Wed Aug 15 01:24:22 2007

Asterisk developer's documentation


lock.h

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2006, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  * \brief General Asterisk channel locking definitions.
00021  *
00022  * - See \ref LockDef
00023  */
00024 
00025 /*! \page LockDef Asterisk thread locking models
00026  *
00027  * This file provides different implementation of the functions,
00028  * depending on the platform, the use of DEBUG_THREADS, and the way
00029  * module-level mutexes are initialized.
00030  *
00031  *  - \b static: the mutex is assigned the value AST_MUTEX_INIT_VALUE
00032  *        this is done at compile time, and is the way used on Linux.
00033  *        This method is not applicable to all platforms e.g. when the
00034  *        initialization needs that some code is run.
00035  *
00036  *  - \b through constructors: for each mutex, a constructor function is
00037  *        defined, which then runs when the program (or the module)
00038  *        starts. The problem with this approach is that there is a
00039  *        lot of code duplication (a new block of code is created for
00040  *        each mutex). Also, it does not prevent a user from declaring
00041  *        a global mutex without going through the wrapper macros,
00042  *        so sane programming practices are still required.
00043  */
00044 
00045 #ifndef _ASTERISK_LOCK_H
00046 #define _ASTERISK_LOCK_H
00047 
00048 #include <pthread.h>
00049 #include <netdb.h>
00050 #include <time.h>
00051 #include <sys/param.h>
00052 
00053 #include "asterisk/logger.h"
00054 
00055 /* internal macro to profile mutexes. Only computes the delay on
00056  * non-blocking calls.
00057  */
00058 #ifndef  HAVE_MTX_PROFILE
00059 #define  __MTX_PROF(a)  return pthread_mutex_lock((a))
00060 #else
00061 #define  __MTX_PROF(a)  do {        \
00062    int i;               \
00063    /* profile only non-blocking events */ \
00064    ast_mark(mtx_prof, 1);        \
00065    i = pthread_mutex_trylock((a));     \
00066    ast_mark(mtx_prof, 0);        \
00067    if (!i)              \
00068       return i;         \
00069    else              \
00070       return pthread_mutex_lock((a)); \
00071    } while (0)
00072 #endif   /* HAVE_MTX_PROFILE */
00073 
00074 #define AST_PTHREADT_NULL (pthread_t) -1
00075 #define AST_PTHREADT_STOP (pthread_t) -2
00076 
00077 #if defined(SOLARIS) || defined(BSD)
00078 #define AST_MUTEX_INIT_W_CONSTRUCTORS
00079 #endif /* SOLARIS || BSD */
00080 
00081 /* Asterisk REQUIRES recursive (not error checking) mutexes
00082    and will not run without them. */
00083 #if defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP)
00084 #define PTHREAD_MUTEX_INIT_VALUE PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
00085 #define AST_MUTEX_KIND        PTHREAD_MUTEX_RECURSIVE_NP
00086 #else
00087 #define PTHREAD_MUTEX_INIT_VALUE PTHREAD_MUTEX_INITIALIZER
00088 #define AST_MUTEX_KIND        PTHREAD_MUTEX_RECURSIVE
00089 #endif /* PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP */
00090 
00091 #ifdef DEBUG_THREADS
00092 
00093 #define __ast_mutex_logger(...)  do { if (canlog) ast_log(LOG_ERROR, __VA_ARGS__); else fprintf(stderr, __VA_ARGS__); } while (0)
00094 
00095 #ifdef THREAD_CRASH
00096 #define DO_THREAD_CRASH do { *((int *)(0)) = 1; } while(0)
00097 #else
00098 #define DO_THREAD_CRASH do { } while (0)
00099 #endif
00100 
00101 #include <errno.h>
00102 #include <string.h>
00103 #include <stdio.h>
00104 #include <unistd.h>
00105 
00106 #define AST_MUTEX_INIT_VALUE { PTHREAD_MUTEX_INIT_VALUE, 1, { NULL }, { 0 }, 0, { NULL }, { 0 } }
00107 #define AST_MUTEX_INIT_VALUE_NOTRACKING \
00108                              { PTHREAD_MUTEX_INIT_VALUE, 0, { NULL }, { 0 }, 0, { NULL }, { 0 } }
00109 
00110 #define AST_MAX_REENTRANCY 10
00111 
00112 struct ast_mutex_info {
00113    pthread_mutex_t mutex;
00114    /*! Track which thread holds this lock */
00115    unsigned int track:1;
00116    const char *file[AST_MAX_REENTRANCY];
00117    int lineno[AST_MAX_REENTRANCY];
00118    int reentrancy;
00119    const char *func[AST_MAX_REENTRANCY];
00120    pthread_t thread[AST_MAX_REENTRANCY];
00121 };
00122 
00123 typedef struct ast_mutex_info ast_mutex_t;
00124 
00125 typedef pthread_cond_t ast_cond_t;
00126 
00127 static pthread_mutex_t empty_mutex;
00128 
00129 /*!
