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 "mm-internal.h" 36 37 static pthread_mutexattr_t attr_recursive; 38 39 static void * 40 evthread_posix_lock_create(void) 41 { 42 pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t)); 43 if (!lock) 44 return NULL; 45 if (pthread_mutex_init(lock, &attr_recursive)) { 46 mm_free(lock); 47 return NULL; 48 } 49 return lock; 50 } 51 52 static void 53 evthread_posix_lock_free(void *_lock) 54 { 55 pthread_mutex_t *lock = _lock; 56 pthread_mutex_destroy(lock); 57 mm_free(lock); 58 } 59 60 static void 61 evthread_posix_lock(int mode, void *_lock) 62 { 63 pthread_mutex_t *lock = _lock; 64 if (0 != (mode & EVTHREAD_LOCK)) 65 pthread_mutex_lock(lock); 66 else 67 pthread_mutex_unlock(lock); 68 } 69 70 static unsigned long 71 evthread_posix_get_id(void) 72 { 73 union { 74 pthread_t thr; 75 unsigned long id; 76 } r; 77 r.thr = pthread_self(); 78 return r.id; 79 } 80 81 int 82 evthread_use_pthreads(void) 83 { 84 /* Set ourselves up to get recursive locks. */ 85 if (pthread_mutexattr_init(&attr_recursive)) 86 return -1; 87 if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE)) 88 return -1; 89 90 evthread_set_lock_create_callbacks( 91 evthread_posix_lock_create, 92 evthread_posix_lock_free); 93 evthread_set_locking_callback(evthread_posix_lock); 94 evthread_set_id_callback(evthread_posix_get_id); 95 return 0; 96 } 97