen after setting up
* semaphores, because on some platforms semaphores count as open files.
*/
set_max_safe_fds();
/*
* Initialize the list of active backends.
*/
BackendList = DLNewList();
#ifdef WIN32
/*
* Initialize I/O completion port used to deliver list of dead children.
*/
win32ChildQueue = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
if (win32ChildQueue == NULL)
ereport(FATAL,
(errmsg("could not create I/O completion port for child queue")));
/*
* Set up a handle that child processes can use to check whether the
* postmaster is still running.
*/
if (DuplicateHandle(GetCurrentProcess(),
GetCurrentProcess(),
GetCurrentProcess(),
&PostmasterHandle,
0,
TRUE,
DUPLICATE_SAME_ACCESS) == 0)
ereport(FATAL,
(errmsg_internal("could not duplicate postmaster handle: error code %d",
(int) GetLastError())));
#endif
/*
* Record postmaster options. We delay this till now to avoid recording
* bogus options (eg, NBuffers too high for available memory).
*/
if (!CreateOptsFile(argc, argv, my_exec_path))
ExitPostmaster(1);
#ifdef EXEC_BACKEND
/* Write out nondefault GUC settings for child processes to use */
write_nondefault_variables(PGC_POSTMASTER);
#endif
/*
* Write the external PID file if requested
*/
if (external_pid_file)
{
FILE *fpidfile = fopen(external_pid_file, "w");
if (fpidfile)
{
fprintf(fpidfile, "%d\n", MyProcPid);
fclose(fpidfile);
/* Should we remove the pid file on postmaster exit? */
}
else
write_stderr("%s: could not write external PID file \"%s\": %s\n",
progname, external_pid_file, strerror(errno));
}
/*
* Set up signal handlers for the postmaster process.
*
* CAUTION: when changing this list, check for side-effects on the signal
* handling setup of child processes. See tcop/postgres.c,
* bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walsendserver.c,
* postmaster/autovacuum.c, postmaster/pgarch.c, postmaster/pgstat.c, and
* postmaster/syslogger.c.
*/
pqinitmask();
PG_SETMASK(&BlockSig);
pqsignal(SIGHUP, SIGHUP_handler); /* reread config file and have
* children do same */
pqsignal(SIGINT, pmdie); /* send SIGTERM and shut down */
pqsignal(SIGQUIT, pmdie); /* send SIGQUIT and die */
pqsignal(SIGTERM, pmdie); /* wait for children and shut down */
pqsignal(SIGALRM, SIG_IGN); /* ignored */
pqsignal(SIGPIPE, SIG_IGN); /* ignored */
pqsignal(SIGUSR1, sigusr1_handler); /* message from child process */
pqsignal(SIGUSR2, dummy_handler); /* unused, reserve for children */
pqsignal(SIGCHLD, reaper); /* handle child termination */
pqsignal(SIGTTIN, SIG_IGN); /* ignored */
pqsignal(SIGTTOU, SIG_IGN); /* ignored */
/* ignore SIGXFSZ, so that ulimit violations work like disk full */
#ifdef SIGXFSZ
pqsignal(SIGXFSZ, SIG_IGN); /* ignored */
#endif
/*
* If enabled, start up syslogger collection subprocess
*/
SysLoggerPID = SysLogger_Start();
/*
* Reset whereToSendOutput from DestDebug (its starting state) to
* DestNone. This stops ereport from sending log messages to stderr unless
* Log_destination permits. We don't do this until the postmaster is
* fully launched, since startup failures may as well be reported to
* stderr.
*/
whereToSendOutput = DestNone;
/*
* Load configuration files for client authentication.
*/
if (!load_hba())
{
/*
* It makes no sense to continue if we fail to load the HBA file,
* since there is no way to connect to the database in this case.
*/
ereport(FATAL,
(errmsg("could not load pg_hba.conf"),
errOmitLocation(true)));
}
load_ident();
/* PostmasterRandom wants its own copy */
gettimeofday(&random_start_time, NULL);
status = ServerLoop();
/*
* ServerLoop probably shouldn't ever return, but if it does, close down.
*/
ExitPostmaster(status != STATUS_OK);
return 0; /* not reached */
}
/**
* Run the startup procedure for an operational (non-mirror/non-quiescent)
* postmaster.
*/
void
StartMasterOrPrimaryPostmasterProcesses(void)
{
if ( ! gHaveCalledOnetimeInitFunctions )
{
/*
* Initialize stats collection subsystem (this does NOT start the
* collector process!)
*/
pgstat_init();
/*
* Initialize the autovacuum subsystem (again, no process start yet)
*/
autovac_init();
gHaveCalledOnetimeInitFunctions = true;
}
XLogStartupInit(); /* required to get collation parameters read from the control file */
/*
* We're ready to rock and roll...
*/
if (SyncMaster)
{
pmState = PM_RUN;
}
else /* non-SyncMaster */
{
StartupPID = StartupDataBase();
Assert(StartupPID != 0);
pmState = PM_STARTUP;
}
}
void
NotifyProcessesOfFilerepStateChange(void)
{
primaryMirrorRecordSegmentStateToPostmasterLocalMemory();
filerep_has_signaled_state_change = false;
}
/*
* Compute and check the directory paths to files that are part of the
* installation (as deduced from the postgres executable's own location)
*/
static void
getInstallationPaths(const char *argv0)
{
DIR *pdir;
/* Locate the postgres executable itself */
if (find_my_exec(argv0, my_exec_path) < 0)
elog(FATAL, "%s: could not locate my own executable path", argv0);
#ifdef EXEC_BACKEND
/* Locate executable backend before we change working directory */
if (find_other_exec(argv0, "postgres", PG_BACKEND_VERSIONSTR,
postgres_exec_path) < 0)
ereport(FATAL,
(errmsg("%s: could not locate matching postgres executable",
argv0)));
#endif
/*
* Locate the pkglib directory --- this has to be set early in case we try
* to load any modules from it in response to postgresql.conf entries.
*/
get_pkglib_path(my_exec_path, pkglib_path);
/*
* Verify that there's a readable directory there; otherwise the Postgres
* installation is incomplete or corrupt. (A typical cause of this
* failure is that the postgres executable has been moved or hardlinked to
* some directory that's not a sibling of the installation lib/
* directory.)
*/
pdir = AllocateDir(pkglib_path);
if (pdir == NULL)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open directory \"%s\": %m",
pkglib_path),
errSendAlert(true),
errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
my_exec_path)));
FreeDir(pdir);
/*
* XXX is it worth similarly checking the share/ directory? If the lib/
* directory is there, then share/ probably is too.
*/
}
/*
* Validate the proposed data directory
*/
static void
checkDataDir(void)
{
struct stat stat_buf;
Assert(DataDir);
if (stat(DataDir, &stat_buf) != 0)
{
if (errno == ENOENT)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("data directory \"%s\" does not exist",
DataDir)));
else
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not read permissions of directory \"%s\": %m",
DataDir)));
}
/* eventual chdir would fail anyway, but let's test ... */
if (!S_ISDIR(stat_buf.st_mode))
ereport(FATAL,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("specified data directory \"%s\" is not a directory",
DataDir)));
/*
* Check that the directory belongs to my userid; if not, reject.
*
* This check is an essential part of the interlock that prevents two
* postmasters from starting in the same directory (see CreateLockFile()).
* Do not remove or weaken it.
*
* XXX can we safely enable this check on Windows?
*/
#if !defined(WIN32) && !defined(__CYGWIN__)
if (stat_buf.st_uid != geteuid())
ereport(FATAL,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("data directory \"%s\" has wrong ownership",
DataDir),
errhint("The server must be started by the user that owns the data directory.")));
#endif
/*
* Check if the directory has group or world access. If so, reject.
*
* It would be possible to allow weaker constraints (for example, allow
* group access) but we cannot make a general assumption that that is
* okay; for example there are platforms where nearly all users
* customarily belong to the same group. Perhaps this test should be
* configurable.
*
* XXX temporarily suppress check when on Windows, because there may not
* be proper support for Unix-y file permissions. Need to think of a
* reasonable check to apply on Windows.
*/
#if !defined(WIN32) && !defined(__CYGWIN__)
if (stat_buf.st_mode & (S_IRWXG | S_IRWXO))
ereport(FATAL,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("data directory \"%s\" has group or world access",
DataDir),
errdetail("Permissions should be u=rwx (0700).")));
#endif
/* Look for PG_VERSION before looking for pg_control */
ValidatePgVersion(DataDir);
/* for mirroring, the check for pg_control was removed. a mirror must be able to start
* without a pg_control file. The check for pg_control will be done
* when the control file is read by xlog initialization.
*/
}
/*
* check if file or directory under "DataDir" exists and is accessible
*/
static void checkPgDir(const char *dir)
{
Assert(DataDir);
struct stat st;
char buf[strlen(DataDir) + strlen(dir) + 32];
snprintf(buf, ARRAY_SIZE(buf), "%s%s", DataDir, dir);
buf[ARRAY_SIZE(buf) - 1] = '\0';
if (stat(buf, &st) != 0)
{
/* check if pg_log is there */
snprintf(buf, ARRAY_SIZE(buf), "%s%s", DataDir, "/pg_log");
if (stat(buf, &st) == 0)
{
elog(LOG, "System file or directory missing (%s), shutting down segment", dir);
}
/* quit all processes and exit */
pmdie(SIGQUIT);
}
}
/*
* check if file or directory under current transaction filespace exists and is accessible
*/
static void checkPgDir2(const char *dir)
{
Assert(DataDir);
struct stat st;
char buf[MAXPGPATH];
char *path = makeRelativeToTxnFilespace((char*)dir);
snprintf(buf, MAXPGPATH, "%s", path);
buf[ARRAY_SIZE(buf) - 1] = '\0';
if (stat(buf, &st) != 0)
{
/* check if pg_log is there */
snprintf(buf, ARRAY_SIZE(buf), "%s%s", DataDir, "/pg_log");
if (stat(buf, &st) == 0)
{
elog(LOG, "System file or directory missing (%s), shutting down segment", path);
}
pfree(path);
/* quit all processes and exit */
pmdie(SIGQUIT);
}
pfree(path);
}
#ifdef USE_TEST_UTILS
/*
* Simulate an unexpected process exit using SimEx
*/
static void SimExProcExit()
{
if (gp_simex_init &&
gp_simex_run &&
pmState == PM_RUN)
{
pid_t pid = 0;
int sig = 0;
const char *procName = NULL;
const char *sigName = NULL;
if (gp_simex_class == SimExESClass_ProcKill)
{
sig = SIGKILL;
sigName = "SIGKILL";
SimExESSubClass subclass = SimEx_CheckInject();
if (subclass == SimExESSubClass_ProcKill_BgWriter)
{
pid = BgWriterPID;
procName = "writer process";
}
else
{
Assert(subclass == SimExESSubClass_OK &&
"Unexpected ES subclass for SIGKILL injection");
}
}
if (pid != 0)
{
Assert(sig != 0);
Assert(procName != NULL);
Assert(sigName != NULL);
ereport(LOG,
(errmsg_internal("sending %s to %s (%d)", sigName, procName, (int) pid)));
signal_child(pid, sig);
}
}
}
#endif /* USE_TEST_UTILS */
#ifdef USE_BONJOUR
/*
* empty callback function for DNSServiceRegistrationCreate()
*/
static void
reg_reply(DNSServiceRegistrationReplyErrorType errorCode, void *context)
{
}
#endif /* USE_BONJOUR */
/*
* Fork away from the controlling terminal (silent_mode option)
*
* Since this requires disconnecting from stdin/stdout/stderr (in case they're
* linked to the terminal), we re-point stdin to /dev/null and stdout/stderr
* to "pg_log/startup.log" from the data directory, where we're already chdir'd.
*/
static void
pmdaemonize(void)
{
#ifndef WIN32
const char *pmlogname = "pg_log/startup.log";
int dvnull;
int pmlog;
pid_t pid;
int res;
/*
* Make sure we can open the files we're going to redirect to. If this
* fails, we want to complain before disconnecting. Mention the full path
* of the logfile in the error message, even though we address it by
* relative path.
*/
dvnull = open(DEVNULL, O_RDONLY, 0);
if (dvnull < 0)
{
write_stderr("%s: could not open file \"%s\": %s\n",
progname, DEVNULL, strerror(errno));
ExitPostmaster(1);
}
pmlog = open(pmlogname, O_CREAT | O_WRONLY | O_APPEND, 0600);
if (pmlog < 0)
{
write_stderr("%s: could not open log file \"%s/%s\": %s\n",
progname, DataDir, pmlogname, strerror(errno));
ExitPostmaster(1);
}
/*
* Okay to fork.
*/
pid = fork_process();
if (pid == (pid_t) -1)
{
write_stderr("%s: could not fork background process: %s\n",
progname, strerror(errno));
ExitPostmaster(1);
}
else if (pid)
{ /* parent */
/* Parent should just exit, without doing any atexit cleanup */
_exit(0);
}
MyProcPid = PostmasterPid = getpid(); /* reset PID vars to child */
MyStartTime = time(NULL);
/*
* Some systems use setsid() to dissociate from the TTY's process group,
* while on others it depends on stdin/stdout/stderr. Do both if possible.
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
{
write_stderr("%s: could not dissociate from controlling TTY: %s\n",
progname, strerror(errno));
ExitPostmaster(1);
}
#endif
/*
* Reassociate stdin/stdout/stderr. fork_process() cleared any pending
* output, so this should be safe. The only plausible error is EINTR,
* which just means we should retry.
*/
do {
res = dup2(dvnull, 0);
} while (res < 0 && errno == EINTR);
close(dvnull);
do {
res = dup2(pmlog, 1);
} while (res < 0 && errno == EINTR);
do {
res = dup2(pmlog, 2);
} while (res < 0 && errno == EINTR);
close(pmlog);
#else /* WIN32 */
/* not supported */
elog(FATAL, "silent_mode is not supported under Windows");
#endif /* WIN32 */
}
static bool
ServiceStartable(PMSubProc *subProc)
{
int flagNeeded;
bool result;
flagNeeded = 0;
if (!SyncMaster)
{
if (AmIMaster())
flagNeeded = PMSUBPROC_FLAG_QD;
else
flagNeeded = PMSUBPROC_FLAG_QE;
}
else
flagNeeded = PMSUBPROC_FLAG_STANDBY;
/*
* GUC gp_enable_gpperfmon controls the start
* of both the 'perfmon' and 'stats sender' processes
*/
if ((subProc->procType == PerfmonProc || subProc->procType == PerfmonSegmentInfoProc)
&& !gp_enable_gpperfmon)
result = 0;
else
result = ((subProc->flags & flagNeeded) != 0);
return result;
}
/**
* Reset pmState to PM_INIT and begin initialization sequence.
*/
static void
RestartAfterPostmasterReset(void)
{
pmState = PM_INIT;
FatalError = false;
/* done..serverLoop will process startup request */
}
static void
BeginResetOfPostmasterAfterChildrenAreShutDown(void)
{
elog(LOG, "BeginResetOfPostmasterAfterChildrenAreShutDown: counter %d", pmResetCounter);
pmResetCounter++;
PrimaryMirrorMode pm_mode;
SegmentState_e s_state;
DataState_e d_state;
FaultType_e f_type;
getPrimaryMirrorStatusCodes(&pm_mode, &s_state, &d_state, &f_type);
/* set flag indicating mirroring fault */
bool hasFaultTypeMirror = false;
setFaultAfterReset(hasFaultTypeMirror);
/* copy most recent transition request to local memory */
copyTransitionParametersToLocalMemory();
/*
* Save the MPP session number from shared-memory before we reset
* everything. There is some risk here accessing the shared-memory,
* but we don't want to reuse session-ids on the master.
*/
if (ProcGetMppLocalProcessCounter(&Save_MppLocalProcessCounter))
ereport(LOG,
(errmsg("gp_session_id high-water mark is %d",
Save_MppLocalProcessCounter)));
/*
* reset shared memory and semaphores;
* this happens before forking the filerep peer reset process;
* the latter process should not use information from shared memory;
*/
shmem_exit(0 /*code*/);
reset_shared(PostPortNumber, true /*isReset*/);
/*
* Remove old temporary files. At this point there can be no other
* Postgres processes running in this directory, so this should be safe.
*/
RemovePgTempFiles();
ereport(LOG,
(errmsg("all server processes terminated; reinitializing")));
RestartAfterPostmasterReset();
}
/**
* loop waiting for immediate shutdown to complete
*/
static void
ImmediateShutdownLoop(void)
{
PG_SETMASK(&BlockSig);
if (need_call_reaper)
{
do_immediate_shutdown_reaper();
}
ExitPostmaster(0);
}
/*
* Main idle loop of postmaster
*/
static int
ServerLoop(void)
{
fd_set readmask;
int nSockets;
time_t now,
last_touch_time;
last_touch_time = time(NULL);
nSockets = initMasks(&readmask);
/* initialize tm sync */
if (SyncMaster)
cdb_init_log_sync();
XLogStartupInit();
for (;;)
{
fd_set rmask;
int selres;
int s;
struct timeval timeout;
/*
* Wait for a connection request to arrive.
*
* We wait at most one minute, to ensure that the other background
* tasks handled below get done even when no requests are arriving.
*
* If we are in PM_WAIT_DEAD_END state, then we don't want to accept
* any new connections, so we don't call select() at all; just sleep
* for a little bit with signals unblocked.
*/
memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
PG_SETMASK(&UnBlockSig);
/*
* we allow new connections in many cases (which could later be rejected because the database is shutting down,
* but that gives a nicer message than potentially hanging the client's connection)
*/
bool acceptNewConnections;
if ( Shutdown == NoShutdown && FatalError)
{
/** during postmaster reset, accept new connections to allow us to coordinate the reset */
acceptNewConnections = pmState < PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN ||
pmState == PM_POSTMASTER_RESET_FILEREP_PEER;
}
else
{
acceptNewConnections = pmState < PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN &&
Shutdown != ImmediateShutdown;
}
/* If something that needs handling is received while we were doing other things with signals
* blocked then we need to skip select as quickly as possible and process it.
*
* This assumes that all signals are delivered immediately upon unblocking.
*
* I think there may still be a race in which we are signaled between the completion of unblock and the sleep.
*/
if (Shutdown == ImmediateShutdown ||
filerep_has_signaled_state_change ||
filerep_requires_postmaster_reset ||
need_call_reaper)
{
/* must set timeout each time; some OSes change it! */
timeout.tv_sec = 0;
timeout.tv_usec = 0;
}
else if (isPrimaryMirrorModeTransitionRequested() ||
! acceptNewConnections )
{
/* must set timeout each time; some OSes change it! */
timeout.tv_sec = 0;
timeout.tv_usec = 100 * 1000;
}
else
{
/* must set timeout each time; some OSes change it! */
timeout.tv_sec = 60;
timeout.tv_usec = 0;
}
#ifdef USE_TEST_UTILS
SimExProcExit();
#endif /* USE_TEST_UTILS */
errno = 0;
if (acceptNewConnections)
{
selres = select(nSockets, &rmask, NULL, NULL, &timeout);
/* check the select() result */
if (selres < 0)
{
if (errno != EINTR && errno != EWOULDBLOCK)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("select() failed in postmaster: %m")));
return STATUS_ERROR;
}
}
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
Postmaster,
DDLNotSpecified,
"", //databaseName
""); // tableName
#endif
}
else
{
/* will be the medium wait time unless waiting for reaper */
pg_usleep( timeout.tv_usec + timeout.tv_sec * 1000 * 1000);
selres = 0;
}
/* Sanity check for system directories on all segments */
if (AmISegment())
{
checkPgDir("");
checkPgDir("/base");
checkPgDir("/global");
checkPgDir("/pg_twophase");
checkPgDir("/pg_utilitymodedtmredo");
checkPgDir2("pg_distributedlog");
checkPgDir2("pg_distributedxidmap");
checkPgDir2("pg_multixact");
checkPgDir2("pg_subtrans");
checkPgDir2("pg_xlog");
checkPgDir2("pg_clog");
checkPgDir2("pg_multixact/members");
checkPgDir2("pg_multixact/offsets");
checkPgDir2("pg_xlog/archive_status");
}
#ifdef USE_TEST_UTILS
SimExProcExit();
#endif /* USE_TEST_UTILS */
/*
* Block all signals until we wait again. (This makes it safe for our
* signal handlers to do nontrivial work.)