00130  * \brief Store lock info for the current thread
00131  *
00132  * This function gets called in ast_mutex_lock() and ast_mutex_trylock() so
00133  * that information about this lock can be stored in this thread's
00134  * lock info struct.  The lock is marked as pending as the thread is waiting
00135  * on the lock.  ast_mark_lock_acquired() will mark it as held by this thread.
00136  */
00137 void ast_store_lock_info(const char *filename, int line_num, 
00138    const char *func, const char *lock_name, void *lock_addr);
00139 
00140 /*!
00141  * \brief Mark the last lock as acquired
00142  */
00143 void ast_mark_lock_acquired(void);
00144 
00145 /*!
00146  * \brief remove lock info for the current thread
00147  *
00148  * this gets called by ast_mutex_unlock so that information on the lock can
00149  * be removed from the current thread's lock info struct.
00150  */
00151 void ast_remove_lock_info(void *lock_addr);
00152 
00153 static void __attribute__((constructor)) init_empty_mutex(void)
00154 {
00155    memset(&empty_mutex, 0, sizeof(empty_mutex));
00156 }
00157 
00158 static inline int __ast_pthread_mutex_init_attr(const char *filename, int lineno, const char *func,
00159                   const char *mutex_name, ast_mutex_t *t,
00160                   pthread_mutexattr_t *attr) 
00161 {
00162 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
00163    int canlog = strcmp(filename, "logger.c");
00164 
00165    if ((t->mutex) != ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00166       if ((t->mutex) != (empty_mutex)) {
00167          __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is already initialized.\n",
00168                   filename, lineno, func, mutex_name);
00169          __ast_mutex_logger("%s line %d (%s): Error: previously initialization of mutex '%s'.\n",
00170                   t->file[0], t->lineno[0], t->func[0], mutex_name);
00171          DO_THREAD_CRASH;
00172          return 0;
00173       }
00174    }
00175 #endif
00176 
00177    t->file[0] = filename;
00178    t->lineno[0] = lineno;
00179    t->func[0] = func;
00180    t->thread[0]  = 0;
00181    t->reentrancy = 0;
00182 
00183    return pthread_mutex_init(&t->mutex, attr);
00184 }
00185 
00186 static inline int __ast_pthread_mutex_init(const char *filename, int lineno, const char *func,
00187                   const char *mutex_name, ast_mutex_t *t)
00188 {
00189    static pthread_mutexattr_t  attr;
00190 
00191    pthread_mutexattr_init(&attr);
00192    pthread_mutexattr_settype(&attr, AST_MUTEX_KIND);
00193 
00194    return __ast_pthread_mutex_init_attr(filename, lineno, func, mutex_name, t, &attr);
00195 }
00196 #define ast_mutex_init(pmutex) __ast_pthread_mutex_init(__FILE__, __LINE__, __PRETTY_FUNCTION__, #pmutex, pmutex)
00197 
00198 static inline int __ast_pthread_mutex_destroy(const char *filename, int lineno, const char *func,
00199                   const char *mutex_name, ast_mutex_t *t)
00200 {
00201    int res;
00202    int canlog = strcmp(filename, "logger.c");
00203 
00204 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
00205    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00206       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00207                filename, lineno, func, mutex_name);
00208    }
00209 #endif
00210 
00211    res = pthread_mutex_trylock(&t->mutex);
00212    switch (res) {
00213    case 0:
00214       pthread_mutex_unlock(&t->mutex);
00215       break;
00216    case EINVAL:
00217       __ast_mutex_logger("%s line %d (%s): Error: attempt to destroy invalid mutex '%s'.\n",
00218               filename, lineno, func, mutex_name);
00219       break;
00220    case EBUSY:
00221       __ast_mutex_logger("%s line %d (%s): Error: attempt to destroy locked mutex '%s'.\n",
00222                filename, lineno, func, mutex_name);
00223       __ast_mutex_logger("%s line %d (%s): Error: '%s' was locked here.\n",
00224                t->file[t->reentrancy-1], t->lineno[t->reentrancy-1], t->func[t->reentrancy-1], mutex_name);
00225       break;
00226    }
00227 
00228    if ((res = pthread_mutex_destroy(&t->mutex)))
