locks/unix/locks.c - apr - Git at Google

 /* ====================================================================
  * 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_general.h"
 #include "apr_portable.h"
 #include "locks.h"
 #include <string.h>

 /* ***APRDOC********************************************************
  * ap_status_t ap_create_lock(ap_context_t *, ap_locktype_e, char *,
  *                            ap_lock_t **)
  *    Create a new instance of a lock structure.
  * arg 1) The context to operate on.
  * arg 2) The type of lock to create, one of:
  *            APR_CROSS_PROCESS -- lock processes from the protected area.
  *            APR_INTRAPROCESS  -- lock threads from the protected area.
  *            APR_LOCKALL       -- lock processes and threads from the
  *                                 protected area.
  * arg 3) 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.
  * arg 4) The newly created lock structure.
  * NOTE:  APR_CROSS_PROCESS may lock both processes and threads, but it is
  *        only garaunteed to lock processes.
  */
 ap_status_t ap_create_lock(ap_context_t *cont, ap_locktype_e type, char *fname, struct lock_t **lock)
 {
     struct lock_t *new;
     ap_status_t stat;

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

     new->cntxt = cont;
     new->type = type;
     new->fname = strdup(fname);

     if (type != APR_CROSS_PROCESS) {
         if ((stat = create_intra_lock(new)) != APR_SUCCESS) {
             return stat;
         }
     }
     if (type != APR_INTRAPROCESS) {
         if ((stat = create_inter_lock(new)) != APR_SUCCESS) {
             return stat;
         }
     }
     *lock = new;
     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_lock(ap_lock_t *)
  *    Lock a protected region.
  * arg 1) The lock to set.
  */
 ap_status_t ap_lock(struct lock_t *lock)
 {
     ap_status_t stat;
     if (lock->type != APR_CROSS_PROCESS) {
         if ((stat = lock_intra(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     if (lock->type != APR_INTRAPROCESS) {
         if ((stat = lock_inter(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_unlock(ap_lock_t *)
  *    Unlock a protected region.
  * arg 1) The lock to reset.
  */
 ap_status_t ap_unlock(struct lock_t *lock)
 {
     ap_status_t stat;

     if (lock->type != APR_CROSS_PROCESS) {
         if ((stat = unlock_intra(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     if (lock->type != APR_INTRAPROCESS) {
         if ((stat = unlock_inter(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_destroy_lock(ap_lock_t *)
  *    Free the memory associated with a lock.
  * arg 1) The lock to free.
  * NOTE:  If the lock is currently active when it is destroyed, it
  *        will be unlocked first.
  */
 ap_status_t ap_destroy_lock(struct lock_t *lock)
 {
     ap_status_t stat;
     if (lock->type != APR_CROSS_PROCESS) {
         if ((stat = destroy_intra_lock(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     if (lock->type != APR_INTRAPROCESS) {
         if ((stat = destroy_inter_lock(lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_child_init_lock(ap_context_t *, char *, ap_lock_t **)
  *    Re-open a lock in a child process.
  * arg 1) The context to operate on.
  * arg 2) 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.  This filename should be the same
  *        one that was passed to ap_create_lock
  * arg 1) The newly re-opened lock structure.
  * NOTE:  This function doesn't always do something, it depends on the
  *        locking mechanism chosen for the platform, but it is a good
  *        idea to call it regardless, because it makes the code more
  *        portable.
  */
 ap_status_t ap_child_init_lock(ap_context_t *cont, char *fname, struct lock_t **lock)
 {
     ap_status_t stat;
     if ((*lock)->type != APR_CROSS_PROCESS) {
         if ((stat = child_init_lock(cont, fname, lock)) != APR_SUCCESS) {
             return stat;
         }
     }
     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_get_lockdata(ap_lock_t *, void *)
  *    Return the context associated with the current lock.
  * arg 1) The currently open lock.
  * arg 2) The user data associated with the lock.
  */
 ap_status_t ap_get_lockdata(struct lock_t *lock, void *data)
 {
     if (lock != NULL) {
         return ap_get_userdata(lock->cntxt, &data);
     }
     else {
         data = NULL;
         return APR_ENOLOCK;
     }
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_set_lockdata(ap_lock_t *, void *)
  *    Return the context associated with the current lock.
  * arg 1) The currently open lock.
  * arg 2) The user data to associate with the lock.
  */
 ap_status_t ap_set_lockdata(struct lock_t *lock, void *data)
 {
     if (lock != NULL) {
         return ap_set_userdata(lock->cntxt, data);
     }
     else {
         data = NULL;
         return APR_ENOLOCK;
     }
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_get_os_lock(ap_lock_t **, ap_os_lock_t *)
  *    onvert the lock from os specific type to apr type
  * arg 1) The apr lock to convert.
  * arg 2) The os specific lock we are converting to.
  */
 ap_status_t ap_get_os_lock(struct lock_t *lock, ap_os_lock_t *oslock)
 {
     if (lock == NULL) {
         return APR_ENOLOCK;
     }
     oslock->crossproc = lock->interproc;
 #if defined (USE_SYSVSEM_SERIALIZE)
     oslock->op_on = lock->op_on;
     oslock->op_off = lock->op_off;
 #elif defined (USE_FCNTL_SERIALIZE)
     oslock->lock_it = lock->lock_it;
     oslock->unlock_it = lock->unlock_it;
 #endif
 #if defined (USE_PTHREAD_SERIALIZE)
     oslock->intraproc = lock->intraproc;
 #endif

