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780 lines
31 KiB
780 lines
31 KiB
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 1999 - 2010, Digium, Inc.
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*
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* Mark Spencer <markster@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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* \brief Asterisk locking-related definitions:
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* - ast_mutex_t, ast_rwlock_t and related functions;
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* - atomic arithmetic instructions;
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* - wrappers for channel locking.
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*
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* - See \ref LockDef
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*/
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/*! \page LockDef Asterisk thread locking models
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*
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* This file provides different implementation of the functions,
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* depending on the platform, the use of DEBUG_THREADS, and the way
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* module-level mutexes are initialized.
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*
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* - \b static: the mutex is assigned the value AST_MUTEX_INIT_VALUE
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* this is done at compile time, and is the way used on Linux.
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* This method is not applicable to all platforms e.g. when the
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* initialization needs that some code is run.
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*
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* - \b through constructors: for each mutex, a constructor function is
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* defined, which then runs when the program (or the module)
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* starts. The problem with this approach is that there is a
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* lot of code duplication (a new block of code is created for
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* each mutex). Also, it does not prevent a user from declaring
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* a global mutex without going through the wrapper macros,
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* so sane programming practices are still required.
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*/
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#ifndef _ASTERISK_LOCK_H
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#define _ASTERISK_LOCK_H
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#include <pthread.h>
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#include <time.h>
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#include <sys/param.h>
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#ifdef HAVE_BKTR
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#include <execinfo.h>
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#endif
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#ifndef HAVE_PTHREAD_RWLOCK_TIMEDWRLOCK
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#include "asterisk/time.h"
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#endif
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#include "asterisk/backtrace.h"
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#include "asterisk/logger.h"
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#include "asterisk/compiler.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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#define AST_PTHREADT_NULL (pthread_t) -1
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#define AST_PTHREADT_STOP (pthread_t) -2
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#if (defined(SOLARIS) || defined(BSD))
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#define AST_MUTEX_INIT_W_CONSTRUCTORS
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#endif /* SOLARIS || BSD */
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/* Asterisk REQUIRES recursive (not error checking) mutexes
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and will not run without them. */
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#if defined(HAVE_PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP) && defined(HAVE_PTHREAD_MUTEX_RECURSIVE_NP)
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#define PTHREAD_MUTEX_INIT_VALUE PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
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#define AST_MUTEX_KIND PTHREAD_MUTEX_RECURSIVE_NP
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#else
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#define PTHREAD_MUTEX_INIT_VALUE PTHREAD_MUTEX_INITIALIZER
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#define AST_MUTEX_KIND PTHREAD_MUTEX_RECURSIVE
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#endif /* PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP */
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#ifdef HAVE_PTHREAD_RWLOCK_INITIALIZER
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#define __AST_RWLOCK_INIT_VALUE PTHREAD_RWLOCK_INITIALIZER
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#else /* HAVE_PTHREAD_RWLOCK_INITIALIZER */
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#define __AST_RWLOCK_INIT_VALUE {0}
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#endif /* HAVE_PTHREAD_RWLOCK_INITIALIZER */
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#ifdef HAVE_BKTR
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#define AST_LOCK_TRACK_INIT_VALUE { { NULL }, { 0 }, 0, { NULL }, { 0 }, {{{ 0 }}}, PTHREAD_MUTEX_INIT_VALUE }
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#else
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#define AST_LOCK_TRACK_INIT_VALUE { { NULL }, { 0 }, 0, { NULL }, { 0 }, PTHREAD_MUTEX_INIT_VALUE }
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#endif
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#define AST_MUTEX_INIT_VALUE { PTHREAD_MUTEX_INIT_VALUE, NULL, {1, 0} }
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#define AST_MUTEX_INIT_VALUE_NOTRACKING { PTHREAD_MUTEX_INIT_VALUE, NULL, {0, 0} }
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#define AST_RWLOCK_INIT_VALUE { __AST_RWLOCK_INIT_VALUE, NULL, {1, 0} }
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#define AST_RWLOCK_INIT_VALUE_NOTRACKING { __AST_RWLOCK_INIT_VALUE, NULL, {0, 0} }
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#define AST_MAX_REENTRANCY 10
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struct ast_channel;
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/*!
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* \brief Lock tracking information.
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*
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* \note Any changes to this struct MUST be reflected in the
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* lock.c:restore_lock_tracking() function.