00229       __ast_mutex_logger("%s line %d (%s): Error destroying mutex: %s\n",
00230                filename, lineno, func, strerror(res));
00231 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
00232    else
00233       t->mutex = PTHREAD_MUTEX_INIT_VALUE;
00234 #endif
00235    t->file[0] = filename;
00236    t->lineno[0] = lineno;
00237    t->func[0] = func;
00238 
00239    return res;
00240 }
00241 
00242 static inline int __ast_pthread_mutex_lock(const char *filename, int lineno, const char *func,
00243                                            const char* mutex_name, ast_mutex_t *t)
00244 {
00245    int res;
00246    int canlog = strcmp(filename, "logger.c");
00247 
00248    if (t->track)
00249       ast_store_lock_info(filename, lineno, func, mutex_name, &t->mutex);
00250 
00251 #if defined(AST_MUTEX_INIT_W_CONSTRUCTORS)
00252    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00253       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00254              filename, lineno, func, mutex_name);
00255       ast_mutex_init(t);
00256    }
00257 #endif /* AST_MUTEX_INIT_W_CONSTRUCTORS */
00258 
00259 #ifdef DETECT_DEADLOCKS
00260    {
00261       time_t seconds = time(NULL);
00262       time_t current;
00263       do {
00264 #ifdef   HAVE_MTX_PROFILE
00265          ast_mark(mtx_prof, 1);
00266 #endif
00267          res = pthread_mutex_trylock(&t->mutex);
00268 #ifdef   HAVE_MTX_PROFILE
00269          ast_mark(mtx_prof, 0);
00270 #endif
00271          if (res == EBUSY) {
00272             current = time(NULL);
00273             if ((current - seconds) && (!((current - seconds) % 5))) {
00274                __ast_mutex_logger("%s line %d (%s): Deadlock? waited %d sec for mutex '%s'?\n",
00275                         filename, lineno, func, (int)(current - seconds), mutex_name);
00276                __ast_mutex_logger("%s line %d (%s): '%s' was locked here.\n",
00277                         t->file[t->reentrancy-1], t->lineno[t->reentrancy-1],
00278                         t->func[t->reentrancy-1], mutex_name);
00279             }
00280             usleep(200);
00281          }
00282       } while (res == EBUSY);
00283    }
00284 #else
00285 #ifdef   HAVE_MTX_PROFILE
00286    ast_mark(mtx_prof, 1);
00287    res = pthread_mutex_trylock(&t->mutex);
00288    ast_mark(mtx_prof, 0);
00289    if (res)
00290 #endif
00291    res = pthread_mutex_lock(&t->mutex);
00292 #endif /* DETECT_DEADLOCKS */
00293 
00294    if (!res) {
00295       if (t->track)
00296          ast_mark_lock_acquired();
00297       if (t->reentrancy < AST_MAX_REENTRANCY) {
00298          t->file[t->reentrancy] = filename;
00299          t->lineno[t->reentrancy] = lineno;
00300          t->func[t->reentrancy] = func;
00301          t->thread[t->reentrancy] = pthread_self();
00302          t->reentrancy++;
00303       } else {
00304          __ast_mutex_logger("%s line %d (%s): '%s' really deep reentrancy!\n",
00305                         filename, lineno, func, mutex_name);
00306       }
00307    } else {
00308       if (t->track)
00309          ast_remove_lock_info(&t->mutex);
00310       __ast_mutex_logger("%s line %d (%s): Error obtaining mutex: %s\n",
00311                filename, lineno, func, strerror(res));
00312       DO_THREAD_CRASH;
00313    }
00314 
00315    return res;
00316 }
00317 
00318 static inline int __ast_pthread_mutex_trylock(const char *filename, int lineno, const char *func,
00319                                               const char* mutex_name, ast_mutex_t *t)
00320 {
00321    int res;
00322    int canlog = strcmp(filename, "logger.c");
00323 
00324 #if defined(AST_MUTEX_INIT_W_CONSTRUCTORS)
00325    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00326       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00327                filename, lineno, func, mutex_name);
00328       ast_mutex_init(t);
00329    }
00330 #endif /* AST_MUTEX_INIT_W_CONSTRUCTORS */
00331 
00332    if (t->track)
00333       ast_store_lock_info(filename, lineno, func, mutex_name, &t->mutex);
00334 
00335    if (!(res = pthread_mutex_trylock(&t->mutex))) {
