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Posted to dev@apr.apache.org by Aaron Bannert <aa...@clove.org> on 2001/09/15 00:15:47 UTC

[PATCH] add apr_proc_mutex for the new Lock API

Adds (cross)process mutexes, implements UNIX, stubs elsewhere. Tested against
httpd-2.0 source in my tree (I'll provide a patch to testlock soon).

Instructions for applying:
1) apply the attached patch
2) add the files from the attached tarball

This API does not yet include equivalence for the
apr_lock_data_{get,set}() functions.  They will of course have to be
added before we can move httpd-2.0 fully over to the new API.

I have provided inline the "interesting" files that make up this
patch, for public reviewal. This includes the public headers, and the
UNIX private headers and implementation.

-aaron

------------------------------------------------------------
Public Header: apr_proc_mutex.h


/* ====================================================================
 * 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/>.
 */

#ifndef APR_PROC_MUTEX_H
#define APR_PROC_MUTEX_H

#include "apr.h"
#include "apr_lock.h"    /* only for apr_lockmech_e_np */
#include "apr_pools.h"
#include "apr_errno.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/**
 * @file apr_proc_mutex.h
 * @brief APR Process Locking Routines
 */

/**
 * @defgroup APR_ProcMutex Process Locking Routines
 * @ingroup APR
 * @{
 */

typedef struct apr_proc_mutex_t apr_proc_mutex_t;

/*   Function definitions */

/**
 * Create and initialize a mutex that can be used to synchronize processes.
 * @param mutex the memory address where the newly created mutex will be
 *        stored.
 * @param fname A file name to use if the lock mechanism requires one.  This
 *        argument should always be provided.  The lock code itself will
 *        determine if it should be used.
 * @param pool the pool from which to allocate the mutex.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_create(apr_proc_mutex_t **mutex,
                                                const char *fname,
                                                apr_pool_t *pool);

/**
 * non-portable interface to apr_proc_mutex_create()
 *
 * Create and initialize a mutex that can be used to synchronize processes.
 * @param mutex the memory address where the newly created mutex will be
 *        stored.
 * @param fname A file name to use if the lock mechanism requires one.  This
 *        argument should always be provided.  The lock code itself will
 *        determine if it should be used.
 * @param mech The mechanism to use for the interprocess lock, if any; one of
 * <PRE>
 *            APR_LOCK_FCNTL
 *            APR_LOCK_FLOCK
 *            APR_LOCK_SYSVSEM
 *            APR_LOCK_PROC_PTHREAD
 *            APR_LOCK_DEFAULT     pick the default mechanism for the platform
 * </PRE>
 * @param pool the pool from which to allocate the mutex.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_create_np(apr_proc_mutex_t **mutex,
                                                   const char *fname,
                                                   apr_lockmech_e_np mech,
                                                   apr_pool_t *pool);
/**
 * Re-open a mutex in a child process.
 * @param mutex The newly re-opened mutex structure.
 * @param fname A file name to use if the mutex mechanism requires one.  This
 *              argument should always be provided.  The mutex code itself will
 *              determine if it should be used.  This filename should be the 
 *              same one that was passed to apr_proc_mutex_create().
 * @param pool The pool to operate on.
 * @remark This function must be called to maintain portability, even
 *         if the underlying lock mechanism does not require it.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_child_init(apr_proc_mutex_t **mutex,
                                                    const char *fname,
                                                    apr_pool_t *pool);

/**
 * Acquire the lock for the given mutex. If the mutex is already locked,
 * the current thread will be put to sleep until the lock becomes available.
 * @param mutex the mutex on which to acquire the lock.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_lock(apr_proc_mutex_t *mutex);

/**
 * Attempt to acquire the lock for the given mutex. If the mutex has already
 * been acquired, the call returns immediately with APR_EBUSY. Note: it
 * is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine
 * if the return value was APR_EBUSY, for portability reasons.
 * @param mutex the mutex on which to attempt the lock acquiring.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_trylock(apr_proc_mutex_t *mutex);

/**
 * Release the lock for the given mutex.
 * @param mutex the mutex from which to release the lock.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_unlock(apr_proc_mutex_t *mutex);

/**
 * Destroy the mutex and free the memory associated with the lock.
 * @param mutex the mutex to destroy.
 */
APR_DECLARE(apr_status_t) apr_proc_mutex_destroy(apr_proc_mutex_t *mutex);