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*/
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struct ast_lock_track {
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const char *file[AST_MAX_REENTRANCY];
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int lineno[AST_MAX_REENTRANCY];
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int reentrancy;
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const char *func[AST_MAX_REENTRANCY];
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pthread_t thread_id[AST_MAX_REENTRANCY];
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#ifdef HAVE_BKTR
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struct ast_bt backtrace[AST_MAX_REENTRANCY];
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#endif
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pthread_mutex_t reentr_mutex;
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};
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struct ast_lock_track_flags {
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/*! non-zero if lock tracking is enabled */
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unsigned int tracking:1;
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/*! non-zero if track is setup */
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volatile unsigned int setup:1;
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};
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/*! \brief Structure for mutex and tracking information.
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*
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* We have tracking information in this structure regardless of DEBUG_THREADS being enabled.
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* The information will just be ignored in the core if a module does not request it..
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*/
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struct ast_mutex_info {
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pthread_mutex_t mutex;
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#if !defined(DEBUG_THREADS) && !defined(DEBUG_THREADS_LOOSE_ABI) && \
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!defined(DETECT_DEADLOCKS)
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/*!
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* These fields are renamed to ensure they are never used when
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* DEBUG_THREADS is not defined.
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*/
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struct ast_lock_track *_track;
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struct ast_lock_track_flags _flags;
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#elif defined(DEBUG_THREADS) || defined(DETECT_DEADLOCKS)
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/*! Track which thread holds this mutex. */
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struct ast_lock_track *track;
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struct ast_lock_track_flags flags;
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#endif
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};
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/*! \brief Structure for rwlock and tracking information.
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*
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* We have tracking information in this structure regardless of DEBUG_THREADS being enabled.
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* The information will just be ignored in the core if a module does not request it..
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*/
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struct ast_rwlock_info {
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pthread_rwlock_t lock;
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#if !defined(DEBUG_THREADS) && !defined(DEBUG_THREADS_LOOSE_ABI) && \
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!defined(DETECT_DEADLOCKS)
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/*!
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* These fields are renamed to ensure they are never used when
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* DEBUG_THREADS is not defined.
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*/
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struct ast_lock_track *_track;
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struct ast_lock_track_flags _flags;
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#elif defined(DEBUG_THREADS) || defined(DETECT_DEADLOCKS)
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/*! Track which thread holds this lock */
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struct ast_lock_track *track;
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struct ast_lock_track_flags flags;
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#endif
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};
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typedef struct ast_mutex_info ast_mutex_t;
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typedef struct ast_rwlock_info ast_rwlock_t;
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typedef pthread_cond_t ast_cond_t;
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int __ast_pthread_mutex_init(int tracking, const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t);
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int __ast_pthread_mutex_destroy(const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t);
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int __ast_pthread_mutex_lock(const char *filename, int lineno, const char *func, const char* mutex_name, ast_mutex_t *t);
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int __ast_pthread_mutex_trylock(const char *filename, int lineno, const char *func, const char* mutex_name, ast_mutex_t *t);
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int __ast_pthread_mutex_unlock(const char *filename, int lineno, const char *func, const char *mutex_name, ast_mutex_t *t);
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#define ast_mutex_init(pmutex) __ast_pthread_mutex_init(1, __FILE__, __LINE__, __PRETTY_FUNCTION__, #pmutex, pmutex)
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#define ast_mutex_init_notracking(pmutex) __ast_pthread_mutex_init(0, __FILE__, __LINE__, __PRETTY_FUNCTION__, #pmutex, pmutex)
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#define ast_mutex_destroy(a) __ast_pthread_mutex_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
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#define ast_mutex_lock(a) __ast_pthread_mutex_lock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
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#define ast_mutex_unlock(a) __ast_pthread_mutex_unlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
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#define ast_mutex_trylock(a) __ast_pthread_mutex_trylock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
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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);
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int __ast_cond_signal(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond);
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int __ast_cond_broadcast(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond);
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int __ast_cond_destroy(const char *filename, int lineno, const char *func, const char *cond_name, ast_cond_t *cond);
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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);
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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);
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#define ast_cond_init(cond, attr) __ast_cond_init(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond, attr)
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#define ast_cond_destroy(cond) __ast_cond_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
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#define ast_cond_signal(cond) __ast_cond_signal(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
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#define ast_cond_broadcast(cond) __ast_cond_broadcast(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
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#define ast_cond_wait(cond, mutex) __ast_cond_wait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex)
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#define ast_cond_timedwait(cond, mutex, time) __ast_cond_timedwait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex, time)
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int __ast_rwlock_init(int tracking, const char *filename, int lineno, const char *func, const char *rwlock_name, ast_rwlock_t *t);
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int __ast_rwlock_destroy(const char *filename, int lineno, const char *func, const char *rwlock_name, ast_rwlock_t *t);
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int __ast_rwlock_unlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name);
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int __ast_rwlock_rdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name);
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int __ast_rwlock_wrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name);
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int __ast_rwlock_timedrdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name, const struct timespec *abs_timeout);
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int __ast_rwlock_timedwrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name, const struct timespec *abs_timeout);
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int __ast_rwlock_tryrdlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name);
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int __ast_rwlock_trywrlock(const char *filename, int lineno, const char *func, ast_rwlock_t *t, const char *name);
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/*!