00336       if (t->track)
00337          ast_mark_lock_acquired();
00338       if (t->reentrancy < AST_MAX_REENTRANCY) {
00339          t->file[t->reentrancy] = filename;
00340          t->lineno[t->reentrancy] = lineno;
00341          t->func[t->reentrancy] = func;
00342          t->thread[t->reentrancy] = pthread_self();
00343          t->reentrancy++;
00344       } else {
00345          __ast_mutex_logger("%s line %d (%s): '%s' really deep reentrancy!\n",
00346                   filename, lineno, func, mutex_name);
00347       }
00348    } else if (t->track) {
00349          ast_remove_lock_info(&t->mutex);
00350    }
00351 
00352    return res;
00353 }
00354 
00355 static inline int __ast_pthread_mutex_unlock(const char *filename, int lineno, const char *func,
00356                     const char *mutex_name, ast_mutex_t *t)
00357 {
00358    int res;
00359    int canlog = strcmp(filename, "logger.c");
00360 
00361 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
00362    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00363       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00364                filename, lineno, func, mutex_name);
00365    }
00366 #endif
00367 
00368    if (t->reentrancy && (t->thread[t->reentrancy-1] != pthread_self())) {
00369       __ast_mutex_logger("%s line %d (%s): attempted unlock mutex '%s' without owning it!\n",
00370                filename, lineno, func, mutex_name);
00371       __ast_mutex_logger("%s line %d (%s): '%s' was locked here.\n",
00372                t->file[t->reentrancy-1], t->lineno[t->reentrancy-1], t->func[t->reentrancy-1], mutex_name);
00373       DO_THREAD_CRASH;
00374    }
00375 
00376    if (--t->reentrancy < 0) {
00377       __ast_mutex_logger("%s line %d (%s): mutex '%s' freed more times than we've locked!\n",
00378                filename, lineno, func, mutex_name);
00379       t->reentrancy = 0;
00380    }
00381 
00382    if (t->reentrancy < AST_MAX_REENTRANCY) {
00383       t->file[t->reentrancy] = NULL;
00384       t->lineno[t->reentrancy] = 0;
00385       t->func[t->reentrancy] = NULL;
00386       t->thread[t->reentrancy] = 0;
00387    }
00388 
00389    if (t->track)
00390       ast_remove_lock_info(&t->mutex);
00391 
00392    if ((res = pthread_mutex_unlock(&t->mutex))) {
00393       __ast_mutex_logger("%s line %d (%s): Error releasing mutex: %s\n", 
00394                filename, lineno, func, strerror(res));
00395       DO_THREAD_CRASH;
00396    }
00397 
00398    return res;
00399 }
00400 
00401 static inline int __ast_cond_init(const char *filename, int lineno, const char *func,
00402               const char *cond_name, ast_cond_t *cond, pthread_condattr_t *cond_attr)
00403 {
00404    return pthread_cond_init(cond, cond_attr);
00405 }
00406 
00407 static inline int __ast_cond_signal(const char *filename, int lineno, const char *func,
00408                 const char *cond_name, ast_cond_t *cond)
00409 {
00410    return pthread_cond_signal(cond);
00411 }
00412 
00413 static inline int __ast_cond_broadcast(const char *filename, int lineno, const char *func,
00414                    const char *cond_name, ast_cond_t *cond)
00415 {
00416    return pthread_cond_broadcast(cond);
00417 }
00418 
00419 static inline int __ast_cond_destroy(const char *filename, int lineno, const char *func,
00420                  const char *cond_name, ast_cond_t *cond)
00421 {
00422    return pthread_cond_destroy(cond);
00423 }
00424 
00425 static inline int __ast_cond_wait(const char *filename, int lineno, const char *func,
00426               const char *cond_name, const char *mutex_name,
00427               ast_cond_t *cond, ast_mutex_t *t)
00428 {
00429    int res;
00430    int canlog = strcmp(filename, "logger.c");
00431 
00432 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
00433    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00434       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00435                filename, lineno, func, mutex_name);
00436    }
00437 #endif
00438 
00439    if (t->reentrancy && (t->thread[t->reentrancy-1] != pthread_self())) {