#ifdef __cplusplus
}
#endif

#endif  /* ! APR_PROC_MUTEX_H */




------------------------------------------------------------
Private Header (UNIX): proc_mutex.h


/* ====================================================================
 * 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/>.
 */

#ifndef PROC_MUTEX_H
#define PROC_MUTEX_H

#include "apr.h"
#include "apr_private.h"
#include "apr_general.h"
#include "apr_lib.h"
#include "apr_proc_mutex.h"
#include "apr_pools.h"
#include "apr_portable.h"

/* System headers required by Locks library */
#if APR_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if APR_HAVE_STDIO_H
#include <stdio.h>
#endif
#if APR_HAVE_FCNTL_H
#include <fcntl.h>
#endif

#ifdef HAVE_SYS_SEM_H
#include <sys/sem.h>
#endif
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#if APR_HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#if APR_HAVE_PTHREAD_H
#include <pthread.h>
#endif
/* End System Headers */

struct apr_proc_mutex_unix_lock_methods_t {
    unsigned int flags;
    apr_status_t (*create)(apr_proc_mutex_t *, const char *);
    apr_status_t (*acquire)(apr_proc_mutex_t *);
    apr_status_t (*tryacquire)(apr_proc_mutex_t *);
    apr_status_t (*release)(apr_proc_mutex_t *);
    apr_status_t (*destroy)(apr_proc_mutex_t *);
    apr_status_t (*child_init)(apr_proc_mutex_t **, apr_pool_t *, const char *);
};
typedef struct apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_lock_methods_t;

/* bit values for flags field in apr_unix_lock_methods_t */
#define APR_PROCESS_LOCK_MECH_IS_GLOBAL          1

#if APR_HAS_SYSVSEM_SERIALIZE
extern const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_sysv_methods;
#endif
#if APR_HAS_FCNTL_SERIALIZE
extern const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_fcntl_methods;
#endif
#if APR_HAS_FLOCK_SERIALIZE
extern const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_flock_methods;
#endif
#if APR_HAS_PROC_PTHREAD_SERIALIZE
extern const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_proc_pthread_methods;
#endif
#if APR_HAS_RWLOCK_SERIALIZE
extern const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_rwlock_methods;
#endif


#if !APR_HAVE_UNION_SEMUN && defined(APR_HAS_SYSVSEM_SERIALIZE)
/* it makes no sense, but this isn't defined on solaris */
union semun {
    long val;
    struct semid_ds *buf;
    ushort *array;
};
#endif

struct apr_proc_mutex_t {
    apr_pool_t *pool;
    const apr_proc_mutex_unix_lock_methods_t *meth;
    const apr_proc_mutex_unix_lock_methods_t *inter_meth;
    apr_lockscope_e scope;
    int curr_locked;
    char *fname;
#if APR_HAS_SYSVSEM_SERIALIZE || APR_HAS_FCNTL_SERIALIZE || APR_HAS_FLOCK_SERIALIZE
    int interproc;
#endif
#if APR_HAS_PROC_PTHREAD_SERIALIZE
    pthread_mutex_t *pthread_interproc;
#endif
#if APR_HAS_THREADS
    /* APR doesn't have threads, no sense in having a thread lock mechanism.
     */

    apr_os_thread_t owner;
    int owner_ref;
#endif
};

void apr_proc_mutex_unix_setup_lock(void);

#endif  /* PROC_MUTEX_H */






------------------------------------------------------------
Implementation (UNIX): proc_mutex.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
 * 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/>.
 */

#include "apr.h"
#include "apr_strings.h"
#include "proc_mutex.h"
#include "fileio.h" /* for apr_mkstemp() */

