| /*------------------------------------------------------------------------- |
| * |
| * Twophase.c |
| * Two-phase commit support functions. |
| * |
| * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group |
| * Portions Copyright (c) 1994, Regents of the University of California |
| * |
| * IDENTIFICATION |
| * $PostgreSQL: pgsql/src/backend/access/transam/twophase.c,v 1.25.2.1 2007/02/13 19:39:48 tgl Exp $ |
| * |
| * NOTES |
| * Each global transaction is associated with a global transaction |
| * identifier (GID). The client assigns a GID to a postgres |
| * transaction with the PREPARE TRANSACTION command. |
| * |
| * We keep all active global transactions in a shared memory array. |
| * When the PREPARE TRANSACTION command is issued, the GID is |
| * reserved for the transaction in the array. This is done before |
| * a WAL entry is made, because the reservation checks for duplicate |
| * GIDs and aborts the transaction if there already is a global |
| * transaction in prepared state with the same GID. |
| * |
| * A global transaction (gxact) also has a dummy PGPROC that is entered |
| * into the ProcArray array; this is what keeps the XID considered |
| * running by TransactionIdIsInProgress. It is also convenient as a |
| * PGPROC to hook the gxact's locks to. |
| * |
| * In order to survive crashes and shutdowns, all prepared |
| * transactions must be stored in permanent storage. This includes |
| * locking information, pending notifications etc. All that state |
| * information is written to the per-transaction state file in |
| * the pg_twophase directory. |
| * |
| *------------------------------------------------------------------------- |
| */ |
| #include "postgres.h" |
| |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include "access/heapam.h" |
| #include "access/xlogmm.h" |
| #include "access/subtrans.h" |
| #include "access/transam.h" |
| #include "access/twophase.h" |
| #include "access/twophase_rmgr.h" |
| #include "access/xact.h" |
| #include "catalog/pg_type.h" |
| #include "funcapi.h" |
| #include "miscadmin.h" |
| #include "pgstat.h" |
| #include "storage/fd.h" |
| #include "storage/procarray.h" |
| #include "storage/smgr.h" |
| #include "utils/builtins.h" |
| #include "utils/faultinjector.h" |
| #include "utils/guc.h" |
| #include "utils/memutils.h" |
| |
| #include "cdb/cdbvars.h" |
| #include "cdb/cdbpersistentrecovery.h" |
| |
| #include "cdb/cdbpersistentrelfile.h" |
| #include "cdb/cdbmirroredflatfile.h" |
| #include "cdb/cdbmirroredfilesysobj.h" |
| #include "cdb/cdbpersistentfilesysobj.h" |
| #include "postmaster/primary_mirror_mode.h" |
| |
| /* GUC variable, can't be changed after startup */ |
| int max_prepared_xacts = 5; |
| |
| /* |
| * This struct describes one global transaction that is in prepared state |
| * or attempting to become prepared. |
| * |
| * The first component of the struct is a dummy PGPROC that is inserted |
| * into the global ProcArray so that the transaction appears to still be |
| * running and holding locks. It must be first because we cast pointers |
| * to PGPROC and pointers to GlobalTransactionData back and forth. |
| * |
| * The lifecycle of a global transaction is: |
| * |
| * 1. After checking that the requested GID is not in use, set up an |
| * entry in the TwoPhaseState->prepXacts array with the correct XID and GID, |
| * with locking_xid = my own XID and valid = false. |
| * |
| * 2. After successfully completing prepare, set valid = true and enter the |
| * contained PGPROC into the global ProcArray. |
| * |
| * 3. To begin COMMIT PREPARED or ROLLBACK PREPARED, check that the entry |
| * is valid and its locking_xid is no longer active, then store my current |
| * XID into locking_xid. This prevents concurrent attempts to commit or |
| * rollback the same prepared xact. |
| * |
| * 4. On completion of COMMIT PREPARED or ROLLBACK PREPARED, remove the entry |
| * from the ProcArray and the TwoPhaseState->prepXacts array and return it to |
| * the freelist. |
| * |
| * Note that if the preparing transaction fails between steps 1 and 2, the |
| * entry will remain in prepXacts until recycled. We can detect recyclable |
| * entries by checking for valid = false and locking_xid no longer active. |
| * |
| * typedef struct GlobalTransactionData *GlobalTransaction appears in |
| * twophase.h |
| */ |
| #define GIDSIZE 200 |
| |
| extern List *expectedTLIs; |
| |
| |
| typedef struct GlobalTransactionData |
| { |
| PGPROC proc; /* dummy proc */ |
| TimestampTz prepared_at; /* time of preparation */ |
| XLogRecPtr prepare_begin_lsn; /* XLOG begging offset of prepare record */ |
| XLogRecPtr prepare_lsn; /* XLOG offset of prepare record */ |
| Oid owner; /* ID of user that executed the xact */ |
| TransactionId locking_xid; /* top-level XID of backend working on xact */ |
| bool valid; /* TRUE if fully prepared */ |
| char gid[GIDSIZE]; /* The GID assigned to the prepared xact */ |
| |
| int prepareAppendOnlyIntentCount; |
| /* |
| * The Append-Only Resync EOF intent count for |
| * a non-crashed prepared transaction. |
| */ |
| } GlobalTransactionData; |
| |
| /* |
| * Two Phase Commit shared state. Access to this struct is protected |
| * by TwoPhaseStateLock. |
| */ |
| typedef struct TwoPhaseStateData |
| { |
| /* Head of linked list of free GlobalTransactionData structs */ |
| SHMEM_OFFSET freeGXacts; |
| |
| /* Number of valid prepXacts entries. */ |
| int numPrepXacts; |
| |
| /* |
| * There are max_prepared_xacts items in this array, but C wants a |
| * fixed-size array. |
| */ |
| GlobalTransaction prepXacts[1]; /* VARIABLE LENGTH ARRAY */ |
| } TwoPhaseStateData; /* VARIABLE LENGTH STRUCT */ |
| |
| static TwoPhaseStateData *TwoPhaseState; |
| |
| |
| |
| /* |
| * The following list is |
| */ |
| static HTAB *crashRecoverPostCheckpointPreparedTransactions_map_ht = NULL; |
| |
| static void add_recover_post_checkpoint_prepared_transactions_map_entry(TransactionId xid, XLogRecPtr *m, char *caller); |
| |
| static void remove_recover_post_checkpoint_prepared_transactions_map_entry(TransactionId xid, char *caller); |
| |
| static void RecordTransactionCommitPrepared(TransactionId xid, |
| const char *gid, |
| int nchildren, |
| TransactionId *children, |
| PersistentEndXactRecObjects *persistentPrepareObjects); |
| static void RecordTransactionAbortPrepared(TransactionId xid, |
| int nchildren, |
| TransactionId *children, |
| PersistentEndXactRecObjects *persistentPrepareObjects); |
| static void ProcessRecords(char *bufptr, TransactionId xid, |
| const TwoPhaseCallback callbacks[]); |
| |
| /* |
| * Generic initialisation of hash table. |
| */ |
| static HTAB * |
| init_hash(const char *name, Size keysize, Size entrysize, int initialSize) |
| { |
| HASHCTL ctl; |
| |
| memset(&ctl, 0, sizeof(ctl)); |
| ctl.keysize = keysize; |
| ctl.entrysize = entrysize; |
| ctl.hash = tag_hash; |
| return hash_create(name, |
| initialSize, |
| &ctl, |
| HASH_ELEM | HASH_FUNCTION); |
| |
| |
| } /* end init_hash */ |
| |
| |
| /* |
| * Add a new mapping to the recover post checkpoint prepared transactions hash table. |
| */ |
| static void |
| add_recover_post_checkpoint_prepared_transactions_map_entry(TransactionId xid, XLogRecPtr *m, char *caller) |
| { |
| prpt_map *entry = NULL; |
| bool found = false; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "add_recover_post_checkpoint_prepared_transactions_map_entry: start of function." |
| ); |
| |
| /* |
| * The table is lazily initialised. |
| */ |
| if (crashRecoverPostCheckpointPreparedTransactions_map_ht == NULL) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "add_recover_post_checkpoint_prepared_transactions_map_entry: initial setup of global hash table. Caller = %s", |
| caller); |
| crashRecoverPostCheckpointPreparedTransactions_map_ht |
| = init_hash("two phase post checkpoint prepared transactions map", |
| sizeof(TransactionId), /* keysize */ |
| sizeof(prpt_map), |
| 10 /* initialize for 10 entries */); |
| } |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "add_recover_post_checkpoint_prepared_transactions_map_entry: add entry xid = %u, XLogRecPtr = %s, caller = %s", |
| xid, |
| XLogLocationToString(m), |
| caller); |
| |
| entry = hash_search(crashRecoverPostCheckpointPreparedTransactions_map_ht, |
| &xid, |
| HASH_ENTER, |
| &found); |
| |
| /* |
| * KAS should probably put out an error if found == true (i.e. it already exists). |