00440       __ast_mutex_logger("%s line %d (%s): attempted unlock mutex '%s' without owning it!\n",
00441                filename, lineno, func, mutex_name);
00442       __ast_mutex_logger("%s line %d (%s): '%s' was locked here.\n",
00443                t->file[t->reentrancy-1], t->lineno[t->reentrancy-1], t->func[t->reentrancy-1], mutex_name);
00444       DO_THREAD_CRASH;
00445    }
00446 
00447    if (--t->reentrancy < 0) {
00448       __ast_mutex_logger("%s line %d (%s): mutex '%s' freed more times than we've locked!\n",
00449                filename, lineno, func, mutex_name);
00450       t->reentrancy = 0;
00451    }
00452 
00453    if (t->reentrancy < AST_MAX_REENTRANCY) {
00454       t->file[t->reentrancy] = NULL;
00455       t->lineno[t->reentrancy] = 0;
00456       t->func[t->reentrancy] = NULL;
00457       t->thread[t->reentrancy] = 0;
00458    }
00459 
00460    if (t->track)
00461       ast_remove_lock_info(&t->mutex);
00462 
00463    if ((res = pthread_cond_wait(cond, &t->mutex))) {
00464       __ast_mutex_logger("%s line %d (%s): Error waiting on condition mutex '%s'\n", 
00465                filename, lineno, func, strerror(res));
00466       DO_THREAD_CRASH;
00467    } else {
00468       if (t->track)
00469          ast_store_lock_info(filename, lineno, func, mutex_name, &t->mutex);
00470 
00471       if (t->reentrancy < AST_MAX_REENTRANCY) {
00472          t->file[t->reentrancy] = filename;
00473          t->lineno[t->reentrancy] = lineno;
00474          t->func[t->reentrancy] = func;
00475          t->thread[t->reentrancy] = pthread_self();
00476          t->reentrancy++;
00477       } else {
00478          __ast_mutex_logger("%s line %d (%s): '%s' really deep reentrancy!\n",
00479                         filename, lineno, func, mutex_name);
00480       }
00481    }
00482 
00483    return res;
00484 }
00485 
00486 static inline int __ast_cond_timedwait(const char *filename, int lineno, const char *func,
00487                    const char *cond_name, const char *mutex_name, ast_cond_t *cond,
00488                    ast_mutex_t *t, const struct timespec *abstime)
00489 {
00490    int res;
00491    int canlog = strcmp(filename, "logger.c");
00492 
00493 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
00494    if ((t->mutex) == ((pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER)) {
00495       __ast_mutex_logger("%s line %d (%s): Error: mutex '%s' is uninitialized.\n",
00496                filename, lineno, func, mutex_name);
00497    }
00498 #endif
00499 
00500    if (t->reentrancy && (t->thread[t->reentrancy-1] != pthread_self())) {
00501       __ast_mutex_logger("%s line %d (%s): attempted unlock mutex '%s' without owning it!\n",
00502                filename, lineno, func, mutex_name);
00503       __ast_mutex_logger("%s line %d (%s): '%s' was locked here.\n",
00504                t->file[t->reentrancy-1], t->lineno[t->reentrancy-1], t->func[t->reentrancy-1], mutex_name);
00505       DO_THREAD_CRASH;
00506    }
00507 
00508    if (--t->reentrancy < 0) {
00509       __ast_mutex_logger("%s line %d (%s): mutex '%s' freed more times than we've locked!\n",
00510                filename, lineno, func, mutex_name);
00511       t->reentrancy = 0;
00512    }
00513 
00514    if (t->reentrancy < AST_MAX_REENTRANCY) {
00515       t->file[t->reentrancy] = NULL;
00516       t->lineno[t->reentrancy] = 0;
00517       t->func[t->reentrancy] = NULL;
00518       t->thread[t->reentrancy] = 0;
00519    }
00520 
00521    if (t->track)
00522       ast_remove_lock_info(&t->mutex);
00523 
00524    if ((res = pthread_cond_timedwait(cond, &t->mutex, abstime)) && (res != ETIMEDOUT)) {
00525       __ast_mutex_logger("%s line %d (%s): Error waiting on condition mutex '%s'\n", 
00526                filename, lineno, func, strerror(res));
00527       DO_THREAD_CRASH;
00528    } else {
00529       if (t->track)
00530          ast_store_lock_info(filename, lineno, func, mutex_name, &t->mutex);
00531 
00532       if (t->reentrancy < AST_MAX_REENTRANCY) {
00533          t->file[t->reentrancy] = filename;
00534          t->lineno[t->reentrancy] = lineno;