#if APR_HAS_SYSVSEM_SERIALIZE

static struct sembuf proc_mutex_op_on;
static struct sembuf proc_mutex_op_off;

static void proc_mutex_sysv_setup(void)
{
    proc_mutex_op_on.sem_num = 0;
    proc_mutex_op_on.sem_op = -1;
    proc_mutex_op_on.sem_flg = SEM_UNDO;
    proc_mutex_op_off.sem_num = 0;
    proc_mutex_op_off.sem_op = 1;
    proc_mutex_op_off.sem_flg = SEM_UNDO;
}

static apr_status_t proc_mutex_sysv_cleanup(void *mutex_)
{
    apr_proc_mutex_t *mutex=mutex_;
    union semun ick;
    
    if (mutex->interproc != -1) {
        ick.val = 0;
        semctl(mutex->interproc, 0, IPC_RMID, ick);
    }
    return APR_SUCCESS;
}    

static apr_status_t proc_mutex_sysv_create(apr_proc_mutex_t *new_mutex,
                                           const char *fname)
{
    union semun ick;
    apr_status_t stat;
    
    new_mutex->interproc = semget(IPC_PRIVATE, 1, IPC_CREAT | 0600);

    if (new_mutex->interproc < 0) {
        stat = errno;
        proc_mutex_sysv_cleanup(new_mutex);
        return stat;
    }
    ick.val = 1;
    if (semctl(new_mutex->interproc, 0, SETVAL, ick) < 0) {
        stat = errno;
        proc_mutex_sysv_cleanup(new_mutex);
        return stat;
    }
    new_mutex->curr_locked = 0;
    apr_pool_cleanup_register(new_mutex->pool,
                              (void *)new_mutex, proc_mutex_sysv_cleanup, 
                              apr_pool_cleanup_null);
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_sysv_acquire(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = semop(mutex->interproc, &proc_mutex_op_on, 1);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked = 1;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_sysv_release(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = semop(mutex->interproc, &proc_mutex_op_off, 1);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked = 0;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_sysv_destroy(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

    if ((stat = proc_mutex_sysv_cleanup(mutex)) == APR_SUCCESS) {
        apr_pool_cleanup_kill(mutex->pool, mutex, proc_mutex_sysv_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

static apr_status_t proc_mutex_sysv_child_init(apr_proc_mutex_t **mutex, apr_pool_t *cont, const char *fname)
{
    return APR_SUCCESS;
}

const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_sysv_methods =
{
#if APR_PROCESS_LOCK_IS_GLOBAL || !APR_HAS_THREADS
    APR_PROCESS_LOCK_MECH_IS_GLOBAL,
#else
    0,
#endif
    proc_mutex_sysv_create,
    proc_mutex_sysv_acquire,
    NULL, /* no tryacquire */
    proc_mutex_sysv_release,
    proc_mutex_sysv_destroy,
    proc_mutex_sysv_child_init
};

#endif /* SysV sem implementation */

#if APR_HAS_PROC_PTHREAD_SERIALIZE

static void proc_mutex_proc_pthread_setup(void)
{
}

static apr_status_t proc_mutex_proc_pthread_cleanup(void *mutex_)
{
    apr_proc_mutex_t *mutex=mutex_;
    apr_status_t stat;

    if (mutex->curr_locked == 1) {
        if ((stat = pthread_mutex_unlock(mutex->pthread_interproc))) {
#ifdef PTHREAD_SETS_ERRNO
            stat = errno;
#endif
            return stat;
        } 
        if (munmap((caddr_t)mutex->pthread_interproc, sizeof(pthread_mutex_t))){
            return errno;
        }
    }
    return APR_SUCCESS;
}    

static apr_status_t proc_mutex_proc_pthread_create(apr_proc_mutex_t *new_mutex,
                                                   const char *fname)
{
    apr_status_t stat;
    int fd;
    pthread_mutexattr_t mattr;

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

    new_mutex->pthread_interproc = (pthread_mutex_t *)mmap(
                                       (caddr_t) 0, 
                                       sizeof(pthread_mutex_t), 
                                       PROT_READ | PROT_WRITE, MAP_SHARED,
                                       fd, 0); 
    if (new_mutex->pthread_interproc == (pthread_mutex_t *) (caddr_t) -1) {
        return errno;
    }
    close(fd);
    if ((stat = pthread_mutexattr_init(&mattr))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }
    if ((stat = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }

#ifdef HAVE_PTHREAD_MUTEXATTR_SETROBUST_NP
    if ((stat = pthread_mutexattr_setrobust_np(&mattr, 
                                               PTHREAD_MUTEX_ROBUST_NP))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }
    if ((stat = pthread_mutexattr_setprotocol(&mattr, PTHREAD_PRIO_INHERIT))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }
#endif

    if ((stat = pthread_mutex_init(new_mutex->pthread_interproc, &mattr))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }

    if ((stat = pthread_mutexattr_destroy(&mattr))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        proc_pthread_cleanup(new_mutex);
        return stat;
    }

    new_mutex->curr_locked = 0;
    apr_pool_cleanup_register(new_mutex->pool,
                              (void *)new_mutex,
                              proc_mutex_proc_pthread_cleanup, 
                              apr_pool_cleanup_null);
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_proc_pthread_acquire(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

    if ((stat = pthread_mutex_lock(mutex->pthread_interproc))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
#ifdef HAVE_PTHREAD_MUTEXATTR_SETROBUST_NP
        /* Okay, our owner died.  Let's try to make it consistent again. */
        if (stat == EOWNERDEAD) {
            pthread_mutex_consistent_np(mutex->pthread_interproc);
        }
        else
            return stat;
#else
        return stat;
#endif
    }
    mutex->curr_locked = 1;
    return APR_SUCCESS;
}

/* TODO: Add proc_mutex_proc_pthread_tryacquire(apr_proc_mutex_t *mutex) */

static apr_status_t proc_mutex_proc_pthread_release(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

    if ((stat = pthread_mutex_unlock(mutex->pthread_interproc))) {
#ifdef PTHREAD_SETS_ERRNO
        stat = errno;
#endif
        return stat;
    }
    mutex->curr_locked = 0;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_proc_pthread_destroy(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;
    if ((stat = proc_mutex_proc_pthread_cleanup(mutex)) == APR_SUCCESS) {
        apr_pool_cleanup_kill(mutex->pool,
                              mutex,
                              proc_mutex_proc_pthread_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

static apr_status_t proc_mutex_proc_pthread_child_init(apr_proc_mutex_t **mutex,
                                            apr_pool_t *cont, 
                                            const char *fname)
{
    return APR_SUCCESS;
}

const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_proc_pthread_methods =
{
    APR_PROCESS_LOCK_MECH_IS_GLOBAL,
    proc_mutex_proc_pthread_create,
    proc_mutex_proc_pthread_acquire,
    NULL, /* no tryacquire */
    proc_mutex_proc_pthread_release,
    proc_mutex_proc_pthread_destroy,
    proc_mutex_proc_pthread_child_init
};

#endif

#if APR_HAS_FCNTL_SERIALIZE

static struct flock proc_mutex_lock_it;
static struct flock proc_mutex_unlock_it;

static apr_status_t proc_mutex_fcntl_release(apr_proc_mutex_t *);

static void proc_mutex_fcntl_setup(void)
{
    proc_mutex_lock_it.l_whence = SEEK_SET;   /* from current point */
    proc_mutex_lock_it.l_start = 0;           /* -"- */
    proc_mutex_lock_it.l_len = 0;             /* until end of file */
    proc_mutex_lock_it.l_type = F_WRLCK;      /* set exclusive/write lock */
    proc_mutex_lock_it.l_pid = 0;             /* pid not actually interesting */
    proc_mutex_unlock_it.l_whence = SEEK_SET; /* from current point */
    proc_mutex_unlock_it.l_start = 0;         /* -"- */
    proc_mutex_unlock_it.l_len = 0;           /* until end of file */
    proc_mutex_unlock_it.l_type = F_UNLCK;    /* set exclusive/write lock */
    proc_mutex_unlock_it.l_pid = 0;           /* pid not actually interesting */
}

static apr_status_t proc_mutex_fcntl_cleanup(void *mutex_)
{
    apr_status_t status;
    apr_proc_mutex_t *mutex=mutex_;

    if (mutex->curr_locked == 1) {
        status = proc_mutex_fcntl_release(mutex);
        if (status != APR_SUCCESS)
            return status;
    }
    close(mutex->interproc);
    
    return APR_SUCCESS;
}    

static apr_status_t proc_mutex_fcntl_create(apr_proc_mutex_t *new_mutex,
                                            const char *fname)
{
    if (fname) {
        new_mutex->fname = apr_pstrdup(new_mutex->pool, fname);
        new_mutex->interproc = open(new_mutex->fname,
                                    O_CREAT | O_WRONLY | O_EXCL, 0644);
    }
    else {
        new_mutex->fname = apr_pstrdup(new_mutex->pool, "/tmp/aprXXXXXX");
        new_mutex->interproc = apr_mkstemp(new_mutex->fname);
    }

