/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 1999 - 2010, Digium, Inc. * * Mark Spencer * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /*! \file * \brief Asterisk locking-related definitions: * - ast_mutex_t, ast_rwlock_t and related functions; * - atomic arithmetic instructions; * - wrappers for channel locking. * * - See \ref LockDef */ /*! \page LockDef Asterisk thread locking models * * This file provides different implementation of the functions, * depending on the platform, the use of DEBUG_THREADS, and the way * module-level mutexes are initialized. * * - \b static: the mutex is assigned the value AST_MUTEX_INIT_VALUE * this is done at compile time, and is the way used on Linux. * This method is not applicable to all platforms e.g. when the * initialization needs that some code is run. * * - \b through constructors: for each mutex, a constructor function is * defined, which then runs when the program (or the module) * starts. The problem with this approach is that there is a * lot of code duplication (a new block of code is created for * each mutex). Also, it does not prevent a user from declaring * a global mutex without going through the wrapper macros, * so sane programming practices are still required. */ #ifndef _ASTERISK_LOCK_H #define _ASTERISK_LOCK_H #include #include #include #ifdef HAVE_BKTR #include #endif #ifndef HAVE_PTHREAD_RWLOCK_TIMEDWRLOCK #include "asterisk/time.h" #endif #include "asterisk/backtrace.h" #include "asterisk/logger.h" #include "asterisk/compiler.h" #define AST_PTHREADT_NULL (pthread_t) -1 #define AST_PTHREADT_STOP (pthread_t) -2 #if (defined(SOLARIS) || defined(BSD)) #define AST_MUTEX_INIT_W_CONSTRUCTORS #endif /* SOLARIS || BSD */ /* Asterisk REQUIRES recursive (not error checking) mutexes and will not run without them. */ #if defined(HAVE_PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP) && defined(HAVE_PTHREAD_MUTEX_RECURSIVE_NP) #define PTHREAD_MUTEX_INIT_VALUE PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP #define AST_MUTEX_KIND PTHREAD_MUTEX_RECURSIVE_NP #else #define PTHREAD_MUTEX_INIT_VALUE PTHREAD_MUTEX_INITIALIZER #define AST_MUTEX_KIND PTHREAD_MUTEX_RECURSIVE #endif /* PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP */ #ifdef HAVE_PTHREAD_RWLOCK_INITIALIZER #define __AST_RWLOCK_INIT_VALUE PTHREAD_RWLOCK_INITIALIZER #else /* HAVE_PTHREAD_RWLOCK_INITIALIZER */ #define __AST_RWLOCK_INIT_VALUE {0} #endif /* HAVE_PTHREAD_RWLOCK_INITIALIZER */ #ifdef HAVE_BKTR #define AST_LOCK_TRACK_INIT_VALUE { { NULL }, { 0 }, 0, { NULL }, { 0 }, {{{ 0 }}}, PTHREAD_MUTEX_INIT_VALUE } #else #define AST_LOCK_TRACK_INIT_VALUE { { NULL }, { 0 }, 0, { NULL }, { 0 }, PTHREAD_MUTEX_INIT_VALUE } #endif #define AST_MUTEX_INIT_VALUE { PTHREAD_MUTEX_INIT_VALUE, NULL, {1, 0} } #define AST_MUTEX_INIT_VALUE_NOTRACKING { PTHREAD_MUTEX_INIT_VALUE, NULL, {0, 0} } #define AST_RWLOCK_INIT_VALUE { __AST_RWLOCK_INIT_VALUE, NULL, {1, 0} } #define AST_RWLOCK_INIT_VALUE_NOTRACKING { __AST_RWLOCK_INIT_VALUE, NULL, {0, 0} } #define AST_MAX_REENTRANCY 10 struct ast_channel; /*! * \brief Lock tracking information. * * \note Any changes to this struct MUST be reflected in the * lock.c:restore_lock_tracking() function. */ struct ast_lock_track { const char *file[AST_MAX_REENTRANCY]; int lineno[AST_MAX_REENTRANCY]; int reentrancy; const char *func[AST_MAX_REENTRANCY]; pthread_t thread_id[AST_MAX_REENTRANCY]; #ifdef HAVE_BKTR struct ast_bt backtrace[AST_MAX_REENTRANCY]; #endif pthread_mutex_t reentr_mutex; }; struct ast_lock_track_flags { /*! non-zero if lock tracking is enabled */ unsigned int tracking:1; /*! non-zero if track is setup */ volatile unsigned int setup:1; }; /*! \brief Structure for mutex and tracking information. * * We have tracking information in this structure regardless of DEBUG_THREADS being enabled. * The information will just be ignored in the core if a module does not request it.. */ struct ast_mutex_info { pthread_mutex_t mutex; #if !defined(DEBUG_THREADS) && !defined(DEBUG_THREADS_LOOSE_ABI) /*! * These fields are renamed to ensure they are never used when * DEBUG_THREADS is not defined. */ struct ast_lock_track *_track; struct ast_lock_track_flags _flags; #elif defined(DEBUG_THREADS) /*! Track which thread holds this mutex. */ struct ast_lock_track *track; struct ast_lock_track_flags flags; #endif }; /*! \brief Structure for rwlock and tracking information. * * We have tracking information in this structure regardless of DEBUG_THREADS being enabled. * The information will just be ignored in the core if a module does not request it.. */ struct ast_rwlock_info { pthread_rwlock_t lock; #if !defined(DEBUG_THREADS) && !defined(DEBUG_THREADS_LOOSE_ABI) /*! * These fields are renamed to ensure they are never used when * DEBUG_THREADS is not defined. */ struct ast_lock_track *_track; struct ast_lock_track_flags _flags; #elif defined(DEBUG_THREADS) /*! Track which thread holds this lock */ struct ast_lock_track *track; struct ast_lock_track_flags flags; #endif }; typedef struct ast_mutex_info ast_mutex_t; typedef struct ast_rwlock_info ast_rwlock_t; typedef pthread_cond_t ast_cond_t; int __ast_pthread_mutex_init(int tracking, const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t); int __ast_pthread_mutex_destroy(const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t); int __ast_pthread_mutex_lock(const char *filename, int lineno, const char *func, const char* mutex_name, ast_mutex_t *t); int __ast_pthread_mutex_trylock(const char *filename, int lineno, const char *func, const char* mutex_name, ast_mutex_t *t); int __ast_pthread_mutex_unlock(const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t); #define ast_mutex_init(pmutex) __ast_pthread_mutex_init(1, __FILE__, __LINE__, __PRETTY_FUNCTION__, #pmutex, pmutex) #define ast_mutex_init_notracking(pmutex) __ast_pthread_mutex_init(0, __FILE__, __LINE__, __PRETTY_FUNCTION__, #pmutex, pmutex) #define ast_mutex_destroy(a) __ast_pthread_mutex_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a) #define ast_mutex_lock(a) __ast_pthread_mutex_lock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a) #define ast_mutex_unlock(a) __ast_pthread_mutex_unlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a) #define ast_mutex_trylock(a) __ast_pthread_mutex_trylock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a) int __ast_cond_init(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond, pthread_condattr_t *cond_attr); int __ast_cond_signal(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond); int __ast_cond_broadcast(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond); int __ast_cond_destroy(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond); int __ast_cond_wait(const char *filename, int lineno, const char *func, const char *cond_name, const char *mutex_name, ast_cond_t *cond, ast_mutex_t *t); int __ast_cond_timedwait(const char *filename, int lineno, const char *func, const char *cond_name, const char *mutex_name, ast_cond_t *cond, ast_mutex_t *t, const struct timespec *abstime); #define ast_cond_init(cond, attr) __ast_cond_init(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond, attr) #define ast_cond_destroy(cond) __ast_cond_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond) #define ast_cond_signal(cond) __ast_cond_signal(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond) #define ast_cond_broadcast(cond) __ast_cond_broadcast(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond) #define ast_cond_wait(cond, mutex) __ast_cond_wait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex) #define ast_cond_timedwait(cond, mutex, time) __ast_cond_timedwait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex, time) int __ast_rwlock_init(int tracking, const char *filename, int lineno, const char *func, const char *rwlock_name, ast_rwlock_t *t); int __ast_rwlock_destroy(const