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asterisk/include/asterisk/lock.h

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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2010, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
*
* 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_mutext_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 <pthread.h>
#include <time.h>
#include <sys/param.h>
#ifdef HAVE_BKTR
#include <execinfo.h>
#endif
#ifndef HAVE_PTHREAD_RWLOCK_TIMEDWRLOCK
#include "asterisk/time.h"
#endif
#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 }
#define AST_MUTEX_INIT_VALUE_NOTRACKING { PTHREAD_MUTEX_INIT_VALUE, NULL, 0 }
#define AST_RWLOCK_INIT_VALUE { __AST_RWLOCK_INIT_VALUE, NULL, 1 }
#define AST_RWLOCK_INIT_VALUE_NOTRACKING { __AST_RWLOCK_INIT_VALUE, NULL, 0 }
#define AST_MAX_REENTRANCY 10
struct ast_channel;
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[AST_MAX_REENTRANCY];
#ifdef HAVE_BKTR
struct ast_bt backtrace[AST_MAX_REENTRANCY];
#endif
pthread_mutex_t reentr_mutex;
};
/*! \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;
/*! Track which thread holds this mutex */
struct ast_lock_track *track;
unsigned int tracking:1;
};
/*! \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;
/*! Track which thread holds this lock */
struct ast_lock_track *track;
unsigned int tracking:1;
};
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
#define __ast_mutex_logger(...) do { if (canlog) ast_log(LOG_ERROR, __VA_ARGS__); else fprintf(stderr, __VA_ARGS__); } while (0)
#ifdef THREAD_CRASH
#define DO_THREAD_CRASH do { *((int *)(0)) = 1; } while(0)
#else
#define DO_THREAD_CRASH do { } while (0)
#endif
#include <errno.h>
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 */
#else
#ifdef HAVE_BKTR
#define ast_remove_lock_info(ignore,me)
#else
#define ast_remove_lock_info(ignore)
#endif /* HAVE_BKTR */
#endif /* !defined(LOW_MEMORY) */
#ifdef HAVE_BKTR
static inline void __dump_backtrace(struct ast_bt *bt, int canlog)
{
char **strings;
ssize_t i;
strings = backtrace_symbols(bt->addresses, bt->num_frames);
for (i = 0; i < bt->num_frames; i++)
__ast_mutex_logger("%s\n", strings[i]);
free(strings);
}
#endif
/*!
* \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 log_show_lock(void *this_lock_addr);
/*!
* \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 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, __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)
{
pthread_mutex_lock(&lt->reentr_mutex);
}
static inline void ast_reentrancy_unlock(struct ast_lock_track *lt)
{
pthread_mutex_unlock(&lt->reentr_mutex);
}
static inline void ast_reentrancy_init(struct ast_lock_track **plt)
{
int i;
pthread_mutexattr_t reentr_attr;
struct ast_lock_track *lt = *plt;
if (!lt) {
lt = *plt = (struct ast_lock_track *) ast_calloc(1, sizeof(*lt));
}
for (i = 0; i < AST_MAX_REENTRANCY; i++) {
lt->file[i] = NULL;
lt->lineno[i] = 0;
lt->func[i] = NULL;
lt->thread[i] = 0;
#ifdef HAVE_BKTR
memset(&lt->backtrace[i], 0, sizeof(lt->backtrace[i]));
#endif
}
lt->reentrancy = 0;
pthread_mutexattr_init(&reentr_attr);
pthread_mutexattr_settype(&reentr_attr, AST_MUTEX_KIND);
pthread_mutex_init(&lt->reentr_mutex, &reentr_attr);
pthread_mutexattr_destroy(&reentr_attr);
}
static inline void delete_reentrancy_cs(struct ast_lock_track **plt)
{
struct ast_lock_track *lt;
if (*plt) {
lt = *plt;
pthread_mutex_destroy(&lt->reentr_mutex);
ast_free(lt);
*plt = NULL;
}
}
#else /* !DEBUG_THREADS */
#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)
#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 */
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