     return APR_SUCCESS;
 }

 /* ***APRDOC********************************************************
  * ap_status_t ap_put_os_lock(ap_context_t *, ap_lock_t **, ap_os_lock_t *)
  *    onvert the lock from os specific type to apr type
  * arg 1) The context to use if it is needed.
  * arg 2) The apr lock we are converting to.
  * arg 3) The os specific lock to convert.
  */
 ap_status_t ap_put_os_lock(ap_context_t *cont, struct lock_t **lock,
                            ap_os_lock_t *thelock)
 {
     if (cont == NULL) {
         return APR_ENOCONT;
     }
     if ((*lock) == NULL) {
         (*lock) = (struct lock_t *)ap_palloc(cont, sizeof(struct lock_t));
         (*lock)->cntxt = cont;
     }
     (*lock)->interproc = thelock->crossproc;
 #if defined (USE_SYSVSEM_SERIALIZE)
     (*lock)->op_on = thelock->op_on;
     (*lock)->op_off = thelock->op_off;
 #elif defined (USE_FCNTL_SERIALIZE)
     (*lock)->lock_it = thelock->lock_it;
     (*lock)->unlock_it = thelock->unlock_it;
 #endif
 #if defined (USE_PTHREAD_SERIALIZE)
     (*lock)->intraproc = thelock->intraproc;
 #endif
     return APR_SUCCESS;
 }
	/* ====================================================================
	* 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_general.h"
	#include "apr_portable.h"
	#include "locks.h"
	#include <string.h>

	/* *APRDOC******************************************************
	* ap_status_t ap_create_lock(ap_context_t , ap_locktype_e, char ,
	* ap_lock_t **)
	* Create a new instance of a lock structure.
	* arg 1) The context to operate on.
	* arg 2) The type of lock to create, one of:
	* APR_CROSS_PROCESS -- lock processes from the protected area.
	* APR_INTRAPROCESS -- lock threads from the protected area.
	* APR_LOCKALL -- lock processes and threads from the
	* protected area.
	* arg 3) 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.
	* arg 4) The newly created lock structure.
	* NOTE: APR_CROSS_PROCESS may lock both processes and threads, but it is
	* only garaunteed to lock processes.
	*/
	ap_status_t ap_create_lock(ap_context_t cont, ap_locktype_e type, char fname, struct lock_t **lock)
	{
	struct lock_t *new;
	ap_status_t stat;

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

	new->cntxt = cont;
	new->type = type;
	new->fname = strdup(fname);

	if (type != APR_CROSS_PROCESS) {
	if ((stat = create_intra_lock(new)) != APR_SUCCESS) {
	return stat;
	}
	}
	if (type != APR_INTRAPROCESS) {
	if ((stat = create_inter_lock(new)) != APR_SUCCESS) {
	return stat;
	}
	}
	*lock = new;
	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_lock(ap_lock_t *)
	* Lock a protected region.
	* arg 1) The lock to set.
	*/
	ap_status_t ap_lock(struct lock_t *lock)
	{
	ap_status_t stat;
	if (lock->type != APR_CROSS_PROCESS) {
	if ((stat = lock_intra(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	if (lock->type != APR_INTRAPROCESS) {
	if ((stat = lock_inter(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_unlock(ap_lock_t *)
	* Unlock a protected region.
	* arg 1) The lock to reset.
	*/
	ap_status_t ap_unlock(struct lock_t *lock)
	{
	ap_status_t stat;