| */ |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "add_recover_post_checkpoint_prepared_transactions_map_entry: add entry xid = %u, address prpt_map = %p", |
| xid, |
| entry); |
| |
| /* |
| * If this is a new entry, we need to add the data, if we found |
| * an entry, we need to update it, so just copy our data |
| * right over the top. |
| */ |
| memcpy(&entry->xlogrecptr, m, sizeof(XLogRecPtr)); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "Transaction id = %u, XLog Rec Ptr = %s, caller = %s", |
| xid, |
| XLogLocationToString(m), |
| caller); |
| |
| } /* end add_recover_post_checkpoint_prepared_transactions_map_entry */ |
| |
| /* |
| * Find a mapping in the recover post checkpoint prepared transactions hash table. |
| */ |
| bool |
| TwoPhaseFindRecoverPostCheckpointPreparedTransactionsMapEntry(TransactionId xid, XLogRecPtr *m, char *caller) |
| { |
| prpt_map *entry = NULL; |
| bool found = false; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "find_recover_post_checkpoint_prepared_transactions_map_entry: start of function." |
| ); |
| MemSet(m, 0, sizeof(XLogRecPtr)); |
| |
| /* |
| * The table is lazily initialised. |
| */ |
| if (crashRecoverPostCheckpointPreparedTransactions_map_ht == NULL) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "find_recover_post_checkpoint_prepared_transactions_map_entry: initial setup of global hash table. Caller = %s", |
| caller); |
| crashRecoverPostCheckpointPreparedTransactions_map_ht |
| = init_hash("two phase post checkpoint prepared transactions map", |
| sizeof(TransactionId), /* keysize */ |
| sizeof(prpt_map), |
| 10 /* initialize for 10 entries */); |
| } |
| |
| entry = hash_search(crashRecoverPostCheckpointPreparedTransactions_map_ht, |
| &xid, |
| HASH_FIND, |
| &found); |
| if (entry == NULL) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "find_recover_post_checkpoint_prepared_transactions_map_entry: did not find entry xid = %u, caller = %s", |
| xid, |
| caller); |
| return false; |
| } |
| |
| memcpy(m, &entry->xlogrecptr, sizeof(XLogRecPtr)); |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "find_recover_post_checkpoint_prepared_transactions_map_entry: found entry xid = %u, XLogRecPtr = %s, caller = %s", |
| xid, |
| XLogLocationToString(m), |
| caller); |
| |
| return true; |
| } /* end add_recover_post_checkpoint_prepared_transactions_map_entry */ |
| |
| |
| /* |
| * Remove a mapping from the recover post checkpoint prepared transactions hash table. |
| */ |
| static void |
| remove_recover_post_checkpoint_prepared_transactions_map_entry(TransactionId xid, char *caller) |
| { |
| prpt_map *entry = NULL; |
| bool found = false;; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "remove_recover_post_checkpoint_prepared_transactions_map_entry: entering..." |
| ); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "remove_recover_post_checkpoint_prepared_transactions_map_entry: TransactionId = %u", |
| xid); |
| |
| if (crashRecoverPostCheckpointPreparedTransactions_map_ht != NULL) |
| { |
| entry = hash_search(crashRecoverPostCheckpointPreparedTransactions_map_ht, |
| &xid, |
| HASH_REMOVE, |
| &found); |
| } |
| |
| /* KAS should probably put out an error if it is not found. */ |
| if (found == true) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "remove_recover_post_checkpoint_prepared_transaction_map_entry found = TRUE"); |
| } |
| else |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "remove_recover_post_checkpoint_prepared_transaction_map_entry found = FALSE"); |
| } |
| |
| } /* end remove_recover_post_checkpoint_prepared_transactions_map_entry */ |
| |
| |
| /* |
| * Initialization of shared memory |
| */ |
| Size |
| TwoPhaseShmemSize(void) |
| { |
| Size size; |
| |
| /* Need the fixed struct, the array of pointers, and the GTD structs */ |
| size = offsetof(TwoPhaseStateData, prepXacts); |
| size = add_size(size, mul_size(max_prepared_xacts, |
| sizeof(GlobalTransaction))); |
| size = MAXALIGN(size); |
| size = add_size(size, mul_size(max_prepared_xacts, |
| sizeof(GlobalTransactionData))); |
| |
| return size; |
| } |
| |
| void |
| TwoPhaseShmemInit(void) |
| { |
| bool found; |
| |
| TwoPhaseState = ShmemInitStruct("Prepared Transaction Table", |
| TwoPhaseShmemSize(), |
| &found); |
| if (!IsUnderPostmaster) |
| { |
| GlobalTransaction gxacts; |
| int i; |
| |
| Assert(!found); |
| TwoPhaseState->freeGXacts = INVALID_OFFSET; |
| TwoPhaseState->numPrepXacts = 0; |
| |
| /* |
| * Initialize the linked list of free GlobalTransactionData structs |
| */ |
| gxacts = (GlobalTransaction) |
| ((char *) TwoPhaseState + |
| MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) + |
| sizeof(GlobalTransaction) * max_prepared_xacts)); |
| for (i = 0; i < max_prepared_xacts; i++) |
| { |
| gxacts[i].proc.links.next = TwoPhaseState->freeGXacts; |
| TwoPhaseState->freeGXacts = MAKE_OFFSET(&gxacts[i]); |
| } |
| } |
| else |
| { |
| Assert(found); |
| } |
| } |
| |
| |
| /* |
| * MarkAsPreparing |
| * Reserve the GID for the given transaction. |
| * |
| * Internally, this creates a gxact struct and puts it into the active array. |
| * NOTE: this is also used when reloading a gxact after a crash; so avoid |
| * assuming that we can use very much backend context. |
| */ |
| GlobalTransaction |
| MarkAsPreparing(TransactionId xid, |
| LocalDistribXactRef *localDistribXactRef, |
| const char *gid, |
| TimestampTz prepared_at, Oid owner, Oid databaseid |
| , XLogRecPtr *xlogrecptr) |
| { |
| GlobalTransaction gxact; |
| int i; |
| int idlen = strlen(gid); |
| |
| if (idlen >= GIDSIZE) |
| ereport(ERROR, |
| (errcode(ERRCODE_INVALID_PARAMETER_VALUE), |
| errmsg("transaction identifier \"%s\" is too long (%d > %d max)", |
| gid, idlen, GIDSIZE))); |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); |
| |
| /* |
| * First, find and recycle any gxacts that failed during prepare. We do |
| * this partly to ensure we don't mistakenly say their GIDs are still |
| * reserved, and partly so we don't fail on out-of-slots unnecessarily. |
| */ |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| gxact = TwoPhaseState->prepXacts[i]; |
| if (!gxact->valid && !TransactionIdIsActive(gxact->locking_xid)) |
| { |
| /* It's dead Jim ... remove from the active array */ |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "MarkAsPreparing: TwoPhaseState->numPrepXacts = %d, subtracting 1", TwoPhaseState->numPrepXacts); |
| TwoPhaseState->numPrepXacts--; |
| TwoPhaseState->prepXacts[i] = TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts]; |
| /* and put it back in the freelist */ |
| gxact->proc.links.next = TwoPhaseState->freeGXacts; |
| TwoPhaseState->freeGXacts = MAKE_OFFSET(gxact); |
| /* Back up index count too, so we don't miss scanning one */ |
| i--; |
| } |
| } |
| |
| /* Check for conflicting GID */ |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| gxact = TwoPhaseState->prepXacts[i]; |
| if (strcmp(gxact->gid, gid) == 0) |
| { |
| ereport(ERROR, |
| (errcode(ERRCODE_DUPLICATE_OBJECT), |
| errmsg("transaction identifier \"%s\" is already in use", |
| gid))); |
| } |
| } |
| |
| /* Get a free gxact from the freelist */ |
| if (TwoPhaseState->freeGXacts == INVALID_OFFSET) |
| ereport(ERROR, |
| (errcode(ERRCODE_OUT_OF_MEMORY), |
| errmsg("maximum number of prepared transactions reached"), |
| errhint("Increase max_prepared_transactions (currently %d).", |
| max_prepared_xacts))); |
| gxact = (GlobalTransaction) MAKE_PTR(TwoPhaseState->freeGXacts); |
| TwoPhaseState->freeGXacts = gxact->proc.links.next; |
| |
| /* Initialize it */ |
| MemSet(&gxact->proc, 0, sizeof(PGPROC)); |
| SHMQueueElemInit(&(gxact->proc.links)); |
| gxact->proc.waitStatus = STATUS_OK; |
| gxact->proc.xid = xid; |
| gxact->proc.xmin = InvalidTransactionId; |
| gxact->proc.pid = 0; |
| gxact->proc.databaseId = databaseid; |
| gxact->proc.roleId = owner; |
| gxact->proc.inVacuum = false; |
| gxact->proc.lwWaiting = false; |
| gxact->proc.lwExclusive = false; |
| gxact->proc.lwWaitLink = NULL; |
| gxact->proc.waitLock = NULL; |
| gxact->proc.waitProcLock = NULL; |
| |
| for (i = 0; i < NUM_LOCK_PARTITIONS; i++) |
| SHMQueueInit(&(gxact->proc.myProcLocks[i])); |
| /* subxid data must be filled later by GXactLoadSubxactData */ |
| gxact->proc.subxids.overflowed = false; |
| gxact->proc.subxids.nxids = 0; |
| |
| gxact->prepared_at = prepared_at; |
