diff options
Diffstat (limited to 'ext/sysvsem/sysvsem.c')
| -rw-r--r-- | ext/sysvsem/sysvsem.c | 352 |
1 files changed, 0 insertions, 352 deletions
diff --git a/ext/sysvsem/sysvsem.c b/ext/sysvsem/sysvsem.c deleted file mode 100644 index 02052242dd..0000000000 --- a/ext/sysvsem/sysvsem.c +++ /dev/null @@ -1,352 +0,0 @@ -/* - +----------------------------------------------------------------------+ - | PHP version 4.0 | - +----------------------------------------------------------------------+ - | Copyright (c) 1997, 1998, 1999 The PHP Group | - +----------------------------------------------------------------------+ - | This source file is subject to version 2.0 of the PHP license, | - | that is bundled with this package in the file LICENSE, and is | - | available at through the world-wide-web at | - | http://www.php.net/license/2_0.txt. | - | If you did not receive a copy of the PHP license and are unable to | - | obtain it through the world-wide-web, please send a note to | - | license@php.net so we can mail you a copy immediately. | - +----------------------------------------------------------------------+ - | Authors: Tom May <tom@go2net.com> | - +----------------------------------------------------------------------+ - */ - -/* $Id$ */ - -/* This has been built and tested on Solaris 2.6 and Linux 2.1.122. - * It may not compile or execute correctly on other systems. - * - * sas: Works for me on Linux 2.0.36 and FreeBSD 3.0-current - */ - -#include "php.h" - -#if HAVE_SYSVSEM - -#include <sys/types.h> -#include <sys/ipc.h> -#include <sys/sem.h> -#include <errno.h> - -#include "php_sysvsem.h" - -#if !HAVE_SEMUN && defined(__GNU_LIBRARY__) && __GNU_LIBRARY__ == 6 - -union semun { - int val; /* value for SETVAL */ - struct semid_ds *buf; /* buffer for IPC_STAT, IPC_SET */ - unsigned short int *array; /* array for GETALL, SETALL */ - struct seminfo *__buf; /* buffer for IPC_INFO */ -}; - -#undef HAVE_SEMUN -#define HAVE_SEMUN 1 - -#endif - -function_entry sysvsem_functions[] = { - {"sem_get", php3_sysvsem_get, NULL}, - {"sem_acquire", php3_sysvsem_acquire, NULL}, - {"sem_release", php3_sysvsem_release, NULL}, - {NULL, NULL, NULL} -}; - -zend_module_entry sysvsem_module_entry = { - "System V semaphores", sysvsem_functions, php3_minit_sysvsem, NULL, NULL, NULL, NULL, STANDARD_MODULE_PROPERTIES -}; - -#if COMPILE_DL -php3_module_entry *get_module() { return &sysvsem_module_entry; } -#endif - - -THREAD_LS sysvsem_module php3_sysvsem_module; - -/* Semaphore functions using System V semaphores. Each semaphore - * actually consists of three semaphores allocated as a unit under the - * same key. Semaphore 0 (SYSVSEM_SEM) is the actual semaphore, it is - * initialized to max_acquire and decremented as processes acquire it. - * The value of semaphore 1 (SYSVSEM_USAGE) is a count of the number - * of processes using the semaphore. After calling semget(), if a - * process finds that the usage count is 1, it will set the value of - * SYSVSEM_SEM to max_acquire. This allows max_acquire to be set and - * track the PHP code without having a global init routine or external - * semaphore init code. Except see the bug regarding a race condition - * php3_sysvsem_get(). Semaphore 2 (SYSVSEM_SETVAL) serializes the - * calls to GETVAL SYSVSEM_USAGE and SETVAL SYSVSEM_SEM. It can be - * acquired only when it is zero. - */ - -#define SYSVSEM_SEM 0 -#define SYSVSEM_USAGE 1 -#define SYSVSEM_SETVAL 2 - - -static void release_sysvsem_sem(sysvsem_sem *sem_ptr) -{ - struct sembuf sop[2]; - - /* Decrement the usage count. */ - - sop[0].sem_num = SYSVSEM_USAGE; - sop[0].sem_op = -1; - sop[0].sem_flg = SEM_UNDO; - - /* Release the semaphore if it has been acquired but not released. */ - - if (sem_ptr->count) { - php_error(E_WARNING, "Releasing SysV semaphore id %d key 0x%x in request cleanup", sem_ptr->id, sem_ptr->key); - - sop[1].sem_num = SYSVSEM_SEM; - sop[1].sem_op = sem_ptr->count; - sop[1].sem_flg = SEM_UNDO; - } - if (semop(sem_ptr->semid, sop, sem_ptr->count ? 