	if (lock->type != APR_CROSS_PROCESS) {
	if ((stat = unlock_intra(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	if (lock->type != APR_INTRAPROCESS) {
	if ((stat = unlock_inter(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_destroy_lock(ap_lock_t *)
	* Free the memory associated with a lock.
	* arg 1) The lock to free.
	* NOTE: If the lock is currently active when it is destroyed, it
	* will be unlocked first.
	*/
	ap_status_t ap_destroy_lock(struct lock_t *lock)
	{
	ap_status_t stat;
	if (lock->type != APR_CROSS_PROCESS) {
	if ((stat = destroy_intra_lock(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	if (lock->type != APR_INTRAPROCESS) {
	if ((stat = destroy_inter_lock(lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_child_init_lock(ap_context_t , char , ap_lock_t **)
	* Re-open a lock in a child process.
	* arg 1) The context to operate on.
	* arg 2) 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. This filename should be the same
	* one that was passed to ap_create_lock
	* arg 1) The newly re-opened lock structure.
	* NOTE: This function doesn't always do something, it depends on the
	* locking mechanism chosen for the platform, but it is a good
	* idea to call it regardless, because it makes the code more
	* portable.
	*/
	ap_status_t ap_child_init_lock(ap_context_t cont, char fname, struct lock_t **lock)
	{
	ap_status_t stat;
	if ((*lock)->type != APR_CROSS_PROCESS) {
	if ((stat = child_init_lock(cont, fname, lock)) != APR_SUCCESS) {
	return stat;
	}
	}
	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_get_lockdata(ap_lock_t , void )
	* Return the context associated with the current lock.
	* arg 1) The currently open lock.
	* arg 2) The user data associated with the lock.
	*/
	ap_status_t ap_get_lockdata(struct lock_t lock, void data)
	{
	if (lock != NULL) {
	return ap_get_userdata(lock->cntxt, &data);
	}
	else {
	data = NULL;
	return APR_ENOLOCK;
	}
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_set_lockdata(ap_lock_t , void )
	* Return the context associated with the current lock.
	* arg 1) The currently open lock.
	* arg 2) The user data to associate with the lock.
	*/
	ap_status_t ap_set_lockdata(struct lock_t lock, void data)
	{
	if (lock != NULL) {
	return ap_set_userdata(lock->cntxt, data);
	}
	else {
	data = NULL;
	return APR_ENOLOCK;
	}
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_get_os_lock(ap_lock_t *, ap_os_lock_t )
	* onvert the lock from os specific type to apr type
	* arg 1) The apr lock to convert.
	* arg 2) The os specific lock we are converting to.
	*/
	ap_status_t ap_get_os_lock(struct lock_t lock, ap_os_lock_t oslock)
	{
	if (lock == NULL) {
	return APR_ENOLOCK;
	}
	oslock->crossproc = lock->interproc;
	#if defined (USE_SYSVSEM_SERIALIZE)
	oslock->op_on = lock->op_on;
	oslock->op_off = lock->op_off;
	#elif defined (USE_FCNTL_SERIALIZE)
	oslock->lock_it = lock->lock_it;
	oslock->unlock_it = lock->unlock_it;
	#endif
	#if defined (USE_PTHREAD_SERIALIZE)
	oslock->intraproc = lock->intraproc;
	#endif

	return APR_SUCCESS;
	}

	/* *APRDOC******************************************************
	* ap_status_t ap_put_os_lock(ap_context_t , ap_lock_t , ap_os_lock_t )
	* onvert the lock from os specific type to apr type
	* arg 1) The context to use if it is needed.
	* arg 2) The apr lock we are converting to.
	* arg 3) The os specific lock to convert.
	*/
	ap_status_t ap_put_os_lock(ap_context_t cont, struct lock_t *lock,
	ap_os_lock_t *thelock)
	{
	if (cont == NULL) {
	return APR_ENOCONT;
	}
	if ((*lock) == NULL) {
	(lock) = (struct lock_t )ap_palloc(cont, sizeof(struct lock_t));
	(*lock)->cntxt = cont;
	}
	(*lock)->interproc = thelock->crossproc;
	#if defined (USE_SYSVSEM_SERIALIZE)
	(*lock)->op_on = thelock->op_on;
	(*lock)->op_off = thelock->op_off;
	#elif defined (USE_FCNTL_SERIALIZE)
	(*lock)->lock_it = thelock->lock_it;
	(*lock)->unlock_it = thelock->unlock_it;
	#endif
	#if defined (USE_PTHREAD_SERIALIZE)
	(*lock)->intraproc = thelock->intraproc;
	#endif
	return APR_SUCCESS;
	}