| /* initialize LSN to 0 (start of WAL) */ |
| gxact->prepare_lsn.xlogid = 0; |
| gxact->prepare_lsn.xrecoff = 0; |
| if (xlogrecptr == NULL) |
| { |
| gxact->prepare_begin_lsn.xlogid = 0; |
| gxact->prepare_begin_lsn.xrecoff = 0; |
| } |
| else |
| { |
| gxact->prepare_begin_lsn.xlogid = xlogrecptr->xlogid; |
| gxact->prepare_begin_lsn.xrecoff = xlogrecptr->xrecoff; |
| /* Assert(xlogrecptr->xrecoff > 0 || xlogrecptr->xlogid > 0); */ |
| } |
| gxact->owner = owner; |
| gxact->locking_xid = xid; |
| |
| gxact->valid = false; |
| strcpy(gxact->gid, gid); |
| gxact->prepareAppendOnlyIntentCount = 0; |
| |
| /* And insert it into the active array */ |
| Assert(TwoPhaseState->numPrepXacts < max_prepared_xacts); |
| TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts++] = gxact; |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| return gxact; |
| } |
| |
| /* |
| * GXactLoadSubxactData |
| * |
| * If the transaction being persisted had any subtransactions, this must |
| * be called before MarkAsPrepared() to load information into the dummy |
| * PGPROC. |
| */ |
| static void |
| GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, |
| TransactionId *children) |
| { |
| /* We need no extra lock since the GXACT isn't valid yet */ |
| if (nsubxacts > PGPROC_MAX_CACHED_SUBXIDS) |
| { |
| gxact->proc.subxids.overflowed = true; |
| nsubxacts = PGPROC_MAX_CACHED_SUBXIDS; |
| } |
| if (nsubxacts > 0) |
| { |
| memcpy(gxact->proc.subxids.xids, children, |
| nsubxacts * sizeof(TransactionId)); |
| gxact->proc.subxids.nxids = nsubxacts; |
| } |
| } |
| |
| /* |
| * MarkAsPrepared |
| * Mark the GXACT as fully valid, and enter it into the global ProcArray. |
| */ |
| static void |
| MarkAsPrepared(GlobalTransaction gxact) |
| { |
| /* Lock here may be overkill, but I'm not convinced of that ... */ |
| LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); |
| Assert(!gxact->valid); |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "MarkAsPrepared: gxact->proc.xid = %d and set valid = true", gxact->proc.xid); |
| gxact->valid = true; |
| LWLockRelease(TwoPhaseStateLock); |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5),"MarkAsPrepared marking GXACT gid = %s as valid (prepared)", |
| gxact->gid); |
| |
| /* |
| * Put it into the global ProcArray so TransactionIdInProgress considers |
| * the XID as still running. |
| */ |
| ProcArrayAdd(&gxact->proc); |
| } |
| |
| /* |
| * LockGXact |
| * Locate the prepared transaction and mark it busy for COMMIT or PREPARE. |
| */ |
| static GlobalTransaction |
| LockGXact(const char *gid, Oid user, bool raiseErrorIfNotFound) |
| { |
| int i; |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5),"LockGXact called to lock identifier = %s.",gid); |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); |
| |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5), "LockGXact checking identifier = %s.",gxact->gid); |
| |
| /* Ignore not-yet-valid GIDs */ |
| if (!gxact->valid) |
| continue; |
| if (strcmp(gxact->gid, gid) != 0) |
| continue; |
| |
| /* Found it, but has someone else got it locked? */ |
| if (TransactionIdIsValid(gxact->locking_xid)) |
| { |
| if (TransactionIdIsActive(gxact->locking_xid)) |
| { |
| LWLockRelease(TwoPhaseStateLock); |
| ereport(ERROR, |
| (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), |
| errmsg("prepared transaction with identifier \"%s\" is busy", |
| gid))); |
| } |
| |
| gxact->locking_xid = InvalidTransactionId; |
| } |
| |
| if (user != gxact->owner && !superuser_arg(user)) |
| { |
| LWLockRelease(TwoPhaseStateLock); |
| ereport(ERROR, |
| (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), |
| errmsg("permission denied to finish prepared transaction"), |
| errhint("Must be superuser or the user that prepared the transaction."))); |
| } |
| |
| /* |
| * Note: it probably would be possible to allow committing from another |
| * database; but at the moment NOTIFY is known not to work and there |
| * may be some other issues as well. Hence disallow until someone |
| * gets motivated to make it work. |
| */ |
| if (MyDatabaseId != gxact->proc.databaseId && (Gp_role != GP_ROLE_EXECUTE)) |
| { |
| LWLockRelease(TwoPhaseStateLock); |
| ereport(ERROR, |
| (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
| errmsg("prepared transaction belongs to another database"), |
| errhint("Connect to the database where the transaction was prepared to finish it."))); |
| } |
| |
| |
| /* OK for me to lock it */ |
| gxact->locking_xid = GetTopTransactionId(); |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| /* we *must* have it locked with a valid xid here! */ |
| Assert(TransactionIdIsValid(gxact->locking_xid)); |
| |
| return gxact; |
| } |
| LWLockRelease(TwoPhaseStateLock); |
| |
| if (raiseErrorIfNotFound) |
| { |
| ereport(ERROR, |
| (errcode(ERRCODE_UNDEFINED_OBJECT), |
| errmsg("prepared transaction with identifier \"%s\" does not exist", |
| gid))); |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * FindCurrentPrepareGXact |
| * Locate the current prepare transaction. |
| */ |
| static GlobalTransaction |
| FindPrepareGXact(const char *gid) |
| { |
| int i; |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5),"FindCurrentPrepareGXact called to lock identifier = %s.",gid); |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); |
| |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5), "FindCurrentPrepareGXact checking identifier = %s.",gxact->gid); |
| |
| if (strcmp(gxact->gid, gid) != 0) |
| continue; |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| return gxact; |
| } |
| LWLockRelease(TwoPhaseStateLock); |
| |
| ereport(ERROR, |
| (errcode(ERRCODE_UNDEFINED_OBJECT), |
| errmsg("prepared transaction with identifier \"%s\" does not exist", |
| gid))); |
| |
| return NULL; |
| } |
| |
| /* |
| * RemoveGXact |
| * Remove the prepared transaction from the shared memory array. |
| * |
| * NB: caller should have already removed it from ProcArray |
| */ |
| static void |
| RemoveGXact(GlobalTransaction gxact) |
| { |
| int i; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "RemoveGXact: entering..."); |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); |
| |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| if (gxact == TwoPhaseState->prepXacts[i]) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "RemoveGXact: about to remove xid = %d", gxact->proc.xid); |
| /* remove from the active array */ |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "RemoveGXact: TwoPhaseState->numPrepXacts = %d, subtracting 1", TwoPhaseState->numPrepXacts); |
| TwoPhaseState->numPrepXacts--; |
| TwoPhaseState->prepXacts[i] = TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts]; |
| |
| /* and put it back in the freelist */ |
| gxact->proc.links.next = TwoPhaseState->freeGXacts; |
| TwoPhaseState->freeGXacts = MAKE_OFFSET(gxact); |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| return; |
| } |
| } |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| elog(ERROR, "failed to find %p in GlobalTransaction array", (void *)gxact); |
| } |
| |
| |
| /* |
| * Returns an array of all prepared transactions for the user-level |
| * function pg_prepared_xact. |
| * |
| * The returned array and all its elements are copies of internal data |
| * structures, to minimize the time we need to hold the TwoPhaseStateLock. |
| * |
| * WARNING -- we return even those transactions that are not fully prepared |
| * yet. The caller should filter them out if he doesn't want them. |
| * |
| * The returned array is palloc'd. |
| */ |
| static int |
| GetPreparedTransactionList(GlobalTransaction *gxacts) |
| { |
| GlobalTransaction array; |
| int num; |
| int i; |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_SHARED); |
| |
| if (TwoPhaseState->numPrepXacts == 0) |
| { |
| LWLockRelease(TwoPhaseStateLock); |
| |
| *gxacts = NULL; |
| return 0; |
| } |
| |
| num = TwoPhaseState->numPrepXacts; |
| array = (GlobalTransaction) palloc(sizeof(GlobalTransactionData) * num); |
| *gxacts = array; |
| for (i = 0; i < num; i++) |
| memcpy(array + i, TwoPhaseState->prepXacts[i], |
| sizeof(GlobalTransactionData)); |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| return num; |
| } |
| |
| |
| /* Working status for pg_prepared_xact */ |
| typedef struct |
| { |
| GlobalTransaction array; |
| int ngxacts; |
| int currIdx; |
| } Working_State; |
| |