*/
PG_SETMASK(&BlockSig);
if (Shutdown == ImmediateShutdown)
{
ImmediateShutdownLoop();
}
if (filerep_requires_postmaster_reset)
{
filerep_requires_postmaster_reset = false;
HandleChildCrash(-1, -1, "");
}
/*
* GPDB Change: Reaper just sets a flag, and we call the real reaper code here.
* I assume this was done because we wanted to excecute some code that wasn't safe in a
* signal handler context (debugging code, most likely).
* But the real reason is lost in antiquity.
*/
if (need_call_reaper)
{
do_reaper();
}
if (filerep_has_signaled_state_change)
{
NotifyProcessesOfFilerepStateChange();
}
/*
* New connection pending on any of our sockets? If so, fork a child
* process to deal with it.
*/
if (selres > 0)
{
int i;
for (i = 0; i < MAXLISTEN; i++)
{
if (ListenSocket[i] == -1)
break;
if (FD_ISSET(ListenSocket[i], &rmask))
{
Port *port;
port = ConnCreate(ListenSocket[i]);
if (port)
{
BackendStartup(port);
/*
* We no longer need the open socket or port structure
* in this process
*/
StreamClose(port->sock);
ConnFree(port);
}
}
}
}
#ifdef USE_TEST_UTILS
SimExProcExit();
#endif /* USE_TEST_UTILS */
if (!FatalError)
{
static int saved_pmResetCounter = 0;
/* Initial start or crash recovery should restart again. */
if (pmState == PM_INIT ||
pmResetCounter != saved_pmResetCounter)
{
StartMasterOrPrimaryPostmasterProcesses();
saved_pmResetCounter = pmResetCounter;
}
}
/* If we have lost the log collector, try to start a new one */
if (SysLoggerPID == 0 && Redirect_stderr)
{
SysLoggerPID = SysLogger_Start();
if (Debug_print_server_processes)
elog(LOG,"restarted 'system logger process' as pid %ld",
(long)SysLoggerPID);
}
if ( isFullPostmasterAndDatabaseIsAllowed())
{
/*
* If no background writer process is running, and we are not in a
* state that prevents it, start one. It doesn't matter if this
* fails, we'll just try again later.
*/
if (BgWriterPID == 0 &&
StartupPidsAllZero() && pmState > PM_STARTUP_PASS4 &&
!FatalError && !SyncMaster &&
pmState < PM_CHILD_STOP_BEGIN)
{
SetBGWriterPID(StartBackgroundWriter());
if (Debug_print_server_processes)
elog(LOG,"restarted 'background writer process' as pid %ld",
(long)BgWriterPID);
/* If shutdown is pending, set it going */
if (Shutdown > NoShutdown && BgWriterPID != 0)
signal_child(BgWriterPID, SIGUSR2);
}
if (CheckpointPID == 0 &&
StartupPidsAllZero() && pmState > PM_STARTUP_PASS4 &&
!FatalError && !SyncMaster &&
Shutdown == NoShutdown)
{
CheckpointPID = StartCheckpointServer();
if (Debug_print_server_processes)
elog(LOG,"restarted 'checkpoint process' as pid %ld",
(long)CheckpointPID);
}
/*
* Start a new autovacuum process, if there isn't one running already.
* (It'll die relatively quickly.) We check that it's not started too
* frequently in autovac_start.
*/
if ((AutoVacuumingActive() || force_autovac) && AutoVacPID == 0 &&
StartupPidsAllZero() && pmState > PM_STARTUP_PASS4 &&
!FatalError && Shutdown == NoShutdown)
{
AutoVacPID = autovac_start();
if (Debug_print_server_processes)
elog(LOG,"restarted 'autovacuum process' as pid %ld",
(long)AutoVacPID);
if (AutoVacPID != 0)
force_autovac = false; /* signal successfully processed */
}
/* If we have lost the stats collector, try to start a new one */
if (PgStatPID == 0 &&
StartupPidsAllZero() && pmState > PM_STARTUP_PASS4 &&
!FatalError && Shutdown == NoShutdown && !SyncMaster)
{
PgStatPID = pgstat_start();
if (Debug_print_server_processes)
elog(LOG,"restarted 'statistics collector process' as pid %ld",
(long)PgStatPID);
}
/* MPP: If we have lost one of our servers, try to start a new one */
for (s=0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid == 0 &&
StartupPidsAllZero() &&
pmState > PM_STARTUP_PASS4 &&
!FatalError &&
Shutdown == NoShutdown &&
ServiceStartable(subProc))
{
subProc->pid =
(subProc->serverStart)();
if (Debug_print_server_processes)
elog(LOG,"started '%s' as pid %ld",
subProc->procName, (long)subProc->pid);
}
}
}
/*
* Touch the socket and lock file every 58 minutes, to ensure that
* they are not removed by overzealous /tmp-cleaning tasks. We assume
* no one runs cleaners with cutoff times of less than an hour ...
*/
now = time(NULL);
if (now - last_touch_time >= 58 * SECS_PER_MINUTE)
{
TouchSocketFile();
TouchSocketLockFile();
last_touch_time = now;
}
}
}
/*
* Initialise the masks for select() for the ports we are listening on.
* Return the number of sockets to listen on.
*/
static int
initMasks(fd_set *rmask)
{
int maxsock = -1;
int i;
FD_ZERO(rmask);
for (i = 0; i < MAXLISTEN; i++)
{
int fd = ListenSocket[i];
if (fd == PGINVALID_SOCKET)
break;
FD_SET(fd, rmask);
if (fd > maxsock)
maxsock = fd;
}
return maxsock + 1;
}
/*
* Read a client's startup packet and do something according to it.
*
* Returns STATUS_OK or STATUS_ERROR, or might call ereport(FATAL) and
* not return at all.
*
* (Note that ereport(FATAL) stuff is sent to the client, so only use it
* if that's what you want. Return STATUS_ERROR if you don't want to
* send anything to the client, which would typically be appropriate
* if we detect a communications failure.)
*/
static int
ProcessStartupPacket(Port *port, bool SSLdone)
{
int32 len;
void *buf;
ProtocolVersion proto;
MemoryContext oldcontext;
char *gpqeid = NULL;
if (pq_getbytes((char *) &len, 4) == EOF)
{
/*
* EOF after SSLdone probably means the client didn't like our
* response to NEGOTIATE_SSL_CODE. That's not an error condition, so
* don't clutter the log with a complaint.else if (strcmp(nameptr, "replication") == 0)
{
if (!parse_bool(valptr, &am_walsender))
ereport(FATAL,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid value for boolean option \"replication\"")));
}
*/
if (!SSLdone)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete startup packet")));
return STATUS_ERROR;
}
len = ntohl(len);
len -= 4;
if (len < (int32) sizeof(ProtocolVersion) ||
len > MAX_STARTUP_PACKET_LENGTH)
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid length of startup packet %ld",(long)len)));
return STATUS_ERROR;
}
/*
* Allocate at least the size of an old-style startup packet, plus one
* extra byte, and make sure all are zeroes. This ensures we will have
* null termination of all strings, in both fixed- and variable-length
* packet layouts.
*/
if (len <= (int32) sizeof(StartupPacket))
buf = palloc0(sizeof(StartupPacket) + 1);
else
buf = palloc0(len + 1);
if (pq_getbytes(buf, len) == EOF)
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete startup packet")));
return STATUS_ERROR;
}
/*
* The first field is either a protocol version number or a special
* request code.
*/
port->proto = proto = ntohl(*((ProtocolVersion *) buf));
if (proto == CANCEL_REQUEST_CODE)
{
processCancelRequest(port, buf);
return 127; /* XXX */
}
else if (proto == PRIMARY_MIRROR_TRANSITION_REQUEST_CODE)
{
/* disable the authentication timeout in case it takes a long time */
if (!disable_sig_alarm(false))
elog(FATAL, "could not disable timer for authorization timeout");
processPrimaryMirrorTransitionRequest(port, buf);
return 127;
}
else if (proto == PRIMARY_MIRROR_TRANSITION_QUERY_CODE)
{
/* disable the authentication timeout in case it takes a long time */
if (!disable_sig_alarm(false))
elog(FATAL, "could not disable timer for authorization timeout");
processPrimaryMirrorTransitionQuery(port, buf);
return 127;
}
/* Otherwise this is probably a normal postgres-message */
if (proto == NEGOTIATE_SSL_CODE && !SSLdone)
{
char SSLok;
#ifdef USE_SSL
/* No SSL when disabled or on Unix sockets */
if (!EnableSSL || IS_AF_UNIX(port->laddr.addr.ss_family))
SSLok = 'N';
else
SSLok = 'S'; /* Support for SSL */
#else
SSLok = 'N'; /* No support for SSL */
#endif
retry1:
if (send(port->sock, &SSLok, 1, 0) != 1)
{
if (errno == EINTR)
goto retry1; /* if interrupted, just retry */
ereport(COMMERROR,
(errcode_for_socket_access(),
errmsg("failed to send SSL negotiation response: %m")));
return STATUS_ERROR; /* close the connection */
}
#ifdef USE_SSL
if (SSLok == 'S' && secure_open_server(port) == -1)
return STATUS_ERROR;
#endif
/* regular startup packet, cancel, etc packet should follow... */
/* but not another SSL negotiation request */
return ProcessStartupPacket(port, true);
}
/* Could add additional special packet types here */
/*
* Set FrontendProtocol now so that ereport() knows what format to send if
* we fail during startup.
*/
FrontendProtocol = proto;
/* Check we can handle the protocol the frontend is using. */
if (PG_PROTOCOL_MAJOR(proto) < PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST) ||
PG_PROTOCOL_MAJOR(proto) > PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST) ||
(PG_PROTOCOL_MAJOR(proto) == PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST) &&
PG_PROTOCOL_MINOR(proto) > PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST)))
ereport(FATAL,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("unsupported frontend protocol %u.%u: server supports %u.0 to %u.%u",
PG_PROTOCOL_MAJOR(proto), PG_PROTOCOL_MINOR(proto),
PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST),
PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST),
PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST))));
/*
* Now fetch parameters out of startup packet and save them into the Port
* structure. All data structures attached to the Port struct must be
* allocated in TopMemoryContext so that they won't disappear when we pass
* them to PostgresMain (see BackendRun). We need not worry about leaking
* this storage on failure, since we aren't in the postmaster process
* anymore.
*/
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
if (PG_PROTOCOL_MAJOR(proto) >= 3)
{
int32 offset = sizeof(ProtocolVersion);
/*
* Scan packet body for name/option pairs. We can assume any string
* beginning within the packet body is null-terminated, thanks to
* zeroing extra byte above.
*/
port->guc_options = NIL;
while (offset < len)
{
char *nameptr = ((char *) buf) + offset;
int32 valoffset;
char *valptr;
if (*nameptr == '\0')
break; /* found packet terminator */
valoffset = offset + strlen(nameptr) + 1;
if (valoffset >= len)
break; /* missing value, will complain below */
valptr = ((char *) buf) + valoffset;
if (strcmp(nameptr, "database") == 0)
port->database_name = pstrdup(valptr);
else if (strcmp(nameptr, "user") == 0)
port->user_name = pstrdup(valptr);
else if (strcmp(nameptr, "options") == 0)
port->cmdline_options = pstrdup(valptr);
else if (strcmp(nameptr, "dboid") == 0)
port->dboid = atoi(valptr);
else if (strcmp(nameptr, "dbdtsoid") == 0)
port->dbdtsoid = atoi(valptr);
else if (strcmp(nameptr, "bootstrap_user") == 0)
port->bootstrap_user = pstrdup(valptr);
else if (strcmp(nameptr, "encoding") == 0)
port->encoding = atoi(valptr);
else if (strcmp(nameptr, "gpqeid") == 0)
gpqeid = valptr;
else
{
/* Assume it's a generic GUC option */
port->guc_options = lappend(port->guc_options,
pstrdup(nameptr));
port->guc_options = lappend(port->guc_options,
pstrdup(valptr));
}
offset = valoffset + strlen(valptr) + 1;
}
/*
* If we didn't find a packet terminator exactly at the end of the
* given packet length, complain.
*/
if (offset != len - 1)
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid startup packet layout: expected terminator as last byte")));
}
else
{
/*
* Get the parameters from the old-style, fixed-width-fields startup
* packet as C strings. The packet destination was cleared first so a
* short packet has zeros silently added. We have to be prepared to
* truncate the pstrdup result for oversize fields, though.
*/
StartupPacket *packet = (StartupPacket *) buf;
port->database_name = pstrdup(packet->database);
if (strlen(port->database_name) > sizeof(packet->database))
port->database_name[sizeof(packet->database)] = '\0';
port->user_name = pstrdup(packet->user);
if (strlen(port->user_name) > sizeof(packet->user))
port->user_name[sizeof(packet->user)] = '\0';
port->cmdline_options = pstrdup(packet->options);
if (strlen(port->cmdline_options) > sizeof(packet->options))
port->cmdline_options[sizeof(packet->options)] = '\0';
port->guc_options = NIL;
}
/* Check a user name was given. */
if (port->user_name == NULL || port->user_name[0] == '\0')
ereport(FATAL,
(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
errmsg("no PostgreSQL user name specified in startup packet")));
/* The database defaults to the user name. */
if (port->database_name == NULL || port->database_name[0] == '\0')
port->database_name = pstrdup(port->user_name);
if (Db_user_namespace)
{
/*
* If user@, it is a global user, remove '@'. We only want to do this
* if there is an '@' at the end and no earlier in the user string or
* they may fake as a local user of another database attaching to this
* database.
*/
if (strchr(port->user_name, '@') ==
port->user_name + strlen(port->user_name) - 1)
*strchr(port->user_name, '@') = '\0';
else
{
/* Append '@' and dbname */
char *db_user;
db_user = palloc(strlen(port->user_name) +
strlen(port->database_name) + 2);
sprintf(db_user, "%s@%s", port->user_name, port->database_name);
port->user_name = db_user;
}
}
/*
* Truncate given database and user names to length of a Postgres name.
* This avoids lookup failures when overlength names are given.
*/
if (strlen(port->database_name) >= NAMEDATALEN)
port->database_name[NAMEDATALEN - 1] = '\0';
if (strlen(port->user_name) >= NAMEDATALEN)
port->user_name[NAMEDATALEN - 1] = '\0';
/*
* CDB: Process "gpqeid" parameter string for qExec startup.
*/
if (gpqeid)
cdbgang_parse_gpqeid_params(port, gpqeid);
/*
* Done putting stuff in TopMemoryContext.
*/
MemoryContextSwitchTo(oldcontext);
/*
* If we're going to reject the connection due to database state, say so
* now instead of wasting cycles on an authentication exchange. (This also
* allows a pg_ping utility to be written.)
