httpd/server/scoreboard.c

	scoreboard.c revision 26dfa083a1662d57ba7cc410eec4e0696b9be469
/* ====================================================================
 * 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
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * 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_shm.h"
static apr_shm_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))

struct ap_sb_handle_t {
    int child_num;
    int thread_num;
};

static int server_limit, thread_limit;
static apr_size_t scoreboard_size;

/*
 * 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
    free(ap_scoreboard_image);
    ap_scoreboard_image = NULL;
    apr_shm_destroy(scoreboard_shm);
#endif
    return APR_SUCCESS;
}

int ap_calc_scoreboard_size(void)
{
    ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);
    ap_mpm_query(AP_MPMQ_HARD_LIMIT_DAEMONS, &server_limit);
    scoreboard_size = sizeof(global_score);
    scoreboard_size += sizeof(process_score) * server_limit;
    scoreboard_size += sizeof(worker_score) * server_limit * thread_limit;
    return scoreboard_size;
}

void ap_init_scoreboard(void *shared_score)
{
    char *more_storage;
    int i;

    ap_scoreboard_image =
        calloc(1, sizeof(scoreboard) + server_limit * sizeof(worker_score *));
    more_storage = shared_score;
    ap_scoreboard_image->global = (global_score *)more_storage;
    more_storage += sizeof(global_score);
    ap_scoreboard_image->parent = (process_score *)more_storage;
    more_storage += sizeof(process_score) * server_limit;
    ap_scoreboard_image->servers =
        (worker_score **)((char*)ap_scoreboard_image + sizeof(scoreboard));
    for (i = 0; i < server_limit; i++) {
        ap_scoreboard_image->servers[i] = (worker_score *)more_storage;
        more_storage += thread_limit * sizeof(worker_score);
    }
    ap_assert(more_storage == (char*)shared_score + scoreboard_size);
}

/* 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 apr_status_t open_scoreboard(apr_pool_t *p)
{
#if APR_HAS_SHARED_MEMORY
    apr_status_t rv;
    char *fname = NULL;

    if (ap_scoreboard_fname) {
        fname = ap_server_root_relative(p, ap_scoreboard_fname);
    }
    rv = apr_shm_create(&scoreboard_shm, scoreboard_size, fname, p);
    if (rv != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                     "Fatal error: could not open(create) scoreboard");
        return rv;
    }
    /* everything will be cleared shortly */
#endif
    return APR_SUCCESS;
}

/* If detach is non-zero, this is a seperate child process,
 * if zero, it is a forked child.
 */
apr_status_t reopen_scoreboard(apr_pool_t *p, int detached)
{
#if APR_HAS_SHARED_MEMORY
    apr_status_t rv;
    char *fname = NULL;

    if (!detached) {
        return APR_SUCCESS;
    }
    if (ap_scoreboard_fname) {
        fname = ap_server_root_relative(p, ap_scoreboard_fname);
    }
    rv = apr_shm_attach(&scoreboard_shm, fname, p);
    if (rv != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                     "Fatal error: could not open(create) scoreboard");
        return rv;
    }
    if (apr_shm_size_get(scoreboard_shm) < scoreboard_size) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                     "Fatal error: shared scoreboard too small for child!");
        apr_shm_detach(scoreboard_shm);
        scoreboard_shm = NULL;
    }
    /* everything will be cleared shortly */
#endif
    return APR_SUCCESS;
}

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->global);
        free(ap_scoreboard_image);
        ap_scoreboard_image = NULL;
    }
    return APR_SUCCESS;
}

/* Create or reinit an existing scoreboard. The MPM can control whether
 * the scoreboard is shared across multiple processes or not
 */
void ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e sb_type)
{
    int running_gen = 0;
    apr_status_t rv;

    if (ap_scoreboard_image)
    running_gen = ap_scoreboard_image->global->running_generation;
    if (ap_scoreboard_image == NULL) {
        ap_calc_scoreboard_size();
        if (sb_type == SB_SHARED) {
            void *sb_shared;
            rv = open_scoreboard(p);
            if (rv || !(sb_shared = apr_shm_baseaddr_get(scoreboard_shm))) {
                exit(APEXIT_INIT); /* XXX need to return an error from this function */
            }
            memset(sb_shared, 0, scoreboard_size);
            ap_init_scoreboard(sb_shared);
        }
        else if (sb_type == SB_SHARED_CHILD) {
            void *sb_shared;
            rv = reopen_scoreboard(p, 1);
            if (rv || !(sb_shared = apr_shm_baseaddr_get(scoreboard_shm))) {
                exit(APEXIT_INIT); /* XXX need to return an error from this function */
            }
            ap_init_scoreboard(sb_shared);
        }
        else {
            /* A simple malloc will suffice */
            void *sb_mem = calloc(1, scoreboard_size);
            if (sb_mem == NULL) {
                ap_log_error(APLOG_MARK, APLOG_CRIT | APLOG_NOERRNO, 0, NULL,
                             "(%d)%s: cannot allocate scoreboard",
                             errno, strerror(errno));
                exit(APEXIT_INIT); /* XXX need to return an error from this function */
            }
            ap_init_scoreboard(sb_mem);
        }
    }
    /* can't just memset() */
    if (sb_type != SB_SHARED_CHILD) {
        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, sizeof(global_score)
                       + (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, 0, 0);
    force_write(scoreboard_fd, &ap_scoreboard_image->global,
        sizeof ap_scoreboard_image->global);
#endif
}

AP_DECLARE(void) ap_increment_counts(ap_sb_handle_t *sb, request_rec *r)
{
    worker_score *ws;

    ws = &ap_scoreboard_image->servers[sb->child_num][sb->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(sb->child_num, sb->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_DAEMONS, &max_daemons_limit);

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

    return -1;
}

AP_DECLARE(void) ap_create_sb_handle(ap_sb_handle_t **new_sbh, apr_pool_t *p,
                                     int child_num, int thread_num)
{
    *new_sbh = (ap_sb_handle_t *)apr_palloc(p, sizeof(ap_sb_handle_t));
    (*new_sbh)->child_num = child_num;
    (*new_sbh)->thread_num = thread_num;
}

AP_DECLARE(int) ap_update_child_status_from_indexes(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 * server_limit + thread_num;
        ps->generation = ap_my_generation;
    }

    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(r->pool, &r->parsed_uri, APR_URI_UNP_OMITPASSWORD),
                           r->assbackwards ? NULL : " ", r->protocol, NULL),
                       sizeof(ws->request));
        }
        apr_cpystrn(ws->vhost, r->server->server_hostname, sizeof(ws->vhost));
    }
    }

    put_scoreboard_info(child_num, thread_num, ws);
    return old_status;
}

AP_DECLARE(int)ap_update_child_status(ap_sb_handle_t *sbh, int status, request_rec *r)
{
    return ap_update_child_status_from_indexes(sbh->child_num, sbh->thread_num,
                                               status, r);
}

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);
}

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

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

AP_DECLARE(global_score *) ap_get_scoreboard_global()
{
    return(ap_scoreboard_image->global);
}