| /* |
| * pg_prepared_xact |
| * Produce a view with one row per prepared transaction. |
| * |
| * This function is here so we don't have to export the |
| * GlobalTransactionData struct definition. |
| */ |
| Datum |
| pg_prepared_xact(PG_FUNCTION_ARGS) |
| { |
| FuncCallContext *funcctx; |
| Working_State *status; |
| |
| if (SRF_IS_FIRSTCALL()) |
| { |
| TupleDesc tupdesc; |
| MemoryContext oldcontext; |
| |
| /* create a function context for cross-call persistence */ |
| funcctx = SRF_FIRSTCALL_INIT(); |
| |
| /* |
| * Switch to memory context appropriate for multiple function calls |
| */ |
| oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); |
| |
| /* build tupdesc for result tuples */ |
| /* this had better match pg_prepared_xacts view in system_views.sql */ |
| tupdesc = CreateTemplateTupleDesc(5, false); |
| TupleDescInitEntry(tupdesc, (AttrNumber) 1, "transaction", |
| XIDOID, -1, 0); |
| TupleDescInitEntry(tupdesc, (AttrNumber) 2, "gid", |
| TEXTOID, -1, 0); |
| TupleDescInitEntry(tupdesc, (AttrNumber) 3, "prepared", |
| TIMESTAMPTZOID, -1, 0); |
| TupleDescInitEntry(tupdesc, (AttrNumber) 4, "ownerid", |
| OIDOID, -1, 0); |
| TupleDescInitEntry(tupdesc, (AttrNumber) 5, "dbid", |
| OIDOID, -1, 0); |
| |
| funcctx->tuple_desc = BlessTupleDesc(tupdesc); |
| |
| /* |
| * Collect all the 2PC status information that we will format and send |
| * out as a result set. |
| */ |
| status = (Working_State *) palloc(sizeof(Working_State)); |
| funcctx->user_fctx = (void *) status; |
| |
| status->ngxacts = GetPreparedTransactionList(&status->array); |
| status->currIdx = 0; |
| |
| MemoryContextSwitchTo(oldcontext); |
| } |
| |
| funcctx = SRF_PERCALL_SETUP(); |
| status = (Working_State *) funcctx->user_fctx; |
| |
| while (status->array != NULL && status->currIdx < status->ngxacts) |
| { |
| GlobalTransaction gxact = &status->array[status->currIdx++]; |
| Datum values[5]; |
| bool nulls[5]; |
| HeapTuple tuple; |
| Datum result; |
| |
| if (!gxact->valid) |
| continue; |
| |
| /* |
| * Form tuple with appropriate data. |
| */ |
| MemSet(values, 0, sizeof(values)); |
| MemSet(nulls, 0, sizeof(nulls)); |
| |
| values[0] = TransactionIdGetDatum(gxact->proc.xid); |
| values[1] = DirectFunctionCall1(textin, CStringGetDatum(gxact->gid)); |
| values[2] = TimestampTzGetDatum(gxact->prepared_at); |
| values[3] = ObjectIdGetDatum(gxact->owner); |
| values[4] = ObjectIdGetDatum(gxact->proc.databaseId); |
| |
| tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls); |
| result = HeapTupleGetDatum(tuple); |
| SRF_RETURN_NEXT(funcctx, result); |
| } |
| |
| SRF_RETURN_DONE(funcctx); |
| } |
| |
| /* |
| * TwoPhaseGetDummyProc |
| * Get the PGPROC that represents a prepared transaction specified by XID |
| */ |
| PGPROC * |
| TwoPhaseGetDummyProc(TransactionId xid) |
| { |
| PGPROC *result = NULL; |
| int i; |
| |
| static TransactionId cached_xid = InvalidTransactionId; |
| static PGPROC *cached_proc = NULL; |
| |
| /* |
| * During a recovery, COMMIT PREPARED, or ABORT PREPARED, we'll be called |
| * repeatedly for the same XID. We can save work with a simple cache. |
| */ |
| if (xid == cached_xid) |
| return cached_proc; |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_SHARED); |
| |
| for (i = 0; i < TwoPhaseState->numPrepXacts; i++) |
| { |
| GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; |
| |
| if (gxact->proc.xid == xid) |
| { |
| result = &gxact->proc; |
| break; |
| } |
| } |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| if (result == NULL) /* should not happen */ |
| elog(ERROR, "failed to find dummy PGPROC for xid %u (%d entries)", xid, TwoPhaseState->numPrepXacts); |
| |
| cached_xid = xid; |
| cached_proc = result; |
| |
| return result; |
| } |
| |
| /************************************************************************/ |
| /* State file support */ |
| /************************************************************************/ |
| |
| #define TwoPhaseFilePath(path, xid) \ |
| snprintf(path, MAXPGPATH, TWOPHASE_DIR "/%08X", xid) |
| #define TwoPhaseSimpleFileName(path, xid) \ |
| snprintf(path, MAXPGPATH, "/%08X", xid) |
| |
| /* |
| * 2PC state file format: |
| * |
| * 1. TwoPhaseFileHeader |
| * 2. TransactionId[] (subtransactions) |
| * 3. RelFileNode[] (files to be deleted at commit) |
| * 4. RelFileNode[] (files to be deleted at abort) |
| * 5. TwoPhaseRecordOnDisk |
| * 6. ... |
| * 7. TwoPhaseRecordOnDisk (end sentinel, rmid == TWOPHASE_RM_END_ID) |
| * 8. CRC32 |
| * |
| * Each segment except the final CRC32 is MAXALIGN'd. |
| */ |
| |
| /* |
| * Header for a 2PC state file |
| */ |
| #define TWOPHASE_MAGIC 0x57F94531 /* format identifier */ |
| |
| typedef struct TwoPhaseFileHeader |
| { |
| uint32 magic; /* format identifier */ |
| uint32 total_len; /* actual file length */ |
| TransactionId xid; /* original transaction XID */ |
| Oid database; /* OID of database it was in */ |
| TimestampTz prepared_at; /* time of preparation */ |
| Oid owner; /* user running the transaction */ |
| int32 nsubxacts; /* number of following subxact XIDs */ |
| int16 persistentPrepareObjectCount; |
| /* number of PersistentEndXactRec style objects */ |
| char gid[GIDSIZE]; /* GID for transaction */ |
| } TwoPhaseFileHeader; |
| |
| /* |
| * Header for each record in a state file |
| * |
| * NOTE: len counts only the rmgr data, not the TwoPhaseRecordOnDisk header. |
| * The rmgr data will be stored starting on a MAXALIGN boundary. |
| */ |
| typedef struct TwoPhaseRecordOnDisk |
| { |
| uint32 len; /* length of rmgr data */ |
| TwoPhaseRmgrId rmid; /* resource manager for this record */ |
| uint16 info; /* flag bits for use by rmgr */ |
| } TwoPhaseRecordOnDisk; |
| |
| /* |
| * During prepare, the state file is assembled in memory before writing it |
| * to WAL and the actual state file. We use a chain of XLogRecData blocks |
| * so that we will be able to pass the state file contents directly to |
| * XLogInsert. |
| */ |
| static struct xllist |
| { |
| XLogRecData *head; /* first data block in the chain */ |
| XLogRecData *tail; /* last block in chain */ |
| uint32 bytes_free; /* free bytes left in tail block */ |
| uint32 total_len; /* total data bytes in chain */ |
| } records; |
| |
| |
| /* |
| * Append a block of data to records data structure. |
| * |
| * NB: each block is padded to a MAXALIGN multiple. This must be |
| * accounted for when the file is later read! |
| * |
| * The data is copied, so the caller is free to modify it afterwards. |
| */ |
| static void |
| save_state_data(const void *data, uint32 len) |
| { |
| uint32 padlen = MAXALIGN(len); |
| |
| if (padlen > records.bytes_free) |
| { |
| records.tail->next = palloc0(sizeof(XLogRecData)); |
| records.tail = records.tail->next; |
| records.tail->buffer = InvalidBuffer; |
| records.tail->len = 0; |
| records.tail->next = NULL; |
| |
| records.bytes_free = Max(padlen, 512); |
| records.tail->data = palloc(records.bytes_free); |
| } |
| |
| memcpy(((char *) records.tail->data) + records.tail->len, data, len); |
| records.tail->len += padlen; |
| records.bytes_free -= padlen; |
| records.total_len += padlen; |
| } |
| |
| /* |
| * Start preparing a state file. |
| * |
| * Initializes data structure and inserts the 2PC file header record. |
| */ |
| void |
| StartPrepare(GlobalTransaction gxact) |
| { |
| TransactionId xid = gxact->proc.xid; |
| TwoPhaseFileHeader hdr; |
| TransactionId *children; |
| |
| int32 persistentPrepareSerializeLen; |
| PersistentEndXactRecObjects persistentPrepareObjects; |
| |
| /* Initialize linked list */ |
| records.head = palloc0(sizeof(XLogRecData)); |
| records.head->buffer = InvalidBuffer; |
| records.head->len = 0; |
| records.head->next = NULL; |
| |
| records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512); |
| records.head->data = palloc(records.bytes_free); |
| |
| records.tail = records.head; |
| |
| records.total_len = 0; |
| |
| /* Create header */ |
| hdr.magic = TWOPHASE_MAGIC; |
| hdr.total_len = 0; /* EndPrepare will fill this in */ |
| hdr.xid = xid; |
| hdr.database = gxact->proc.databaseId; |
| hdr.prepared_at = gxact->prepared_at; |
| hdr.owner = gxact->owner; |
| hdr.nsubxacts = xactGetCommittedChildren(&children); |
| persistentPrepareSerializeLen = |
| PersistentEndXactRec_FetchObjectsFromSmgr( |
| &persistentPrepareObjects, |
| EndXactRecKind_Prepare, |
| &hdr.persistentPrepareObjectCount); |