    if (new_mutex->interproc < 0) {
        proc_mutex_fcntl_cleanup(new_mutex);
        return errno;
    }

    new_mutex->curr_locked = 0;
    unlink(new_mutex->fname);
    apr_pool_cleanup_register(new_mutex->pool,
                              (void*)new_mutex,
                              proc_mutex_fcntl_cleanup, 
                              apr_pool_cleanup_null);
    return APR_SUCCESS; 
}

static apr_status_t proc_mutex_fcntl_acquire(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = fcntl(mutex->interproc, F_SETLKW, &proc_mutex_lock_it);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked=1;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_fcntl_release(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = fcntl(mutex->interproc, F_SETLKW, &proc_mutex_unlock_it);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked=0;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_fcntl_destroy(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;
    if ((stat = proc_mutex_fcntl_cleanup(mutex)) == APR_SUCCESS) {
        apr_pool_cleanup_kill(mutex->pool, mutex, proc_mutex_fcntl_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

static apr_status_t proc_mutex_fcntl_child_init(apr_proc_mutex_t **mutex,
                                                apr_pool_t *pool, 
                                                const char *fname)
{
    return APR_SUCCESS;
}

const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_fcntl_methods =
{
#if APR_PROCESS_LOCK_IS_GLOBAL || !APR_HAS_THREADS
    APR_PROCESS_LOCK_MECH_IS_GLOBAL,
#else
    0,
#endif
    proc_mutex_fcntl_create,
    proc_mutex_fcntl_acquire,
    NULL, /* no tryacquire */
    proc_mutex_fcntl_release,
    proc_mutex_fcntl_destroy,
    proc_mutex_fcntl_child_init
};

#endif /* fcntl implementation */

#if APR_HAS_FLOCK_SERIALIZE

static apr_status_t proc_mutex_flock_release(apr_proc_mutex_t *);

static void proc_mutex_flock_setup(void)
{
}

static apr_status_t proc_mutex_flock_cleanup(void *mutex_)
{
    apr_status_t status;
    apr_proc_mutex_t *mutex=mutex_;

    if (mutex->curr_locked == 1) {
        status = proc_mutex_flock_release(mutex);
        if (status != APR_SUCCESS)
            return status;
    }
    close(mutex->interproc);
    unlink(mutex->fname);
    return APR_SUCCESS;
}    

static apr_status_t proc_mutex_flock_create(apr_proc_mutex_t *new_mutex,
                                            const char *fname)
{
    if (fname) {
        new_mutex->fname = apr_pstrdup(new_mutex->pool, fname);
        new_mutex->interproc = open(new_mutex->fname,
                                    O_CREAT | O_WRONLY | O_EXCL, 0600);
    }
    else {
        new_mutex->fname = apr_pstrdup(new_mutex->pool, "/tmp/aprXXXXXX");
        new_mutex->interproc = apr_mkstemp(new_mutex->fname);
    }

    if (new_mutex->interproc < 0) {
        proc_mutex_flock_cleanup(new_mutex);
        return errno;
    }
    new_mutex->curr_locked = 0;
    apr_pool_cleanup_register(new_mutex->pool, (void *)new_mutex,
                              proc_mutex_flock_cleanup,
                              apr_pool_cleanup_null);
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_flock_acquire(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = flock(mutex->interproc, LOCK_EX);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked = 1;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_flock_release(apr_proc_mutex_t *mutex)
{
    int rc;

    do {
        rc = flock(mutex->interproc, LOCK_UN);
    } while (rc < 0 && errno == EINTR);
    if (rc < 0) {
        return errno;
    }
    mutex->curr_locked = 0;
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_flock_destroy(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;
    if ((stat = proc_mutex_flock_cleanup(mutex)) == APR_SUCCESS) {
        apr_pool_cleanup_kill(mutex->pool, mutex, proc_mutex_flock_cleanup);
        return APR_SUCCESS;
    }
    return stat;
}

static apr_status_t proc_mutex_flock_child_init(apr_proc_mutex_t **mutex,
                                                apr_pool_t *pool, 
                                                const char *fname)
{
    apr_proc_mutex_t *new_mutex;

    new_mutex = (apr_proc_mutex_t *)apr_palloc(pool, sizeof(apr_proc_mutex_t));