*/
switch (port->canAcceptConnections)
{
case CAC_STARTUP:
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errSendAlert(false),
errOmitLocation(true),
errmsg(POSTMASTER_IN_STARTUP_MSG)));
break;
case CAC_SHUTDOWN:
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errSendAlert(false),
errOmitLocation(true),
errmsg("the database system is shutting down")));
break;
case CAC_RECOVERY:
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errSendAlert(true),
errOmitLocation(true),
errmsg(POSTMASTER_IN_RECOVERY_MSG)));
break;
case CAC_MIRROR_OR_QUIESCENT:
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errSendAlert(true),
errOmitLocation(true),
errmsg("the database system is in mirror or uninitialized mode")));
break;
case CAC_TOOMANY:
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errSendAlert(true),
errOmitLocation(true),
errmsg("sorry, too many clients already")));
break;
case CAC_OK:
break;
}
return STATUS_OK;
}
/**
* Reads the next string up to a newline
* if no string can be read then NULL is returned
* otherwise a newly allocated, NULL-terminated string is returned
*/
static char *
readNextStringFromString(char *buf, int *offsetInOut, int length)
{
char *result;
int offset = *offsetInOut;
int strEnd = offset;
if (offset == length)
{
return NULL;
}
while (strEnd < length && buf[strEnd] != '\n')
{
strEnd++;
}
result = palloc(sizeof(char) * (strEnd - offset + 1));
memcpy(result, buf + offset, strEnd - offset);
result[strEnd - offset] = '\0';
/* skip over newline */
if ( strEnd < length)
strEnd++;
/* result */
*offsetInOut = strEnd;
return result;
}
#ifdef FAULT_INJECTOR
/**
* Returns 0 if the string could not be read and sets *wasRead (if wasRead is non-NULL) to false
*/
static int
readIntFromString( char *buf, int *offsetInOut, int length, bool *wasRead)
{
int res;
char *val = readNextStringFromString(buf, offsetInOut, length);
if (val == NULL)
{
if (wasRead)
*wasRead = false;
return 0;
}
if (wasRead)
*wasRead = true;
res = atoi(val);
pfree(val);
return res;
}
#endif
static void sendPrimaryMirrorTransitionResult( const char *msg)
{
StringInfoData buf;
initStringInfo(&buf);
pq_beginmessage(&buf, '\0');
pq_send_ascii_string(&buf, msg);
pq_endmessage(&buf);
pq_flush();
}
#define PROTOCOL_VIOLATION ("protocol_violation")
static void
processTransitionRequest_beginPostmasterReset(void)
{
char statusBuf[10000];
PrimaryMirrorModeTransitionArguments args = primaryMirrorGetArgumentsFromLocalMemory();
bool resetRequired = false;
if (args.mode == PMModeMaster)
{
elog(LOG, "request to reset is ignored by the master");
snprintf(statusBuf, sizeof(statusBuf), "Failure: attempt to reset the master");
}
sendPrimaryMirrorTransitionResult(statusBuf);
if (resetRequired)
{
SendPostmasterSignal(PMSIGNAL_POSTMASTER_RESET_BY_PEER);
}
}
static void
processTransitionRequest_getPostmasterResetStatus(void)
{
char statusBuf[10000];
/* note: this uses the FatalError, pmState, and pmResetCounter values inherited at the time of forking
* the process to satisfy the transition request. This is enough for our purposes. */
if (FatalError && pmState == PM_POSTMASTER_RESET_FILEREP_PEER)
{
snprintf(statusBuf, sizeof(statusBuf), "Success:\nisInResetPivotPoint\n%09d", pmResetCounter);
}
else
{
snprintf(statusBuf, sizeof(statusBuf), "Success:\nresetStatusServerIsStartingOrStopping\n%09d", pmResetCounter);
}
sendPrimaryMirrorTransitionResult(statusBuf);
}
static void
processTransitionRequest_getStatus(void)
{
char statusBuf[10000];
getPrimaryMirrorModeStatus(statusBuf, sizeof(statusBuf));
sendPrimaryMirrorTransitionResult(statusBuf);
}
static void
processTransitionRequest_getCollationAndDataDir(void)
{
char statusBuf[10000 + MAXPGPATH];
snprintf(statusBuf, sizeof(statusBuf), "Success: lc_collate:%s\n"
"lc_monetary:%s\n"
"lc_numeric:%s\n"
"datadir:%s\n",
locale_collate,
locale_monetary,
locale_numeric,
data_directory );
sendPrimaryMirrorTransitionResult(statusBuf);
}
static void
processTransitionRequest_getVersion(void)
{
char statusBuf[10000];
snprintf(statusBuf, sizeof(statusBuf), "Success:%s", TextDatumGetCString(pgsql_version(NULL /* fcinfo */)));
sendPrimaryMirrorTransitionResult(statusBuf);
}
static void processTransitionRequest_getFaultInjectStatus(void * buf, int *offsetPtr, int length)
{
#ifdef FAULT_INJECTOR
init_ps_display("filerep fault inject status process", "", "", "");
char *faultName = readNextStringFromString(buf, offsetPtr, length);
bool isDone = false;
if ( ! faultName)
{
sendPrimaryMirrorTransitionResult(PROTOCOL_VIOLATION);
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid fault injection status packet (missing some data values)")));
return;
}
if (FaultInjector_IsFaultInjected(FaultInjectorIdentifierStringToEnum(faultName))) {
isDone = true;
}
sendPrimaryMirrorTransitionResult(isDone ? "Success: done" : "Success: waitMore");
#else
sendPrimaryMirrorTransitionResult("Failure: Fault Injector not available");
#endif
}
static void
processTransitionRequest_faultInject(void * inputBuf, int *offsetPtr, int length)
{
#ifdef FAULT_INJECTOR
bool wasRead;
char *faultName = readNextStringFromString(inputBuf, offsetPtr, length);
char *type = readNextStringFromString(inputBuf, offsetPtr, length);
char *ddlStatement = readNextStringFromString(inputBuf, offsetPtr, length);
char *databaseName = readNextStringFromString(inputBuf, offsetPtr, length);
char *tableName = readNextStringFromString(inputBuf, offsetPtr, length);
int numOccurrences = readIntFromString(inputBuf, offsetPtr, length, &wasRead);
int sleepTimeSeconds = readIntFromString(inputBuf, offsetPtr, length, &wasRead);
FaultInjectorEntry_s faultInjectorEntry;
char buf[1000];
init_ps_display("filerep fault inject process", "", "", "");
if ( ! wasRead)
{
sendPrimaryMirrorTransitionResult(PROTOCOL_VIOLATION);
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid fault injection packet (missing some data values)")));
snprintf(buf, sizeof(buf), "Failure: invalid fault injection packet (missing some data values)");
goto exit;
}
elog(DEBUG1, "FAULT INJECTED: Name %s Type %s, DDL %s, DB %s, Table %s, NumOccurrences %d SleepTime %d",
faultName, type, ddlStatement, databaseName, tableName, numOccurrences, sleepTimeSeconds );
faultInjectorEntry.faultInjectorIdentifier = FaultInjectorIdentifierStringToEnum(faultName);
if (faultInjectorEntry.faultInjectorIdentifier == FaultInjectorIdNotSpecified ||
faultInjectorEntry.faultInjectorIdentifier == FaultInjectorIdMax) {
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not recognize fault name")));
snprintf(buf, sizeof(buf), "Failure: could not recognize fault name");
goto exit;
}
faultInjectorEntry.faultInjectorType = FaultInjectorTypeStringToEnum(type);
if (faultInjectorEntry.faultInjectorType == FaultInjectorTypeNotSpecified ||
faultInjectorEntry.faultInjectorType == FaultInjectorTypeMax) {
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not recognize fault type")));
snprintf(buf, sizeof(buf), "Failure: could not recognize fault type");
goto exit;
}
faultInjectorEntry.sleepTime = sleepTimeSeconds;
if (sleepTimeSeconds < 0 || sleepTimeSeconds > 7200) {
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid sleep time, allowed range [0, 7200 sec]")));
snprintf(buf, sizeof(buf), "Failure: invalid sleep time, allowed range [0, 7200 sec]");
goto exit;
}
faultInjectorEntry.ddlStatement = FaultInjectorDDLStringToEnum(ddlStatement);
if (faultInjectorEntry.ddlStatement == DDLMax) {
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not recognize DDL statement")));
snprintf(buf, sizeof(buf), "Failure: could not recognize DDL statement");
goto exit;
}
snprintf(faultInjectorEntry.databaseName, sizeof(faultInjectorEntry.databaseName), "%s", databaseName);
snprintf(faultInjectorEntry.tableName, sizeof(faultInjectorEntry.tableName), "%s", tableName);
faultInjectorEntry.occurrence = numOccurrences;
if (numOccurrences > 1000) {
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid occurrence number, allowed range [1, 1000]")));
snprintf(buf, sizeof(buf), "Failure: invalid occurrence number, allowed range [1, 1000]");
goto exit;
}
if (FaultInjector_SetFaultInjection(&faultInjectorEntry) == STATUS_OK) {
if (faultInjectorEntry.faultInjectorType == FaultInjectorTypeStatus) {
snprintf(buf, sizeof(buf), "%s", faultInjectorEntry.bufOutput);
} else {
snprintf(buf, sizeof(buf), "Success:");
}
} else {
snprintf(buf, sizeof(buf), "Failure: %s", faultInjectorEntry.bufOutput);
}
exit:
sendPrimaryMirrorTransitionResult(buf);
#else
sendPrimaryMirrorTransitionResult("Failure: Fault Injector not available");
#endif
}
/**
* Called during startup packet processing.
*
* Note that we don't worry about freeing memory here because this is
* called on a new backend which is closed after this operation
*/
static void
processPrimaryMirrorTransitionRequest(Port *port, void *pkt)
{
PrimaryMirrorTransitionPacket *transition = (PrimaryMirrorTransitionPacket *) pkt;
void * buf;
char *targetModeStr;
int length, offset;
length = (int)ntohl(transition->dataLength);
if (length > 10000000 || length < 1)
{
sendPrimaryMirrorTransitionResult(PROTOCOL_VIOLATION);
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("corrupt length value %d in primary mirror transition packet", length)));
Assert(0);
return;
}
buf = palloc0(length+1);
if (pq_getbytes(buf, length) == EOF)
{
sendPrimaryMirrorTransitionResult(PROTOCOL_VIOLATION);
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete primary mirror transition packet")));
return;
}
((char*)buf)[length] = '\0';
offset = 0;
/* read off the transition requested, see if it is a special named one to handle */
bool handledRequest = true;
targetModeStr = readNextStringFromString(buf, &offset, length);
if (targetModeStr == NULL)
{
sendPrimaryMirrorTransitionResult(PROTOCOL_VIOLATION);
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid primary mirror transition packet (unable to read target mode value)")));
}
else if (strcmp("beginPostmasterReset", targetModeStr) == 0)
{
processTransitionRequest_beginPostmasterReset();
}
else if (strcmp("getPostmasterResetStatus", targetModeStr) == 0)
{
processTransitionRequest_getPostmasterResetStatus();
}
else if (strcmp("getStatus", targetModeStr) == 0)
{
processTransitionRequest_getStatus();
}
else if (strcmp("getCollationAndDataDirSettings", targetModeStr) == 0)
{
processTransitionRequest_getCollationAndDataDir();
}
else if (strcmp("getVersion", targetModeStr) == 0 )
{
processTransitionRequest_getVersion();
}
else if (strcmp("getFaultInjectStatus", targetModeStr ) == 0)
{
processTransitionRequest_getFaultInjectStatus(buf, &offset, length);
}
else if (strcmp("faultInject", targetModeStr) == 0)
{
processTransitionRequest_faultInject(buf, &offset, length);
}
else
{
handledRequest = false;
}
if (handledRequest)
{
/* return if the request wasn't handled by one of the non-else branches above */
return;
}
}
static void
sendPrimaryMirrorTransitionQuery(uint32 mode, uint32 segstate, uint32 datastate, uint32 faulttype)
{
StringInfoData buf;
initStringInfo(&buf);
pq_beginmessage(&buf, '\0');
pq_sendint(&buf, mode, 4);
pq_sendint(&buf, segstate, 4);
pq_sendint(&buf, datastate, 4);
pq_sendint(&buf, faulttype, 4);
pq_endmessage(&buf);
pq_flush();
}
/**
* Called during startup packet processing.
*
* Note that we don't worry about freeing memory here because this is
* called on a new backend which is closed after this operation
*/
static void
processPrimaryMirrorTransitionQuery(Port *port, void *pkt)
{
PrimaryMirrorTransitionPacket *transition = (PrimaryMirrorTransitionPacket *) pkt;
int length;
PrimaryMirrorMode pm_mode;
SegmentState_e s_state;
DataState_e d_state;
FaultType_e f_type;
init_ps_display("filerep status query process", "", "", "");
length = (int)ntohl(transition->dataLength);
if (length != 0)
{
ereport(COMMERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("corrupt length value %d in primary mirror query packet", length)));
return;
}
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet
(
SegmentProbeResponse,
DDLNotSpecified,
"", //databaseName
"" // tableName
)
;
#endif
getPrimaryMirrorStatusCodes(&pm_mode, &s_state, &d_state, &f_type);
/* check if segment is mirrorless primary */
if (pm_mode == PMModeMirrorlessSegment)
{
Assert(d_state == DataStateNotInitialized);
/* report segment as in sync to conform with master's segment configuration */
d_state = DataStateInSync;
}
sendPrimaryMirrorTransitionQuery((uint32)pm_mode, (uint32)s_state, (uint32)d_state, (uint32)f_type);
return;
}
/*
* The client has sent a cancel request packet, not a normal
* start-a-new-connection packet. Perform the necessary processing.
* Nothing is sent back to the client.
*/
static void
processCancelRequest(Port *port, void *pkt)
{
CancelRequestPacket *canc = (CancelRequestPacket *) pkt;
int backendPID;
long cancelAuthCode;
Backend *bp;
#ifndef EXEC_BACKEND
Dlelem *curr;
#else
int i;
#endif
backendPID = (int) ntohl(canc->backendPID);
cancelAuthCode = (long) ntohl(canc->cancelAuthCode);
/*
* See if we have a matching backend. In the EXEC_BACKEND case, we can no
* longer access the postmaster's own backend list, and must rely on the
* duplicate array in shared memory.
*/
#ifndef EXEC_BACKEND
for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
{
bp = (Backend *) DLE_VAL(curr);
#else
for (i = MaxLivePostmasterChildren() - 1; i >= 0; i--)
{
bp = (Backend *) &ShmemBackendArray[i];
#endif
if (bp->pid == backendPID)
{
if (bp->cancel_key == cancelAuthCode)
{
/* Found a match; signal that backend to cancel current op */
ereport(DEBUG2,
(errmsg_internal("processing cancel request: sending SIGINT to process %d",
backendPID)));
signal_child(bp->pid, SIGINT);
}
else
/* Right PID, wrong key: no way, Jose */
ereport(LOG,
(errmsg("wrong key in cancel request for process %d",
backendPID)));
return;
}
}
/* No matching backend */
ereport(LOG,
(errmsg("PID %d in cancel request did not match any process",
backendPID)));
}
/*
* canAcceptConnections --- check to see if database state allows connections.
*/
static enum CAC_state
canAcceptConnections(void)
{
/*
* Can't start backends when in startup/shutdown/recovery state.
*/
if (pmState != PM_RUN)
{
if (Shutdown > NoShutdown)
return CAC_SHUTDOWN; /* shutdown is pending */
if (!FatalError &&
(pmState == PM_STARTUP ||
pmState == PM_STARTUP_PASS2 ||
pmState == PM_STARTUP_PASS3 ||
pmState == PM_STARTUP_PASS4 ||
pmState == PM_RECOVERY ||
pmState == PM_RECOVERY_CONSISTENT))
return CAC_STARTUP; /* normal startup */
return CAC_RECOVERY; /* else must be crash recovery */
}
/*
* Don't start too many children.
*
* We allow more connections than we can have backends here because some
* might still be authenticating; they might fail auth, or some existing
* backend might exit before the auth cycle is completed. The exact
* MaxBackends limit is enforced when a new backend tries to join the
* shared-inval backend array.
*
* The limit here must match the sizes of the per-child-process arrays;
* see comments for MaxLivePostmasterChildren().
*/
if (CountChildren() >= MaxLivePostmasterChildren())
return CAC_TOOMANY;
return CAC_OK;
}
/*
* ConnCreate -- create a local connection data structure
*/
static Port *
ConnCreate(int serverFd)
{
Port *port;
if (!(port = (Port *) calloc(1, sizeof(Port))))
{
ereport(LOG,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
ExitPostmaster(1);
}
if (StreamConnection(serverFd, port) != STATUS_OK)
{
if (port->sock >= 0)
StreamClose(port->sock);
ConnFree(port);
port = NULL;
}
else
{
/*
* Precompute password salt values to use for this connection. It's
* slightly annoying to do this long in advance of knowing whether
* we'll need 'em or not, but we must do the random() calls before we
* fork, not after. Else the postmaster's random sequence won't get
* advanced, and all backends would end up using the same salt...
*/
RandomSalt(port->md5Salt);
}
/*
* Allocate GSSAPI specific state struct
*/
#ifndef EXEC_BACKEND
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
port->gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
if (!port->gss)
{
ereport(LOG,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
ExitPostmaster(1);
}
#endif
#endif
return port;
}
/*
* ConnFree -- free a local connection data structure
*/
static void
ConnFree(Port *conn)
{
#ifdef USE_SSL
secure_close(conn);
#endif
if (conn->gss)
free(conn->gss);
free(conn);
}
/*
* ClosePostmasterPorts -- close all the postmaster's open sockets
*
* This is called during child process startup to release file descriptors
* that are not needed by that child process. The postmaster still has
* them open, of course.
*
* Note: we pass am_syslogger as a boolean because we don't want to set
* the global variable yet when this is called.
*/
void
ClosePostmasterPorts(bool am_syslogger)
{
int i;
/* Close the listen sockets */
for (i = 0; i < MAXLISTEN; i++)
{
if (ListenSocket[i] != -1)
{
StreamClose(ListenSocket[i]);
ListenSocket[i] = -1;
}
}
/* If using syslogger, close the read side of the pipe */
if (!am_syslogger)
{
#ifndef WIN32
if (syslogPipe[0] >= 0)
close(syslogPipe[0]);
syslogPipe[0] = -1;
#else
if (syslogPipe[0])
CloseHandle(syslogPipe[0]);
syslogPipe[0] = 0;
#endif
}
}
/*
* reset_shared -- reset shared memory and semaphores
* @param isReset if true, then this is a reset (as opposed to the initial creation of shared memory on startup)
*/
static void
reset_shared(int port, bool isReset)
{
if (isReset)
{
ereport(LOG,
(errmsg("resetting shared memory")));
}
else
{
/* On startup, we get here before we know what file we should be using for logging */
ereport(DEBUG1,
(errmsg("setting up shared memory")));
}
/*
* Create or re-create shared memory and semaphores.
*
* Note: in each "cycle of life" we will normally assign the same IPC keys
* (if using SysV shmem and/or semas), since the port number is used to
* determine IPC keys. This helps ensure that we will clean up dead IPC
* objects if the postmaster crashes and is restarted.
*/
CreateSharedMemoryAndSemaphores(false, port);
if (isReset)
{
primaryMirrorHandlePostmasterReset();
}
setInitialRequestedPrimaryMirrorMode(gInitialMode);
}
/*
* SIGHUP -- reread config files, and tell children to do same
*/
static void
SIGHUP_handler(SIGNAL_ARGS)
{
int save_errno = errno;
PG_SETMASK(&BlockSig);
if (Shutdown <= SmartShutdown)
{
ereport(LOG,
(errmsg("received SIGHUP, reloading configuration files"),
errOmitLocation(true)));
ProcessConfigFile(PGC_SIGHUP);
SignalChildren(SIGHUP);
signal_child_if_up(StartupPID, SIGHUP);
signal_child_if_up(StartupPass2PID, SIGHUP);
signal_child_if_up(StartupPass3PID, SIGHUP);
signal_child_if_up(StartupPass4PID, SIGHUP);
signal_child_if_up(BgWriterPID, SIGHUP);
signal_child_if_up(CheckpointPID, SIGHUP);
signal_child_if_up(AutoVacPID, SIGHUP);
signal_child_if_up(PgArchPID, SIGHUP);
{
int ii;
for (ii=0; ii < MaxPMSubType; ii++)
{
PMSubProc *subProc = &PMSubProcList[ii];
signal_child_if_up(subProc->pid, SIGHUP);
}
}
signal_child_if_up(SysLoggerPID, SIGHUP);
signal_child_if_up(PgStatPID, SIGHUP);
/* Reload authentication config files too */
if (!load_hba())
ereport(WARNING,
(errmsg("pg_hba.conf not reloaded")));
load_ident();
#ifdef EXEC_BACKEND
/* Update the starting-point file for future children */
write_nondefault_variables(PGC_SIGHUP);
#endif
}
PG_SETMASK(&UnBlockSig);
errno = save_errno;
}
/*
* pmdie -- signal handler for processing various postmaster signals.
*/
static void
pmdie(SIGNAL_ARGS)
{
int save_errno = errno;
PG_SETMASK(&BlockSig);
ereport(DEBUG2,
(errmsg_internal("postmaster received signal %d",
postgres_signal_arg)));
switch (postgres_signal_arg)
{
case SIGTERM:
/*
* Smart Shutdown:
*
* Wait for children to end their work, then shut down.
*/
if (Shutdown >= SmartShutdown)
break;
Shutdown = SmartShutdown;
ereport(LOG,
(errmsg("received smart shutdown request"),
errSendAlert(true),
errOmitLocation(true)));
need_call_reaper = true;
if ( pmState < PM_CHILD_STOP_BEGIN)
pmState = PM_CHILD_STOP_BEGIN;
break;
case SIGINT:
/*
* Fast Shutdown:
*
* Abort all children with SIGTERM (rollback active transactions
* and exit) and shut down when they are gone.
*/
if (Shutdown >= FastShutdown)
break;
Shutdown = FastShutdown;
ereport(LOG,
(errmsg("received fast shutdown request"),
errSendAlert(true),
errOmitLocation(true)));
need_call_reaper = true;
if ( pmState < PM_CHILD_STOP_BEGIN)
pmState = PM_CHILD_STOP_BEGIN;
else
{
/* we were already stopping children ... rerun the signals for the current state to
* ensure that the correct signal level is applied */
pmStateMachineMustRunActions = true;
}
break;
case SIGQUIT:
/*
* Immediate Shutdown:
*
* abort all children with SIGQUIT and exit without attempt to
* properly shut down data base system.
*/
ereport(LOG,
(errmsg("received immediate shutdown request"),
errSendAlert(true),
errOmitLocation(true)));
SignalChildren(SIGQUIT);
signal_child_if_up(StartupPID, SIGQUIT);
signal_child_if_up(StartupPass2PID, SIGQUIT);
signal_child_if_up(StartupPass3PID, SIGQUIT);
signal_child_if_up(StartupPass4PID, SIGQUIT);
StopServices(0, SIGQUIT);
signal_child_if_up(BgWriterPID, SIGQUIT);
signal_child_if_up(CheckpointPID, SIGQUIT);
signal_child_if_up(AutoVacPID, SIGQUIT);
signal_child_if_up(PgArchPID, SIGQUIT);
signal_child_if_up(PgStatPID, SIGQUIT);
/* if you add more processes here then also update do_immediate_shutdown_reaper */
Shutdown = ImmediateShutdown;
break;
}
if (Debug_print_server_processes)
elog(LOG,"returning from pmdie");
PG_SETMASK(&UnBlockSig);
errno = save_errno;
}
static void
zeroIfPidEqual(int pid, pid_t *ptrToPidToCheckAndZero)
{
if ( pid == *ptrToPidToCheckAndZero)
{
*ptrToPidToCheckAndZero = 0;
}
}
/* These macros hide platform variations in getting child status.