00535          t->func[t->reentrancy] = func;
00536          t->thread[t->reentrancy] = pthread_self();
00537          t->reentrancy++;
00538       } else {
00539          __ast_mutex_logger("%s line %d (%s): '%s' really deep reentrancy!\n",
00540                         filename, lineno, func, mutex_name);
00541       }
00542    }
00543 
00544    return res;
00545 }
00546 
00547 #define ast_mutex_destroy(a) __ast_pthread_mutex_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
00548 #define ast_mutex_lock(a) __ast_pthread_mutex_lock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
00549 #define ast_mutex_unlock(a) __ast_pthread_mutex_unlock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
00550 #define ast_mutex_trylock(a) __ast_pthread_mutex_trylock(__FILE__, __LINE__, __PRETTY_FUNCTION__, #a, a)
00551 #define ast_cond_init(cond, attr) __ast_cond_init(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond, attr)
00552 #define ast_cond_destroy(cond) __ast_cond_destroy(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
00553 #define ast_cond_signal(cond) __ast_cond_signal(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
00554 #define ast_cond_broadcast(cond) __ast_cond_broadcast(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, cond)
00555 #define ast_cond_wait(cond, mutex) __ast_cond_wait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex)
00556 #define ast_cond_timedwait(cond, mutex, time) __ast_cond_timedwait(__FILE__, __LINE__, __PRETTY_FUNCTION__, #cond, #mutex, cond, mutex, time)
00557 
00558 #else /* !DEBUG_THREADS */
00559 
00560 
00561 typedef pthread_mutex_t ast_mutex_t;
00562 
00563 #define AST_MUTEX_INIT_VALUE  ((ast_mutex_t) PTHREAD_MUTEX_INIT_VALUE)
00564 #define AST_MUTEX_INIT_VALUE_NOTRACKING \
00565    ((ast_mutex_t) PTHREAD_MUTEX_INIT_VALUE)
00566 
00567 static inline int ast_mutex_init(ast_mutex_t *pmutex)
00568 {
00569    pthread_mutexattr_t attr;
00570 
00571    pthread_mutexattr_init(&attr);
00572    pthread_mutexattr_settype(&attr, AST_MUTEX_KIND);
00573 
00574    return pthread_mutex_init(pmutex, &attr);
00575 }
00576 
00577 #define ast_pthread_mutex_init(pmutex,a) pthread_mutex_init(pmutex,a)
00578 
00579 static inline int ast_mutex_unlock(ast_mutex_t *pmutex)
00580 {
00581    return pthread_mutex_unlock(pmutex);
00582 }
00583 
00584 static inline int ast_mutex_destroy(ast_mutex_t *pmutex)
00585 {
00586    return pthread_mutex_destroy(pmutex);
00587 }
00588 
00589 static inline int ast_mutex_lock(ast_mutex_t *pmutex)
00590 {
00591    __MTX_PROF(pmutex);
00592 }
00593 
00594 static inline int ast_mutex_trylock(ast_mutex_t *pmutex)
00595 {
00596    return pthread_mutex_trylock(pmutex);
00597 }
00598 
00599 typedef pthread_cond_t ast_cond_t;
00600 
00601 static inline int ast_cond_init(ast_cond_t *cond, pthread_condattr_t *cond_attr)
00602 {
00603    return pthread_cond_init(cond, cond_attr);
00604 }
00605 
00606 static inline int ast_cond_signal(ast_cond_t *cond)
00607 {
00608    return pthread_cond_signal(cond);
00609 }
00610 
00611 static inline int ast_cond_broadcast(ast_cond_t *cond)
00612 {
00613    return pthread_cond_broadcast(cond);
00614 }
00615 
00616 static inline int ast_cond_destroy(ast_cond_t *cond)
00617 {
00618    return pthread_cond_destroy(cond);
00619 }
00620 
00621 static inline int ast_cond_wait(ast_cond_t *cond, ast_mutex_t *t)
00622 {
00623    return pthread_cond_wait(cond, t);
00624 }
00625 
00626 static inline int ast_cond_timedwait(ast_cond_t *cond, ast_mutex_t *t, const struct timespec *abstime)
00627 {
00628    return pthread_cond_timedwait(cond, t, abstime);
00629 }
00630 
00631 #endif /* !DEBUG_THREADS */
00632 
00633 #if defined(AST_MUTEX_INIT_W_CONSTRUCTORS)
00634 /* If AST_MUTEX_INIT_W_CONSTRUCTORS is defined, use file scope
00635  constructors/destructors to create/destroy mutexes.  */
00636 #define __AST_MUTEX_DEFINE(scope, mutex, init_val) \
00637    scope ast_mutex_t mutex = init_val; \
00638 static void  __attribute__ ((constructor)) init_##mutex(void) \
00639 { \
00640    ast_mutex_init(&mutex); \
00641 } \