    memcpy(new_mutex, *mutex, sizeof *new_mutex);
    new_mutex->pool = pool;
    new_mutex->fname = apr_pstrdup(pool, fname);
    new_mutex->interproc = open(new_mutex->fname, O_WRONLY, 0600);
    if (new_mutex->interproc == -1) {
        proc_mutex_flock_destroy(new_mutex);
        return errno;
    }
    *mutex = new_mutex;
    return APR_SUCCESS;
}

const apr_proc_mutex_unix_lock_methods_t apr_proc_mutex_unix_flock_methods =
{
#if APR_PROCESS_LOCK_IS_GLOBAL || !APR_HAS_THREADS
    APR_PROCESS_LOCK_MECH_IS_GLOBAL,
#else
    0,
#endif
    proc_mutex_flock_create,
    proc_mutex_flock_acquire,
    NULL, /* no tryacquire */
    proc_mutex_flock_release,
    proc_mutex_flock_destroy,
    proc_mutex_flock_child_init
};

#endif /* flock implementation */

void apr_proc_mutex_unix_setup_lock(void)
{
#if APR_HAS_SYSVSEM_SERIALIZE
    proc_mutex_sysv_setup();
#endif
#if APR_HAS_PROC_PTHREAD_SERIALIZE
    proc_mutex_proc_pthread_setup();
#endif
#if APR_HAS_FCNTL_SERIALIZE
    proc_mutex_fcntl_setup();
#endif
#if APR_HAS_FLOCK_SERIALIZE
    proc_mutex_flock_setup();
#endif
}









static apr_status_t proc_mutex_choose_method(apr_proc_mutex_t *new_mutex, apr_lockmech_e_np mech)
{
    switch (mech) {
    case APR_LOCK_FCNTL:
#if APR_HAS_FCNTL_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_fcntl_methods;
#else
        return APR_ENOTIMPL;
#endif
        break;
    case APR_LOCK_FLOCK:
#if APR_HAS_FLOCK_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_flock_methods;
#else
        return APR_ENOTIMPL;
#endif
        break;
    case APR_LOCK_SYSVSEM:
#if APR_HAS_SYSVSEM_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_sysv_methods;
#else
        return APR_ENOTIMPL;
#endif
        break;
    case APR_LOCK_PROC_PTHREAD:
#if APR_HAS_PROC_PTHREAD_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_proc_pthread_methods;
#else
        return APR_ENOTIMPL;
#endif
        break;
    case APR_LOCK_DEFAULT:
#if APR_USE_FLOCK_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_flock_methods;
#elif APR_USE_SYSVSEM_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_sysv_methods;
#elif APR_USE_FCNTL_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_fcntl_methods;
#elif APR_USE_PROC_PTHREAD_SERIALIZE
        new_mutex->inter_meth = &apr_proc_mutex_unix_proc_pthread_methods;
#else
        return APR_ENOTIMPL;
#endif
        break;
    default:
        return APR_ENOTIMPL;
    }
    return APR_SUCCESS;
}

static apr_status_t proc_mutex_create(apr_proc_mutex_t *new_mutex, apr_lockmech_e_np mech, const char *fname)
{
    apr_status_t stat;

    if (new_mutex->scope != APR_INTRAPROCESS) {
        if ((stat = proc_mutex_choose_method(new_mutex, mech)) != APR_SUCCESS) {
            return stat;
        }
    }

    new_mutex->meth = new_mutex->inter_meth;

    if ((stat = new_mutex->meth->create(new_mutex, fname)) != APR_SUCCESS) {
        return stat;
    }

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_proc_mutex_create(apr_proc_mutex_t **mutex,
                                                const char *fname,
                                                apr_pool_t *pool)
{
    return apr_proc_mutex_create_np(mutex, fname, APR_LOCK_DEFAULT, pool);
}

APR_DECLARE(apr_status_t) apr_proc_mutex_create_np(apr_proc_mutex_t **mutex,
                                                   const char *fname,
                                                   apr_lockmech_e_np mech,
                                                   apr_pool_t *pool)
{
    apr_proc_mutex_t *new_mutex;
    apr_status_t stat;

    new_mutex = (apr_proc_mutex_t *)apr_pcalloc(pool,
                                                sizeof(apr_proc_mutex_t));

    new_mutex->pool  = pool;
#if APR_HAS_SYSVSEM_SERIALIZE || APR_HAS_FCNTL_SERIALIZE || APR_HAS_FLOCK_SERIALIZE
    new_mutex->interproc = -1;
#endif

    if ((stat = proc_mutex_create(new_mutex, mech, fname)) != APR_SUCCESS)
        return stat;