* They are used by do_reaper and do_immediate_shutdown_reaper
*/
#ifdef HAVE_WAITPID
int status; /* child exit status */
#define REAPER_LOOPTEST() ((pid = waitpid(-1, &status, WNOHANG)) > 0)
#define REAPER_LOOPHEADER() (exitstatus = status)
#else /* !HAVE_WAITPID */
#ifndef WIN32
union wait status; /* child exit status */
#define REAPER_LOOPTEST() ((pid = wait3(&status, WNOHANG, NULL)) > 0)
#define REAPER_LOOPHEADER() (exitstatus = status.w_status)
#else /* WIN32 */
#define REAPER_LOOPTEST() ((pid = win32_waitpid(&exitstatus)) > 0)
#define REAPER_LOOPHEADER()
#endif /* WIN32 */
#endif /* HAVE_WAITPID */
/**
* Check for dead processes during immediate shutdown
*/
static void
do_immediate_shutdown_reaper(void)
{
int s;
int pid; /* process id of dead child process */
int exitstatus; /* its exit status */
need_call_reaper = 0;
ereport(DEBUG4, (errmsg_internal("reaping dead processes")));
while (REAPER_LOOPTEST())
{
REAPER_LOOPHEADER();
for (Dlelem *curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
{
Backend *bp = (Backend *) DLE_VAL(curr);
zeroIfPidEqual(pid, &bp->pid);
}
zeroIfPidEqual(pid, &StartupPID);
zeroIfPidEqual(pid, &StartupPass2PID);
zeroIfPidEqual(pid, &StartupPass3PID);
zeroIfPidEqual(pid, &StartupPass4PID);
/* services */
for (s = 0; s < MaxPMSubType; s++)
{
zeroIfPidEqual(pid, &PMSubProcList[s].pid);
}
zeroIfPidEqual(pid, &BgWriterPID);
zeroIfPidEqual(pid, &CheckpointPID);
zeroIfPidEqual(pid, &AutoVacPID);
zeroIfPidEqual(pid, &PgArchPID);
zeroIfPidEqual(pid, &PgStatPID);
}
}
/*
* Startup succeeded, commence normal operations
*/
static bool CommenceNormalOperations(void)
{
bool didServiceProcessWork = false;
int s;
FatalError = false;
pmState = PM_RUN;
/*
* Load the flat authorization file into postmaster's cache. The
* startup process has recomputed this from the database contents,
* so we wait till it finishes before loading it.
*/
load_role();
/*
* Crank up the background writer, if we didn't do that already
* when we entered consistent recovery state. It doesn't matter
* if this fails, we'll just try again later.
*/
if (BgWriterPID == 0)
{
SetBGWriterPID(StartBackgroundWriter());
if (Debug_print_server_processes)
{
elog(LOG,"on startup successful: started 'background writer' as pid %ld",
(long)BgWriterPID);
}
}
if (CheckpointPID == 0)
{
CheckpointPID = StartCheckpointServer();
if (Debug_print_server_processes)
{
elog(LOG,"on startup successful: started 'checkpoint service' as pid %ld",
(long)CheckpointPID);
}
}
/*
* Likewise, start other special children as needed. In a restart
* situation, some of them may be alive already.
*/
if (Shutdown > NoShutdown && BgWriterPID != 0)
signal_child(BgWriterPID, SIGUSR2);
else if (Shutdown == NoShutdown)
{
if (XLogArchivingActive() && PgArchPID == 0)
{
PgArchPID = pgarch_start();
if (Debug_print_server_processes)
{
elog(LOG,"on startup successful: started 'archiver process' as pid %ld",
(long)PgArchPID);
didServiceProcessWork = true;
}
}
if (PgStatPID == 0)
{
PgStatPID = pgstat_start();
if (Debug_print_server_processes)
{
elog(LOG,"on startup successful: started 'statistics collector process' as pid %ld",
(long)PgStatPID);
didServiceProcessWork = true;
}
}
for (s = 0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid == 0 &&
ServiceStartable(subProc))
{
subProc->pid =
(subProc->serverStart)();
if (Debug_print_server_processes)
{
elog(LOG,"on startup successful: started '%s' as pid %ld",
subProc->procName, (long)subProc->pid);
didServiceProcessWork = true;
}
}
}
}
/* at this point we are really open for business */
{
char version[512];
strcpy(version, PG_VERSION_STR " compiled on " __DATE__ " " __TIME__);
#ifdef USE_ASSERT_CHECKING
strcat(version, " (with assert checking)");
#endif
ereport(LOG,(errmsg("%s", version)));
ereport(LOG,
(errmsg("database system is ready to accept connections"),
errdetail("%s",version),
errSendAlert(true),
errOmitLocation(true)));
}
return didServiceProcessWork;
}
/*
* Reaper -- signal handler to cleanup after a child process dies.
*/
static void
reaper(SIGNAL_ARGS)
{
need_call_reaper = 1;
}
static void do_reaper()
{
int save_errno = errno;
int s;
int pid; /* process id of dead child process */
int exitstatus; /* its exit status */
bool wasServiceProcess = false;
bool didServiceProcessWork = false;
need_call_reaper = 0;
ereport(DEBUG4,
(errmsg_internal("reaping dead processes")));
while (REAPER_LOOPTEST())
{
REAPER_LOOPHEADER();
Assert(pid != 0);
bool resetRequired = freeProcEntryAndReturnReset(pid);
if (Debug_print_server_processes)
{
char *procName;
procName = GetServerProcessTitle(pid);
if (procName != NULL)
{
elog(LOG,"'%s' pid %ld exit status %d",
procName, (long)pid, exitstatus);
didServiceProcessWork = true; /* TODO: Should this be set in code that depends on a Debug GUC ? */
}
}
/*
* Check if this child was a startup process.
*/
if (pid == StartupPID)
{
StartupPID = 0;
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/*
* Unexpected exit of startup process (including FATAL exit)
* during PM_STARTUP is treated as catastrophic. There are no
* other processes running yet, so we can just exit.
*/
if (pmState == PM_STARTUP && !EXIT_STATUS_0(exitstatus))
{
LogChildExit(LOG, _("startup process"),
pid, exitstatus);
ereport(LOG,
(errmsg("aborting startup due to startup process failure")));
ExitPostmaster(1);
}
/*
* Startup process exited in response to a shutdown request (or it
* completed normally regardless of the shutdown request).
*/
if (Shutdown > NoShutdown &&
(EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
{
/* PostmasterStateMachine logic does the rest */
continue;
}
/*
* Any unexpected exit (including FATAL exit) of the startup
* process is treated as a crash, except that we don't want to
* reinitialize.
*/
if (!EXIT_STATUS_0(exitstatus))
{
RecoveryError = true;
HandleChildCrash(pid, exitstatus,
_("startup process"));
continue;
}
/*
* When we are not doing single backend startup, we do
* multiple startup passes.
*
* If Crash Recovery is needed we do Pass 2 and 3.
*
* Pass 4 is a verification pass done in for a clean shutdown as
* well as after Crash Recovery.
*/
if (XLogStartupMultipleRecoveryPassesNeeded())
{
Assert(StartupPass2PID == 0);
StartupPass2PID = StartupPass2DataBase();
Assert(StartupPass2PID != 0);
pmState = PM_STARTUP_PASS2;
}
else if (XLogStartupIntegrityCheckNeeded())
{
/*
* Clean shutdown case and wants (and can do) integrity checks.
*/
Assert(StartupPass4PID == 0);
StartupPass4PID = StartupPass4DataBase();
Assert(StartupPass4PID != 0);
pmState = PM_STARTUP_PASS4;
}
else
{
/*
* Startup succeeded, commence normal operations
*/
if (CommenceNormalOperations())
didServiceProcessWork = true;
}
continue;
}
/*
* Check if this child was a startup pass 2 process.
*/
if (pid == StartupPass2PID)
{
StartupPass2PID = 0;
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/*
* Unexpected exit of startup process (including FATAL exit)
* during PM_STARTUP is treated as catastrophic. There are no
* other processes running yet, so we can just exit.
*/
if (pmState == PM_STARTUP_PASS2 && !EXIT_STATUS_0(exitstatus))
{
LogChildExit(LOG, _("startup pass 2 process"),
pid, exitstatus);
ereport(LOG,
(errmsg("aborting startup due to startup process failure")));
ExitPostmaster(1);
}
/*
* Startup process exited in response to a shutdown request (or it
* completed normally regardless of the shutdown request).
*/
if (Shutdown > NoShutdown &&
(EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
{
/* PostmasterStateMachine logic does the rest */
continue;
}
/*
* Any unexpected exit (including FATAL exit) of the startup
* process is treated as a crash, except that we don't want to
* reinitialize.
*/
if (!EXIT_STATUS_0(exitstatus))
{
RecoveryError = true;
HandleChildCrash(pid, exitstatus,
_("startup pass 2 process"));
continue;
}
Assert(StartupPass3PID == 0);
StartupPass3PID = StartupPass3DataBase();
Assert(StartupPass3PID != 0);
pmState = PM_STARTUP_PASS3;
continue;
}
/*
* Check if this child was a startup pass 3 process.
*/
if (pid == StartupPass3PID)
{
StartupPass3PID = 0;
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/*
* Unexpected exit of startup process (including FATAL exit)
* during PM_STARTUP is treated as catastrophic. There are no
* other processes running yet, so we can just exit.
*/
if (pmState == PM_STARTUP_PASS3 && !EXIT_STATUS_0(exitstatus))
{
LogChildExit(LOG, _("startup pass 3 process"),
pid, exitstatus);
ereport(LOG,
(errmsg("aborting startup due to startup process failure")));
ExitPostmaster(1);
}
/*
* Startup process exited in response to a shutdown request (or it
* completed normally regardless of the shutdown request).
*/
if (Shutdown > NoShutdown &&
(EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
{
/* PostmasterStateMachine logic does the rest */
continue;
}
/*
* Any unexpected exit (including FATAL exit) of the startup
* process is treated as a crash, except that we don't want to
* reinitialize.
*/
if (!EXIT_STATUS_0(exitstatus))
{
RecoveryError = true;
HandleChildCrash(pid, exitstatus,
_("startup pass 3 process"));
continue;
}
if (XLogStartupIntegrityCheckNeeded())
{
/*
* Wants (and can do) integrity checks.
*/
Assert(StartupPass4PID == 0);
StartupPass4PID = StartupPass4DataBase();
Assert(StartupPass4PID != 0);
pmState = PM_STARTUP_PASS4;
}
else
{
/*
* Startup succeeded, commence normal operations
*/
if (CommenceNormalOperations())
didServiceProcessWork = true;
}
continue;
}
/*
* Check if this child was a startup pass 4 process.
*/
if (pid == StartupPass4PID)
{
StartupPass4PID = 0;
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/*
* Unexpected exit of startup process (including FATAL exit)
* during PM_STARTUP is treated as catastrophic. There are no
* other processes running yet, so we can just exit.
*/
if (pmState == PM_STARTUP_PASS4 && !EXIT_STATUS_0(exitstatus))
{
LogChildExit(LOG, _("startup pass 4 process"),
pid, exitstatus);
ereport(LOG,
(errmsg("aborting startup due to startup process failure")));
ExitPostmaster(1);
}
/*
* Startup process exited in response to a shutdown request (or it
* completed normally regardless of the shutdown request).
*/
if (Shutdown > NoShutdown &&
(EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
{
/* PostmasterStateMachine logic does the rest */
continue;
}
/*
* Any unexpected exit (including FATAL exit) of the startup
* process is treated as a crash, except that we don't want to
* reinitialize.
*/
if (!EXIT_STATUS_0(exitstatus))
{
RecoveryError = true;
HandleChildCrash(pid, exitstatus,
_("startup pass 4 process"));
continue;
}
if (PgStatPID == 0)
{
PgStatPID = pgstat_start();
if (Debug_print_server_processes)
elog(LOG,"on startup successful: started 'statistics collector process' as pid %ld",
(long)PgStatPID);
didServiceProcessWork = true;
}
/*
* Startup succeeded, commence normal operations
*/
if (CommenceNormalOperations())
didServiceProcessWork = true;
continue;
}
/*
* MPP: Was it one of our servers? If so, just try to start a new one;
* no need to force reset of the rest of the system. (If fail, we'll
* try again in future cycles of the main loop.)
*/
wasServiceProcess = false;
for (s = 0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid != 0 &&
pid == subProc->pid)
{
subProc->pid = 0;
if (!EXIT_STATUS_0(exitstatus))
LogChildExit(LOG, subProc->procName,
pid, exitstatus);
if (ServiceStartable(subProc))
{
if (StartupPidsAllZero() &&
!FatalError && Shutdown == NoShutdown)
{
/*
* Before we attempt a restart -- let's make
* sure that any backend Proc structures are
* tidied up.
*/
if (subProc->cleanupBackend == true)
{
Assert(subProc->procName && strcmp(subProc->procName, "perfmon process") != 0);
CleanupBackend(pid, exitstatus, resetRequired);
}
/*
* MPP-7676, we can't restart during
* do_reaper() since we may initiate a
* postmaster reset (in which case we'll wind
* up waiting for the restarted process to
* die). Leave the startup to ServerLoop().
*/
/*
subProc->pid =
(subProc->serverStart)();
if (Debug_print_server_processes)
{
elog(LOG,"restarted '%s' as pid %ld", subProc->procName, (long)subProc->pid);
didServiceProcessWork = true;
}
*/
}
}
wasServiceProcess = true;
break;
}
}
if (wasServiceProcess)
continue;
/*
* Was it the bgwriter?
*/
if (pid == BgWriterPID)
{
SetBGWriterPID(0);
if (EXIT_STATUS_0(exitstatus) &&
(pmState == PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT
|| (FatalError && pmState >= PM_CHILD_STOP_BEGIN)))
{
Assert(Shutdown > NoShutdown);
/* clean exit: PostmasterStateMachine logic does the rest */
continue;
}
/*
* Any unexpected exit of the bgwriter (including FATAL exit) is treated as a crash.
*/
HandleChildCrash(pid, exitstatus,
_("background writer process"));
/*
* If the bgwriter crashed while trying to write the shutdown
* checkpoint, we may as well just stop here; any recovery
* required will happen on next postmaster start.
*/
if (Shutdown > NoShutdown &&
!DLGetHead(BackendList) &&
AutoVacPID == 0)
{
ereport(LOG,
(errmsg("abnormal database system shutdown"),errSendAlert(true)));
ExitPostmaster(1);
}
/* Else, proceed as in normal crash recovery */
continue;
}
/*
* Was it the checkpoint server process? Normal or FATAL exit can be
* ignored; we'll start a new one at the next iteration of the
* postmaster's main loop, if necessary. Any other exit condition
* is treated as a crash.
*/
if (pid == CheckpointPID)
{
CheckpointPID = 0;
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
HandleChildCrash(pid, exitstatus,
_("checkpoint process"));
continue;
}
/*
* Was it the autovacuum process? Normal or FATAL exit can be
* ignored; we'll start a new one at the next iteration of the
* postmaster's main loop, if necessary. Any other exit condition
* is treated as a crash.
*/
if (pid == AutoVacPID)
{
AutoVacPID = 0;
autovac_stopped();
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus) && resetRequired)
HandleChildCrash(pid, exitstatus,
_("autovacuum process"));
continue;
}
/*
* Was it the archiver? If so, just try to start a new one; no need
* to force reset of the rest of the system. (If fail, we'll try
* again in future cycles of the main loop.) But if we were waiting
* for it to shut down, advance to the next shutdown step.
*/
if (pid == PgArchPID)
{
PgArchPID = 0;
if (!EXIT_STATUS_0(exitstatus))
LogChildExit(LOG, _("archiver process"),
pid, exitstatus);
if (XLogArchivingActive() && pmState == PM_RUN)
{
PgArchPID = pgarch_start();
if (Debug_print_server_processes)
{
elog(LOG,"restarted 'archiver process' as pid %ld",
(long)PgArchPID);
didServiceProcessWork = true;
}
}
continue;
}
/*
* Was it the statistics collector? If so, just try to start a new
* one; no need to force reset of the rest of the system. (If fail,
* we'll try again in future cycles of the main loop.)
*/
if (pid == PgStatPID)
{
PgStatPID = 0;
if (!EXIT_STATUS_0(exitstatus))
LogChildExit(LOG, _("statistics collector process"),
pid, exitstatus);
if (pmState == PM_RUN)
{
PgStatPID = pgstat_start();
if (Debug_print_server_processes)
{
elog(LOG,"restarted 'statistics collector process' as pid %ld",
(long)PgStatPID);
didServiceProcessWork = true;
}
}
continue;
}
/* Was it the system logger? If so, try to start a new one */
if (pid == SysLoggerPID)
{
SysLoggerPID = 0;
/* for safety's sake, launch new logger *first* */
SysLoggerPID = SysLogger_Start();
if (Debug_print_server_processes)
{
elog(LOG,"restarted 'system logger process' as pid %ld",
(long)SysLoggerPID);
didServiceProcessWork = true; /* TODO: Should this be set in code that depends on a Debug GUC? */
}
if (!EXIT_STATUS_0(exitstatus))
LogChildExit(LOG, _("system logger process"),
pid, exitstatus);
continue;
}
/*
* Else do standard backend child cleanup.
*/
CleanupBackend(pid, exitstatus, resetRequired);
} /* loop over pending child-death reports */
/*
* TODO: All of the code in this if block should be in PostmasterStateMachine, and
* this code should be removed. Chuck
*
* TODO: CHAD_PM should this also proceed through normal child exit state logic and simply
* do something at the right time (when, for example, all post-bgwriters are done) (When that state is
* reached and we have fatalerror with no shutdown request then do the shared memory reset and restart)
*/
if (FatalError)
{
PrimaryMirrorMode pm_mode;
SegmentState_e s_state;
DataState_e d_state;
FaultType_e f_type;
getPrimaryMirrorStatusCodes(&pm_mode, &s_state, &d_state, &f_type);
/*
* Wait for all important children to exit, then reset shmem and
* redo database startup. (We can ignore the archiver and stats processes
* here since they are not connected to shmem.)
*/
if (DLGetHead(BackendList) ||
StartupPID != 0 ||
StartupPass2PID != 0 ||
StartupPass3PID != 0 ||
StartupPass4PID != 0 ||
BgWriterPID != 0 ||
CheckpointPID != 0 ||
AutoVacPID != 0 ||
ServiceProcessesExist(0))
{
/* important child is still going...wait longer */
goto reaper_done;
}
if ( RecoveryError )
{
ereport(LOG,
(errmsg("database recovery failed; exiting")));
/*
* If recovery failed, wait for all non-syslogger children to exit, and
* then exit postmaster. We don't try to reinitialize when recovery fails,
* because more than likely it will just fail again and we will keep
* trying forever.
*/
ExitPostmaster(1);
}
if ( Shutdown > NoShutdown)
{
ereport(LOG,
(errmsg("error during requested shutdown; exiting")));
/**
* We hit a fatal error because of, or prior to, a requested shutdown. Just exit now.
*/
ExitPostmaster(1);
}
if ( pmState != PM_POSTMASTER_RESET_FILEREP_PEER )
{
BeginResetOfPostmasterAfterChildrenAreShutDown();
}
/** fall-through, state machine will handle PM_INIT or PM_POSTMASTER_RESET_FILEREP_PEER */
}
/*
* After cleaning out the SIGCHLD queue, see if we have any state changes
* or actions to make.