2 : 1) == -1) { - php_error(E_WARNING, "semop() failed in release_sysvsem_sem for key 0x%x: %s", sem_ptr->key, strerror(errno)); - } - - efree(sem_ptr); -} - - -int php3_minit_sysvsem(INIT_FUNC_ARGS) -{ - php3_sysvsem_module.le_sem = register_list_destructors(release_sysvsem_sem, NULL); - - return SUCCESS; -} - -#define SETVAL_WANTS_PTR - -#if defined(_AIX) -#undef SETVAL_WANTS_PTR -#endif - -/* {{{ proto int sem_get(int key [, int max_acquire [, int perm]]) - Return an id for the semaphore with the given key, and allow max_acquire (default 1) processes to acquire it simultaneously. */ -PHP_FUNCTION(sysvsem_get) -{ - pval **arg_key, **arg_max_acquire, **arg_perm; - int key, max_acquire, perm; - int semid; - struct sembuf sop[3]; - int count; - sysvsem_sem *sem_ptr; -#if HAVE_SEMUN - union semun un; -#endif - - max_acquire = 1; - perm = 0666; - - switch (ARG_COUNT(ht)) { - case 1: - if (getParametersEx(1, &arg_key)==FAILURE) { - RETURN_FALSE; - } - convert_to_long_ex(arg_key); - key = (int)(*arg_key)->value.lval; - break; - case 2: - if (getParametersEx(2, &arg_key, &arg_max_acquire)==FAILURE) { - RETURN_FALSE; - } - convert_to_long_ex(arg_key); - key = (int)(*arg_key)->value.lval; - convert_to_long_ex(arg_max_acquire); - max_acquire = (int)(*arg_max_acquire)->value.lval; - break; - case 3: - if (getParametersEx(3, &arg_key, &arg_max_acquire, &arg_perm)==FAILURE) { - RETURN_FALSE; - } - convert_to_long_ex(arg_key); - convert_to_long_ex(arg_max_acquire); - convert_to_long_ex(arg_perm); - key = (int)(*arg_key)->value.lval; - max_acquire = (int)(*arg_max_acquire)->value.lval; - perm = (int)(*arg_perm)->value.lval; - break; - default: - WRONG_PARAM_COUNT; - break; - } - - /* Get/create the semaphore. Note that we rely on the semaphores - * being zeroed when they are created. Despite the fact that - * the(?) Linux semget() man page says they are not initialized, - * the kernel versions 2.0.x and 2.1.z do in fact zero them. - */ - - semid = semget(key, 3, perm|IPC_CREAT); - if (semid == -1) { - php_error(E_WARNING, "semget() failed for key 0x%x: %s", key, strerror(errno)); - RETURN_FALSE; - } - - /* Find out how many processes are using this semaphore. Note - * that on Linux (at least) there is a race condition here because - * semaphore undo on process exit is not atomic, so we could - * acquire SYSVSEM_SETVAL before a crashed process has decremented - * SYSVSEM_USAGE in which case count will be greater than it - * should be and we won't set max_acquire. Fortunately this - * doesn't actually matter in practice. - */ - - /* Wait for sem 1 to be zero . . . */ - - sop[0].sem_num = SYSVSEM_SETVAL; - sop[0].sem_op = 0; - sop[0].sem_flg = 0; - - /* . . . and increment it so it becomes non-zero . . . */ - - sop[1].sem_num = SYSVSEM_SETVAL; - sop[1].sem_op = 1; - sop[1].sem_flg = SEM_UNDO; - - /* . . . and increment the usage count. */ - - sop[2].sem_num = SYSVSEM_USAGE; - sop[2].sem_op = 1; - sop[2].sem_flg = SEM_UNDO; - while (semop(semid, sop, 3) == -1) { - if (errno != EINTR) { - php_error(E_WARNING, "semop() failed acquiring SYSVSEM_SETVAL for key 0x%x: %s", key, strerror(errno)); - break; - } - } - - /* Get the usage count. */ -#if HAVE_SEMUN - count = semctl(semid, SYSVSEM_USAGE, GETVAL, un); -#else - count = semctl(semid, SYSVSEM_USAGE, GETVAL, NULL); -#endif - if (count == -1) { - php_error(E_WARNING, "semctl(GETVAL) failed for key 0x%x: %s", key, strerror(errno)); - } - - /* If we are the only user, then take this opportunity to set the max. */ - - if (count == 1) { -#if HAVE_SEMUN - /* This is correct for Linux which has union semun. */ - union semun semarg; - semarg.val = max_acquire; - if (semctl(semid, SYSVSEM_SEM, SETVAL, semarg) == -1) { - php_error(E_WARNING, "semctl(SETVAL) failed for key 0x%x: %s", key, strerror(errno)); - } -#elif defined(SETVAL_WANTS_PTR) - /* This is correct for Solaris 2.6 which does not have union semun. */ - if (semctl(semid, SYSVSEM_SEM, SETVAL, &max_acquire) == -1) { - php_error(E_WARNING, "semctl(SETVAL) failed for key 0x%x: %s", key, strerror(errno)); - } -#else - /* This works for i.e. AIX */ - if (semctl(semid, SYSVSEM_SEM, SETVAL, max_acquire) == -1) { - php_error(E_WARNING, "semctl(SETVAL) failed for key 0x%x: %s", key, strerror(errno)); - } -#endif - } - - /* Set semaphore 1 back to zero. */ - - sop[0].sem_num = SYSVSEM_SETVAL; - sop[0].sem_op = -1; - sop[0].sem_flg = SEM_UNDO; - while (semop(semid, sop, 1) == -1) { - if (errno != EINTR) { - php_error(E_WARNING, "semop() failed releasing SYSVSEM_SETVAL for key 0x%x: %s", key, strerror(errno)); - break; - } - } - - sem_ptr = (sysvsem_sem *) emalloc(sizeof(sysvsem_sem)); - sem_ptr->key = key; - sem_ptr->semid = semid; - sem_ptr->count = 0; - - return_value->value.lval = php3_list_insert(sem_ptr, php3_sysvsem_module.le_sem); - return_value->type = IS_LONG; - - sem_ptr->id = (int)return_value->value.lval; -} -/* }}} */ - -static void _php3_sysvsem_semop(INTERNAL_FUNCTION_PARAMETERS, int acquire) -{ - pval **arg_id; - int id, type; - sysvsem_sem *sem_ptr; - struct sembuf sop; - - switch(ARG_COUNT(ht)) { - case 1: - if (getParametersEx(1, &arg_id)==FAILURE) { - RETURN_FALSE; - } - convert_to_long_ex(arg_id); - id = (int)(*arg_id)->value.lval; - break; - default: - WRONG_PARAM_COUNT; - break; - } - - sem_ptr = (sysvsem_sem *) php3_list_find(id, &type); - if (type!=php3_sysvsem_module.le_sem) { - php_error(E_WARNING, "%d is not a SysV semaphore index", id); - RETURN_FALSE; - } - - if (!acquire && sem_ptr->count == 0) { - php_error(E_WARNING, "SysV semaphore index %d (key 0x%x) is not currently acquired", id, sem_ptr->key); - RETURN_FALSE; - } - - sop.sem_num = SYSVSEM_SEM; - sop.sem_op = acquire ? -1 : 1; - sop.sem_flg = SEM_UNDO; - - while (semop(sem_ptr->semid, &sop, 1) == -1) { - if (errno != EINTR) { - php_error(E_WARNING, "semop(%s) failed for key 0x%x: %s", - acquire ? "acquire" : "release", sem_ptr->key, strerror(errno)); - RETURN_FALSE; - } - } - - sem_ptr->count -= acquire ? -1 : 1; - RETURN_TRUE; -} - - -/* {{{ proto int sem_acquire(int id) - Acquires the semaphore with the given id, blocking if necessary. */ -PHP_FUNCTION(sysvsem_acquire) -{ - _php3_sysvsem_semop(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1); -} -/* }}} */ - -/* {{{ proto int sem_release(int id) - Releases the semaphore with the given id. */ -PHP_FUNCTION(sysvsem_release) -{ - _php3_sysvsem_semop(INTERNAL_FUNCTION_PARAM_PASSTHRU, 0); -} -/* }}} */ - -#endif /* HAVE_SYSVSEM */ -/* - * Local variables: - * tab-width: 4 - * c-basic-offset: 4 - * End: - */ |