    *mutex = new_mutex;
    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_proc_mutex_child_init(apr_proc_mutex_t **mutex,
                                                    const char *fname,
                                                    apr_pool_t *pool)
{
    return (*mutex)->meth->child_init(mutex, pool, fname);
}

APR_DECLARE(apr_status_t) apr_proc_mutex_lock(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

#if APR_HAS_THREADS
    if (apr_os_thread_equal(mutex->owner, apr_os_thread_current())) {
        mutex->owner_ref++;
        return APR_SUCCESS;
    }
#endif

    if ((stat = mutex->meth->acquire(mutex)) != APR_SUCCESS) {
        return stat;
    }

#if APR_HAS_THREADS
    mutex->owner = apr_os_thread_current();
    mutex->owner_ref = 1;
#endif

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_proc_mutex_trylock(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

#if APR_HAS_THREADS
    if (apr_os_thread_equal(mutex->owner, apr_os_thread_current())) {
        mutex->owner_ref++;
        return APR_SUCCESS;
    }
#endif

    if ((stat = mutex->meth->tryacquire(mutex)) != APR_SUCCESS) {
        return stat;
    }

#if APR_HAS_THREADS
    mutex->owner = apr_os_thread_current();
    mutex->owner_ref = 1;
#endif

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_proc_mutex_unlock(apr_proc_mutex_t *mutex)
{
    apr_status_t stat;

#if APR_HAS_THREADS
    if (apr_os_thread_equal(mutex->owner, apr_os_thread_current())) {
        mutex->owner_ref--;
        if (mutex->owner_ref > 0)
            return APR_SUCCESS;
    }
#endif

    if ((stat = mutex->meth->release(mutex)) != APR_SUCCESS) {
        return stat;
    }

#if APR_HAS_THREADS
    memset(&mutex->owner, 0, sizeof mutex->owner);
    mutex->owner_ref = 0;
#endif
    
    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_proc_mutex_destroy(apr_proc_mutex_t *mutex)
{
    return mutex->meth->destroy(mutex);
}



Index: locks/beos/Makefile.in
===================================================================
RCS file: /home/cvspublic/apr/locks/beos/Makefile.in,v
retrieving revision 1.15
diff -u -r1.15 Makefile.in
--- locks/beos/Makefile.in	2001/09/13 01:04:23	1.15
+++ locks/beos/Makefile.in	2001/09/14 21:09:56
@@ -2,7 +2,8 @@
 TARGETS = locks.lo \
 	thread_mutex.lo \
 	thread_rwlock.lo \
-	thread_cond.lo
+	thread_cond.lo \
+	proc_mutex.lo
 
 # bring in rules.mk for standard functionality
 @INCLUDE_RULES@
Index: locks/os2/Makefile.in
===================================================================
RCS file: /home/cvspublic/apr/locks/os2/Makefile.in,v
retrieving revision 1.15
diff -u -r1.15 Makefile.in
--- locks/os2/Makefile.in	2001/09/13 01:04:23	1.15
+++ locks/os2/Makefile.in	2001/09/14 21:09:56
@@ -2,7 +2,8 @@
 TARGETS = locks.lo \
 	thread_mutex.lo \
 	thread_rwlock.lo \
-	thread_cond.lo
+	thread_cond.lo \
+    proc_mutex.lo
 
 # bring in rules.mk for standard functionality
 @INCLUDE_RULES@
Index: locks/unix/Makefile.in
===================================================================
RCS file: /home/cvspublic/apr/locks/unix/Makefile.in,v
retrieving revision 1.21
diff -u -r1.21 Makefile.in
--- locks/unix/Makefile.in	2001/09/13 01:04:23	1.21
+++ locks/unix/Makefile.in	2001/09/14 21:09:56
@@ -5,7 +5,8 @@
 	intraproc.lo \
 	thread_mutex.lo \
 	thread_rwlock.lo \
-	thread_cond.lo
+	thread_cond.lo \
+    proc_mutex.lo
 
