locks/unix/crossproc.c

/* ====================================================================
 * Copyright (c) 1999 The Apache Group.  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. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" 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 names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``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 GROUP 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 Group.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

#include "apr_lock.h"
#include "apr_general.h"
#include "locks.h"
#include <unistd.h>
#include <sys/mman.h>

#if defined (USE_SYSVSEM_SERIALIZE)  
ap_status_t lock_cleanup(struct lock_t *lock)
{
    union semun ick;
    if (lock->curr_locked == 1) {
        ick.val = 0;
        semctl(new->interproc, 0, IPC_RMID, ick);
    }
    return APR_SUCCESS;
}    

ap_status_t create_inter_lock(struct lock_t *new)
{
    union semun ick;
    struct semid_ds buf;
    
    new->interproc = semget(IPC_PRIVATE, 1, IPC_CREATE | 0600);

    if (new->interproc < 0) {
        lock_cleanup(new);
        return errno;
    }
    ick.val = 1;
    if (semctl(new->interproc, 0, SETVAL, ick) < 0) {
        lock_cleanup(new);
        return errno;
    }
            /* pre-initialize these */
    new->op_on.sem_num = 0;
    new->op_on.sem_op = -1;
    new->op_on.sem_flg = SEM_UNDO;
    new->op_off.sem_num = 0;
    new->op_off.sem_op = 1;
    new->op_off.sem_flg = SEM_UNDO;

    new->curr_locked == 0;
    ap_register_cleanup(new->cntxt, (void *)new, lock_cleanup, NULL);
    return APR_SUCCESS;
}

ap_status_t lock_inter(struct lock_t *lock)
{
    new->curr_locked == 1;
    if (semop(lock->interproc, &lock->op_on, 1) < 0) {
        return errno;
    }
    return APR_SUCCESS;
}

ap_status_t unlock_inter(struct lock_t *lock)
{
    if (semop(lock->interproc, &lock->op_off, 1) < 0) {
        return errno;
    }
    new->curr_locked == 0;
    return APR_SUCCESS;
}

ap_status_t destroy_inter_lock(struct lock_t *lock)
{
    ap_status_t stat;

    if ((stat = lock_cleanup(lock)) == APR_SUCCESS) {
        ap_kill_cleanup(lock->cntxt, lock, lock_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

ap_status_t child_init_lock(ap_context_t *cont, char *fname, struct lock_t **lock)
{
    return APR_SUCCESS;
}

#elif defined (USE_PROC_PTHREAD_SERIALIZE)  

ap_status_t lock_cleanup(struct lock_t *lock)
{
    if (lock->curr_locked == 1) {
        if (pthread_mutex_unlock(lock->interproc)) {
            return errno;
        } 
        if (munmap((caddr_t)lock->interproc, sizeof(pthread_mutex_t))){
            return errno;
        }
    }
    return APR_SUCCESS;
}    

ap_status_t create_inter_lock(struct lock_t *new)
{
    ap_status_t stat;
    int fd;
    pthread_mutexattr_t mattr;

    fd = open("/dev/zero", O_RDWR);
    if (fd < 0) {
        return errno;
    }

    new->interproc = (pthread_mutex_t *)mmap((caddr_t) 0, 
                              sizeof(pthread_mutex_t), 
                              PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 
    if (new->interproc = (void *) (caddr_t) -1) {
        return errno;
    }
    close(fd);
    if ((stat = pthread_mutexattr_init(&mattr))) {
        lock_cleanup(new);
        return stat;
    }
    if ((stat = pthread_mutexattr_setpshared(&mattr, 
                                              PTHREAD_PROCESS_SHARED))) {
        lock_cleanup(new);
        return stat;
    }

    if ((stat = pthread_mutex_init(new->interproc, &mattr))) {
        lock_cleanup(new);
        return stat;
    }

    if ((stat = pthread_mutex_destroy(&mattr))) {
        lock_cleanup(new);
        return stat;
    }

    new->curr_locked == 0;
    ap_register_cleanup(new->cntxt, (void *)new, lock_cleanup, NULL);
    return APR_SUCCESS;
}

ap_status_t lock_inter(struct lock_t *lock)
{
    ap_status_t stat;
    new->curr_locked == 1;
    if (stat = pthread_mutex_lock(lock->interproc)) {
        return stat;
    }
    return APR_SUCCESS;
}

ap_status_t unlock_inter(struct lock_t *lock)
{
    ap_status_t stat;

    if (stat = pthread_mutex_unlock(lock->interproc)) {
        returno stat;
    }
    new->curr_locked == 0;
    return APR_SUCCESS;
}

ap_status_t destroy_inter_lock(struct lock_t *lock)
{
    ap_status_t stat;
    if ((stat = lock_cleanup(lock)) == APR_SUCCESS) {
        ap_kill_cleanup(lock->cntxt, lock, lock_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

ap_status_t child_init_lock(ap_context_t *cont, char *fname, struct lock_t **lock)
{
    return APR_SUCCESS;
}