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* \brief wrapper for rwlock with tracking enabled
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* \return 0 on success, non zero for error
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* \since 1.6.1
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*/
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#define ast_rwlock_init(rwlock) __ast_rwlock_init(1, __FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock)
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/*!
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* \brief wrapper for ast_rwlock_init with tracking disabled
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* \return 0 on success, non zero for error
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* \since 1.6.1
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*/
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#define ast_rwlock_init_notracking(rwlock) __ast_rwlock_init(0, __FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock)
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#define ast_rwlock_destroy(rwlock) __ast_rwlock_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #rwlock, rwlock)
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#define ast_rwlock_unlock(a) __ast_rwlock_unlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a)
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#define ast_rwlock_rdlock(a) __ast_rwlock_rdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a)
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#define ast_rwlock_wrlock(a) __ast_rwlock_wrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a)
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#define ast_rwlock_tryrdlock(a) __ast_rwlock_tryrdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a)
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#define ast_rwlock_trywrlock(a) __ast_rwlock_trywrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a)
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#define ast_rwlock_timedrdlock(a, b) __ast_rwlock_timedrdlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a, b)
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#define ast_rwlock_timedwrlock(a, b) __ast_rwlock_timedwrlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, #a, b)
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#define ROFFSET ((lt->reentrancy > 0) ? (lt->reentrancy-1) : 0)
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#ifdef DEBUG_THREADS
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#ifdef THREAD_CRASH
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#define DO_THREAD_CRASH do { *((int *)(0)) = 1; } while(0)
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#else
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#define DO_THREAD_CRASH do { } while (0)
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#endif
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#include <errno.h>
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enum ast_lock_type {
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AST_MUTEX,
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AST_RDLOCK,
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AST_WRLOCK,
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};
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/*!
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* \brief Store lock info for the current thread
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*
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* This function gets called in ast_mutex_lock() and ast_mutex_trylock() so
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* that information about this lock can be stored in this thread's
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* lock info struct. The lock is marked as pending as the thread is waiting
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* on the lock. ast_mark_lock_acquired() will mark it as held by this thread.
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*/
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void ast_store_lock_info(enum ast_lock_type type, const char *filename,
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int line_num, const char *func, const char *lock_name, void *lock_addr, struct ast_bt *bt);
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/*!
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* \brief Mark the last lock as acquired
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*/
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void ast_mark_lock_acquired(void *lock_addr);
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/*!
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* \brief Mark the last lock as failed (trylock)
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*/
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void ast_mark_lock_failed(void *lock_addr);
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/*!
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* \brief remove lock info for the current thread
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*
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* this gets called by ast_mutex_unlock so that information on the lock can
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* be removed from the current thread's lock info struct.
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*/
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void ast_remove_lock_info(void *lock_addr, struct ast_bt *bt);
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void ast_suspend_lock_info(void *lock_addr);
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void ast_restore_lock_info(void *lock_addr);
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/*!
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* \brief log info for the current lock with ast_log().
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*
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* this function would be mostly for debug. If you come across a lock
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* that is unexpectedly but momentarily locked, and you wonder who
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* are fighting with for the lock, this routine could be called, IF
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* you have the thread debugging stuff turned on.
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* \param this_lock_addr lock address to return lock information
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* \since 1.6.1
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*/
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void ast_log_show_lock(void *this_lock_addr);
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/*!
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* \brief Generate a lock dump equivalent to "core show locks".
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*
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* The lock dump generated is generally too large to be output by a
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* single ast_verbose/log/debug/etc. call. Only ast_cli() handles it
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* properly without changing BUFSIZ in logger.c.
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*
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* Note: This must be ast_free()d when you're done with it.
