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kc3-lang/libevent/evthread_pthread.c

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  • Author : Nick Mathewson
    Date : 2012-02-29 15:47:16
    Hash : 946b5841
    Message : Clean up lingering _identifiers.

  • evthread_pthread.c
  • /*
     * Copyright 2009-2012 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.
     */
    #include "event2/event-config.h"
    #include "evconfig-private.h"
    
    /* With glibc we need to define _GNU_SOURCE to get PTHREAD_MUTEX_RECURSIVE.
     * This comes from evconfig-private.h
     */
    #include <pthread.h>
    
    struct event_base;
    #include "event2/thread.h"
    
    #include <stdlib.h>
    #include <string.h>
    #include "mm-internal.h"
    #include "evthread-internal.h"
    
    static pthread_mutexattr_t attr_recursive;
    
    static void *
    evthread_posix_lock_alloc(unsigned locktype)
    {
    	pthread_mutexattr_t *attr = NULL;
    	pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t));
    	if (!lock)
    		return NULL;
    	if (locktype & EVTHREAD_LOCKTYPE_RECURSIVE)
    		attr = &attr_recursive;
    	if (pthread_mutex_init(lock, attr)) {
    		mm_free(lock);
    		return NULL;
    	}
    	return lock;
    }
    
    static void
    evthread_posix_lock_free(void *lock_, unsigned locktype)
    {
    	pthread_mutex_t *lock = lock_;
    	pthread_mutex_destroy(lock);
    	mm_free(lock);
    }
    
    static int
    evthread_posix_lock(unsigned mode, void *lock_)
    {
    	pthread_mutex_t *lock = lock_;
    	if (mode & EVTHREAD_TRY)
    		return pthread_mutex_trylock(lock);
    	else
    		return pthread_mutex_lock(lock);
    }
    
    static int
    evthread_posix_unlock(unsigned mode, void *lock_)
    {
    	pthread_mutex_t *lock = lock_;
    	return pthread_mutex_unlock(lock);
    }
    
    static unsigned long
    evthread_posix_get_id(void)
    {
    	union {
    		pthread_t thr;
    #if EVENT__SIZEOF_PTHREAD_T > EVENT__SIZEOF_LONG
    		ev_uint64_t id;
    #else
    		unsigned long id;
    #endif
    	} r;
    #if EVENT__SIZEOF_PTHREAD_T < EVENT__SIZEOF_LONG
    	memset(&r, 0, sizeof(r));
    #endif
    	r.thr = pthread_self();
    	return (unsigned long)r.id;
    }
    
    static void *
    evthread_posix_cond_alloc(unsigned condflags)
    {
    	pthread_cond_t *cond = mm_malloc(sizeof(pthread_cond_t));
    	if (!cond)
    		return NULL;
    	if (pthread_cond_init(cond, NULL)) {
    		mm_free(cond);
    		return NULL;
    	}
    	return cond;
    }
    
    static void
    evthread_posix_cond_free(void *cond_)
    {
    	pthread_cond_t *cond = cond_;
    	pthread_cond_destroy(cond);
    	mm_free(cond);
    }
    
    static int
    evthread_posix_cond_signal(void *cond_, int broadcast)
    {
    	pthread_cond_t *cond = cond_;
    	int r;
    	if (broadcast)
    		r = pthread_cond_broadcast(cond);
    	else
    		r = pthread_cond_signal(cond);
    	return r ? -1 : 0;
    }
    
    static int
    evthread_posix_cond_wait(void *cond_, void *lock_, const struct timeval *tv)
    {
    	int r;
    	pthread_cond_t *cond = cond_;
    	pthread_mutex_t *lock = lock_;
    
    	if (tv) {
    		struct timeval now, abstime;
    		struct timespec ts;
    		evutil_gettimeofday(&now, NULL);
    		evutil_timeradd(&now, tv, &abstime);
    		ts.tv_sec = abstime.tv_sec;
    		ts.tv_nsec = abstime.tv_usec*1000;
    		r = pthread_cond_timedwait(cond, lock, &ts);
    		if (r == ETIMEDOUT)
    			return 1;
    		else if (r)
    			return -1;
    		else
    			return 0;
    	} else {
    		r = pthread_cond_wait(cond, lock);
    		return r ? -1 : 0;
    	}
    }
    
    int
    evthread_use_pthreads(void)
    {
    	struct evthread_lock_callbacks cbs = {
    		EVTHREAD_LOCK_API_VERSION,
    		EVTHREAD_LOCKTYPE_RECURSIVE,
    		evthread_posix_lock_alloc,
    		evthread_posix_lock_free,
    		evthread_posix_lock,
    		evthread_posix_unlock
    	};
    	struct evthread_condition_callbacks cond_cbs = {
    		EVTHREAD_CONDITION_API_VERSION,
    		evthread_posix_cond_alloc,
    		evthread_posix_cond_free,
    		evthread_posix_cond_signal,
    		evthread_posix_cond_wait
    	};
    	/* 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_callbacks(&cbs);
    	evthread_set_condition_callbacks(&cond_cbs);
    	evthread_set_id_callback(evthread_posix_get_id);
    	return 0;
    }