*/
PostmasterStateMachine();
reaper_done:
if (Debug_print_server_processes && didServiceProcessWork)
elog(LOG,"returning from reaper");
errno = save_errno;
}
static bool
ServiceProcessesExist(int excludeFlags)
{
int s;
for (s=0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid != 0 &&
(subProc->flags & excludeFlags) == 0)
return true;
}
return false;
}
static bool
StopServices(int excludeFlags, int signal)
{
int s;
bool signaled = false;
for (s=0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid != 0 &&
(subProc->flags & excludeFlags) == 0)
{
signal_child(subProc->pid, signal);
signaled = true;
}
}
return signaled;
}
static char *
GetServerProcessTitle(int pid)
{
int s;
for (s=0; s < MaxPMSubType; s++)
{
PMSubProc *subProc = &PMSubProcList[s];
if (subProc->pid == pid)
return subProc->procName;
}
if (pid == BgWriterPID)
return "background writer process";
if (pid == CheckpointPID)
return "checkpoint process";
else if (pid == AutoVacPID)
return "autovacuum process";
else if (pid == PgStatPID)
return "statistics collector process";
else if (pid == PgArchPID)
return "archiver process";
else if (pid == SysLoggerPID)
return "system logger process";
else if (pid == StartupPID)
return "startup process";
else if (pid == StartupPass2PID)
return "startup pass 2 process";
else if (pid == StartupPass3PID)
return "startup pass 3 process";
else if (pid == StartupPass4PID)
return "startup pass 4 process";
else if (pid == PostmasterPid)
return "postmaster process";
return NULL;
}
/*
* CleanupBackend -- cleanup after terminated backend.
*
* Remove all local state associated with backend.
*/
static void
CleanupBackend(int pid,
int exitstatus, /* child's exit status. */
bool resetRequired) /* postmaster reset is required */
{
Dlelem *curr;
LogChildExit(DEBUG2, _("server process"), pid, exitstatus);
/*
* If a backend dies in an ugly way then we must signal all other backends
* to quickdie. If exit status is zero (normal) or one (FATAL exit), we
* assume everything is all right and proceed to remove the backend from
* the active backend list.
*/
#ifdef WIN32
/*
* On win32, also treat ERROR_WAIT_NO_CHILDREN (128) as nonfatal
* case, since that sometimes happens under load when the process fails
* to start properly (long before it starts using shared memory).
*/
if (exitstatus == ERROR_WAIT_NO_CHILDREN)
{
LogChildExit(LOG, _("server process"), pid, exitstatus);
exitstatus = 0;
}
#endif
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus) && resetRequired)
{
HandleChildCrash(pid, exitstatus, _("server process"));
return;
}
for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
{
Backend *bp = (Backend *) DLE_VAL(curr);
if (bp->pid == pid)
{
if (!bp->dead_end)
{
if (!ReleasePostmasterChildSlot(bp->child_slot))
{
/*
* Uh-oh, the child failed to clean itself up. Treat as a
* crash after all.
*/
HandleChildCrash(pid, exitstatus, _("server process"));
return;
}
#ifdef EXEC_BACKEND
ShmemBackendArrayRemove(bp);
#endif
}
DLRemove(curr);
free(bp);
break;
}
}
}
/*
* HandleChildCrash -- cleanup after failed backend, bgwriter, walwriter,
* or autovacuum.
*
* The objectives here are to clean up our local state about the child
* process, and to signal all other remaining children to quickdie.
*
* @param pid the pid of the crashed child, or -1 if don't know the pid and don't want to log the failed child (this
* can happen when the filerep controller process signals us to reset, or when a primary/mirror peer
* signals us to reset)
*/
static void
HandleChildCrash(int pid, int exitstatus, const char *procname)
{
Dlelem *curr,
*next;
Backend *bp;
/*
* Make log entry unless there was a previous crash (if so, nonzero exit
* status is to be expected in SIGQUIT response; don't clutter log)
*/
if (!FatalError)
{
if (pid != -1)
{
LogChildExit(LOG, procname, pid, exitstatus);
}
ereport(LOG,
(errmsg("terminating any other active server processes")));
}
/* Process regular backends */
for (curr = DLGetHead(BackendList); curr; curr = next)
{
next = DLGetSucc(curr);
bp = (Backend *) DLE_VAL(curr);
if (bp->pid == pid)
{
/*
* Found entry for freshly-dead backend, so remove it.
*/
if (!bp->dead_end)
{
(void) ReleasePostmasterChildSlot(bp->child_slot);
#ifdef EXEC_BACKEND
ShmemBackendArrayRemove(bp);
#endif
}
DLRemove(curr);
free(bp);
/* Keep looping so we can signal remaining backends */
}
else
{
/*
* This backend is still alive. Unless we did so already, tell it
* to commit hara-kiri.
*
* SIGQUIT is the special signal that says exit without proc_exit
* and let the user know what's going on. But if SendStop is set
* (-s on command line), then we send SIGSTOP instead, so that we
* can get core dumps from all backends by hand.
*
* We could exclude dead_end children here, but at least in the
* SIGSTOP case it seems better to include them.
*/
if (!FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) bp->pid)));
signal_child(bp->pid, (SendStop ? SIGSTOP : SIGQUIT));
}
}
}
/* Take care of the startup process too */
if (pid == StartupPID)
StartupPID = 0;
else if (StartupPID != 0 && !FatalError)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) StartupPID)));
signal_child(StartupPID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the startup process too */
if (pid == StartupPass2PID)
StartupPass2PID = 0;
else if (StartupPass2PID != 0 && !FatalError)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) StartupPass2PID)));
signal_child(StartupPass2PID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the startup process too */
if (pid == StartupPass3PID)
StartupPass3PID = 0;
else if (StartupPass3PID != 0 && !FatalError)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) StartupPass3PID)));
signal_child(StartupPass3PID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the startup process too */
if (pid == StartupPass4PID)
StartupPass4PID = 0;
else if (StartupPass4PID != 0 && !FatalError)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) StartupPass4PID)));
signal_child(StartupPass4PID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the bgwriter too */
if (pid == BgWriterPID)
{
SetBGWriterPID(0);
}
else if (BgWriterPID != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) BgWriterPID)));
signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the checkpoint too */
if (pid == CheckpointPID)
{
CheckpointPID = 0;
}
else if (CheckpointPID != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) CheckpointPID)));
signal_child(CheckpointPID, (SendStop ? SIGSTOP : SIGQUIT));
}
/* Take care of the autovacuum daemon too */
if (pid == AutoVacPID)
AutoVacPID = 0;
else if (AutoVacPID != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
(SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) AutoVacPID)));
signal_child(AutoVacPID, (SendStop ? SIGSTOP : SIGQUIT));
}
/*
* Force a power-cycle of the pgarch process too. (This isn't absolutely
* necessary, but it seems like a good idea for robustness, and it
* simplifies the state-machine logic in the case where a shutdown request
* arrives during crash processing.)
*/
if (PgArchPID != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
"SIGQUIT",
(int) PgArchPID)));
signal_child(PgArchPID, SIGQUIT);
}
/* Force a power-cycle of the seqserver process too */
/* (Shouldn't be necessary, but just for luck) */
{
int ii;
for (ii=0; ii < MaxPMSubType; ii++)
{
PMSubProc *subProc = &PMSubProcList[ii];
if (subProc->pid != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
"SIGQUIT",
(int) subProc->pid)));
signal_child(subProc->pid, SIGQUIT);
}
}
}
/*
* Force a power-cycle of the pgstat process too. (This isn't absolutely
* necessary, but it seems like a good idea for robustness, and it
* simplifies the state-machine logic in the case where a shutdown request
* arrives during crash processing.)
*/
if (PgStatPID != 0 && !FatalError)
{
ereport((Debug_print_server_processes ? LOG : DEBUG2),
(errmsg_internal("sending %s to process %d",
"SIGQUIT",
(int) PgStatPID)));
signal_child(PgStatPID, SIGQUIT);
allow_immediate_pgstat_restart();
}
/* We do NOT restart the syslogger */
FatalError = true;
/* We now transit into a state of waiting for children to die */
if (pmState <= PM_RUN )
{
pmState = PM_CHILD_STOP_BEGIN;
}
}
// This is a duplicate of strsignal, for those platforms that have it.
static const char *
signal_to_name(int signal)
{
#if defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
// sys_siglist knows all possible signal names on ths platform.
if (signal < NSIG)
return sys_siglist[signal];
else
return NULL;
#else
switch (signal)
{
case SIGINT: return "SIGINT";
case SIGTERM: return "SIGTERM";
case SIGQUIT: return "SIGQUIT";
case SIGSTOP: return "SIGSTOP";
case SIGUSR1: return "SIGUSR1";
case SIGUSR2: return "SIGUSR2";
default: return NULL;
}
#endif
}
/*
* Log the death of a child process.
*/
static void
LogChildExit(int lev, const char *procname, int pid, int exitstatus)
{
char pidLabel[100];
sprintf(pidLabel, " (PID %d)", pid);
if (WIFEXITED(exitstatus))
ereport(lev,
/*------
translator: %s is a noun phrase describing a child process, such as
"server process" */
(errmsg("%s%s exited with exit code %d",
procname, pidLabel, WEXITSTATUS(exitstatus))));
else if (WIFSIGNALED(exitstatus))
#if defined(WIN32)
ereport(lev,
/*------
translator: %s is a noun phrase describing a child process, such as
"server process" */
(errmsg("%s%s was terminated by exception 0x%X",
procname, pidLabel, WTERMSIG(exitstatus)),
errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value.")));
#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
ereport(lev,
/*------
translator: %s is a noun phrase describing a child process, such as
"server process" */
// strsignal() is preferred over the deprecated use of sys_siglist, on platforms that support it.
// Solaris and Linux do support it, but I think MAC OSX doesn't?
(errmsg("%s%s was terminated by signal %d: %s",
procname, pidLabel, WTERMSIG(exitstatus),
WTERMSIG(exitstatus) < NSIG ?
sys_siglist[WTERMSIG(exitstatus)] : "(unknown)")));
#else
{
// If we don't have strsignal or sys_siglist, do our own translation
const char *signalName;
signalName = signal_to_name(WTERMSIG(exitstatus));
if (signalName == NULL)
signalName = "(unknown)";
ereport(lev,
/*------
translator: %s is a noun phrase describing a child process, such as
"server process" */
(errmsg("%s%s was terminated by signal %d: %s",
procname, pidLabel, WTERMSIG(exitstatus), signalName)));
}
#endif
else
ereport(lev,
/*------
translator: %s is a noun phrase describing a child process, such as
"server process" */
(errmsg("%s%s exited with unrecognized status %d",
procname, pidLabel, exitstatus)));
}
/**
* POSTMASTER STATE MACHINE WAITING!
*/
/**
* Check to see if PM_CHILD_STOP_WAIT_BACKENDS state is done
*/
static PMState StateMachineCheck_WaitBackends(void)
{
bool moveToNextState = false;
Assert(pmState == PM_CHILD_STOP_WAIT_BACKENDS );
/*
* If we are in a state-machine state that implies waiting for backends to
* exit, see if they're all gone, and change state if so.
*/
if (! isPrimaryMirrorModeAFullPostmaster(true))
{
/* wait_backends has ended because we don't have any! */
moveToNextState = true;
}
else
{
// note: if wal writer is added, check this here: WalWriterPID == 0 &&
int childCount = CountChildren();
bool autovacShutdown = AutoVacPID == 0;
if (childCount == 0 &&
(BgWriterPID == 0 || !FatalError) && /* todo: CHAD_PM why wait for BgWriterPID here? Can't we just allow
normal state advancement to hit there? */
autovacShutdown)
{
/* note: on fatal error, children are killed all at once by HandleChildCrash, so asserts are not valid */
if ( ! FatalError )
{
Assert(StartupPID == 0);
}
/*
* PM_CHILD_STOP_WAIT_BACKENDS state ends when we have no regular backends
* (including autovac workers) and no walwriter or autovac launcher.
* If we are doing crash recovery then we expect the bgwriter to exit
* too, otherwise not. The archiver, stats, and syslogger processes
* are disregarded since they are not connected to shared memory; we
* also disregard dead_end children here.
*/
if (FatalError)
{
moveToNextState = true;
}
else
{
/*
* This state change causes ServerLoop to stop creating new ones.
*/
Assert(Shutdown > NoShutdown);
moveToNextState = true;
}
}
else
{
if ( Debug_print_server_processes )
{
elog(LOG, "Postmaster State Machine: waiting on backends, children %d, av %s",
childCount,
autovacShutdown ? "stopped" : "running" );
}
}
}
return moveToNextState ? (pmState+1) : pmState;
}
/**
* Check to see if PM_POSTMASTER_RESET_FILEREP_PEER state is done,
*
* possibly
*/
static PMState StateMachineCheck_WaitFilerepPeerReset(void)
{
Assert(pmState == PM_POSTMASTER_RESET_FILEREP_PEER );
switch (peerResetResult)
{
case PEER_RESET_NONE:
/* no change */
break;
case PEER_RESET_FAILED:
/* mark fault in shared memory */
setTransitionToFault();
RestartAfterPostmasterReset();
break;
case PEER_RESET_SUCCEEDED:
RestartAfterPostmasterReset();
break;
}
return pmState;
}
/**
* Check to see if PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN state is done
*/
static PMState StateMachineCheck_WaitDeadEndChildren(void)
{
bool moveToNextState = false;
Assert(pmState == PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN );
/*
* PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN state ends when the BackendList is entirely empty
* (ie, no dead_end children remain), and the archiver and stats
* collector are gone too.
*
* The reason we wait for those two is to protect them against a new
* postmaster starting conflicting subprocesses; this isn't an
* ironclad protection, but it at least helps in the
* shutdown-and-immediately-restart scenario. Note that they have
* already been sent appropriate shutdown signals, either during a
* normal state transition leading up to PM_WAIT_DEAD_END, or during
* FatalError processing.
*/
if (DLGetHead(BackendList) == NULL)
{
/* These other guys should be dead already */
/* todo: ALL other processes should be dead at this point */
/* note: on fatal error, children are killed all at once by HandleChildCrash, so asserts are not valid */
if ( ! FatalError )
{
Assert(StartupPID == 0);
Assert(BgWriterPID == 0);
Assert(CheckpointPID == 0);
Assert(AutoVacPID == 0);
}
/* syslogger is not considered here */
moveToNextState = true;
}
return moveToNextState ? (pmState+1) : pmState;
}
/**
* Check to see if PM_CHILD_STOP_WAIT_STARTUP_PROCESSES state is done
*/
static PMState StateMachineCheck_WaitStartupProcesses(void)
{
Assert(pmState == PM_CHILD_STOP_WAIT_STARTUP_PROCESSES);
bool moveToNextState = StartupPID == 0 && StartupPass2PID == 0 && StartupPass3PID == 0 && StartupPass4PID == 0;
return moveToNextState ? (pmState+1) : pmState;
}
/**
* Check to see if PM_CHILD_STOP_WAIT_PREBGWRITER state is done
*/
static PMState StateMachineCheck_WaitPreBgWriter(void)
{
Assert(pmState == PM_CHILD_STOP_WAIT_PREBGWRITER );
/* waiting for pre-bgwriter services to exit */
bool moveToNextState =
(!ServiceProcessesExist(/* excludeFlags */ PMSUBPROC_FLAG_STOP_AFTER_BGWRITER) &&
CheckpointPID == 0);
return moveToNextState ? (pmState+1) : pmState;
}
/**
* Check to see if PM_CHILD_STOP_WAIT_POSTBGWRITER state is done
*/
static PMState StateMachineCheck_WaitPostBgWriter(void)
{
Assert(pmState == PM_CHILD_STOP_WAIT_POSTBGWRITER);
/* waiting for post-bgwriter services to exit */
bool moveToNextState = true;
/* note: on fatal error, children are killed all at once by HandleChildCrash, so asserts are not valid */
if ( ! FatalError )
{
Assert(BgWriterPID == 0);
}
if ( ServiceProcessesExist(/* excludeFlags */ 0))
moveToNextState = false;
else if (PgArchPID != 0 ||
PgStatPID != 0)
{
moveToNextState = false;
}
return moveToNextState ? (pmState+1) : pmState;
}
/**
* Check to see if PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT state is done
*/
static PMState StateMachineCheck_WaitBgWriterCheckpointComplete(void)
{
Assert(pmState == PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT);
/* waiting for bgwriter to FINISH ckpt and exit */
bool moveToNextState = BgWriterPID == 0;
return moveToNextState ? (pmState+1) : pmState;
}
/***************************************
* POSTMASTER STATE MACHINE TRANSITIONS
***************************************/
/**
* Called to transition to PM_CHILD_STOP_WAIT_STARTUP_PROCESSES -- so tell any startup processes to complete
*/
static void StateMachineTransition_ShutdownStartupProcesses(void)
{
if ( Shutdown == FastShutdown )
{
signal_child_if_up(StartupPID, SIGTERM);
signal_child_if_up(StartupPass2PID, SIGTERM);
signal_child_if_up(StartupPass3PID, SIGTERM);
signal_child_if_up(StartupPass4PID, SIGTERM);
}
else
{
/* else: normal shutdown, wait for startup to complete naturally */
}
}
/**
* Called to transition to PM_CHILD_STOP_WAIT_BACKENDS : waiting for all backends to finish
*/
static void StateMachineTransition_ShutdownBackends(void)
{
if ( Shutdown == FastShutdown )
{
/* shut down all backend, including autovac workers */
SignalChildren(SIGTERM);
}
else
{
/* only autovacuum workers are told to shut down immediately */
SignalAutovacWorkers(SIGTERM);
}
/* and the autovac launcher too */
signal_child_if_up(AutoVacPID, SIGTERM);
}
/**
* Called to transition to PM_CHILD_STOP_WAIT_PREBGWRITER : waiting for pre-bgwriter processes to finish
*/
static void StateMachineTransition_ShutdownPreBgWriter(void)
{
/* SIGUSR2, regardless of shutdown mode */
StopServices(/* excludeFlags */ PMSUBPROC_FLAG_STOP_AFTER_BGWRITER, SIGUSR2 );
signal_child_if_up(CheckpointPID, SIGUSR2);
}
/**
* Called to transition to PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT : waiting for bgwriter to run a checkpoint and quit
*/
static void StateMachineTransition_ShutdownBgWriterWithCheckpoint(void)
{
if (! FatalError &&
! RecoveryError &&
! SyncMaster &&
isFullPostmasterAndDatabaseIsAllowed())
{
/* Start the bgwriter if not running */
if (BgWriterPID == 0 )
{
SetBGWriterPID(StartBackgroundWriter());
}
}
/* SIGUSR2, regardless of shutdown mode */
signal_child_if_up(BgWriterPID, SIGUSR2);
}
/**
* Called to transition to PM_CHILD_STOP_WAIT_POSTBGWRITER : waiting for post-bgwriter services to exit
*/
static void StateMachineTransition_ShutdownPostBgWriter(void)
{
/* these services take the same signal regardless of fast vs smart shutdown */
StopServices(/* excludeFlags */ 0, SIGUSR2);
signal_child_if_up(PgArchPID, SIGQUIT);
signal_child_if_up(PgStatPID, SIGQUIT);
}
/**
* Called to transition tp PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN : waiting for dead-end children to complete
*/
static void StateMachineTransition_ShutdownDeadEndChildren(void)
{
/* nothing to do, just waiting */
}
/**
* Called to transition to final PM_CHILD_STOP_WAIT_NO_CHILDREN state. Note that in some cases this will
* actually exit the process because a requested shutdown is complete!
*/
static void StateMachineTransition_NoChildren(void)
{
Assert(pmState == PM_CHILD_STOP_WAIT_NO_CHILDREN);
if(Shutdown > NoShutdown)
{
/*
* If we've been told to shut down, we exit as soon as there are no
* remaining children. If there was a crash, cleanup will occur at the
* next startup. (Before PostgreSQL 8.3, we tried to recover from the
* crash before exiting, but that seems unwise if we are quitting because
* we got SIGTERM from init --- there may well not be time for recovery
* before init decides to SIGKILL us.)
*
* Note that the syslogger continues to run. It will exit when it sees
* EOF on its input pipe, which happens when there are no more upstream
* processes.
*/
if (FatalError)
{
ereport(LOG, (errmsg("abnormal database system shutdown"),errSendAlert(true)));
ExitPostmaster(1);
}
else
{
/*
* Terminate backup mode to avoid recovery after a clean fast
* shutdown.