| StrNCpy(hdr.gid, gxact->gid, GIDSIZE); |
| |
| save_state_data(&hdr, sizeof(TwoPhaseFileHeader)); |
| |
| /* Add the additional info about subxacts and deletable files */ |
| if (hdr.nsubxacts > 0) |
| { |
| save_state_data(children, hdr.nsubxacts * sizeof(TransactionId)); |
| /* While we have the child-xact data, stuff it in the gxact too */ |
| GXactLoadSubxactData(gxact, hdr.nsubxacts, children); |
| pfree(children); |
| } |
| if (hdr.persistentPrepareObjectCount > 0) |
| { |
| char *persistentPrepareBuffer; |
| int16 objectCount; |
| |
| Assert(persistentPrepareSerializeLen > 0); |
| persistentPrepareBuffer = |
| (char*)palloc(persistentPrepareSerializeLen); |
| |
| PersistentEndXactRec_Serialize( |
| &persistentPrepareObjects, |
| EndXactRecKind_Prepare, |
| &objectCount, |
| (uint8*)persistentPrepareBuffer, |
| persistentPrepareSerializeLen); |
| |
| if (Debug_persistent_print) |
| { |
| elog(Persistent_DebugPrintLevel(), |
| "StartPrepare: persistentPrepareSerializeLen %d", |
| persistentPrepareSerializeLen); |
| PersistentEndXactRec_Print("StartPrepare", &persistentPrepareObjects); |
| } |
| |
| save_state_data(persistentPrepareBuffer, persistentPrepareSerializeLen); |
| |
| pfree(persistentPrepareBuffer); |
| } |
| |
| #ifdef FAULT_INJECTOR |
| FaultInjector_InjectFaultIfSet( |
| StartPrepareTx, |
| DDLNotSpecified, |
| "", // databaseName |
| ""); // tableName |
| #endif |
| |
| } |
| |
| |
| /* |
| * Finish preparing state file. |
| * |
| * Writes state file (the prepare record) to WAL. |
| */ |
| void EndPrepare(GlobalTransaction gxact) |
| { |
| CHECKPOINT_START_LOCK_DECLARE; |
| |
| TransactionId xid = gxact->proc.xid; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), "EndPrepare: xid = %d", xid); |
| |
| /* Add the end sentinel to the list of 2PC records */ |
| RegisterTwoPhaseRecord(TWOPHASE_RM_END_ID, 0, NULL, 0); |
| |
| /* |
| * We have to lock out checkpoint start here, too; otherwise a checkpoint |
| * starting immediately after the WAL record is inserted could complete |
| * without fsync'ing our state file. (This is essentially the same kind |
| * of race condition as the COMMIT-to-clog-write case that |
| * RecordTransactionCommit uses CheckpointStartLock for; see notes there.) |
| * |
| * We save the PREPARE record's location in the gxact for later use by |
| * CheckPointTwoPhase. |
| * |
| * NOTE: Critical seciton and CheckpointStartLock were moved up. |
| */ |
| CHECKPOINT_START_LOCK; |
| |
| START_CRIT_SECTION(); |
| |
| gxact->prepare_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE, records.head); |
| gxact->prepare_begin_lsn = XLogLastInsertBeginLoc(); |
| |
| /* Add the prepared record to our global list */ |
| add_recover_post_checkpoint_prepared_transactions_map_entry(xid, &gxact->prepare_begin_lsn, "EndPrepare"); |
| |
| XLogFlush(gxact->prepare_lsn); |
| |
| /* If we crash now, we have prepared: WAL replay will fix things */ |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "EndPrepare: proc.xid %u, prepare_lsn %s, gid %s", xid, |
| XLogLocationToString(&gxact->prepare_lsn), gxact->gid); |
| |
| if (Debug_abort_after_segment_prepared) |
| { |
| elog(PANIC, |
| "Raise an error as directed by Debug_abort_after_segment_prepared"); |
| } |
| |
| /* |
| * Mark the prepared transaction as valid. As soon as xact.c marks MyProc |
| * as not running our XID (which it will do immediately after this |
| * function returns), others can commit/rollback the xact. |
| * |
| * NB: a side effect of this is to make a dummy ProcArray entry for the |
| * prepared XID. This must happen before we clear the XID from MyProc, |
| * else there is a window where the XID is not running according to |
| * TransactionIdInProgress, and onlookers would be entitled to assume the |
| * xact crashed. Instead we have a window where the same XID appears |
| * twice in ProcArray, which is OK. |
| */ |
| MarkAsPrepared(gxact); |
| |
| END_CRIT_SECTION(); |
| |
| /* |
| * Now we can release the checkpoint start lock: a checkpoint starting |
| * after this will certainly see the gxact as a candidate for fsyncing. |
| */ |
| CHECKPOINT_START_UNLOCK; |
| |
| #ifdef FAULT_INJECTOR |
| FaultInjector_InjectFaultIfSet( |
| EndPreparedTwoPhaseSleep, |
| DDLNotSpecified, |
| "", // databaseName |
| ""); // tableName |
| #endif |
| |
| records.tail = records.head = NULL; |
| } /* end EndPrepare */ |
| |
| |
| /* |
| * Register a 2PC record to be written to state file. |
| */ |
| void |
| RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, |
| const void *data, uint32 len) |
| { |
| TwoPhaseRecordOnDisk record; |
| |
| record.rmid = rmid; |
| record.info = info; |
| record.len = len; |
| save_state_data(&record, sizeof(TwoPhaseRecordOnDisk)); |
| if (len > 0) |
| save_state_data(data, len); |
| } |
| |
| |
| void |
| PrepareIntentAppendOnlyCommitWork(char *gid) |
| { |
| GlobalTransaction gxact; |
| |
| gxact = FindPrepareGXact(gid); |
| |
| Assert(gxact->prepareAppendOnlyIntentCount >= 0); |
| gxact->prepareAppendOnlyIntentCount++; |
| } |
| |
| void |
| PrepareDecrAppendOnlyCommitWork(char *gid) |
| { |
| GlobalTransaction gxact; |
| |
| gxact = FindPrepareGXact(gid); |
| |
| Assert(gxact->prepareAppendOnlyIntentCount >= 1); |
| gxact->prepareAppendOnlyIntentCount--; |
| } |
| |
| |
| /* |
| * FinishPreparedTransaction: execute COMMIT PREPARED or ROLLBACK PREPARED |
| */ |
| bool |
| FinishPreparedTransaction(const char *gid, bool isCommit, bool raiseErrorIfNotFound) |
| { |
| CHECKPOINT_START_LOCK_DECLARE; |
| |
| GlobalTransaction gxact; |
| TransactionId xid; |
| char *buf; |
| char *bufptr = NULL; |
| char *dummy; |
| TwoPhaseFileHeader *hdr; |
| TransactionId *children; |
| |
| PersistentEndXactRecObjects persistentPrepareObjects; |
| int32 deserializeLen; |
| |
| int prepareAppendOnlyIntentCount; |
| |
| /* |
| * Validate the GID, and lock the GXACT to ensure that two backends do not |
| * try to commit the same GID at once. |
| */ |
| gxact = LockGXact(gid, GetUserId(), raiseErrorIfNotFound); |
| if (!raiseErrorIfNotFound && gxact == NULL) |
| { |
| return false; |
| } |
| |
| xid = gxact->proc.xid; |
| |
| elog((Debug_print_full_dtm ? LOG : DEBUG5), |
| "FinishPreparedTransaction(): got xid %d for gid '%s'", xid, gid); |
| |
| /* |
| * Check for recovery control file, and if so set up state for offline |
| * recovery |
| */ |
| XLogReadRecoveryCommandFile(DEBUG5); |
| |
| /* Now we can determine the list of expected TLIs */ |
| expectedTLIs = XLogReadTimeLineHistory(ThisTimeLineID); |
| |
| XLogRecPtr tfXLogRecPtr; |
| XLogRecord *tfRecord = NULL; |
| |
| /* get the two phase information from the xlog */ |
| |
| LWLockAcquire(TwoPhaseStateLock, LW_SHARED); |
| |
| int tfsIndex = 0; |
| for (tfsIndex = 0; tfsIndex < TwoPhaseState->numPrepXacts; tfsIndex++) |
| { |
| GlobalTransaction gxact = TwoPhaseState->prepXacts[tfsIndex]; |
| |
| if (gxact->valid && gxact->proc.xid == xid) |
| { |
| tfXLogRecPtr = gxact->prepare_begin_lsn; |
| elog(DEBUG1, "FinishPreparedTransaction: found TwoPhaseState entry for %d", xid); |
| break; |
| } |
| } |
| if (tfsIndex == TwoPhaseState->numPrepXacts) |
| elog( ERROR, "FinishPreparedTransaction: Did not find xid = %d in TwoPhaseState" |
| , xid |
| ); |
| |
| LWLockRelease(TwoPhaseStateLock); |
| |
| XLogCloseReadRecord(); |
| tfRecord = XLogReadRecord(&tfXLogRecPtr, LOG); |
| if (tfRecord == NULL) |
| { |
| /* |
| * Invalid XLOG record means record is corrupted. |
| * Failover is required, hopefully mirror is in healthy state. |
| */ |
| ereport(WARNING, |
| (errmsg("primary failure, " |
| "xlog record is invalid, " |
| "failover requested"), |
| errhint("run gprecoverseg to re-establish mirror connectivity"))); |
| |
| ereport(ERROR, |
| (errcode(ERRCODE_DATA_CORRUPTED), |
| errmsg("xlog record is invalid"), |
| errSendAlert(true))); |
| } |
| |
| buf = XLogRecGetData(tfRecord); |
| |
| if (buf == NULL) |
| ereport(ERROR, |
| (errcode(ERRCODE_DATA_CORRUPTED), |
| errmsg("two-phase state information for transaction %u is corrupt", |
| xid), |
| errSendAlert(true))); |
| |
| /* |
| * Disassemble the header area |
| */ |
| hdr = (TwoPhaseFileHeader *) buf; |
| Assert(TransactionIdEquals(hdr->xid, xid)); |
| bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader)); |
| children = (TransactionId *) bufptr; |
| bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId)); |
| |
| /* |