00642 static void  __attribute__ ((destructor)) fini_##mutex(void) \
00643 { \
00644    ast_mutex_destroy(&mutex); \
00645 }
00646 #else /* !AST_MUTEX_INIT_W_CONSTRUCTORS */
00647 /* By default, use static initialization of mutexes. */ 
00648 #define __AST_MUTEX_DEFINE(scope, mutex, init_val) \
00649    scope ast_mutex_t mutex = init_val
00650 #endif /* AST_MUTEX_INIT_W_CONSTRUCTORS */
00651 
00652 #define pthread_mutex_t use_ast_mutex_t_instead_of_pthread_mutex_t
00653 #define pthread_mutex_lock use_ast_mutex_lock_instead_of_pthread_mutex_lock
00654 #define pthread_mutex_unlock use_ast_mutex_unlock_instead_of_pthread_mutex_unlock
00655 #define pthread_mutex_trylock use_ast_mutex_trylock_instead_of_pthread_mutex_trylock
00656 #define pthread_mutex_init use_ast_mutex_init_instead_of_pthread_mutex_init
00657 #define pthread_mutex_destroy use_ast_mutex_destroy_instead_of_pthread_mutex_destroy
00658 #define pthread_cond_t use_ast_cond_t_instead_of_pthread_cond_t
00659 #define pthread_cond_init use_ast_cond_init_instead_of_pthread_cond_init
00660 #define pthread_cond_destroy use_ast_cond_destroy_instead_of_pthread_cond_destroy
00661 #define pthread_cond_signal use_ast_cond_signal_instead_of_pthread_cond_signal
00662 #define pthread_cond_broadcast use_ast_cond_broadcast_instead_of_pthread_cond_broadcast
00663 #define pthread_cond_wait use_ast_cond_wait_instead_of_pthread_cond_wait
00664 #define pthread_cond_timedwait use_ast_cond_timedwait_instead_of_pthread_cond_timedwait
00665 
00666 #define AST_MUTEX_DEFINE_STATIC(mutex) __AST_MUTEX_DEFINE(static, mutex, AST_MUTEX_INIT_VALUE)
00667 #define AST_MUTEX_DEFINE_STATIC_NOTRACKING(mutex) __AST_MUTEX_DEFINE(static, mutex, AST_MUTEX_INIT_VALUE_NOTRACKING)
00668 
00669 #define AST_MUTEX_INITIALIZER __use_AST_MUTEX_DEFINE_STATIC_rather_than_AST_MUTEX_INITIALIZER__
00670 
00671 #define gethostbyname __gethostbyname__is__not__reentrant__use__ast_gethostbyname__instead__
00672 
00673 #ifndef __linux__
00674 #define pthread_create __use_ast_pthread_create_instead__
00675 #endif
00676 
00677 typedef pthread_rwlock_t ast_rwlock_t;
00678 
00679 static inline int ast_rwlock_init(ast_rwlock_t *prwlock)
00680 {
00681    pthread_rwlockattr_t attr;
00682 
00683    pthread_rwlockattr_init(&attr);
00684 
00685 #ifdef HAVE_PTHREAD_RWLOCK_PREFER_WRITER_NP
00686    pthread_rwlockattr_setkind_np(&attr, PTHREAD_RWLOCK_PREFER_WRITER_NP);
00687 #endif
00688 
00689    return pthread_rwlock_init(prwlock, &attr);
00690 }
00691 
00692 static inline int ast_rwlock_destroy(ast_rwlock_t *prwlock)
00693 {
00694    return pthread_rwlock_destroy(prwlock);
00695 }
00696 
00697 static inline int ast_rwlock_unlock(ast_rwlock_t *prwlock)
00698 {
00699    return pthread_rwlock_unlock(prwlock);
00700 }
00701 
00702 static inline int ast_rwlock_rdlock(ast_rwlock_t *prwlock)
00703 {
00704    return pthread_rwlock_rdlock(prwlock);
00705 }
00706 
00707 static inline int ast_rwlock_tryrdlock(ast_rwlock_t *prwlock)
00708 {
00709    return pthread_rwlock_tryrdlock(prwlock);
00710 }
00711 
00712 static inline int ast_rwlock_wrlock(ast_rwlock_t *prwlock)
00713 {
00714    return pthread_rwlock_wrlock(prwlock);
00715 }
00716 
00717 static inline int ast_rwlock_trywrlock(ast_rwlock_t *prwlock)
00718 {
00719    return pthread_rwlock_trywrlock(prwlock);
00720 }
00721 
00722 /* Statically declared read/write locks */
00723 
00724 #ifndef HAVE_PTHREAD_RWLOCK_INITIALIZER
00725 #define __AST_RWLOCK_DEFINE(scope, rwlock) \
00726         scope ast_rwlock_t rwlock; \
00727 static void  __attribute__ ((constructor)) init_##rwlock(void) \
00728 { \
00729         ast_rwlock_init(&rwlock); \
00730 } \
00731 static void  __attribute__ ((destructor)) fini_##rwlock(void) \
00732 { \
00733         ast_rwlock_destroy(&rwlock); \
00734 }
00735 #else
00736 #define AST_RWLOCK_INIT_VALUE PTHREAD_RWLOCK_INITIALIZER
00737 #define __AST_RWLOCK_DEFINE(scope, rwlock) \
00738         scope ast_rwlock_t rwlock = AST_RWLOCK_INIT_VALUE
00739 #endif
00740 
00741 #define AST_RWLOCK_DEFINE_STATIC(rwlock) __AST_RWLOCK_DEFINE(static, rwlock)
00742 
00743 /*
00744  * Initial support for atomic instructions.
