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kc3-lang/libevent/evthread_pthread.c

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  • Author : Nick Mathewson
    Date : 2009-07-17 20:22:56
    Hash : 4ba6eda4
    Message : Make evthread_use_pthreads() actually return 0 on success. svn:r1356

  • evthread_pthread.c
  • /*
     * Copyright 2009 Niels Provos and Nick Mathewson
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    #ifdef HAVE_CONFIG_H
    #include "event-config.h"
    #endif
    
    /* With glibc we need to define this to get PTHREAD_MUTEX_RECURSIVE. */
    #define _GNU_SOURCE
    #include <pthread.h>
    
    struct event_base;
    #include <event2/thread.h>
    
    #include "mm-internal.h"
    
    static pthread_mutexattr_t attr_recursive;
    
    static void *
    evthread_posix_lock_create(void)
    {
    	pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t));
    	if (!lock)
    		return NULL;
    	if (pthread_mutex_init(lock, &attr_recursive)) {
    		mm_free(lock);
    		return NULL;
    	}
    	return lock;
    }
    
    static void
    evthread_posix_lock_free(void *_lock)
    {
    	pthread_mutex_t *lock = _lock;
    	pthread_mutex_destroy(lock);
    	mm_free(lock);
    }
    
    static void
    evthread_posix_lock(int mode, void *_lock)
    {
    	pthread_mutex_t *lock = _lock;
    	if (0 != (mode & EVTHREAD_LOCK))
    		pthread_mutex_lock(lock);
    	else
    		pthread_mutex_unlock(lock);
    }
    
    static unsigned long
    evthread_posix_get_id(void)
    {
    	union {
    		pthread_t thr;
    		unsigned long id;
    	} r;
    	r.thr = pthread_self();
    	return r.id;
    }
    
    int
    evthread_use_pthreads(void)
    {
    	/* Set ourselves up to get recursive locks. */
    	if (pthread_mutexattr_init(&attr_recursive))
    		return -1;
    	if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE))
    		return -1;
    
    	evthread_set_lock_create_callbacks(
    	    evthread_posix_lock_create,
    	    evthread_posix_lock_free);
    	evthread_set_locking_callback(evthread_posix_lock);
    	evthread_set_id_callback(evthread_posix_get_id);
    	return 0;
    }