| * Although we return the end of the PersistentEndXactRec object, we really want the |
| * rounded-up aligned next buffer. So, that is why we compute the deserialized length |
| * and calculated the next buffer with it. |
| */ |
| deserializeLen = |
| PersistentEndXactRec_DeserializeLen( |
| (uint8*)bufptr, |
| hdr->persistentPrepareObjectCount); |
| |
| PersistentEndXactRec_Deserialize( |
| (uint8*)bufptr, |
| hdr->persistentPrepareObjectCount, |
| &persistentPrepareObjects, |
| (uint8**)&dummy); |
| |
| if (Debug_persistent_print) |
| { |
| elog(Persistent_DebugPrintLevel(), |
| "FinishPreparedTransaction: deserializedLen %d, persistentPrepareObjectCount %d", |
| deserializeLen, |
| hdr->persistentPrepareObjectCount); |
| PersistentEndXactRec_Print("FinishPreparedTransaction", &persistentPrepareObjects); |
| } |
| |
| bufptr += MAXALIGN(deserializeLen); |
| |
| // NOTE: This use to be inside RecordTransactionCommitPrepared and |
| // NOTE: RecordTransactionAbortPrepared. Moved out here so the mirrored |
| // NOTE: can cover both the XLOG record and the mirrored pg_twophase file |
| // NOTE: work. |
| START_CRIT_SECTION(); |
| |
| /* |
| * We have to lock out checkpoint start here when updating persistent relation information |
| * like Appendonly segment's committed EOF. Otherwise there might be a window betwwen |
| * the time some data is added to an appendonly segment file and its EOF updated in the |
| * persistent relation tables. If there is a checkpoint before updating the peristent tables |
| * and the system crash after the checkpoint, then during crash recovery we would not resync |
| * to the right EOFs (MPP-18261). |
| * When we use CheckpointStartLock, we make sure we already have the MirroredLock |
| * first. |
| */ |
| CHECKPOINT_START_LOCK; |
| |
| /* |
| * The order of operations here is critical: make the XLOG entry for |
| * commit or abort, then mark the transaction committed or aborted in |
| * pg_clog, then remove its PGPROC from the global ProcArray (which means |
| * TransactionIdIsInProgress will stop saying the prepared xact is in |
| * progress), then run the post-commit or post-abort callbacks. The |
| * callbacks will release the locks the transaction held. |
| */ |
| if (isCommit) |
| RecordTransactionCommitPrepared(xid, |
| gid, |
| hdr->nsubxacts, children, |
| &persistentPrepareObjects); |
| else |
| RecordTransactionAbortPrepared(xid, |
| hdr->nsubxacts, children, |
| &persistentPrepareObjects); |
| |
| prepareAppendOnlyIntentCount = gxact->prepareAppendOnlyIntentCount; |
| |
| ProcArrayRemove(&gxact->proc, isCommit); |
| |
| /* |
| * In case we fail while running the callbacks, mark the gxact invalid so |
| * no one else will try to commit/rollback, and so it can be recycled |
| * properly later. It is still locked by our XID so it won't go away yet. |
| * |
| * (We assume it's safe to do this without taking TwoPhaseStateLock.) |
| */ |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "FinishPreparedTransaction: gxact->proc.xid = %d and set valid = false", gxact->proc.xid); |
| gxact->valid = false; |
| |
| /* |
| * We have to remove any files that were supposed to be dropped. For |
| * consistency with the regular xact.c code paths, must do this before |
| * releasing locks, so do it before running the callbacks. |
| * |
| * NB: this code knows that we couldn't be dropping any temp rels ... |
| */ |
| |
| PersistentFileSysObj_PreparedEndXactAction( |
| xid, |
| gid, |
| &persistentPrepareObjects, |
| isCommit, |
| prepareAppendOnlyIntentCount); |
| |
| /* And now do the callbacks */ |
| if (isCommit) |
| ProcessRecords(bufptr, xid, twophase_postcommit_callbacks); |
| else |
| ProcessRecords(bufptr, xid, twophase_postabort_callbacks); |
| |
| /* |
| * And now we can clean up our mess. |
| */ |
| remove_recover_post_checkpoint_prepared_transactions_map_entry(xid, "FinishPreparedTransaction"); |
| |
| RemoveGXact(gxact); |
| |
| CHECKPOINT_START_UNLOCK; |
| |
| END_CRIT_SECTION(); |
| |
| /* Need to figure out the memory allocation and deallocationfor "buffer". For now, just let it leak. */ |
| |
| return true; |
| } |
| |
| /* |
| * Scan a 2PC state file (already read into memory by ReadTwoPhaseFile) |
| * and call the indicated callbacks for each 2PC record. |
| */ |
| static void |
| ProcessRecords(char *bufptr, TransactionId xid, |
| const TwoPhaseCallback callbacks[]) |
| { |
| for (;;) |
| { |
| TwoPhaseRecordOnDisk *record = (TwoPhaseRecordOnDisk *) bufptr; |
| |
| Assert(record->rmid <= TWOPHASE_RM_MAX_ID); |
| if (record->rmid == TWOPHASE_RM_END_ID) |
| break; |
| |
| bufptr += MAXALIGN(sizeof(TwoPhaseRecordOnDisk)); |
| |
| if (callbacks[record->rmid] != NULL) |
| callbacks[record->rmid] (xid, record->info, |
| (void *) bufptr, record->len); |
| |
| bufptr += MAXALIGN(record->len); |
| } |
| } |
| |
| /* |
| * Remove the 2PC file for the specified XID. |
| * |
| * If giveWarning is false, do not complain about file-not-present; |
| * this is an expected case during WAL replay. |
| */ |
| void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning) |
| { |
| |
| remove_recover_post_checkpoint_prepared_transactions_map_entry(xid, |
| "RemoveTwoPhaseFile: Removing from list"); |
| |
| } /* end RemoveTwoPhaseFile */ |
| |
| /* |
| * This is used in WAL replay. |
| * |
| */ |
| void RecreateTwoPhaseFile(TransactionId xid, void *content, int len, |
| XLogRecPtr *xlogrecptr) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), "RecreateTwoPhaseFile: entering..."); |
| |
| add_recover_post_checkpoint_prepared_transactions_map_entry(xid, xlogrecptr, "RecreateTwoPhaseFile: add entry to hash list"); |
| } |
| |
| /* |
| * CheckPointTwoPhase -- handle 2PC component of checkpointing. |
| * |
| * We must fsync the state file of any GXACT that is valid and has a PREPARE |
| * LSN <= the checkpoint's redo horizon. (If the gxact isn't valid yet or |
| * has a later LSN, this checkpoint is not responsible for fsyncing it.) |
| * |
| * This is deliberately run as late as possible in the checkpoint sequence, |
| * because GXACTs ordinarily have short lifespans, and so it is quite |
| * possible that GXACTs that were valid at checkpoint start will no longer |
| * exist if we wait a little bit. |
| * |
| * If a GXACT remains valid across multiple checkpoints, it'll be fsynced |
| * each time. This is considered unusual enough that we don't bother to |
| * expend any extra code to avoid the redundant fsyncs. (They should be |
| * reasonably cheap anyway, since they won't cause I/O.) |
| */ |
| void |
| CheckPointTwoPhase(XLogRecPtr redo_horizon) |
| { |
| |
| /* |
| * I think this is not needed with the new two phase logic. |
| * We have already attached all the prepared transactions to |
| * the checkpoint record. For now, just return from this. |
| */ |
| return; |
| |
| } |
| |
| |
| /* |
| * PrescanPreparedTransactions |
| * |
| * This function will return the oldest valid XID, and will also set |
| * the ShmemVariableCache->nextXid to the next available XID. |
| * |
| * This function is run during database startup, after we have completed |
| * reading WAL. ShmemVariableCache->nextXid has been set to one more than |
| * the highest XID for which evidence exists in WAL. The |
| * crashRecoverPostCheckpointPreparedTransactions_map_ht has already been |
| * populated with all pre and post checkpoint inflight transactions. |
| * |
| * Wwe will advance nextXid beyond any subxact XIDs belonging to valid |
| * prepared xacts. We need to do this since subxact commit doesn't |
| * write a WAL entry, and so there might be no evidence in WAL of those |
| * subxact XIDs. |
| * |
| * Our other responsibility is to determine and return the oldest valid XID |
| * among the prepared xacts (if none, return ShmemVariableCache->nextXid). |
| * This is needed to synchronize pg_subtrans startup properly. |
| */ |
| TransactionId |
| PrescanPreparedTransactions(void) |
| { |
| prpt_map *entry = NULL; |
| TransactionId origNextXid = ShmemVariableCache->nextXid; |
| TransactionId result = origNextXid; |
| XLogRecPtr *tfXLogRecPtr = NULL; |
| XLogRecord *tfRecord = NULL; |
| HASH_SEQ_STATUS hsStatus; |
| TwoPhaseFileHeader *hdr = NULL; |
| TransactionId xid; |
| TransactionId *subxids; |
| |
| if (crashRecoverPostCheckpointPreparedTransactions_map_ht != NULL) |
| { |
| hash_seq_init(&hsStatus,crashRecoverPostCheckpointPreparedTransactions_map_ht); |
| |