char *filename, int lineno, const char *func, const char *rwlock_name, ast_rwlock_t *t); int __ast_rwlock_unlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name); int __ast_rwlock_rdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name); int __ast_rwlock_wrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name); int __ast_rwlock_timedrdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name, const struct timespec *abs_timeout); int __ast_rwlock_timedwrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name, const struct timespec *abs_timeout); int __ast_rwlock_tryrdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name); int __ast_rwlock_trywrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name); /*! * \brief wrapper for rwlock with tracking enabled * \return 0 on success, non zero for error * \since 1.6.1 */ #define ast_rwlock_init(rwlock) __ast_rwlock_init(1, __FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock) /*! * \brief wrapper for ast_rwlock_init with tracking disabled * \return 0 on success, non zero for error * \since 1.6.1 */ #define ast_rwlock_init_notracking(rwlock) __ast_rwlock_init(0, __FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock) #define ast_rwlock_destroy(rwlock) __ast_rwlock_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock) #define ast_rwlock_unlock(a) __ast_rwlock_unlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a) #define ast_rwlock_rdlock(a) __ast_rwlock_rdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a) #define ast_rwlock_wrlock(a) __ast_rwlock_wrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a) #define ast_rwlock_tryrdlock(a) __ast_rwlock_tryrdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a) #define ast_rwlock_trywrlock(a) __ast_rwlock_trywrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a) #define ast_rwlock_timedrdlock(a, b) __ast_rwlock_timedrdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a, b) #define ast_rwlock_timedwrlock(a, b) __ast_rwlock_timedwrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a, b) #define ROFFSET ((lt->reentrancy > 0) ? (lt->reentrancy-1) : 0) #ifdef DEBUG_THREADS #ifdef THREAD_CRASH #define DO_THREAD_CRASH do { *((int *)(0)) = 1; } while(0) #else #define DO_THREAD_CRASH do { } while (0) #endif #include enum ast_lock_type { AST_MUTEX, AST_RDLOCK, AST_WRLOCK, }; /*! * \brief Store lock info for the current thread * * This function gets called in ast_mutex_lock() and ast_mutex_trylock() so * that information about this lock can be stored in this thread's * lock info struct. The lock is marked as pending as the thread is waiting * on the lock. ast_mark_lock_acquired() will mark it as held by this thread. */ #if !defined(LOW_MEMORY) #ifdef HAVE_BKTR void ast_store_lock_info(enum ast_lock_type type, const char *filename, int line_num, const char *func, const char *lock_name, void *lock_addr, struct ast_bt *bt); #else void ast_store_lock_info(enum ast_lock_type type, const char *filename, int line_num, const char *func, const char *lock_name, void *lock_addr); #endif /* HAVE_BKTR */ #else #ifdef HAVE_BKTR #define ast_store_lock_info(I,DONT,CARE,ABOUT,THE,PARAMETERS,BUD) #else #define ast_store_lock_info(I,DONT,CARE,ABOUT,THE,PARAMETERS) #endif /* HAVE_BKTR */ #endif /* !defined(LOW_MEMORY) */ /*! * \brief Mark the last lock as acquired */ #if !defined(LOW_MEMORY) void ast_mark_lock_acquired(void *lock_addr); #else #define ast_mark_lock_acquired(ignore) #endif /*! * \brief Mark the last lock as failed (trylock) */ #if !defined(LOW_MEMORY) void ast_mark_lock_failed(void *lock_addr); #else #define ast_mark_lock_failed(ignore) #endif /*! * \brief remove lock info for the current thread * * this gets called by ast_mutex_unlock so that information on the lock can * be removed from the current thread's lock info struct. */ #if !defined(LOW_MEMORY) #ifdef HAVE_BKTR void ast_remove_lock_info(void *lock_addr, struct ast_bt *bt); #else void ast_remove_lock_info(void *lock_addr); #endif /* HAVE_BKTR */ void ast_suspend_lock_info(void *lock_addr); void ast_restore_lock_info(void *lock_addr); #else #ifdef HAVE_BKTR #define ast_remove_lock_info(ignore,me) #else #define ast_remove_lock_info(ignore) #endif /* HAVE_BKTR */ #define ast_suspend_lock_info(ignore); #define ast_restore_lock_info(ignore); #endif /* !defined(LOW_MEMORY) */ /*! * \brief log info for the current lock with ast_log(). * * this function would be mostly for debug. If you come across a lock * that is unexpectedly but momentarily locked, and you wonder who * are fighting with for the lock, this routine could be called, IF * you have the thread debugging stuff turned on. * \param this_lock_addr lock address to return lock information * \since 1.6.1 */ void ast_log_show_lock(void *this_lock_addr); /*! * \brief Generate a lock dump equivalent to "core show locks". * * The lock dump generated is generally too large to be output by a * single ast_verbose/log/debug/etc. call. Only ast_cli() handles it * properly without changing BUFSIZ in logger.c. * * Note: This must be ast_free()d when you're done with it. * * \retval An ast_str containing the lock dump * \retval NULL on error * \since 12 */ struct ast_str *ast_dump_locks(void); /*! * \brief retrieve lock info for the specified mutex * * this gets called during deadlock avoidance, so that the information may * be preserved as to what location originally acquired the lock. */ #if !defined(LOW_MEMORY) int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, int *lineno, char *func, size_t func_size, char *mutex_name, size_t mutex_name_size); #else #define ast_find_lock_info(a,b,c,d,e,f,g,h) -1 #endif /*! * \brief Unlock a lock briefly * * used during deadlock avoidance, to preserve the original location where * a lock was originally acquired. */ #define AO2_DEADLOCK_AVOIDANCE(obj) \ do { \ char __filename[80], __func[80], __mutex_name[80]; \ int __lineno; \ int __res = ast_find_lock_info(ao2_object_get_lockaddr(obj), __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \ int __res2 = ao2_unlock(obj); \ usleep(1); \ if (__res < 0) { /* Could happen if the ao2 object does not have a mutex. */ \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock ao2 object '%s': %s and no lock info found! I will NOT try to relock.\n", #obj, strerror(__res2)); \ } else { \ ao2_lock(obj); \ } \ } else { \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock ao2 object '%s': %s. {{{Originally locked at %s line %d: (%s) '%s'}}} I will NOT try to relock.\n", #obj, strerror(__res2), __filename, __lineno, __func, __mutex_name); \ } else { \ __ao2_lock(obj, AO2_LOCK_REQ_MUTEX, __filename, __func, __lineno, __mutex_name); \ } \ } \ } while (0) #define CHANNEL_DEADLOCK_AVOIDANCE(chan) \ do { \ char __filename[80], __func[80], __mutex_name[80]; \ int __lineno; \ int __res = ast_find_lock_info(ao2_object_get_lockaddr(chan), __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \ int __res2 = ast_channel_unlock(chan); \ usleep(1); \ if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock channel '%s': %s and no lock info found! I will NOT try to relock.\n", #chan, strerror(__res2)); \ } else { \ ast_channel_lock(chan); \ } \ } else { \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock channel '%s': %s. {{{Originally locked at %s line %d: (%s) '%s'}}} I will NOT try to relock.\n", #chan, strerror(__res2), __filename, __lineno, __func, __mutex_name); \ } else { \ __ao2_lock(chan, AO2_LOCK_REQ_MUTEX, __filename, __func, __lineno, __mutex_name); \ } \ } \ } while (0) #define DEADLOCK_AVOIDANCE(lock) \ do { \ char __filename[80], __func[80], __mutex_name[80]; \ int __lineno; \ int __res = ast_find_lock_info(lock, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \ int __res2 = ast_mutex_unlock(lock); \ usleep(1); \ if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \ if (__res2 == 0) { \ ast_mutex_lock(lock); \ } else { \ ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s and no lock info found! I will NOT try to relock.