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*
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* \retval An ast_str containing the lock dump
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* \retval NULL on error
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* \since 12
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*/
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struct ast_str *ast_dump_locks(void);
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/*!
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* \brief retrieve lock info for the specified mutex
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*
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* this gets called during deadlock avoidance, so that the information may
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* be preserved as to what location originally acquired the lock.
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*/
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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);
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/*!
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* \brief Unlock a lock briefly
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*
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* used during deadlock avoidance, to preserve the original location where
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* a lock was originally acquired.
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*/
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#define AO2_DEADLOCK_AVOIDANCE(obj) \
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do { \
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char __filename[80], __func[80], __mutex_name[80]; \
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int __lineno; \
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int __res = ast_find_lock_info(ao2_object_get_lockaddr(obj), __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
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int __res2 = ao2_unlock(obj); \
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usleep(1); \
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if (__res < 0) { /* Could happen if the ao2 object does not have a mutex. */ \
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if (__res2) { \
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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)); \
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} else { \
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ao2_lock(obj); \
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} \
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} else { \
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if (__res2) { \
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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); \
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} else { \
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__ao2_lock(obj, AO2_LOCK_REQ_MUTEX, __filename, __func, __lineno, __mutex_name); \
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} \
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} \
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} while (0)
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#define CHANNEL_DEADLOCK_AVOIDANCE(chan) \
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do { \
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char __filename[80], __func[80], __mutex_name[80]; \
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int __lineno; \
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int __res = ast_find_lock_info(ao2_object_get_lockaddr(chan), __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
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int __res2 = ast_channel_unlock(chan); \
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usleep(1); \
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if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \
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if (__res2) { \
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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)); \
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} else { \
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ast_channel_lock(chan); \
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} \
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} else { \
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if (__res2) { \
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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); \
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} else { \
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__ao2_lock(chan, AO2_LOCK_REQ_MUTEX, __filename, __func, __lineno, __mutex_name); \
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} \
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} \
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} while (0)
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#define DEADLOCK_AVOIDANCE(lock) \
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do { \
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char __filename[80], __func[80], __mutex_name[80]; \
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int __lineno; \
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int __res = ast_find_lock_info(lock, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
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int __res2 = ast_mutex_unlock(lock); \
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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
|
|
|
|
/*!
|
|
* \brief Support for atomic instructions.
|
|
*
|
|
* These macros implement a uniform interface to use built-in atomic functionality.
|
|
* If available __atomic built-ins are prefered. Legacy __sync built-ins are used
|
|
* as a fallback for older compilers.
|
|
*
|
|
* Detailed documentation can be found in the GCC manual, all API's are modeled after
|
|
* the __atomic interfaces but using the namespace ast_atomic.
|
|
*
|
|
* The memorder argument is always ignored by legacy __sync functions. Invalid
|
|
* memorder arguments do not produce errors unless __atomic functions are supported
|
|
* as the argument is erased by the preprocessor.
|
|
*
|
|
* \note ast_atomic_fetch_nand and ast_atomic_nand_fetch purposely do not exist.
|
|
* It's implementation was broken prior to gcc-4.4.
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
#include "asterisk/inline_api.h"
|
|
|
|
#if defined(HAVE_C_ATOMICS)
|
|
/*! Atomic += */
|
|
#define ast_atomic_fetch_add(ptr, val, memorder) __atomic_fetch_add((ptr), (val), (memorder))
|
|
#define ast_atomic_add_fetch(ptr, val, memorder) __atomic_add_fetch((ptr), (val), (memorder))
|
|
|
|
/*! Atomic -= */
|
|
#define ast_atomic_fetch_sub(ptr, val, memorder) __atomic_fetch_sub((ptr), (val), (memorder))
|
|
#define ast_atomic_sub_fetch(ptr, val, memorder) __atomic_sub_fetch((ptr), (val), (memorder))
|
|
|
|
/*! Atomic &= */
|
|
#define ast_atomic_fetch_and(ptr, val, memorder) __atomic_fetch_and((ptr), (val), (memorder))
|
|
#define ast_atomic_and_fetch(ptr, val, memorder) __atomic_and_fetch((ptr), (val), (memorder))
|
|
|
|
/*! Atomic |= */
|
|
#define ast_atomic_fetch_or(ptr, val, memorder) __atomic_fetch_or((ptr), (val), (memorder))
|
|
#define ast_atomic_or_fetch(ptr, val, memorder) __atomic_or_fetch((ptr), (val), (memorder))
|
|
|
|
/*! Atomic xor = */
|
|
#define ast_atomic_fetch_xor(ptr, val, memorder) __atomic_fetch_xor((ptr), (val), (memorder))
|
|
#define ast_atomic_xor_fetch(ptr, val, memorder) __atomic_xor_fetch((ptr), (val), (memorder))
|
|
|
|
#if 0
|
|
/* Atomic compare and swap
|
|
*
|
|
* See comments near the __atomic implementation for why this is disabled.
