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_create(void) 42 { 43 pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t)); 44 if (!lock) 45 return NULL; 46 if (pthread_mutex_init(lock, &attr_recursive)) { 47 mm_free(lock); 48 return NULL; 49 } 50 return lock; 51 } 52 53 static void 54 evthread_posix_lock_free(void *_lock) 55 { 56 pthread_mutex_t *lock = _lock; 57 pthread_mutex_destroy(lock); 58 mm_free(lock); 59 } 60 61 static void 62 evthread_posix_lock(int mode, void *_lock) 63 { 64 pthread_mutex_t *lock = _lock; 65 if (0 != (mode & EVTHREAD_LOCK)) 66 pthread_mutex_lock(lock); 67 else 68 pthread_mutex_unlock(lock); 69 } 70 71 static unsigned long 72 evthread_posix_get_id(void) 73 { 74 union { 75 pthread_t thr; 76 unsigned long id; 77 } r; 78 r.thr = pthread_self(); 79 return r.id; 80 } 81 82 int 83 evthread_use_pthreads(void) 84 { 85 /* Set ourselves up to get recursive locks. */ 86 if (pthread_mutexattr_init(&attr_recursive)) 87 return -1; 88 if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE)) 89 return -1; 90 91 evthread_set_lock_create_callbacks( 92 evthread_posix_lock_create, 93 evthread_posix_lock_free); 94 evthread_set_locking_callback(evthread_posix_lock); 95 evthread_set_id_callback(evthread_posix_get_id); 96 return 0; 97 } 98