*/
/* GPDB doesn't have backup mode, so nothing to cancel */
//CancelBackup();
/* Normal exit from the postmaster is here */
ExitPostmaster(0);
}
}
else if (RecoveryError)
{
ereport(LOG,
(errmsg("database recovery failed; exiting")));
/*
* If recovery failed, wait for all non-syslogger children to exit, and
* then exit postmaster. We don't try to reinitialize when recovery fails,
* because more than likely it will just fail again and we will keep
* trying forever.
*/
ExitPostmaster(1);
}
else if (FatalError)
{
BeginResetOfPostmasterAfterChildrenAreShutDown();
}
else
{
Assert(!"NoChildren state reached when not in shutdown and not experiencing a fatal error");
}
}
/*
* Advance the postmaster's state machine and take actions as appropriate
*
*
* Right now, this state machine is concerned with the orderly shutdown sequence.
* We should be able to make it cover startup and PM_RUN as well (where we restart crashed processes)
*
* Note also that because of the fact that it only handles orderly shutdown directly, pmState is
* sometimes changed by a transition or wait function (as when resetting the filerep peer during postmaster
* reset). This could probably be structured better so it all worked better
*
*
* This is common code for pmdie() and reaper(), which receive the signals
* that might mean we need to change state.
*
*/
static void
PostmasterStateMachine(void)
{
int passThroughStateMachine;
const int minStateForLogging = PM_CHILD_STOP_BEGIN;
#define DO_STATE_MACHINE_LOGGING (pmState >= minStateForLogging && Debug_print_server_processes)
for (passThroughStateMachine = 0;; passThroughStateMachine++)
{
int nextPmState = pmState;
Assert(passThroughStateMachine < 100);
if (DO_STATE_MACHINE_LOGGING)
{
elog(LOG, "Postmaster State Machine: checking state %s", gPmStateLabels[pmState]);
}
/* first, look at the current pmState and see if that state has been completed */
switch ( pmState )
{
case PM_INIT:
case PM_STARTUP:
case PM_STARTUP_PASS2:
case PM_STARTUP_PASS3:
case PM_STARTUP_PASS4:
case PM_RECOVERY:
case PM_RECOVERY_CONSISTENT:
case PM_RUN:
nextPmState = pmState;
break;
case PM_CHILD_STOP_BEGIN:
nextPmState = pmState + 1; /* immediately move to next step and run its transition actions ... */
break;
/* shutdown has been requested -- check to make sure startup processes are done */
case PM_CHILD_STOP_WAIT_STARTUP_PROCESSES:
nextPmState = StateMachineCheck_WaitStartupProcesses();
break;
/* waiting for live backends to exit */
case PM_CHILD_STOP_WAIT_BACKENDS:
nextPmState = StateMachineCheck_WaitBackends();
break;
/* waiting for pre-backend services to exit */
case PM_CHILD_STOP_WAIT_PREBGWRITER:
nextPmState = StateMachineCheck_WaitPreBgWriter();
break;
/* waiting for bgwriter to do shutdown ckpt */
case PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT:
nextPmState = StateMachineCheck_WaitBgWriterCheckpointComplete();
break;
/* waiting for pre-backend services to exit */
case PM_CHILD_STOP_WAIT_POSTBGWRITER:
nextPmState = StateMachineCheck_WaitPostBgWriter();
break;
/* waiting for dead_end children to exit */
case PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN:
nextPmState = StateMachineCheck_WaitDeadEndChildren();
break;
case PM_CHILD_STOP_WAIT_NO_CHILDREN:
Assert(!"Unreachable state");
break;
case PM_POSTMASTER_RESET_FILEREP_PEER:
nextPmState = StateMachineCheck_WaitFilerepPeerReset();
break;
default:
Assert(!"Invalid pmState");
break;
}
if ( nextPmState != pmState )
{
pmState = nextPmState;
if ( DO_STATE_MACHINE_LOGGING )
elog(LOG, "Postmaster State Machine: entering state %s", gPmStateLabels[pmState]);
}
else if ( pmStateMachineMustRunActions)
{
if ( DO_STATE_MACHINE_LOGGING )
elog(LOG, "Postmaster State Machine: rerunning actions for %s", gPmStateLabels[pmState]);
}
else
{
if ( DO_STATE_MACHINE_LOGGING )
elog(LOG, "Postmaster State Machine: no change from %s", gPmStateLabels[pmState]);
/* current state was not completed ... quit and wait to be called again */
break;
}
pmStateMachineMustRunActions = false;
switch ( pmState )
{
case PM_INIT:
case PM_STARTUP:
case PM_STARTUP_PASS2:
case PM_STARTUP_PASS3:
case PM_STARTUP_PASS4:
case PM_RECOVERY:
case PM_RECOVERY_CONSISTENT:
case PM_RUN:
break;
case PM_CHILD_STOP_BEGIN:
Assert("Unreachable state; the only change of pmState to PM_CHILD_STOP_BEGIN is in the pmdie handler.");
break;
case PM_CHILD_STOP_WAIT_STARTUP_PROCESSES:
/* shutdown has been requested -- check to make sure startup processes are done */
StateMachineTransition_ShutdownStartupProcesses();
break;
case PM_CHILD_STOP_WAIT_BACKENDS:
/* tell live backends to exit */
StateMachineTransition_ShutdownBackends();
break;
case PM_CHILD_STOP_WAIT_PREBGWRITER :
/* tell pre-bgwriter services to exit */
StateMachineTransition_ShutdownPreBgWriter();
break;
case PM_CHILD_STOP_WAIT_BGWRITER_CHECKPOINT:
/* tell bgwriter to do shutdown ckpt and exit */
StateMachineTransition_ShutdownBgWriterWithCheckpoint();
break;
case PM_CHILD_STOP_WAIT_POSTBGWRITER :
/* tell post-bgwriter services to exit */
StateMachineTransition_ShutdownPostBgWriter();
break;
case PM_CHILD_STOP_WAIT_DEAD_END_CHILDREN:
/* waiting for dead_end children to exit */
StateMachineTransition_ShutdownDeadEndChildren();
break;
case PM_CHILD_STOP_WAIT_NO_CHILDREN:
/* all children are done, now we can exit or restart after crash, perhaps set up a transition to
* StateMachineTransition_ResetFilerepPeer
*/
StateMachineTransition_NoChildren();
break;
case PM_POSTMASTER_RESET_FILEREP_PEER:
Assert(!"Invalid pmState PM_POSTMASTER_RESET_FILEREP_PEER : "
"is not reached through a nextPmState assignment");
break;
default:
Assert(!"Invalid pmState");
break;
}
/* and now loop again to see if the new pmState has already been satisfied, most likely if our
* current actions on entering the state were no-ops */
}
}
/*
* Send a signal to a postmaster child process
*
* On systems that have setsid(), each child process sets itself up as a
* process group leader. For signals that are generally interpreted in the
* appropriate fashion, we signal the entire process group not just the
* direct child process. This allows us to, for example, SIGQUIT a blocked
* archive_recovery script, or SIGINT a script being run by a backend via
* system().
*
* There is a race condition for recently-forked children: they might not
* have executed setsid() yet. So we signal the child directly as well as
* the group. We assume such a child will handle the signal before trying
* to spawn any grandchild processes. We also assume that signaling the
* child twice will not cause any problems.
*/
static void
signal_child(pid_t pid, int signal)
{
if (Debug_print_server_processes)
{
char *procName;
procName = GetServerProcessTitle(pid);
if (procName != NULL)
{
const char *signalName;
signalName = signal_to_name(signal);
if (signalName != NULL)
elog(LOG,"signal %s sent to '%s' pid %ld",
signalName, procName, (long)pid);
else
elog(LOG,"signal %d sent to '%s' pid %ld",
signal, procName, (long)pid);
}
}
if (kill(pid, signal) < 0)
elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) pid, signal);
#ifdef HAVE_SETSID
switch (signal)
{
case SIGINT:
case SIGTERM:
case SIGQUIT:
case SIGSTOP:
if (kill(-pid, signal) < 0)
elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) (-pid), signal);
break;
default:
break;
}
#endif
}
/*
* Send a signal to all backend children, including autovacuum workers
* (but NOT special children; dead_end children are never signaled, either).
* If only_autovac is TRUE, only the autovacuum worker processes are signalled.
*/
static void
SignalSomeChildren(int signal, bool only_autovac)
{
Dlelem *curr;
for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
{
Backend *bp = (Backend *) DLE_VAL(curr);
if (bp->dead_end)
continue;
if (only_autovac && !bp->is_autovacuum)
continue;
ereport((Debug_print_server_processes ? LOG : DEBUG4),
(errmsg_internal("sending signal %d to process %d",
signal, (int) bp->pid)));
signal_child(bp->pid, signal);
}
}
/*
* BackendStartup -- start backend process
*
* returns: STATUS_ERROR if the fork failed, STATUS_OK otherwise.
*
* Note: if you change this code, also consider StartAutovacuumWorker.
*/
static int
BackendStartup(Port *port)
{
Backend *bn; /* for backend cleanup */
pid_t pid;
/*
* Create backend data structure. Better before the fork() so we can
* handle failure cleanly.
*/
bn = (Backend *) malloc(sizeof(Backend));
if (!bn)
{
ereport(LOG,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
return STATUS_ERROR;
}
/*
* Compute the cancel key that will be assigned to this backend. The
* backend will have its own copy in the forked-off process' value of
* MyCancelKey, so that it can transmit the key to the frontend.
*/
MyCancelKey = PostmasterRandom();
bn->cancel_key = MyCancelKey;
/* Pass down canAcceptConnections state */
port->canAcceptConnections = canAcceptConnections();
bn->dead_end = (port->canAcceptConnections != CAC_OK);
/*
* Unless it's a dead_end child, assign it a child slot number
*/
if (!bn->dead_end)
bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
else
bn->child_slot = 0;
#ifdef EXEC_BACKEND
pid = backend_forkexec(port);
#else /* !EXEC_BACKEND */
pid = fork_process();
if (pid == 0) /* child */
{
free(bn);
/*
* Let's clean up ourselves as the postmaster child, and close the
* postmaster's listen sockets. (In EXEC_BACKEND case this is all
* done in SubPostmasterMain.)
*/
IsUnderPostmaster = true; /* we are a postmaster subprocess now */
MyProcPid = getpid(); /* reset MyProcPid */
MyStartTime = time(NULL);
/* We don't want the postmaster's proc_exit() handlers */
on_exit_reset();
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Perform additional initialization and client authentication */
BackendInitialize(port);
/* And run the backend */
int brres = BackendRun(port);
cleanupQD2RMComm();
proc_exit(brres);
}
#endif /* EXEC_BACKEND */
if (pid < 0)
{
/* in parent, fork failed */
int save_errno = errno;
if (!bn->dead_end)
(void) ReleasePostmasterChildSlot(bn->child_slot);
free(bn);
errno = save_errno;
ereport(LOG,
(errmsg("could not fork new process for connection: %m")));
report_fork_failure_to_client(port, save_errno);
return STATUS_ERROR;
}
/* in parent, successful fork */
ereport(DEBUG2,
(errmsg_internal("forked new backend, pid=%d socket=%d",
(int) pid, port->sock)));
/*
* Everything's been successful, it's safe to add this backend to our list
* of backends.
*/
bn->pid = pid;
bn->is_autovacuum = false;
DLInitElem(&bn->elem, bn);
DLAddHead(BackendList, &bn->elem);
#ifdef EXEC_BACKEND
if (!bn->dead_end)
ShmemBackendArrayAdd(bn);
#endif
return STATUS_OK;
}
/*
* Try to report backend fork() failure to client before we close the
* connection. Since we do not care to risk blocking the postmaster on
* this connection, we set the connection to non-blocking and try only once.
*
* This is grungy special-purpose code; we cannot use backend libpq since
* it's not up and running.
*/
static void
report_fork_failure_to_client(Port *port, int errnum)
{
char buffer[1000];
int rc;
/* Format the error message packet (always V2 protocol) */
snprintf(buffer, sizeof(buffer), "E%s%s\n",
_("could not fork new process for connection: "),
strerror(errnum));
/* Set port to non-blocking. Don't do send() if this fails */
if (!pg_set_noblock(port->sock))
return;
/* We'll retry after EINTR, but ignore all other failures */
do
{
rc = send(port->sock, buffer, strlen(buffer) + 1, 0);
} while (rc < 0 && errno == EINTR);
}
/*
* split_opts -- split a string of options and append it to an argv array
*
* NB: the string is destructively modified!
*
* Since no current POSTGRES arguments require any quoting characters,
* we can use the simple-minded tactic of assuming each set of space-
* delimited characters is a separate argv element.
*
* If you don't like that, well, we *used* to pass the whole option string
* as ONE argument to execl(), which was even less intelligent...
*/
static void
split_opts(char **argv, int *argcp, char *s)
{
while (s && *s)
{
while (isspace((unsigned char) *s))
++s;
if (*s == '\0')
break;
argv[(*argcp)++] = s;
while (*s && !isspace((unsigned char) *s))
++s;
if (*s)
*s++ = '\0';
}
}
/*
* BackendInitialize -- initialize an interactive (postmaster-child)
* backend process, and perform client authentication.
*
* returns: nothing. Will not return at all if there's any failure.
*
* Note: this code does not depend on having any access to shared memory.
* In the EXEC_BACKEND case, we are physically attached to shared memory
* but have not yet set up most of our local pointers to shmem structures.
*/
static void
BackendInitialize(Port *port)
{
int status;
char remote_host[NI_MAXHOST];
char remote_port[NI_MAXSERV];
char remote_ps_data[NI_MAXHOST];
MemoryContext old;
/* Save port etc. for ps status */
MyProcPort = port;
old = MemoryContextSwitchTo(TopMemoryContext);
initStringInfo(&MyProcPort->override_options);
MemoryContextSwitchTo(old);
/*
* PreAuthDelay is a debugging aid for investigating problems in the
* authentication cycle: it can be set in postgresql.conf to allow time to
* attach to the newly-forked backend with a debugger. (See also the -W
* backend switch, which we allow clients to pass through PGOPTIONS, but
* it is not honored until after authentication.)
*/
if (PreAuthDelay > 0)
pg_usleep(PreAuthDelay * 1000000L);
/* This flag will remain set until InitPostgres finishes authentication */
ClientAuthInProgress = true; /* limit visibility of log messages */
/* save process start time */
port->SessionStartTime = GetCurrentTimestamp();
MyStartTime = timestamptz_to_time_t(port->SessionStartTime);
/* set these to empty in case they are needed before we set them up */
port->remote_host = "";
port->remote_port = "";
/*
* Initialize libpq and enable reporting of ereport errors to the client.
* Must do this now because authentication uses libpq to send messages.
*/
pq_init(); /* initialize libpq to talk to client */
whereToSendOutput = DestRemote; /* now safe to ereport to client */
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too. (We do this now on the off chance
* that something might spawn a child process during authentication.)
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* We arrange for a simple exit(1) if we receive SIGTERM or SIGQUIT during
* any client authentication related communication. Otherwise the
* postmaster cannot shutdown the database FAST or IMMED cleanly if a
* buggy client blocks a backend during authentication.
*/
pqsignal(SIGTERM, authdie);
pqsignal(SIGQUIT, authdie);
pqsignal(SIGALRM, authdie);
PG_SETMASK(&StartupBlockSig);
/*
* Get the remote host name and port for logging and status display.
*/
remote_host[0] = '\0';
remote_port[0] = '\0';
if (pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
remote_host, sizeof(remote_host),
remote_port, sizeof(remote_port),
(log_hostname ? 0 : NI_NUMERICHOST) | NI_NUMERICSERV))
{
int ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
remote_host, sizeof(remote_host),
remote_port, sizeof(remote_port),
NI_NUMERICHOST | NI_NUMERICSERV);
if (ret)
ereport(WARNING,
(errmsg_internal("pg_getnameinfo_all() failed: %s",
gai_strerror(ret))));
}
snprintf(remote_ps_data, sizeof(remote_ps_data),
remote_port[0] == '\0' ? "%s" : "%s(%s)",
remote_host, remote_port);
if (Log_connections)
ereport(LOG,
(errmsg("connection received: host=%s%s%s",
remote_host, remote_port[0] ? " port=" : "",
remote_port),
errOmitLocation(true)));
/*
* save remote_host and remote_port in port structure
*/
port->remote_host = strdup(remote_host);
port->remote_port = strdup(remote_port);
/*
* In EXEC_BACKEND case, we didn't inherit the contents of pg_hba.conf
* etcetera from the postmaster, and have to load them ourselves. Build
* the PostmasterContext (which didn't exist before, in this process) to
* contain the data.
*
* FIXME: [fork/exec] Ugh. Is there a way around this overhead?
*/
#ifdef EXEC_BACKEND
Assert(PostmasterContext == NULL);
PostmasterContext = AllocSetContextCreate(TopMemoryContext,
"Postmaster",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
MemoryContextSwitchTo(PostmasterContext);
if (!load_hba())
{
/*
* It makes no sense to continue if we fail to load the HBA file,
* since there is no way to connect to the database in this case.
*/
ereport(FATAL,
(errmsg("could not load pg_hba.conf")));
}
load_ident();
load_role();
#endif
/*
* Ready to begin client interaction. We will give up and exit(0) after a
* time delay, so that a broken client can't hog a connection
* indefinitely. PreAuthDelay doesn't count against the time limit.
*/
if (!enable_sig_alarm(AuthenticationTimeout * 1000, false))
elog(FATAL, "could not set timer for authorization timeout");
/*
* Receive the startup packet (which might turn out to be a cancel request
* packet).
*/
status = ProcessStartupPacket(port, false);
/*
* Stop here if it was bad or a cancel packet. ProcessStartupPacket
* already did any appropriate error reporting.
*/
if (status != STATUS_OK)
proc_exit(0);
/*
* Now that we have the user and database name, we can set the process
* title for ps. It's good to do this as early as possible in startup.
*/
if (SyncMaster)
init_ps_display("gpsyncagent process", "", "", "");
else
init_ps_display(port->user_name, port->database_name, remote_ps_data,
update_process_title ? "authentication" : "");
/*
* Now perform authentication exchange.
*/
ClientAuthentication(port);
/*
* Done with authentication. Disable timeout, and prevent SIGTERM/SIGQUIT
* again until backend startup is complete.
*/
if (!disable_sig_alarm(false))
elog(FATAL, "could not disable timer for authorization timeout");
PG_SETMASK(&BlockSig);
if (Log_connections)
ereport(LOG,
(errmsg("connection authorized: user=%s database=%s",
port->user_name, port->database_name),
errOmitLocation(true)));
}
/*
* BackendRun -- set up the backend's argument list and invoke PostgresMain()
*
* returns:
* Shouldn't return at all.
* If PostgresMain() fails, return status.
*/
static int
BackendRun(Port *port)
{
char **av;
int maxac;
int ac;
long secs;
int usecs;
char protobuf[32];
int i;
/*
* Don't want backend to be able to see the postmaster random number
* generator state. We have to clobber the static random_seed *and* start
* a new random sequence in the random() library function.
*/
random_seed = 0;
random_start_time.tv_usec = 0;
/* slightly hacky way to get integer microseconds part of timestamptz */
TimestampDifference(0, port->SessionStartTime, &secs, &usecs);
srandom((unsigned int) (MyProcPid ^ usecs));
/* ----------------
* Now, build the argv vector that will be given to PostgresMain.
*
* The layout of the command line is
* postgres [secure switches] -y databasename [insecure switches]
* where the switches after -y come from the client request.
*
* The maximum possible number of commandline arguments that could come
* from ExtraOptions or port->cmdline_options is (strlen + 1) / 2; see
* split_opts().