| entry = (prpt_map *)hash_seq_search(&hsStatus); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "PrescanPreparedTransactions: address entry = %p", |
| entry); |
| |
| if (entry != NULL) |
| tfXLogRecPtr = (XLogRecPtr *) &entry->xlogrecptr; |
| } |
| |
| while (tfXLogRecPtr != NULL) |
| { |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "PrescanPreparedTransactions: XLogRecPtr = %s", |
| XLogLocationToString(tfXLogRecPtr)); |
| |
| |
| tfRecord = XLogReadRecord(tfXLogRecPtr, LOG); |
| hdr = (TwoPhaseFileHeader *) XLogRecGetData(tfRecord); |
| xid = hdr->xid; |
| |
| if (TransactionIdDidCommit(xid) == false && TransactionIdDidAbort(xid) == false) |
| { |
| /* |
| * Incorporate xid into the running-minimum result. |
| */ |
| if (TransactionIdPrecedes(xid, result)) |
| result = xid; |
| |
| /* |
| * Examine subtransaction XIDs ... they should all follow main |
| * XID, and they may force us to advance nextXid. |
| */ |
| subxids = (TransactionId *)((char *)hdr + MAXALIGN(sizeof(TwoPhaseFileHeader))); |
| for (int i = 0; i < hdr->nsubxacts; i++) |
| { |
| TransactionId subxid = subxids[i]; |
| |
| Assert(TransactionIdFollows(subxid, xid)); |
| if (TransactionIdFollowsOrEquals(subxid, ShmemVariableCache->nextXid)) |
| { |
| ShmemVariableCache->nextXid = subxid; |
| TransactionIdAdvance(ShmemVariableCache->nextXid); |
| } |
| } /* end for (int i = 0; i < hdr->nsubxacts; i++) */ |
| } /* end if (TransactionIdDidCommit(xid) == false && TransactionIdDidAbort(xid) == false) */ |
| |
| /* Get the next entry */ |
| entry = (prpt_map *)hash_seq_search(&hsStatus); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "PrescanPreparedTransactions: address entry = %p", |
| entry); |
| |
| if (entry != NULL) |
| tfXLogRecPtr = (XLogRecPtr *) &entry->xlogrecptr; |
| else |
| tfXLogRecPtr = NULL; |
| |
| } /* end while (tfXLogRecPtr != NULL) */ |
| |
| return result; |
| } /* end PrescanPreparedTransactions */ |
| |
| |
| /* |
| * RecoverPreparedTransactions |
| * |
| * Scan the global list of post checkpoint records and reload shared-memory state for each |
| * prepared transaction (reacquire locks, etc). This is run during database |
| * startup. |
| */ |
| void RecoverPreparedTransactions() |
| { |
| prpt_map *entry = NULL; |
| XLogRecPtr *tfXLogRecPtr = NULL; |
| XLogRecord *tfRecord = NULL; |
| PersistentEndXactRecObjects persistentPrepareObjects; |
| LocalDistribXactRef localDistribXactRef; |
| TwoPhaseFileHeader *hdr = NULL; |
| HASH_SEQ_STATUS hsStatus; |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), "Entering RecoverPreparedTransactions"); |
| |
| if (crashRecoverPostCheckpointPreparedTransactions_map_ht != NULL) |
| { |
| hash_seq_init(&hsStatus,crashRecoverPostCheckpointPreparedTransactions_map_ht); |
| |
| entry = (prpt_map *)hash_seq_search(&hsStatus); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "RecoverPreparedTransactions: address entry = %p", |
| entry); |
| |
| if (entry != NULL) |
| tfXLogRecPtr = (XLogRecPtr *) &entry->xlogrecptr; |
| } |
| |
| while (tfXLogRecPtr != NULL) |
| { |
| TransactionId xid; |
| char *bufptr; |
| TransactionId *subxids; |
| GlobalTransaction gxact; |
| |
| tfRecord = XLogReadRecord(tfXLogRecPtr, LOG); |
| |
| hdr = (TwoPhaseFileHeader *) XLogRecGetData(tfRecord); |
| |
| elog(Persistent_DebugPrintLevel(), |
| "RecoverPreparedTransactions: prepared twophase record total_len = %u, xid = %d", |
| hdr->total_len, hdr->xid); |
| |
| xid = hdr->xid; |
| bufptr = (char *) hdr + MAXALIGN(sizeof(TwoPhaseFileHeader)); |
| subxids = (TransactionId *) bufptr; |
| bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId)); |
| |
| PersistentEndXactRec_Deserialize((uint8*) bufptr, |
| hdr->persistentPrepareObjectCount, &persistentPrepareObjects, |
| (uint8**) &bufptr); |
| |
| if (Debug_persistent_print) { |
| elog( |
| Persistent_DebugPrintLevel(), |
| "RecoverPreparedTransactions: deserializeLen %d, persistentPrepareObjectCount %d", |
| PersistentEndXactRec_DeserializeLen((uint8*) bufptr, |
| hdr->persistentPrepareObjectCount), |
| hdr->persistentPrepareObjectCount); |
| PersistentEndXactRec_Print("RecoverPreparedTransactions", |
| &persistentPrepareObjects); |
| } |
| /* |
| * Reconstruct subtrans state for the transaction --- needed |
| * because pg_subtrans is not preserved over a restart. Note that |
| * we are linking all the subtransactions directly to the |
| * top-level XID; there may originally have been a more complex |
| * hierarchy, but there's no need to restore that exactly. |
| */ |
| for (int iSub = 0; iSub < hdr->nsubxacts; iSub++) |
| SubTransSetParent(subxids[iSub], xid); |
| |
| gxact = MarkAsPreparing( xid |
| ,&localDistribXactRef |
| , hdr->gid |
| , hdr->prepared_at |
| , hdr->owner |
| , hdr->database |
| , tfXLogRecPtr |
| ); |
| GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids); |
| MarkAsPrepared(gxact); |
| |
| /* |
| * Recover other state (notably locks) using resource managers |
| */ |
| ProcessRecords(bufptr, xid, twophase_recover_callbacks); |
| |
| /* Get the next entry */ |
| entry = (prpt_map *)hash_seq_search(&hsStatus); |
| |
| if (Debug_persistent_print) |
| elog(Persistent_DebugPrintLevel(), |
| "RecoverPreparedTransactions: address entry = %p", |
| entry); |
| |
| if (entry != NULL) |
| tfXLogRecPtr = (XLogRecPtr *) &entry->xlogrecptr; |
| else |
| tfXLogRecPtr = NULL; |
| |
| } /* end while (xlogrecptr = (XLogRecPtr *)hash_seq_search(&hsStatus)) */ |
| |
| } |
| |
| /* |
| * RecordTransactionCommitPrepared |
| * |
| * This is basically the same as RecordTransactionCommit: in particular, |
| * we must take the CheckpointStartLock to avoid a race condition. |
| * |
| * We know the transaction made at least one XLOG entry (its PREPARE), |
| * so it is never possible to optimize out the commit record. |
| */ |
| static void |
| RecordTransactionCommitPrepared(TransactionId xid, |
| const char *gid, |
| int nchildren, |
| TransactionId *children, |
| PersistentEndXactRecObjects *persistentPrepareObjects) |
| { |
| int16 persistentCommitObjectCount; |
| char *persistentCommitBuffer = NULL; |
| |
| XLogRecData rdata[3]; |
| int lastrdata = 0; |
| xl_xact_commit_prepared xlrec; |
| XLogRecPtr recptr; |
| |
| /* |
| * Look at the prepare information with respect to a commit. |
| */ |
| persistentCommitObjectCount = |
| PersistentEndXactRec_ObjectCount( |
| persistentPrepareObjects, |
| EndXactRecKind_Commit); |
| |
| /* |
| * Ensure the caller already has MirroredLock then CheckpointStartLock. |
| */ |
| |
| /* Emit the XLOG commit record */ |
| xlrec.xid = xid; |
| xlrec.crec.xtime = time(NULL); |
| xlrec.crec.persistentCommitObjectCount = persistentCommitObjectCount; |
| xlrec.crec.nsubxacts = nchildren; |
| rdata[0].data = (char *) (&xlrec); |
| rdata[0].len = MinSizeOfXactCommitPrepared; |
| rdata[0].buffer = InvalidBuffer; |
| /* dump persistent commit objects */ |
| if (persistentCommitObjectCount > 0) |
| { |
| int32 persistentCommitSerializeLen; |
| int16 objectCount; |
| |
| persistentCommitSerializeLen = |
| PersistentEndXactRec_SerializeLen( |
| persistentPrepareObjects, |
| EndXactRecKind_Commit); |
| |
| Assert(persistentCommitSerializeLen > 0); |
| persistentCommitBuffer = |
| (char*)palloc(persistentCommitSerializeLen); |
| |
| PersistentEndXactRec_Serialize( |
| persistentPrepareObjects, |
| EndXactRecKind_Commit, |
| &objectCount, |
| (uint8*)persistentCommitBuffer, |
| persistentCommitSerializeLen); |
| |
| if (Debug_persistent_print) |
| { |
| elog(Persistent_DebugPrintLevel(), |
| "RecordTransactionCommitPrepared: persistentCommitSerializeLen %d, objectCount %d", |
| persistentCommitSerializeLen, |
| objectCount); |
| PersistentEndXactRec_Print("RecordTransactionCommitPrepared", persistentPrepareObjects); |
| } |
| |
| rdata[0].next = &(rdata[1]); |
| rdata[1].data = persistentCommitBuffer; |
| rdata[1].len = persistentCommitSerializeLen; |
| rdata[1].buffer = InvalidBuffer; |
| lastrdata = 1; |
| } |
| /* dump committed child Xids */ |
| if (nchildren > 0) |
| { |
| rdata[lastrdata].next = &(rdata[2]); |
| rdata[2].data = (char *) children; |
| rdata[2].len = nchildren * sizeof(TransactionId); |
| rdata[2].buffer = InvalidBuffer; |
| lastrdata = 2; |
| } |
| rdata[lastrdata].next = NULL; |
| |
| #ifdef FAULT_INJECTOR |
| FaultInjector_InjectFaultIfSet( |
| TwoPhaseTransactionCommitPrepared, |
| DDLNotSpecified, |
| "" /* databaseName */, |