\n", #lock, strerror(__res2)); \ } \ } else { \ if (__res2 == 0) { \ __ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \ } else { \ ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s. {{{Originally locked at %s line %d: (%s) '%s'}}} I will NOT try to relock.\n", #lock, strerror(__res2), __filename, __lineno, __func, __mutex_name); \ } \ } \ } while (0) /*! * \brief Deadlock avoidance unlock * * In certain deadlock avoidance scenarios, there is more than one lock to be * unlocked and relocked. Therefore, this pair of macros is provided for that * purpose. Note that every DLA_UNLOCK _MUST_ be paired with a matching * DLA_LOCK. The intent of this pair of macros is to be used around another * set of deadlock avoidance code, mainly CHANNEL_DEADLOCK_AVOIDANCE, as the * locking order specifies that we may safely lock a channel, followed by its * pvt, with no worries about a deadlock. In any other scenario, this macro * may not be safe to use. */ #define DLA_UNLOCK(lock) \ do { \ char __filename[80], __func[80], __mutex_name[80]; \ int __lineno; \ int __res = ast_find_lock_info(lock, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \ int __res2 = ast_mutex_unlock(lock); /*! * \brief Deadlock avoidance lock * * In certain deadlock avoidance scenarios, there is more than one lock to be * unlocked and relocked. Therefore, this pair of macros is provided for that * purpose. Note that every DLA_UNLOCK _MUST_ be paired with a matching * DLA_LOCK. The intent of this pair of macros is to be used around another * set of deadlock avoidance code, mainly CHANNEL_DEADLOCK_AVOIDANCE, as the * locking order specifies that we may safely lock a channel, followed by its * pvt, with no worries about a deadlock. In any other scenario, this macro * may not be safe to use. */ #define DLA_LOCK(lock) \ if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s and no lock info found! I will NOT try to relock.\n", #lock, strerror(__res2)); \ } else { \ ast_mutex_lock(lock); \ } \ } else { \ if (__res2) { \ ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s. {{{Originally locked at %s line %d: (%s) '%s'}}} I will NOT try to relock.\n", #lock, strerror(__res2), __filename, __lineno, __func, __mutex_name); \ } else { \ __ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \ } \ } \ } while (0) static inline void ast_reentrancy_lock(struct ast_lock_track *lt) { int res; if ((res = pthread_mutex_lock(<->reentr_mutex))) { fprintf(stderr, "ast_reentrancy_lock failed: '%s' (%d)\n", strerror(res), res); #if defined(DO_CRASH) || defined(THREAD_CRASH) abort(); #endif } } static inline void ast_reentrancy_unlock(struct ast_lock_track *lt) { int res; if ((res = pthread_mutex_unlock(<->reentr_mutex))) { fprintf(stderr, "ast_reentrancy_unlock failed: '%s' (%d)\n", strerror(res), res); #if defined(DO_CRASH) || defined(THREAD_CRASH) abort(); #endif } } #else /* !DEBUG_THREADS */ #define AO2_DEADLOCK_AVOIDANCE(obj) \ ao2_unlock(obj); \ usleep(1); \ ao2_lock(obj); #define CHANNEL_DEADLOCK_AVOIDANCE(chan) \ ast_channel_unlock(chan); \ usleep(1); \ ast_channel_lock(chan); #define DEADLOCK_AVOIDANCE(lock) \ do { \ int __res; \ if (!(__res = ast_mutex_unlock(lock))) { \ usleep(1); \ ast_mutex_lock(lock); \ } else { \ ast_log(LOG_WARNING, "Failed to unlock mutex '%s' (%s). I will NOT try to relock. {{{ THIS IS A BUG. }}}\n", #lock, strerror(__res)); \ } \ } while (0) #define DLA_UNLOCK(lock) ast_mutex_unlock(lock) #define DLA_LOCK(lock) ast_mutex_lock(lock) #endif /* !DEBUG_THREADS */ #if defined(AST_MUTEX_INIT_W_CONSTRUCTORS) /* * If AST_MUTEX_INIT_W_CONSTRUCTORS is defined, use file scope constructors * and destructors to create/destroy global mutexes. */ #define __AST_MUTEX_DEFINE(scope, mutex, init_val, track) \ scope ast_mutex_t mutex = init_val; \ static void __attribute__((constructor)) init_##mutex(void) \ { \ if (track) \ ast_mutex_init(&mutex); \ else \ ast_mutex_init_notracking(&mutex); \ } \ \ static void __attribute__((destructor)) fini_##mutex(void) \ { \ ast_mutex_destroy(&mutex); \ } #else /* !AST_MUTEX_INIT_W_CONSTRUCTORS */ /* By default, use static initialization of mutexes. */ #define __AST_MUTEX_DEFINE(scope, mutex, init_val, track) scope ast_mutex_t mutex = init_val #endif /* AST_MUTEX_INIT_W_CONSTRUCTORS */ #define AST_MUTEX_DEFINE_STATIC(mutex) __AST_MUTEX_DEFINE(static, mutex, AST_MUTEX_INIT_VALUE, 1) #define AST_MUTEX_DEFINE_STATIC_NOTRACKING(mutex) __AST_MUTEX_DEFINE(static, mutex, AST_MUTEX_INIT_VALUE_NOTRACKING, 0) /* Statically declared read/write locks */ #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS #define __AST_RWLOCK_DEFINE(scope, rwlock, init_val, track) \ scope ast_rwlock_t rwlock = init_val; \ static void __attribute__((constructor)) init_##rwlock(void) \ { \ if (track) \ ast_rwlock_init(&rwlock); \ else \ ast_rwlock_init_notracking(&rwlock); \ } \ static void __attribute__((destructor)) fini_##rwlock(void) \ { \ ast_rwlock_destroy(&rwlock); \ } #else #define __AST_RWLOCK_DEFINE(scope, rwlock, init_val, track) scope ast_rwlock_t rwlock = init_val #endif #define AST_RWLOCK_DEFINE_STATIC(rwlock) __AST_RWLOCK_DEFINE(static, rwlock, AST_RWLOCK_INIT_VALUE, 1) #define AST_RWLOCK_DEFINE_STATIC_NOTRACKING(rwlock) __AST_RWLOCK_DEFINE(static, rwlock, AST_RWLOCK_INIT_VALUE_NOTRACKING, 0) /*! * \brief Scoped Locks * * Scoped locks provide a way to use RAII locks. In other words, * declaration of a scoped lock will automatically define and lock * the lock. When the lock goes out of scope, it will automatically * be unlocked. * * \code * int some_function(struct ast_channel *chan) * { * SCOPED_LOCK(lock, chan, ast_channel_lock, ast_channel_unlock); * * if (!strcmp(ast_channel_name(chan, "foo")) { * return 0; * } * * return -1; * } * \endcode * * In the above example, neither return path requires explicit unlocking * of the channel. * * \note * Care should be taken when using SCOPED_LOCKS in conjunction with ao2 objects. * ao2 objects should be unlocked before they are unreffed. Since SCOPED_LOCK runs * once the variable goes out of scope, this can easily lead to situations where the * variable gets unlocked after it is unreffed. * * \param varname The unique name to give to the scoped lock. You are not likely to reference * this outside of the SCOPED_LOCK invocation. * \param lock The variable to lock. This can be anything that can be passed to a locking * or unlocking function. * \param lockfunc The function to call to lock the lock * \param unlockfunc The function to call to unlock the lock */ #define SCOPED_LOCK(varname, lock, lockfunc, unlockfunc) \ RAII_VAR(typeof((lock)), varname, ({lockfunc((lock)); (lock); }), unlockfunc) /*! * \brief scoped lock specialization for mutexes */ #define SCOPED_MUTEX(varname, lock) SCOPED_LOCK(varname, (lock), ast_mutex_lock, ast_mutex_unlock) /*! * \brief scoped lock specialization for read locks */ #define SCOPED_RDLOCK(varname, lock) SCOPED_LOCK(varname, (lock), ast_rwlock_rdlock, ast_rwlock_unlock) /*! * \brief scoped lock specialization for write locks */ #define SCOPED_WRLOCK(varname, lock) SCOPED_LOCK(varname, (lock), ast_rwlock_wrlock, ast_rwlock_unlock) /*! * \brief scoped lock specialization for ao2 mutexes. */ #define SCOPED_AO2LOCK(varname, obj) SCOPED_LOCK(varname, (obj), ao2_lock, ao2_unlock) /*! * \brief scoped lock specialization for ao2 read locks. */ #define SCOPED_AO2RDLOCK(varname, obj) SCOPED_LOCK(varname, (obj), ao2_rdlock, ao2_unlock) /*! * \brief scoped lock specialization for ao2 write locks. */ #define SCOPED_AO2WRLOCK(varname, obj) SCOPED_LOCK(varname, (obj), ao2_wrlock, ao2_unlock) /*! * \brief scoped lock specialization for channels. */ #define SCOPED_CHANNELLOCK(varname, chan) SCOPED_LOCK(varname, (chan), ast_channel_lock, ast_channel_unlock) #ifndef __CYGWIN__ /* temporary disabled for cygwin */ #define pthread_mutex_t use_ast_mutex_t_instead_of_pthread_mutex_t #define pthread_cond_t use_ast_cond_t_instead_of_pthread_cond_t #endif #define pthread_mutex_lock use_ast_mutex_lock_instead_of_pthread_mutex_lock #define pthread_mutex_unlock use_ast_mutex_unlock_instead_of_pthread_mutex_unlock #define pthread_mutex_trylock use_ast_mutex_trylock_instead_of_pthread_mutex_trylock #define pthread_mutex_init use_ast_mutex_init_instead_of_pthread_mutex_init #define pthread_mutex_destroy use_ast_mutex_destroy_instead_of_pthread_mutex_destroy #define pthread_cond_init use_ast_cond_init_instead_of_pthread_cond_init #define pthread_cond_destroy use_ast_cond_destroy_instead_of_pthread_cond_destroy #define pthread_cond_signal use_ast_cond_signal_instead_of_pthread_cond_signal #define pthread_cond_broadcast use_ast_cond_broadcast_instead_of_pthread_cond_broadcast #define pthread_cond_wait use_ast_cond_wait_instead_of_pthread_cond_wait #define pthread_cond_timedwait use_ast_cond_timedwait_instead_of_pthread_cond_timedwait #define AST_MUTEX_INITIALIZER __use_AST_MUTEX_DEFINE_STATIC_rather_than_AST_MUTEX_INITIALIZER__ #define gethostbyname __gethostbyname__is__not__reentrant__use__ast_gethostbyname__instead__ #ifndef __linux__ #define pthread_create __use_ast_pthread_create_instead__ #endif /* * Support for atomic instructions. * For platforms that have it, use the native cpu instruction to * implement them. For other platforms, resort to a 'slow' version * (defined in utils.c) that protects the atomic instruction with * a single lock. * The slow versions is always available, for testing purposes, * as ast_atomic_fetchadd_int_slow() */ int ast_atomic_fetchadd_int_slow(volatile int *p, int v); #include "asterisk/inline_api.h" #if defined(HAVE_OSX_ATOMICS) #include "libkern/OSAtomic.h" #endif /*! \brief Atomically add v to *p and return * the previous value of *p. * This can be used to handle reference counts, and the return value * can be used to generate unique identifiers. */ #if defined(HAVE_GCC_ATOMICS) AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { return __sync_fetch_and_add(p, v); }) #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4) AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { return OSAtomicAdd32(v, (int32_t *) p) - v; }) #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8) AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { return OSAtomicAdd64(v, (int64_t *) p) - v; }) #elif defined (__i386__) || defined(__x86_64__) #ifdef sun AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { __asm __volatile ( " lock; xaddl %0, %1 ; " : "+r" (v), /* 0 (result) */ "=m" (*p) /* 1 */ : "m" (*p)); /* 2 */ return (v); }) #else /* ifndef sun */ AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { __asm __volatile ( " lock xaddl %0, %1 ; " : "+r" (v), /* 0 (result) */ "=m" (*p) /* 1 */ : "m" (*p)); /* 2 */ return (v); }) #endif #else /* low performance version in utils.c */ AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { return ast_atomic_fetchadd_int_slow(p, v); }) #endif /*! \brief decrement *p by 1 and return true if the variable has reached 0. * Useful e.g. to check if a refcount has reached 0. */ #if defined(HAVE_GCC_ATOMICS) AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), { return __sync_sub_and_fetch(p, 1) == 0; }) #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4) AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), { return OSAtomicAdd32( -1, (int32_t *) p) == 0; }) #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8) AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), { return OSAtomicAdd64( -1, (int64_t *) p) == 0; }) #else AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), { int a = ast_atomic_fetchadd_int(p, -1); return a == 1; /* true if the value is 0 now (so it was 1 previously) */ }) #endif #endif /* _ASTERISK_LOCK_H */