server/scoreboard.c

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * Portions of this software are based upon public domain software
 * originally written at the National Center for Supercomputing Applications,
 * University of Illinois, Urbana-Champaign.
 */

#include "apr.h"
#include "apr_strings.h"
#include "apr_portable.h"
#include "apr_lib.h"

#define APR_WANT_STRFUNC
#include "apr_want.h"

#if APR_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#include "ap_config.h"
#include "httpd.h"
#include "http_log.h"
#include "http_main.h"
#include "http_core.h"
#include "http_config.h"
#include "ap_mpm.h"

#include "mpm.h"
#include "scoreboard.h"

AP_DECLARE_DATA scoreboard *ap_scoreboard_image = NULL;
AP_DECLARE_DATA const char *ap_scoreboard_fname=NULL;
AP_DECLARE_DATA int ap_extended_status = 0;
AP_DECLARE_DATA apr_time_t ap_restart_time = 0;

#if APR_HAS_SHARED_MEMORY
#include "apr_shmem.h"
static apr_shmem_t *scoreboard_shm = NULL;
#endif

APR_HOOK_STRUCT(
    APR_HOOK_LINK(pre_mpm)
)
 
AP_IMPLEMENT_HOOK_VOID(pre_mpm,
                       (apr_pool_t *p, ap_scoreboard_e sb_type),
                       (p, sb_type))

/*
 * ToDo:
 * This function should be renamed to cleanup_shared
 * and it should handle cleaning up a scoreboard shared
 * between processes using any form of IPC (file, shared memory
 * segment, etc.). Leave it as is now because it is being used
 * by various MPMs. 
 */
static apr_status_t ap_cleanup_shared_mem(void *d)
{
#if APR_HAS_SHARED_MEMORY
    apr_shm_free(scoreboard_shm, ap_scoreboard_image);
    ap_scoreboard_image = NULL;
    apr_shm_destroy(scoreboard_shm);
#endif
    return APR_SUCCESS;
}

/* ToDo: This function should be made to handle setting up 
 * a scoreboard shared between processes using any IPC technique, 
 * not just a shared memory segment
 */
static void setup_shared(apr_pool_t *p)
{
#if APR_HAS_SHARED_MEMORY
    char buf[512];
    char errmsg[120];
    const char *fname;
    apr_status_t rv;

    fname = ap_server_root_relative(p, ap_scoreboard_fname);
    rv = apr_shm_init(&scoreboard_shm, SCOREBOARD_SIZE, fname, p);
    if (rv != APR_SUCCESS) {
        apr_snprintf(buf, sizeof(buf), "%s: could not open(create) scoreboard: %s",
                    ap_server_argv0, apr_strerror(rv, errmsg, sizeof errmsg));
        fprintf(stderr, "%s\n", buf);
        exit(APEXIT_INIT);
    }
    ap_scoreboard_image = apr_shm_malloc(scoreboard_shm, SCOREBOARD_SIZE);
    if (ap_scoreboard_image == NULL) {
        apr_snprintf(buf, sizeof(buf), "%s: cannot allocate scoreboard",
                    ap_server_argv0);
        perror(buf); /* o.k. since MM sets errno */
        apr_shm_destroy(scoreboard_shm);
        exit(APEXIT_INIT);
    }
    ap_scoreboard_image->global.running_generation = 0;
#endif
}

AP_DECLARE(void) reopen_scoreboard(apr_pool_t *p)
{
}

/* ap_cleanup_scoreboard
 * 
 */
apr_status_t ap_cleanup_scoreboard(void *d) {
    if (ap_scoreboard_image == NULL)
        return APR_SUCCESS;
    if (ap_scoreboard_image->global.sb_type == SB_SHARED) {
        ap_cleanup_shared_mem(NULL);
    }
    else {
        free(ap_scoreboard_image);
        ap_scoreboard_image = NULL;
    }
    return APR_SUCCESS;
}

/* ap_create_scoreboard(apr_pool_t*, ap_scoreboard_e t)
 *
 * Create or reinit an existing scoreboard. The MPM can control whether
 * the scoreboard is shared across multiple processes or not
 *
 * ###: Is there any reason to export this symbol in the first place?
 */
AP_DECLARE_NONSTD(void) ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e sb_type)
{
    int running_gen = 0;
    if (ap_scoreboard_image)
	running_gen = ap_scoreboard_image->global.running_generation;
    if (ap_scoreboard_image == NULL) {
        if (sb_type == SB_SHARED) {
            setup_shared(p);
        }
        else {
            /* A simple malloc will suffice */
            char buf[512];
            ap_scoreboard_image = (scoreboard *) malloc(SCOREBOARD_SIZE);
            if (ap_scoreboard_image == NULL) {
                apr_snprintf(buf, sizeof(buf), "%s: cannot allocate scoreboard",
                             ap_server_argv0);
                perror(buf); /* o.k. since MM sets errno */
                exit(APEXIT_INIT);            
            }
        }
    }
    memset(ap_scoreboard_image, 0, SCOREBOARD_SIZE);
    ap_scoreboard_image->global.sb_type = sb_type;
    ap_scoreboard_image->global.running_generation = running_gen;
    ap_restart_time = apr_time_now();
    apr_pool_cleanup_register(p, NULL, ap_cleanup_scoreboard, apr_pool_cleanup_null);
}