| "" /* tableName */); |
| #endif |
| |
| recptr = XLogInsert(RM_XACT_ID, |
| XLOG_XACT_COMMIT_PREPARED | XLOG_NO_TRAN, |
| rdata); |
| |
| /* we don't currently try to sleep before flush here ... */ |
| |
| /* Flush XLOG to disk */ |
| XLogFlush(recptr); |
| |
| /* Mark the transaction committed in pg_clog */ |
| TransactionIdCommit(xid); |
| |
| /* to avoid race conditions, the parent must commit first */ |
| TransactionIdCommitTree(nchildren, children); |
| |
| if (persistentCommitBuffer != NULL) |
| pfree(persistentCommitBuffer); |
| } |
| |
| /* |
| * RecordTransactionAbortPrepared |
| * |
| * This is basically the same as RecordTransactionAbort. |
| * |
| * We know the transaction made at least one XLOG entry (its PREPARE), |
| * so it is never possible to optimize out the abort record. |
| */ |
| static void |
| RecordTransactionAbortPrepared(TransactionId xid, |
| int nchildren, |
| TransactionId *children, |
| PersistentEndXactRecObjects *persistentPrepareObjects) |
| { |
| int16 persistentAbortObjectCount; |
| char *persistentAbortBuffer = NULL; |
| |
| XLogRecData rdata[3]; |
| int lastrdata = 0; |
| xl_xact_abort_prepared xlrec; |
| XLogRecPtr recptr; |
| |
| /* |
| * Catch the scenario where we aborted partway through |
| * RecordTransactionCommitPrepared ... |
| */ |
| if (TransactionIdDidCommit(xid)) |
| elog(PANIC, "cannot abort transaction %u, it was already committed", |
| xid); |
| |
| /* |
| * Look at the prepare information with respect to an abort. |
| */ |
| persistentAbortObjectCount = |
| PersistentEndXactRec_ObjectCount( |
| persistentPrepareObjects, |
| EndXactRecKind_Abort); |
| |
| /* Emit the XLOG abort record */ |
| xlrec.xid = xid; |
| xlrec.arec.xtime = time(NULL); |
| xlrec.arec.persistentAbortObjectCount = persistentAbortObjectCount; |
| xlrec.arec.nsubxacts = nchildren; |
| rdata[0].data = (char *) (&xlrec); |
| rdata[0].len = MinSizeOfXactAbortPrepared; |
| rdata[0].buffer = InvalidBuffer; |
| /* dump persistent abort objects */ |
| if (persistentAbortObjectCount > 0) |
| { |
| int32 persistentAbortSerializeLen; |
| int16 objectCount; |
| |
| persistentAbortSerializeLen = |
| PersistentEndXactRec_SerializeLen( |
| persistentPrepareObjects, |
| EndXactRecKind_Abort); |
| |
| Assert(persistentAbortSerializeLen > 0); |
| persistentAbortBuffer = |
| (char*)palloc(persistentAbortSerializeLen); |
| |
| PersistentEndXactRec_Serialize( |
| persistentPrepareObjects, |
| EndXactRecKind_Abort, |
| &objectCount, |
| (uint8*)persistentAbortBuffer, |
| persistentAbortSerializeLen); |
| |
| if (Debug_persistent_print) |
| { |
| elog(Persistent_DebugPrintLevel(), |
| "RecordTransactionAbortPrepared: persistentAbortSerializeLen %d", |
| persistentAbortSerializeLen); |
| PersistentEndXactRec_Print("RecordTransactionAbortPrepared", persistentPrepareObjects); |
| } |
| |
| rdata[0].next = &(rdata[1]); |
| rdata[1].data = persistentAbortBuffer; |
| rdata[1].len = persistentAbortSerializeLen; |
| rdata[1].buffer = InvalidBuffer; |
| lastrdata = 1; |
| } |
| /* dump committed child Xids */ |
| if (nchildren > 0) |
| { |
| rdata[lastrdata].next = &(rdata[2]); |
| rdata[2].data = (char *) children; |
| rdata[2].len = nchildren * sizeof(TransactionId); |
| rdata[2].buffer = InvalidBuffer; |
| lastrdata = 2; |
| } |
| rdata[lastrdata].next = NULL; |
| |
| #ifdef FAULT_INJECTOR |
| FaultInjector_InjectFaultIfSet( |
| TwoPhaseTransactionAbortPrepared, |
| DDLNotSpecified, |
| "" /* databaseName */, |
| "" /* tableName */); |
| #endif |
| |
| recptr = XLogInsert(RM_XACT_ID, |
| XLOG_XACT_ABORT_PREPARED | XLOG_NO_TRAN, |
| rdata); |
| |
| /* Always flush, since we're about to remove the 2PC state file */ |
| XLogFlush(recptr); |
| |
| /* |
| * Mark the transaction aborted in clog. This is not absolutely necessary |
| * but we may as well do it while we are here. |
| */ |
| TransactionIdAbort(xid); |
| TransactionIdAbortTree(nchildren, children); |
| |
| if (persistentAbortBuffer != NULL) |
| pfree(persistentAbortBuffer); |
| |
| } |
| |
| /* |
| * This function will gather up all the current prepared transaction xlog pointers, |
| * and pass that information back to the caller. |
| */ |
| void |
| getTwoPhasePreparedTransactionData(prepared_transaction_agg_state **ptas, char *caller) |
| { |
| |
| int numberOfPrepareXacts = TwoPhaseState->numPrepXacts; |
| GlobalTransaction *globalTransactionArray = TwoPhaseState->prepXacts; |
| TransactionId xid; |
| XLogRecPtr *recordPtr = NULL; |
| int maxCount; |
| |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "getTwoPhasePreparedTransactionData: start of function from caller %s", |
| caller); |
| |
| Assert(*ptas == NULL); |
| |
| TwoPhaseAddPreparedTransactionInit(ptas, &maxCount); |
| |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "getTwoPhasePreparedTransactionData: numberOfPrepareXacts = %d", |
| numberOfPrepareXacts); |
| |
| for (int i = 0; i < numberOfPrepareXacts; i++) |
| { |
| if ((globalTransactionArray[i])->valid == false) |
| /* Skip any invalid prepared transacitons. */ |
| continue; |
| xid = (globalTransactionArray[i])->proc.xid; |
| recordPtr = &(globalTransactionArray[i])->prepare_begin_lsn; |
| |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "getTwoPhasePreparedTransactionData: add entry xid = %u, XLogRecPtr = %s, caller = %s", |
| xid, |
| XLogLocationToString(recordPtr), |
| caller); |
| |
| TwoPhaseAddPreparedTransaction( ptas |
| ,&maxCount |
| , xid |
| , recordPtr |
| , caller |
| ); |
| } |
| |
| |
| } /* end getTwoPhasePreparedTransactionData */ |
| |
| |
| /* |
| * This function will allocate enough space to accomidate maxCount values. |
| */ |
| void |
| TwoPhaseAddPreparedTransactionInit( |
| prepared_transaction_agg_state **ptas, int *maxCount) |
| { |
| int len; |
| |
| Assert (*ptas == NULL); |
| |
| *maxCount = 10; // Start off with at least this much room. |
| len = PREPARED_TRANSACTION_CHECKPOINT_BYTES(*maxCount); |
| *ptas = (prepared_transaction_agg_state*)palloc0(len); |
| |
| } /* end TwoPhaseAddPreparedTransactionInit */ |
| |
| |
| /* |
| * This function adds another entry to the list of prepared transactions. |
| */ |
| void |
| TwoPhaseAddPreparedTransaction( prepared_transaction_agg_state **ptas |
| , int *maxCount |
| , TransactionId xid |
| , XLogRecPtr *xlogPtr |
| , char *caller |
| ) |
| { |
| int len; |
| int count; |
| prpt_map *m; |
| |
| Assert(*ptas != NULL); |
| Assert(*maxCount > 0); |
| |
| count = (*ptas)->count; |
| Assert(count <= *maxCount); |
| |
| if (count == *maxCount) |
| { |
| prepared_transaction_agg_state *oldPtas; |
| |
| oldPtas = *ptas; |
| |
| (*maxCount) *= 2; // Double. |
| len = PREPARED_TRANSACTION_CHECKPOINT_BYTES(*maxCount); |
| *ptas = (prepared_transaction_agg_state*)palloc0(len); |
| memcpy(*ptas, oldPtas, PREPARED_TRANSACTION_CHECKPOINT_BYTES(count)); |
| pfree(oldPtas); |
| } |
| |
| m = &(*ptas)->maps[count]; |
| m->xid = xid; |
| m->xlogrecptr.xlogid = xlogPtr->xlogid; |
| m->xlogrecptr.xrecoff = xlogPtr->xrecoff; |
| |
| if (Debug_persistent_recovery_print) |
| { |
| SUPPRESS_ERRCONTEXT_DECLARE; |
| |
| SUPPRESS_ERRCONTEXT_PUSH(); |
| |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "TwoPhaseAddPreparedTransaction: add entry XLogRecPtr = %s, caller = %s", |
| XLogLocationToString(xlogPtr), |
| caller); |
| |
| SUPPRESS_ERRCONTEXT_POP(); |
| } |
| |
| (*ptas)->count++; |
| |
| |
| } /* end TwoPhaseAddPreparedTransaction */ |
| |
| |
| /* |
| * Return a pointer to the oldest XLogRecPtr in the list or NULL if the list is empty. |
| */ |
| XLogRecPtr * |
| getTwoPhaseOldestPreparedTransactionXLogRecPtr(XLogRecData *rdata) |
| { |
| prepared_transaction_agg_state *ptas = (prepared_transaction_agg_state *)rdata->data; |
| int map_count = ptas->count; |
| prpt_map *m = ptas->maps; |
| XLogRecPtr *oldest = NULL; |
| |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "getTwoPhaseOldestPreparedTransactionXLogRecPtr: map_count = %d", map_count); |
| |
| if (map_count > 0) |
| { |
| oldest = &(m[0].xlogrecptr); |
| for (int i = 1; i < map_count; i++) |
| { |
| elog(PersistentRecovery_DebugPrintLevel(), |
| "getTwoPhaseOldestPreparedTransactionXLogRecPtr: checkpoint prepared pointer %d = %s", i, XLogLocationToString(oldest)); |
| if (XLByteLE(m[i].xlogrecptr, *oldest)) |
| oldest = &(m[i].xlogrecptr); |
| } |
| } |
| |
| return oldest; |
| |
| } /* end getTwoPhaseOldestPreparedTransactionXLogRecPtr */ |
| |