* ----------------
*/
maxac = 10; /* for fixed args supplied below */
maxac += (strlen(ExtraOptions) + 1) / 2;
if (port->cmdline_options)
maxac += (strlen(port->cmdline_options) + 1) / 2;
av = (char **) MemoryContextAlloc(TopMemoryContext,
maxac * sizeof(char *));
ac = 0;
av[ac++] = "postgres";
/*
* Pass any backend switches specified with -o in the postmaster's own
* command line. We assume these are secure. (It's OK to mangle
* ExtraOptions now, since we're safely inside a subprocess.)
*/
split_opts(av, &ac, ExtraOptions);
/* Tell the backend what protocol the frontend is using. */
snprintf(protobuf, sizeof(protobuf), "-v%u", port->proto);
av[ac++] = protobuf;
/*
* Tell the backend it is being called from the postmaster, and which
* database to use. -y marks the end of secure switches.
*/
av[ac++] = "-y";
av[ac++] = port->database_name;
/*
* Pass the (insecure) option switches from the connection request. (It's
* OK to mangle port->cmdline_options now.)
*/
if (port->cmdline_options)
split_opts(av, &ac, port->cmdline_options);
av[ac] = NULL;
Assert(ac < maxac);
/*
* Release postmaster's working memory context so that backend can recycle
* the space. Note this does not trash *MyProcPort, because ConnCreate()
* allocated that space with malloc() ... else we'd need to copy the Port
* data here. Also, subsidiary data such as the username isn't lost
* either; see ProcessStartupPacket().
*/
MemoryContextSwitchTo(TopMemoryContext);
MemoryContextDelete(PostmasterContext);
PostmasterContext = NULL;
/*
* Debug: print arguments being passed to backend
*/
ereport(DEBUG3,
(errmsg_internal("%s child[%d]: starting with (",
progname, (int) getpid())));
for (i = 0; i < ac; ++i)
ereport(DEBUG3,
(errmsg_internal("\t%s", av[i])));
ereport(DEBUG3,
(errmsg_internal(")")));
ClientAuthInProgress = false; /* client_min_messages is active now */
if (SyncMaster)
return (SyncAgentMain(ac, av, port->user_name));
else
return (PostgresMain(ac, av, port->user_name));
}
#ifdef EXEC_BACKEND
/*
* postmaster_forkexec -- fork and exec a postmaster subprocess
*
* The caller must have set up the argv array already, except for argv[2]
* which will be filled with the name of the temp variable file.
*
* Returns the child process PID, or -1 on fork failure (a suitable error
* message has been logged on failure).
*
* All uses of this routine will dispatch to SubPostmasterMain in the
* child process.
*/
pid_t
postmaster_forkexec(int argc, char *argv[])
{
Port port;
/* This entry point passes dummy values for the Port variables */
memset(&port, 0, sizeof(port));
return internal_forkexec(argc, argv, &port);
}
/*
* backend_forkexec -- fork/exec off a backend process
*
* Some operating systems (WIN32) don't have fork() so we have to simulate
* it by storing parameters that need to be passed to the child and
* then create a new child process.
*
* returns the pid of the fork/exec'd process, or -1 on failure
*/
static pid_t
backend_forkexec(Port *port)
{
char *av[4];
int ac = 0;
av[ac++] = "postgres";
av[ac++] = "--forkbackend";
av[ac++] = NULL; /* filled in by internal_forkexec */
av[ac] = NULL;
Assert(ac < lengthof(av));
return internal_forkexec(ac, av, port);
}
#ifndef WIN32
/*
* internal_forkexec non-win32 implementation
*
* - writes out backend variables to the parameter file
* - fork():s, and then exec():s the child process
*/
static pid_t
internal_forkexec(int argc, char *argv[], Port *port)
{
static unsigned long tmpBackendFileNum = 0;
pid_t pid;
char tmpfilename[MAXPGPATH];
BackendParameters param;
FILE *fp;
if (!save_backend_variables(&param, port))
return -1; /* log made by save_backend_variables */
/* Calculate name for temp file */
snprintf(tmpfilename, MAXPGPATH, "%s/%s.backend_var.%d.%lu",
PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
MyProcPid, ++tmpBackendFileNum);
/* Open file */
fp = AllocateFile(tmpfilename, PG_BINARY_W);
if (!fp)
{
/* As in OpenTemporaryFile, try to make the temp-file directory */
mkdir(PG_TEMP_FILES_DIR, S_IRWXU);
fp = AllocateFile(tmpfilename, PG_BINARY_W);
if (!fp)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not create file \"%s\": %m",
tmpfilename)));
return -1;
}
}
if (fwrite(&param, sizeof(param), 1, fp) != 1)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not write to file \"%s\": %m", tmpfilename)));
FreeFile(fp);
return -1;
}
/* Release file */
if (FreeFile(fp))
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not write to file \"%s\": %m", tmpfilename)));
return -1;
}
/* Make sure caller set up argv properly */
Assert(argc >= 3);
Assert(argv[argc] == NULL);
Assert(strncmp(argv[1], "--fork", 6) == 0);
Assert(argv[2] == NULL);
/* Insert temp file name after --fork argument */
argv[2] = tmpfilename;
/* Fire off execv in child */
if ((pid = fork_process()) == 0)
{
if (execv(postgres_exec_path, argv) < 0)
{
ereport(LOG,
(errmsg("could not execute server process \"%s\": %m",
postgres_exec_path)));
/* We're already in the child process here, can't return */
exit(1);
}
}
return pid; /* Parent returns pid, or -1 on fork failure */
}
#else /* WIN32 */
/*
* internal_forkexec win32 implementation
*
* - starts backend using CreateProcess(), in suspended state
* - writes out backend variables to the parameter file
* - during this, duplicates handles and sockets required for
* inheritance into the new process
* - resumes execution of the new process once the backend parameter
* file is complete.
*/
static pid_t
internal_forkexec(int argc, char *argv[], Port *port)
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
int i;
int j;
char cmdLine[MAXPGPATH * 2];
HANDLE paramHandle;
BackendParameters *param;
SECURITY_ATTRIBUTES sa;
char paramHandleStr[32];
win32_deadchild_waitinfo *childinfo;
/* Make sure caller set up argv properly */
Assert(argc >= 3);
Assert(argv[argc] == NULL);
Assert(strncmp(argv[1], "--fork", 6) == 0);
Assert(argv[2] == NULL);
/* Set up shared memory for parameter passing */
ZeroMemory(&sa, sizeof(sa));
sa.nLength = sizeof(sa);
sa.bInheritHandle = TRUE;
paramHandle = CreateFileMapping(INVALID_HANDLE_VALUE,
&sa,
PAGE_READWRITE,
0,
sizeof(BackendParameters),
NULL);
if (paramHandle == INVALID_HANDLE_VALUE)
{
elog(LOG, "could not create backend parameter file mapping: error code %d",
(int) GetLastError());
return -1;
}
param = MapViewOfFile(paramHandle, FILE_MAP_WRITE, 0, 0, sizeof(BackendParameters));
if (!param)
{
elog(LOG, "could not map backend parameter memory: error code %d",
(int) GetLastError());
CloseHandle(paramHandle);
return -1;
}
/* Insert temp file name after --fork argument */
sprintf(paramHandleStr, "%lu", (DWORD) paramHandle);
argv[2] = paramHandleStr;
/* Format the cmd line */
cmdLine[sizeof(cmdLine) - 1] = '\0';
cmdLine[sizeof(cmdLine) - 2] = '\0';
snprintf(cmdLine, sizeof(cmdLine) - 1, "\"%s\"", postgres_exec_path);
i = 0;
while (argv[++i] != NULL)
{
j = strlen(cmdLine);
snprintf(cmdLine + j, sizeof(cmdLine) - 1 - j, " \"%s\"", argv[i]);
}
if (cmdLine[sizeof(cmdLine) - 2] != '\0')
{
elog(LOG, "subprocess command line too long");
return -1;
}
memset(&pi, 0, sizeof(pi));
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
/*
* Create the subprocess in a suspended state. This will be resumed later,
* once we have written out the parameter file.
*/
if (!CreateProcess(NULL, cmdLine, NULL, NULL, TRUE, CREATE_SUSPENDED,
NULL, NULL, &si, &pi))
{
elog(LOG, "CreateProcess call failed: %m (error code %d)",
(int) GetLastError());
return -1;
}
if (!save_backend_variables(param, port, pi.hProcess, pi.dwProcessId))
{
/*
* log made by save_backend_variables, but we have to clean up the
* mess with the half-started process
*/
if (!TerminateProcess(pi.hProcess, 255))
ereport(ERROR,
(errmsg_internal("could not terminate unstarted process: error code %d",
(int) GetLastError())));
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return -1; /* log made by save_backend_variables */
}
/* Drop the parameter shared memory that is now inherited to the backend */
if (!UnmapViewOfFile(param))
elog(LOG, "could not unmap view of backend parameter file: error code %d",
(int) GetLastError());
if (!CloseHandle(paramHandle))
elog(LOG, "could not close handle to backend parameter file: error code %d",
(int) GetLastError());
/*
* Reserve the memory region used by our main shared memory segment before we
* resume the child process.
*/
if (!pgwin32_ReserveSharedMemoryRegion(pi.hProcess))
{
/*
* Failed to reserve the memory, so terminate the newly created
* process and give up.
*/
if (!TerminateProcess(pi.hProcess, 255))
ereport(ERROR,
(errmsg_internal("could not terminate process that failed to reserve memory: error code %d",
(int) GetLastError())));
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return -1; /* logging done made by pgwin32_ReserveSharedMemoryRegion() */
}
/*
* Now that the backend variables are written out, we start the child
* thread so it can start initializing while we set up the rest of the
* parent state.
*/
if (ResumeThread(pi.hThread) == -1)
{
if (!TerminateProcess(pi.hProcess, 255))
{
ereport(ERROR,
(errmsg_internal("could not terminate unstartable process: error code %d",
(int) GetLastError())));
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return -1;
}
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
ereport(ERROR,
(errmsg_internal("could not resume thread of unstarted process: error code %d",
(int) GetLastError())));
return -1;
}
/*
* Queue a waiter for to signal when this child dies. The wait will be
* handled automatically by an operating system thread pool.
*
* Note: use malloc instead of palloc, since it needs to be thread-safe.
* Struct will be free():d from the callback function that runs on a
* different thread.
*/
childinfo = malloc(sizeof(win32_deadchild_waitinfo));
if (!childinfo)
ereport(FATAL,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
childinfo->procHandle = pi.hProcess;
childinfo->procId = pi.dwProcessId;
if (!RegisterWaitForSingleObject(&childinfo->waitHandle,
pi.hProcess,
pgwin32_deadchild_callback,
childinfo,
INFINITE,
WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD))
ereport(FATAL,
(errmsg_internal("could not register process for wait: error code %d",
(int) GetLastError())));
/* Don't close pi.hProcess here - the wait thread needs access to it */
CloseHandle(pi.hThread);
return pi.dwProcessId;
}
#endif /* WIN32 */
#ifdef EXEC_BACKEND
/* This should really be in a header file */
NON_EXEC_STATIC void
PerfmonMain(int argc, char *argv[]);
#endif
/*
* SubPostmasterMain -- Get the fork/exec'd process into a state equivalent
* to what it would be if we'd simply forked on Unix, and then
* dispatch to the appropriate place.
*
* The first two command line arguments are expected to be "--forkFOO"
* (where FOO indicates which postmaster child we are to become), and
* the name of a variables file that we can read to load data that would
* have been inherited by fork() on Unix. Remaining arguments go to the
* subprocess FooMain() routine.
*/
int
SubPostmasterMain(int argc, char *argv[])
{
Port port;
MemoryContext old;
/* Do this sooner rather than later... */
IsUnderPostmaster = true; /* we are a postmaster subprocess now */
MyProcPid = getpid(); /* reset MyProcPid */
MyStartTime = time(NULL);
/*
* make sure stderr is in binary mode before anything can possibly be
* written to it, in case it's actually the syslogger pipe, so the pipe
* chunking protocol isn't disturbed. Non-logpipe data gets translated on
* redirection (e.g. via pg_ctl -l) anyway.
*/
#ifdef WIN32
_setmode(fileno(stderr), _O_BINARY);
#endif
/* Lose the postmaster's on-exit routines (really a no-op) */
on_exit_reset();
/* In EXEC_BACKEND case we will not have inherited these settings */
IsPostmasterEnvironment = true;
whereToSendOutput = DestNone;
/* Setup essential subsystems (to ensure elog() behaves sanely) */
MemoryContextInit();
InitializeGUCOptions();
/* Read in the variables file */
memset(&port, 0, sizeof(Port));
old = MemoryContextSwitchTo(TopMemoryContext);
initStringInfo(&port->override_options);
MemoryContextSwitchTo(old);
read_backend_variables(argv[2], &port);
/*
* Set up memory area for GSS information. Mirrors the code in ConnCreate
* for the non-exec case.
*/
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
port.gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
if (!port.gss)
ereport(FATAL,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
#endif
/* Check we got appropriate args */
if (argc < 3)
elog(FATAL, "invalid subpostmaster invocation");
/*
* If appropriate, physically re-attach to shared memory segment. We want
* to do this before going any further to ensure that we can attach at the
* same address the postmaster used.
*/
if (strcmp(argv[1], "--forkbackend") == 0 ||
strcmp(argv[1], "--forkavlauncher") == 0 ||
strcmp(argv[1], "--forkavworker") == 0 ||
strcmp(argv[1], "--forkautovac") == 0 ||
strcmp(argv[1], "--forkseqserver") == 0 ||
strcmp(argv[1], "--forkboot") == 0)
PGSharedMemoryReAttach();
/*
* Start our win32 signal implementation. This has to be done after we
* read the backend variables, because we need to pick up the signal pipe
* from the parent process.
*/
#ifdef WIN32
pgwin32_signal_initialize();
#endif
/* In EXEC_BACKEND case we will not have inherited these settings */
pqinitmask();
PG_SETMASK(&BlockSig);
/* Read in remaining GUC variables */
read_nondefault_variables();
/*
* Reload any libraries that were preloaded by the postmaster. Since we
* exec'd this process, those libraries didn't come along with us; but we
* should load them into all child processes to be consistent with the
* non-EXEC_BACKEND behavior.
*/
process_shared_preload_libraries();
/* Run backend or appropriate child */
if (strcmp(argv[1], "--forkbackend") == 0)
{
Assert(argc == 3); /* shouldn't be any more args */
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/*
* Need to reinitialize the SSL library in the backend, since the
* context structures contain function pointers and cannot be passed
* through the parameter file.
*
* XXX should we do this in all child processes? For the moment it's
* enough to do it in backend children.
*/
#ifdef USE_SSL
if (EnableSSL)
secure_initialize();
#endif
/*
* Perform additional initialization and client authentication.
*
* We want to do this before InitProcess() for a couple of reasons: 1.
* so that we aren't eating up a PGPROC slot while waiting on the
* client. 2. so that if InitProcess() fails due to being out of
* PGPROC slots, we have already initialized libpq and are able to
* report the error to the client.
*/
BackendInitialize(&port);
/* Restore basic shared memory pointers */
InitShmemAccess(UsedShmemSegAddr);
/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
InitProcess();
/*
* Attach process to shared data structures. If testing EXEC_BACKEND
* on Linux, you must run this as root before starting the postmaster:
*
* echo 0 >/proc/sys/kernel/randomize_va_space
*
* This prevents a randomized stack base address that causes child
* shared memory to be at a different address than the parent, making
* it impossible to attached to shared memory. Return the value to
* '1' when finished.
*/
CreateSharedMemoryAndSemaphores(false, 0);
/* And run the backend */
proc_exit(BackendRun(&port));
}
if (strcmp(argv[1], "--forkboot") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Restore basic shared memory pointers */
InitShmemAccess(UsedShmemSegAddr);
/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
InitAuxiliaryProcess();
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, 0);
AuxiliaryProcessMain(argc - 2, argv + 2);
proc_exit(0);
}
if (strcmp(argv[1], "--forkautovac") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Restore basic shared memory pointers */
InitShmemAccess(UsedShmemSegAddr);
/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
InitProcess();
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, 0);
AutoVacMain(argc - 2, argv + 2);
proc_exit(0);
}
if (strcmp(argv[1], "--forkarch") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Do not want to attach to shared memory */
PgArchiverMain(argc, argv);
proc_exit(0);
}
if (strcmp(argv[1], "--forkcol") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Do not want to attach to shared memory */
PgstatCollectorMain(argc, argv);
proc_exit(0);
}
if (strcmp(argv[1], "--forklog") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(true);
/* Do not want to attach to shared memory */
SysLoggerMain(argc, argv);
proc_exit(0);
}
if (strcmp(argv[1], "--forkseqserver") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Restore basic shared memory pointers */
InitShmemAccess(UsedShmemSegAddr);
/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
InitAuxiliaryProcess();
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, 0);
SeqServerMain(argc - 2, argv + 2);
proc_exit(0);
}
if (strcmp(argv[1], "--forkftsprobe") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Restore basic shared memory pointers */
InitShmemAccess(UsedShmemSegAddr);
/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
InitAuxiliaryProcess();
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, 0);
FtsProbeMain(argc - 2, argv + 2);
proc_exit(0);
}
if (strcmp(argv[1], "--forkperfmon") == 0)
{
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Do not want to attach to shared memory */
PerfmonMain(argc - 2, argv + 2);
proc_exit(0);
}
return 1; /* shouldn't get here */
}
#endif /* EXEC_BACKEND */
/*
* ExitPostmaster -- cleanup
*
* Do NOT call exit() directly --- always go through here!
*/
static void
ExitPostmaster(int status)
{
/* should cleanup shared memory and kill all backends */
/*
* Not sure of the semantics here. When the Postmaster dies, should the
* backends all be killed? probably not.
*
* MUST -- vadim 05-10-1999
*/
proc_exit(status);
}
/*
* sigusr1_handler - handle signal conditions from child processes
*/
static void
sigusr1_handler(SIGNAL_ARGS)
{
int save_errno = errno;
PG_SETMASK(&BlockSig);
/*
* RECOVERY_STARTED and RECOVERY_CONSISTENT signals are ignored in
* unexpected states. If the startup process quickly starts up, completes
* recovery, exits, we might process the death of the startup process
* first. We don't want to go back to recovery in that case.
*/
if (CheckPostmasterSignal(PMSIGNAL_RECOVERY_STARTED) &&
pmState == PM_STARTUP)
{
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/* WAL redo has started. We're out of reinitialization. */
FatalError = false;
/*
* Crank up the background writer. It doesn't matter if this fails,
* we'll just try again later.
*/
Assert(BgWriterPID == 0);
SetBGWriterPID(StartBackgroundWriter());
pmState = PM_RECOVERY;
}
if (CheckPostmasterSignal(PMSIGNAL_RECOVERY_CONSISTENT) &&
pmState == PM_RECOVERY)
{
Assert(isPrimaryMirrorModeAFullPostmaster(true));
/*
* Load the flat authorization file into postmaster's cache. The
* startup process won't have recomputed this from the database yet,
* so it may change following recovery.
*/
load_role();
/*
* Likewise, start other special children as needed.
*/
Assert(PgStatPID == 0);
PgStatPID = pgstat_start();
/* XXX at this point we could accept read-only connections */
ereport(DEBUG1,
(errmsg("database system is in consistent recovery mode")));
pmState = PM_RECOVERY_CONSISTENT;
}
if (CheckPostmasterSignal(PMSIGNAL_PASSWORD_CHANGE))
{
/*
* Authorization file has changed.
*/
load_role();
}
if (CheckPostmasterSignal(PMSIGNAL_WAKEN_CHILDREN))
{
/*
* Send SIGUSR1 to all children (triggers CatchupInterruptHandler).
* See storage/ipc/sinval[adt].c for the use of this.