|
|
*/
|
|
#define ast_atomic_compare_exchange_n(ptr, expected, desired, success_memorder, failure_memorder) \
|
|
__atomic_compare_exchange_n((ptr), (expected), (desired), 0, success_memorder, failure_memorder)
|
|
|
|
#define ast_atomic_compare_exchange(ptr, expected, desired, success_memorder, failure_memorder) \
|
|
__atomic_compare_exchange((ptr), (expected), (desired), 0, success_memorder, failure_memorder)
|
|
#endif
|
|
|
|
#elif defined(HAVE_GCC_ATOMICS)
|
|
/*! Atomic += */
|
|
#define ast_atomic_fetch_add(ptr, val, memorder) __sync_fetch_and_add((ptr), (val))
|
|
#define ast_atomic_add_fetch(ptr, val, memorder) __sync_add_and_fetch((ptr), (val))
|
|
|
|
/*! Atomic -= */
|
|
#define ast_atomic_fetch_sub(ptr, val, memorder) __sync_fetch_and_sub((ptr), (val))
|
|
#define ast_atomic_sub_fetch(ptr, val, memorder) __sync_sub_and_fetch((ptr), (val))
|
|
|
|
/*! Atomic &= */
|
|
#define ast_atomic_fetch_and(ptr, val, memorder) __sync_fetch_and_and((ptr), (val))
|
|
#define ast_atomic_and_fetch(ptr, val, memorder) __sync_and_and_fetch((ptr), (val))
|
|
|
|
/*! Atomic |= */
|
|
#define ast_atomic_fetch_or(ptr, val, memorder) __sync_fetch_and_or((ptr), (val))
|
|
#define ast_atomic_or_fetch(ptr, val, memorder) __sync_or_and_fetch((ptr), (val))
|
|
|
|
/*! Atomic xor = */
|
|
#define ast_atomic_fetch_xor(ptr, val, memorder) __sync_fetch_and_xor((ptr), (val))
|
|
#define ast_atomic_xor_fetch(ptr, val, memorder) __sync_xor_and_fetch((ptr), (val))
|
|
|
|
#if 0
|
|
/* Atomic compare and swap
|
|
*
|
|
* The \a expected argument is a pointer, I'm guessing __atomic built-ins
|
|
* perform all memory reads/writes in a single atomic operation. I don't
|
|
* believe this is possible to exactly replicate using __sync built-ins.
|
|
* Will need to determine potential use cases of this feature and write a
|
|
* wrapper which provides consistant behavior between __sync and __atomic
|
|
* implementations.
|
|
*/
|
|
#define ast_atomic_compare_exchange_n(ptr, expected, desired, success_memorder, failure_memorder) \
|
|
__sync_bool_compare_and_swap((ptr), *(expected), (desired))
|
|
|
|
#define ast_atomic_compare_exchange(ptr, expected, desired, success_memorder, failure_memorder) \
|
|
__sync_bool_compare_and_swap((ptr), *(expected), *(desired))
|
|
#endif
|
|
|
|
#else
|
|
#error "Atomics not available."
|
|
#endif
|
|
|
|
/*! Atomic flag set */
|
|
#define ast_atomic_flag_set(ptr, val, memorder) ast_atomic_fetch_or((ptr), (val), (memorder))
|
|
|
|
/*! Atomic flag clear */
|
|
#define ast_atomic_flag_clear(ptr, val, memorder) ast_atomic_fetch_and((ptr), ~(val), (memorder))
|
|
|
|
/*!
|
|
* \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.
|
|
*/
|
|
AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
|
|
{
|
|
return ast_atomic_fetch_add(p, v, __ATOMIC_RELAXED);
|
|
})
|
|
|
|
/*!
|
|
* \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.
|
|
*/
|
|
AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
|
|
{
|
|
return ast_atomic_sub_fetch(p, 1, __ATOMIC_RELAXED) == 0;
|
|
})
|
|
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
|
}
|
|
#endif
|
|
|
|
/*! @} */
|
|
|
|
#endif /* _ASTERISK_LOCK_H */
|