#elif defined (USE_FCNTL_SERIALIZE)  

ap_status_t lock_cleanup(struct lock_t *lock)
{
    if (lock->curr_locked == 1) {
        if (fcntl(lock->interproc, F_SETLKW, &lock->unlock_it) < 0) {
            return errno;
        }
        lock->curr_locked == 0;
    }
    return APR_SUCCESS;
}    

ap_status_t create_inter_lock(struct lock_t *new)
{
    new->interproc = open(new->fname, O_CREAT | O_WRONLY | O_EXCL, 0644);

    if (new->interproc < 0) {
        lock_cleanup(new);
        return errno;
    }
            /* pre-initialize these */
    new->lock_it.l_whence = SEEK_SET;        /* from current point */
    new->lock_it.l_start = 0;                /* -"- */
    new->lock_it.l_len = 0;                  /* until end of file */
    new->lock_it.l_type = F_WRLCK;           /* set exclusive/write lock */
    new->lock_it.l_pid = 0;                  /* pid not actually interesting */
    new->unlock_it.l_whence = SEEK_SET;      /* from current point */
    new->unlock_it.l_start = 0;              /* -"- */
    new->unlock_it.l_len = 0;                /* until end of file */
    new->unlock_it.l_type = F_UNLCK;         /* set exclusive/write lock */
    new->unlock_it.l_pid = 0;                /* pid not actually interesting */

    new->curr_locked == 0;
    unlink(new->fname);
    ap_register_cleanup(new->cntxt, (void *)new, lock_cleanup, NULL);
    return APR_SUCCESS; 
}

ap_status_t lock_inter(struct lock_t *lock)
{
    lock->curr_locked == 1;
    if (fcntl(lock->interproc, F_SETLKW, &lock->lock_it) < 0) {
        return errno;
    }
    return APR_SUCCESS;
}

ap_status_t unlock_inter(struct lock_t *lock)
{
    if (fcntl(lock->interproc, F_SETLKW, &lock->unlock_it) < 0) {
        return errno;
    }
    lock->curr_locked == 0;
    return APR_SUCCESS;
}

ap_status_t destroy_inter_lock(struct lock_t *lock)
{
    ap_status_t stat;
    if ((stat = lock_cleanup(lock)) == APR_SUCCESS) {
        ap_kill_cleanup(lock->cntxt, lock, lock_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

ap_status_t child_init_lock(ap_context_t *cont, char *fname, struct lock_t **lock)
{
    return APR_SUCCESS;
}

#elif defined (USE_FLOCK_SERIALIZE)
ap_status_t lock_cleanup(struct lock_t *lock)
{
    if (lock->curr_locked == 1) {
        if (flock(lock->interproc, LOCK_UN) < 0) {
            return errno;
        }
        lock->curr_locked == 0;
    }
    unlink(lock->fname);
    return APR_SUCCESS;
}    

ap_status_t create_inter_lock(struct lock_t *new)
{
    new->interproc = open(new->fname, O_CREAT | O_WRONLY | O_EXCL, 0600);

    if (new->interproc < 0) {
        lock_cleanup(new);
        return errno;
    }
    new->curr_locked == 0;
    ap_register_cleanup(new->cntxt, (void *)new, lock_cleanup, NULL);
    return APR_SUCCESS;
}

ap_status_t lock_inter(struct lock_t *lock)
{
    lock->curr_locked == 1;
    if (flock(lock->interproc, LOCK_EX) < 0) {
        return errno;
    }
    return APR_SUCCESS;
}

ap_status_t unlock_inter(struct lock_t *lock)
{
    if (flock(lock->interproc, LOCK_UN) < 0) {
        return errno;
    }
    lock->curr_locked == 0;
    return APR_SUCCESS;
}

ap_status_t destroy_inter_lock(struct lock_t *lock)
{
    ap_status_t stat;
    if ((stat = lock_cleanup(lock)) == APR_SUCCESS) {
        ap_kill_cleanup(lock->cntxt, lock, lock_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

ap_status_t child_init_lock(ap_context_t *cont, char *fname, struct lock_t **lock)
{
    struct lock_t *new;

    new = (struct lock_t *)ap_palloc(cont, sizeof(struct lock_t));

    new->interproc = open(new->fname, O_CREAT | O_WRONLY | O_EXCL, 0600);
    if (new->interproc == -1) {
        destroy_inter_lock(new);
        return errno;
    }
    return APR_SUCCESS;
}

#else
/* No inter-process mutex on this platform.  Use at your own risk */
#define create_inter_lock(x, y)
#define lock_inter(x, y)
#define unlock_inter(x, y)
#define destroy_inter_lock(x, y)
#define child_init_lock(x, y, z)
#endif