*/
if (Shutdown <= SmartShutdown)
{
SignalChildren(SIGUSR1);
signal_child_if_up(AutoVacPID, SIGUSR1);
}
}
if (CheckPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER) &&
PgArchPID != 0)
{
/*
* Send SIGUSR1 to archiver process, to wake it up and begin archiving
* next transaction log file.
*/
signal_child(PgArchPID, SIGUSR1);
}
if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE) &&
SysLoggerPID != 0)
{
/* Tell syslogger to rotate logfile */
signal_child(SysLoggerPID, SIGUSR1);
}
if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC))
{
/*
* Start one iteration of the autovacuum daemon, even if autovacuuming
* is nominally not enabled. This is so we can have an active defense
* against transaction ID wraparound. We set a flag for the main loop
* to do it rather than trying to do it here --- this is because the
* autovac process itself may send the signal, and we want to handle
* that by launching another iteration as soon as the current one
* completes.
*/
force_autovac = true;
}
if (CheckPostmasterSignal(PMSIGNAL_POSTMASTER_RESET_BY_PEER))
{
/*
* set a flag that will be handled in the main loop;
* this signal comes from handling of postmaster
* reset as requested by the primary/mirror peer;
*/
filerep_requires_postmaster_reset = true;
}
PG_SETMASK(&UnBlockSig);
errno = save_errno;
}
/*
* Dummy signal handler
*
* We use this for signals that we don't actually use in the postmaster,
* but we do use in backends. If we were to SIG_IGN such signals in the
* postmaster, then a newly started backend might drop a signal that arrives
* before it's able to reconfigure its signal processing. (See notes in
* tcop/postgres.c.)
*/
static void
dummy_handler(SIGNAL_ARGS)
{
}
/*
* RandomSalt
*/
static void
RandomSalt(char *md5Salt)
{
long rand;
/*
* We use % 255, sacrificing one possible byte value, so as to ensure that
* all bits of the random() value participate in the result. While at it,
* add one to avoid generating any null bytes.
*/
rand = PostmasterRandom();
md5Salt[0] = (rand % 255) + 1;
rand = PostmasterRandom();
md5Salt[1] = (rand % 255) + 1;
rand = PostmasterRandom();
md5Salt[2] = (rand % 255) + 1;
rand = PostmasterRandom();
md5Salt[3] = (rand % 255) + 1;
}
/*
* PostmasterRandom
*/
static long
PostmasterRandom(void)
{
/*
* Select a random seed at the time of first receiving a request.
*/
if (random_seed == 0)
{
do
{
struct timeval random_stop_time;
gettimeofday(&random_stop_time, NULL);
/*
* We are not sure how much precision is in tv_usec, so we swap
* the high and low 16 bits of 'random_stop_time' and XOR them
* with 'random_start_time'. On the off chance that the result is
* 0, we loop until it isn't.
*/
random_seed = random_start_time.tv_usec ^
((random_stop_time.tv_usec << 16) |
((random_stop_time.tv_usec >> 16) & 0xffff));
}
while (random_seed == 0);
srandom(random_seed);
}
return random();
}
/*
* Count up number of child processes (excluding special children and
* dead_end children)
*/
static int
CountChildren(void)
{
Dlelem *curr;
int cnt = 0;
for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
{
Backend *bp = (Backend *) DLE_VAL(curr);
if (!bp->dead_end)
cnt++;
}
return cnt;
}
/*
* StartChildProcess -- start an auxiliary process for the postmaster
*
* xlop determines what kind of child will be started. All child types
* initially go to AuxiliaryProcessMain, which will handle common setup.
*
* Return value of StartChildProcess is subprocess' PID, or 0 if failed
* to start subprocess.
*/
static pid_t
StartChildProcess(AuxProcType type)
{
pid_t pid;
char *av[10];
int ac = 0;
char typebuf[32];
/*
* Set up command-line arguments for subprocess
*/
av[ac++] = "postgres";
#ifdef EXEC_BACKEND
av[ac++] = "--forkboot";
av[ac++] = NULL; /* filled in by postmaster_forkexec */
#endif
snprintf(typebuf, sizeof(typebuf), "-x%d", type);
av[ac++] = typebuf;
av[ac] = NULL;
Assert(ac < lengthof(av));
switch (type)
{
case BgWriterProcess:
case CheckpointProcess:
case StartupProcess:
case StartupPass2Process:
case StartupPass3Process:
case StartupPass4Process:
case WalWriterProcess:
Assert(isPrimaryMirrorModeAFullPostmaster(true));
break;
case CheckerProcess:
case BootstrapProcess:
break;
}
#ifdef EXEC_BACKEND
pid = postmaster_forkexec(ac, av);
#else /* !EXEC_BACKEND */
pid = fork_process();
if (pid == 0) /* child */
{
IsUnderPostmaster = true; /* we are a postmaster subprocess now */
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Lose the postmaster's on-exit routines and port connections */
on_exit_reset();
/* Release postmaster's working memory context */
MemoryContextSwitchTo(TopMemoryContext);
MemoryContextDelete(PostmasterContext);
PostmasterContext = NULL;
AuxiliaryProcessMain(ac, av);
ExitPostmaster(0);
}
#endif /* EXEC_BACKEND */
if (pid < 0)
{
/* in parent, fork failed */
int save_errno = errno;
errno = save_errno;
switch (type)
{
case StartupProcess:
ereport(LOG,
(errmsg("could not fork startup process: %m")));
break;
case StartupPass2Process:
ereport(LOG,
(errmsg("could not fork startup pass 2 process: %m")));
break;
case StartupPass3Process:
ereport(LOG,
(errmsg("could not fork startup pass 3 process: %m")));
break;
case StartupPass4Process:
ereport(LOG,
(errmsg("could not fork startup pass 4 process: %m")));
break;
case BgWriterProcess:
ereport(LOG,
(errmsg("could not fork background writer process: %m")));
break;
case CheckpointProcess:
ereport(LOG,
(errmsg("could not fork background checkpoint process: %m")));
break;
default:
ereport(LOG,
(errmsg("could not fork process: %m")));
break;
}
/*
* fork failure is fatal during startup, but there's no need to choke
* immediately if starting other child types fails.
*/
if (type == StartupProcess)
ExitPostmaster(1);
return 0;
}
/*
* in parent, successful fork
*/
return pid;
}
/*
* Create the opts file
*/
static bool
CreateOptsFile(int argc, char *argv[], char *fullprogname)
{
FILE *fp;
int i;
#define OPTS_FILE "postmaster.opts"
if ((fp = fopen(OPTS_FILE, "w")) == NULL)
{
elog(LOG, "could not create file \"%s\": %m", OPTS_FILE);
return false;
}
fprintf(fp, "%s", fullprogname);
for (i = 1; i < argc; i++)
fprintf(fp, " \"%s\"", argv[i]);
fputs("\n", fp);
if (fclose(fp))
{
elog(LOG, "could not write file \"%s\": %m", OPTS_FILE);
return false;
}
return true;
}
/*
* MaxLivePostmasterChildren
*
* This reports the number of entries needed in per-child-process arrays
* (the PMChildFlags array, and if EXEC_BACKEND the ShmemBackendArray).
* These arrays include regular backends and autovac workers, but not special
* children nor dead_end children. This allows the arrays to have a fixed
* maximum size, to wit the same too-many-children limit enforced by
* canAcceptConnections(). The exact value isn't too critical as long as
* it's more than MaxBackends.
*/
int
MaxLivePostmasterChildren(void)
{
return 2 * MaxBackends;
}
#ifdef EXEC_BACKEND
/*
* The following need to be available to the save/restore_backend_variables
* functions
*/
extern slock_t *ShmemLock;
extern LWLock *LWLockArray;
extern PROC_HDR *ProcGlobal;
extern PGPROC *AuxiliaryProcs;
extern PMSignalData *PMSignalState;
extern int pgStatSock;
#ifndef WIN32
#define write_inheritable_socket(dest, src, childpid) (*(dest) = (src))
#define read_inheritable_socket(dest, src) (*(dest) = *(src))
#else
static void write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE child);
static void write_inheritable_socket(InheritableSocket *dest, SOCKET src,
pid_t childPid);
static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src);
#endif
/* Save critical backend variables into the BackendParameters struct */
#ifndef WIN32
static bool
save_backend_variables(BackendParameters *param, Port *port)
#else
static bool
save_backend_variables(BackendParameters *param, Port *port,
HANDLE childProcess, pid_t childPid)
#endif
{
memcpy(&param->port, port, sizeof(Port));
write_inheritable_socket(&param->portsocket, port->sock, childPid);
strlcpy(param->DataDir, DataDir, MAXPGPATH);
memcpy(&param->ListenSocket, &ListenSocket, sizeof(ListenSocket));
param->MyCancelKey = MyCancelKey;
param->MyPMChildSlot = MyPMChildSlot;
param->UsedShmemSegID = UsedShmemSegID;
param->UsedShmemSegAddr = UsedShmemSegAddr;
param->ShmemLock = ShmemLock;
param->ShmemVariableCache = ShmemVariableCache;
param->ShmemBackendArray = ShmemBackendArray;
param->LWLockArray = LWLockArray;
param->ProcGlobal = ProcGlobal;
param->AuxiliaryProcs = AuxiliaryProcs;
param->PMSignalState = PMSignalState;
write_inheritable_socket(&param->pgStatSock, pgStatSock, childPid);
param->PostmasterPid = PostmasterPid;
param->PgStartTime = PgStartTime;
param->PgReloadTime = PgReloadTime;
param->redirection_done = redirection_done;
#ifdef WIN32
param->PostmasterHandle = PostmasterHandle;
write_duplicated_handle(&param->initial_signal_pipe,
pgwin32_create_signal_listener(childPid),
childProcess);
#endif
memcpy(&param->syslogPipe, &syslogPipe, sizeof(syslogPipe));
strlcpy(param->my_exec_path, my_exec_path, MAXPGPATH);
strlcpy(param->pkglib_path, pkglib_path, MAXPGPATH);
strlcpy(param->ExtraOptions, ExtraOptions, MAXPGPATH);
strlcpy(param->lc_collate, setlocale(LC_COLLATE, NULL), LOCALE_NAME_BUFLEN);
strlcpy(param->lc_ctype, setlocale(LC_CTYPE, NULL), LOCALE_NAME_BUFLEN);
return true;
}
#ifdef WIN32
/*
* Duplicate a handle for usage in a child process, and write the child
* process instance of the handle to the parameter file.
*/
static void
write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE childProcess)
{
HANDLE hChild = INVALID_HANDLE_VALUE;
if (!DuplicateHandle(GetCurrentProcess(),
src,
childProcess,
&hChild,
0,
TRUE,
DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS))
ereport(ERROR,
(errmsg_internal("could not duplicate handle to be written to backend parameter file: error code %d",
(int) GetLastError())));
*dest = hChild;
}
/*
* Duplicate a socket for usage in a child process, and write the resulting
* structure to the parameter file.
* This is required because a number of LSPs (Layered Service Providers) very
* common on Windows (antivirus, firewalls, download managers etc) break
* straight socket inheritance.
*/
static void
write_inheritable_socket(InheritableSocket *dest, SOCKET src, pid_t childpid)
{
dest->origsocket = src;
if (src != 0 && src != -1)
{
/* Actual socket */
if (WSADuplicateSocket(src, childpid, &dest->wsainfo) != 0)
ereport(ERROR,
(errmsg("could not duplicate socket %d for use in backend: error code %d",
src, WSAGetLastError())));
}
}
/*
* Read a duplicate socket structure back, and get the socket descriptor.
*/
static void
read_inheritable_socket(SOCKET *dest, InheritableSocket *src)
{
SOCKET s;
if (src->origsocket == -1 || src->origsocket == 0)
{
/* Not a real socket! */
*dest = src->origsocket;
}
else
{
/* Actual socket, so create from structure */
s = WSASocket(FROM_PROTOCOL_INFO,
FROM_PROTOCOL_INFO,
FROM_PROTOCOL_INFO,
&src->wsainfo,
0,
0);
if (s == INVALID_SOCKET)
{
write_stderr("could not create inherited socket: error code %d\n",
WSAGetLastError());
exit(1);
}
*dest = s;
/*
* To make sure we don't get two references to the same socket, close
* the original one. (This would happen when inheritance actually
* works..
*/
closesocket(src->origsocket);
}
}
#endif
static void
read_backend_variables(char *id, Port *port)
{
BackendParameters param;
#ifndef WIN32
/* Non-win32 implementation reads from file */
FILE *fp;
/* Open file */
fp = AllocateFile(id, PG_BINARY_R);
if (!fp)
{
write_stderr("could not read from backend variables file \"%s\": %s\n",
id, strerror(errno));
exit(1);
}
if (fread(&param, sizeof(param), 1, fp) != 1)
{
write_stderr("could not read from backend variables file \"%s\": %s\n",
id, strerror(errno));
exit(1);
}
/* Release file */
FreeFile(fp);
if (unlink(id) != 0)
{
write_stderr("could not remove file \"%s\": %s\n",
id, strerror(errno));
exit(1);
}
#else
/* Win32 version uses mapped file */
HANDLE paramHandle;
BackendParameters *paramp;
paramHandle = (HANDLE) atol(id);
paramp = MapViewOfFile(paramHandle, FILE_MAP_READ, 0, 0, 0);
if (!paramp)
{
write_stderr("could not map view of backend variables: error code %d\n",
(int) GetLastError());
exit(1);
}
memcpy(&param, paramp, sizeof(BackendParameters));
if (!UnmapViewOfFile(paramp))
{
write_stderr("could not unmap view of backend variables: error code %d\n",
(int) GetLastError());
exit(1);
}
if (!CloseHandle(paramHandle))
{
write_stderr("could not close handle to backend parameter variables: error code %d\n",
(int) GetLastError());
exit(1);
}
#endif
restore_backend_variables(&param, port);
}
/* Restore critical backend variables from the BackendParameters struct */
static void
restore_backend_variables(BackendParameters *param, Port *port)
{
memcpy(port, &param->port, sizeof(Port));
read_inheritable_socket(&port->sock, &param->portsocket);
SetDataDir(param->DataDir);
memcpy(&ListenSocket, &param->ListenSocket, sizeof(ListenSocket));
MyCancelKey = param->MyCancelKey;
MyPMChildSlot = param->MyPMChildSlot;
UsedShmemSegID = param->UsedShmemSegID;
UsedShmemSegAddr = param->UsedShmemSegAddr;
ShmemLock = param->ShmemLock;
ShmemVariableCache = param->ShmemVariableCache;
ShmemBackendArray = param->ShmemBackendArray;
LWLockArray = param->LWLockArray;
ProcGlobal = param->ProcGlobal;
AuxiliaryProcs = param->AuxiliaryProcs;
PMSignalState = param->PMSignalState;
read_inheritable_socket(&pgStatSock, &param->pgStatSock);
PostmasterPid = param->PostmasterPid;
PgStartTime = param->PgStartTime;
PgReloadTime = param->PgReloadTime;
redirection_done = param->redirection_done;
#ifdef WIN32
PostmasterHandle = param->PostmasterHandle;
pgwin32_initial_signal_pipe = param->initial_signal_pipe;
#endif
memcpy(&syslogPipe, &param->syslogPipe, sizeof(syslogPipe));
strlcpy(my_exec_path, param->my_exec_path, MAXPGPATH);
strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH);
strlcpy(ExtraOptions, param->ExtraOptions, MAXPGPATH);
setlocale(LC_COLLATE, param->lc_collate);
setlocale(LC_CTYPE, param->lc_ctype);
}
Size
ShmemBackendArraySize(void)
{
return mul_size(MaxLivePostmasterChildren(), sizeof(Backend));
}
void
ShmemBackendArrayAllocation(void)
{
Size size = ShmemBackendArraySize();
ShmemBackendArray = (Backend *) ShmemAlloc(size);
/* Mark all slots as empty */
memset(ShmemBackendArray, 0, size);
}
static void
ShmemBackendArrayAdd(Backend *bn)
{
/* The array slot corresponding to my PMChildSlot should be free */
int i = bn->child_slot - 1;
Assert(ShmemBackendArray[i].pid == 0);
ShmemBackendArray[i] = *bn;
}
static void
ShmemBackendArrayRemove(Backend *bn)
{
int i = bn->child_slot - 1;
Assert(ShmemBackendArray[i].pid == bn->pid);
/* Mark the slot as empty */
ShmemBackendArray[i].pid = 0;
}
#endif /* EXEC_BACKEND */
#ifdef WIN32
static pid_t
win32_waitpid(int *exitstatus)
{
DWORD dwd;
ULONG_PTR key;
OVERLAPPED *ovl;
/*
* Check if there are any dead children. If there are, return the pid of
* the first one that died.
*/
if (GetQueuedCompletionStatus(win32ChildQueue, &dwd, &key, &ovl, 0))
{
*exitstatus = (int) key;
return dwd;
}
return -1;
}
/*
* Note! Code below executes on a thread pool! All operations must
* be thread safe! Note that elog() and friends must *not* be used.
*/
static void WINAPI
pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
{
win32_deadchild_waitinfo *childinfo = (win32_deadchild_waitinfo *) lpParameter;
DWORD exitcode;
if (TimerOrWaitFired)
return; /* timeout. Should never happen, since we use
* INFINITE as timeout value. */
/*
* Remove handle from wait - required even though it's set to wait only
* once
*/
UnregisterWaitEx(childinfo->waitHandle, NULL);
if (!GetExitCodeProcess(childinfo->procHandle, &exitcode))
{
/*
* Should never happen. Inform user and set a fixed exitcode.
*/
write_stderr("could not read exit code for process\n");
exitcode = 255;
}
if (!PostQueuedCompletionStatus(win32ChildQueue, childinfo->procId, (ULONG_PTR) exitcode, NULL))
write_stderr("could not post child completion status\n");
/*
* Handle is per-process, so we close it here instead of in the
* originating thread
*/
CloseHandle(childinfo->procHandle);
/*
* Free struct that was allocated before the call to
* RegisterWaitForSingleObject()
*/
free(childinfo);
/* Queue SIGCHLD signal */
pg_queue_signal(SIGCHLD);
}
#endif /* WIN32 */
#if defined(pg_on_solaris)
/* SOLARIS */
static void
setProcAffinity(int id)
{
int i, r;
processor_info_t info;
int cpu_count=0;
int cpus[64];
int proc_to_bind;
memset(cpus, 0, sizeof(cpus));
/* first we figure out how many processors we're dealing with (up
* to 64). Note: we can't just assume that when we see the first
* failure that we're done -- The Solaris documentation claims
* that there can be "gaps." */
for (i=0; i < 64; i++)
{
r = processor_info(i, &info);
if (r == 0)
{
cpu_count++;
cpus[cpu_count - 1] = i;
}
}
/* now we use the id our caller provided to pick a processor. */
proc_to_bind = cpus[id % cpu_count];
r = processor_bind(P_PID, P_MYID, proc_to_bind, NULL);
/* ignore an error -- we'll just stay with out old (default
* binding) */
if (r == 0)
elog(LOG, "Bound postmaster to processor %d", proc_to_bind);
else
elog(LOG, "process_bind() failed, will remain unbound");
return;
}
#elif defined(HAVE_NUMA_H) && defined(HAVE_LIBNUMA)
/* LINUX */
static void
setProcAffinity(int id)
{
int limit;
nodemask_t mask;
if (numa_available() < 0)
{
elog(LOG, "Numa unavailable, will remain unbound.");
return;
}
limit = numa_max_node() + 1;
nodemask_zero(&mask);
nodemask_set(&mask, (id % limit));
elog(LOG, "Numa binding to numa-node %d", (id % limit));
/* this sets the memory */
numa_bind(&mask);
return;
}
#else
/* UNSUPPORTED */
static void
setProcAffinity(int id)
{
elog(LOG, "gp_proc_affinity setting ignored; feature not configured");
}
#endif