00745  * For platforms that have it, use the native cpu instruction to
00746  * implement them. For other platforms, resort to a 'slow' version
00747  * (defined in utils.c) that protects the atomic instruction with
00748  * a single lock.
00749  * The slow versions is always available, for testing purposes,
00750  * as ast_atomic_fetchadd_int_slow()
00751  */
00752 
00753 int ast_atomic_fetchadd_int_slow(volatile int *p, int v);
00754 
00755 #include "asterisk/inline_api.h"
00756 
00757 #if defined(HAVE_OSX_ATOMICS)
00758 #include "libkern/OSAtomic.h"
00759 #endif
00760 
00761 /*! \brief Atomically add v to *p and return * the previous value of *p.
00762  * This can be used to handle reference counts, and the return value
00763  * can be used to generate unique identifiers.
00764  */
00765 
00766 #if defined(HAVE_GCC_ATOMICS)
00767 AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
00768 {
00769    return __sync_fetch_and_add(p, v);
00770 })
00771 #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4)
00772 AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
00773 {
00774    return OSAtomicAdd32(v, (int32_t *) p);
00775 })
00776 #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8)
00777 AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
00778 {
00779    return OSAtomicAdd64(v, (int64_t *) p);
00780 #elif defined (__i386__)
00781 AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
00782 {
00783    __asm __volatile (
00784    "       lock   xaddl   %0, %1 ;        "
00785    : "+r" (v),                     /* 0 (result) */   
00786      "=m" (*p)                     /* 1 */
00787    : "m" (*p));                    /* 2 */
00788    return (v);
00789 })
00790 #else   /* low performance version in utils.c */
00791 AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v),
00792 {
00793    return ast_atomic_fetchadd_int_slow(p, v);
00794 })
00795 #endif
00796 
00797 /*! \brief decrement *p by 1 and return true if the variable has reached 0.
00798  * Useful e.g. to check if a refcount has reached 0.
00799  */
00800 #if defined(HAVE_GCC_ATOMICS)
00801 AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
00802 {
00803    return __sync_sub_and_fetch(p, 1) == 0;
00804 })
00805 #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4)
00806 AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
00807 {
00808    return OSAtomicAdd32( -1, (int32_t *) p) == 0;
00809 })
00810 #elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8)
00811 AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
00812 {
00813    return OSAtomicAdd64( -1, (int64_t *) p) == 0;
00814 #else
00815 AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
00816 {
00817    int a = ast_atomic_fetchadd_int(p, -1);
00818    return a == 1; /* true if the value is 0 now (so it was 1 previously) */
00819 })
00820 #endif
00821 
00822 #ifndef DEBUG_CHANNEL_LOCKS
00823 /*! \brief Lock a channel. If DEBUG_CHANNEL_LOCKS is defined 
00824    in the Makefile, print relevant output for debugging */
00825 #define ast_channel_lock(x)      ast_mutex_lock(&x->lock)
00826 /*! \brief Unlock a channel. If DEBUG_CHANNEL_LOCKS is defined 
00827    in the Makefile, print relevant output for debugging */
00828 #define ast_channel_unlock(x)    ast_mutex_unlock(&x->lock)
00829 /*! \brief Try locking a channel. If DEBUG_CHANNEL_LOCKS is defined 
00830    in the Makefile, print relevant output for debugging */
00831 #define ast_channel_trylock(x)      ast_mutex_trylock(&x->lock)
00832 #else
00833 
00834 struct ast_channel;
00835 
00836 /*! \brief Lock AST channel (and print debugging output)
00837 \note You need to enable DEBUG_CHANNEL_LOCKS for this function */
00838 int ast_channel_lock(struct ast_channel *chan);
00839 
00840 /*! \brief Unlock AST channel (and print debugging output)
00841 \note You need to enable DEBUG_CHANNEL_LOCKS for this function
00842 */
00843 int ast_channel_unlock(struct ast_channel *chan);
00844 
00845 /*! \brief Lock AST channel (and print debugging output)
00846 \note   You need to enable DEBUG_CHANNEL_LOCKS for this function */
00847 int ast_channel_trylock(struct ast_channel *chan);
00848 #endif
00849 
00850 #endif /* _ASTERISK_LOCK_H */

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