 # bring in rules.mk for standard functionality
 @INCLUDE_RULES@


Re: [PATCH] add apr_proc_mutex for the new Lock API

Posted by Ryan Bloom <rb...@covalent.net>.
On Friday 14 September 2001 03:51 pm, Greg Stein wrote:
> On Fri, Sep 14, 2001 at 03:23:35PM -0700, Aaron Bannert wrote:
> > One note, more of a question to the other APR developers...see my inline
> > comment:
> >
> > On Fri, Sep 14, 2001 at 03:15:47PM -0700, Aaron Bannert wrote:
> > [snip]
> >
> > > #if !APR_HAVE_UNION_SEMUN && defined(APR_HAS_SYSVSEM_SERIALIZE)
> > > /* it makes no sense, but this isn't defined on solaris */
> > > union semun {
> > >     long val;
> > >     struct semid_ds *buf;
> > >     ushort *array;
> > > };
> > > #endif
> >
> > [snip]
> >
> > Since this is now defined in include/arch/unix/proc_mutex.h AND
> > include/arch/unix/lock.h, if both are #included into a file there
> > will be redifition errors/warnings. Should we invent a symbol to
> > protect this section from double-inclusion?
>
> No. It should just be defined in one spot (say lock.h), and proc_mutex.h
> would then include lock.h.
>
> Why would we even think of duplicating the definition, and then patching
> around that?

I agree with Greg, with one exception.  It should live in proc_mutex.h, which 
lock.h includes, because lock.h is going to go away when the locking API is 
done being re-written.

Ryan
______________________________________________________________
Ryan Bloom				rbb@apache.org
Covalent Technologies			rbb@covalent.net
--------------------------------------------------------------

Re: [PATCH] add apr_proc_mutex for the new Lock API

Posted by Aaron Bannert <aa...@clove.org>.
On Fri, Sep 14, 2001 at 03:51:26PM -0700, Greg Stein wrote:
> No. It should just be defined in one spot (say lock.h), and proc_mutex.h
> would then include lock.h.
> 
> Why would we even think of duplicating the definition, and then patching
> around that?

Putting it in one place is fine, it works as-is right now. This is kind
of a sore spot for POSIX, and I'm just trying to work around that.

-aaron

Re: [PATCH] add apr_proc_mutex for the new Lock API

Posted by Greg Stein <gs...@lyra.org>.
On Fri, Sep 14, 2001 at 03:23:35PM -0700, Aaron Bannert wrote:
> One note, more of a question to the other APR developers...see my inline
> comment:
> 
> On Fri, Sep 14, 2001 at 03:15:47PM -0700, Aaron Bannert wrote:
> [snip] 
> > #if !APR_HAVE_UNION_SEMUN && defined(APR_HAS_SYSVSEM_SERIALIZE)
> > /* it makes no sense, but this isn't defined on solaris */
> > union semun {
> >     long val;
> >     struct semid_ds *buf;
> >     ushort *array;
> > };
> > #endif
> [snip] 
> 
> Since this is now defined in include/arch/unix/proc_mutex.h AND
> include/arch/unix/lock.h, if both are #included into a file there
> will be redifition errors/warnings. Should we invent a symbol to
> protect this section from double-inclusion?

No. It should just be defined in one spot (say lock.h), and proc_mutex.h
would then include lock.h.

Why would we even think of duplicating the definition, and then patching
around that?

Cheers,
-g

-- 
Greg Stein, http://www.lyra.org/

Re: [PATCH] add apr_proc_mutex for the new Lock API

Posted by Aaron Bannert <aa...@clove.org>.
One note, more of a question to the other APR developers...see my inline
comment:

On Fri, Sep 14, 2001 at 03:15:47PM -0700, Aaron Bannert wrote:
[snip] 
> #if !APR_HAVE_UNION_SEMUN && defined(APR_HAS_SYSVSEM_SERIALIZE)
> /* it makes no sense, but this isn't defined on solaris */
> union semun {
>     long val;
>     struct semid_ds *buf;
>     ushort *array;
> };
> #endif
[snip] 

Since this is now defined in include/arch/unix/proc_mutex.h AND
include/arch/unix/lock.h, if both are #included into a file there
will be redifition errors/warnings. Should we invent a symbol to
protect this section from double-inclusion?

-aaron