1 /* 2 * Copyright 2009 Niels Provos and Nick Mathewson 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. The name of the author may not be used to endorse or promote products 13 * derived from this software without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 #include "event-config.h" 27 28 /* With glibc we need to define this to get PTHREAD_MUTEX_RECURSIVE. */ 29 #define _GNU_SOURCE 30 #include <pthread.h> 31 32 struct event_base; 33 #include <event2/thread.h> 34 35 #include <stdlib.h> 36 #include "mm-internal.h" 37 38 static pthread_mutexattr_t attr_recursive; 39 40 static void * 41 evthread_posix_lock_alloc(unsigned locktype) 42 { 43 pthread_mutexattr_t *attr = NULL; 44 pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t)); 45 if (!lock) 46 return NULL; 47 if (locktype & EVTHREAD_LOCKTYPE_RECURSIVE) 48 attr = &attr_recursive; 49 if (pthread_mutex_init(lock, attr)) { 50 mm_free(lock); 51 return NULL; 52 } 53 return lock; 54 } 55 56 static void 57 evthread_posix_lock_free(void *_lock, unsigned locktype) 58 { 59 pthread_mutex_t *lock = _lock; 60 pthread_mutex_destroy(lock); 61 mm_free(lock); 62 } 63 64 static int 65 evthread_posix_lock(unsigned mode, void *_lock) 66 { 67 pthread_mutex_t *lock = _lock; 68 if (mode & EVTHREAD_TRY) 69 return pthread_mutex_trylock(lock); 70 else 71 return pthread_mutex_lock(lock); 72 } 73 74 static int 75 evthread_posix_unlock(unsigned mode, void *_lock) 76 { 77 pthread_mutex_t *lock = _lock; 78 return pthread_mutex_unlock(lock); 79 } 80 81 static unsigned long 82 evthread_posix_get_id(void) 83 { 84 union { 85 pthread_t thr; 86 unsigned long id; 87 } r; 88 r.thr = pthread_self(); 89 return r.id; 90 } 91 92 int 93 evthread_use_pthreads(void) 94 { 95 struct evthread_lock_callbacks cbs = { 96 EVTHREAD_LOCK_API_VERSION, 97 EVTHREAD_LOCKTYPE_RECURSIVE, 98 evthread_posix_lock_alloc, 99 evthread_posix_lock_free, 100 evthread_posix_lock, 101 evthread_posix_unlock 102 }; 103 /* Set ourselves up to get recursive locks. */ 104 if (pthread_mutexattr_init(&attr_recursive)) 105 return -1; 106 if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE)) 107 return -1; 108 109 evthread_set_lock_callbacks(&cbs); 110 evthread_set_id_callback(evthread_posix_get_id); 111 return 0; 112 } 113