/* Routines called to deal with the scoreboard image
 * --- note that we do *not* need write locks, since update_child_status
 * only updates a *single* record in place, and only one process writes to
 * a given scoreboard slot at a time (either the child process owning that
 * slot, or the parent, noting that the child has died).
 *
 * As a final note --- setting the score entry to getpid() is always safe,
 * since when the parent is writing an entry, it's only noting SERVER_DEAD
 * anyway.
 */

void ap_sync_scoreboard_image(void)
{
}

AP_DECLARE(int) ap_exists_scoreboard_image(void)
{
    return (ap_scoreboard_image ? 1 : 0);
}

static APR_INLINE void put_scoreboard_info(int child_num, int thread_num, 
				       worker_score *new_score_rec)
{
    /* XXX - needs to be fixed to account for threads */
#ifdef SCOREBOARD_FILE
    lseek(scoreboard_fd, (long) child_num * sizeof(worker_score), 0);
    force_write(scoreboard_fd, new_score_rec, sizeof(worker_score));
#endif
}

void update_scoreboard_global(void)
{
#ifdef SCOREBOARD_FILE
    lseek(scoreboard_fd,
	  (char *) &ap_scoreboard_image->global -(char *) ap_scoreboard_image, 0);
    force_write(scoreboard_fd, &ap_scoreboard_image->global,
		sizeof ap_scoreboard_image->global);
#endif
}

AP_DECLARE(void) ap_increment_counts(int child_num, int thread_num, request_rec *r)
{
    worker_score *ws;

    ws = &ap_scoreboard_image->servers[child_num][thread_num];

#ifdef HAVE_TIMES
    times(&ws->times);
#endif
    ws->access_count++;
    ws->my_access_count++;
    ws->conn_count++;
    ws->bytes_served += r->bytes_sent;
    ws->my_bytes_served += r->bytes_sent;
    ws->conn_bytes += r->bytes_sent;

    put_scoreboard_info(child_num, thread_num, ws);
}

AP_DECLARE(int) find_child_by_pid(apr_proc_t *pid)
{
    int i;
    int max_daemons_limit;

    ap_mpm_query(AP_MPMQ_MAX_DAEMON_USED, &max_daemons_limit);

    for (i = 0; i < max_daemons_limit; ++i)
	if (ap_scoreboard_image->parent[i].pid == pid->pid)
	    return i;

    return -1;
}

int ap_update_child_status(int child_num, int thread_num, int status, request_rec *r)
{
    int old_status;
    worker_score *ws;
    process_score *ps;

    if (child_num < 0)
	return -1;

    ws = &ap_scoreboard_image->servers[child_num][thread_num];
    old_status = ws->status;
    ws->status = status;

    ps = &ap_scoreboard_image->parent[child_num];
    
    if (status == SERVER_READY
	&& old_status == SERVER_STARTING) {
        ws->thread_num = child_num * HARD_SERVER_LIMIT + thread_num;
        ps->generation = ap_my_generation;
        ws->vhostrec = NULL;
    }

    if (ap_extended_status) {
    ws->last_used = apr_time_now();
	if (status == SERVER_READY || status == SERVER_DEAD) {
	    /*
	     * Reset individual counters
	     */
	    if (status == SERVER_DEAD) {
		ws->my_access_count = 0L;
		ws->my_bytes_served = 0L;
	    }
	    ws->conn_count = (unsigned short) 0;
	    ws->conn_bytes = (unsigned long) 0;
	}
	if (r) {
	    conn_rec *c = r->connection;
	    apr_cpystrn(ws->client, ap_get_remote_host(c, r->per_dir_config,
				  REMOTE_NOLOOKUP, NULL), sizeof(ws->client));
	    if (r->the_request == NULL) {
		    apr_cpystrn(ws->request, "NULL", sizeof(ws->request));
	    } else if (r->parsed_uri.password == NULL) {
		    apr_cpystrn(ws->request, r->the_request, sizeof(ws->request));
	    } else {
		/* Don't reveal the password in the server-status view */
		    apr_cpystrn(ws->request, apr_pstrcat(r->pool, r->method, " ",
					       apr_uri_unparse_components(r->pool, &r->parsed_uri, UNP_OMITPASSWORD),
					       r->assbackwards ? NULL : " ", r->protocol, NULL),
				       sizeof(ws->request));
	    }
	    ws->vhostrec =  r->server;
	}
    }
    
    put_scoreboard_info(child_num, thread_num, ws);
    return old_status;
}

void ap_time_process_request(int child_num, int thread_num, int status)
{
    worker_score *ws;

    if (child_num < 0)
	return;

    ws = &ap_scoreboard_image->servers[child_num][thread_num];

    if (status == START_PREQUEST) {
        ws->start_time = apr_time_now(); 
    }
    else if (status == STOP_PREQUEST) {
        ws->stop_time = apr_time_now(); 
    }
    put_scoreboard_info(child_num, thread_num, ws);
}

worker_score *ap_get_servers_scoreboard(int x, int y)
{
    if (((x < 0) || (HARD_SERVER_LIMIT < x)) ||
        ((y < 0) || (HARD_THREAD_LIMIT < y))) {
        return(NULL); /* Out of range */
    }
    return(&ap_scoreboard_image->servers[x][y]);
}

process_score *ap_get_parent_scoreboard(int x)
{
    if ((x < 0) || (HARD_SERVER_LIMIT < x)) {
        return(NULL); /* Out of range */
    }
    return(&ap_scoreboard_image->parent[x]);
}