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/*
* Copyright (C) 2010 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*/
/* This program is used to test that sem_post() will wake up all
* threads that are waiting on a single semaphore, and not all of
* them.
*/
#include <pthread.h>
#include <semaphore.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
static sem_t semaphore;
/* Thread function, just wait for the semaphore */
static void*
thread_func(void* arg)
{
sem_t *psem = (sem_t *)arg;
void *me = (void *)pthread_self();
printf("thread %p waiting\n", me);
sem_wait(psem);
printf("thread %p exiting\n", me);
return me;
}
#define MAX_THREADS 50
int main(void)
{
pthread_t t[MAX_THREADS];
int nn, value;
/* Initialize to 1, first thread will exit immediately.
* this is used to exercize more of the semaphore code path */
if ( sem_init( &semaphore, 0, 1 ) < 0 ) {
printf( "Could not initialize semaphore: %s\n", strerror(errno) );
return 1;
}
for ( nn = 0; nn < MAX_THREADS; nn++ ) {
if ( pthread_create( &t[nn], NULL, thread_func, &semaphore ) < 0 ) {
printf("Could not create thread %d: %s\n", nn+1, strerror(errno) );
return 2;
}
}
sleep( 1 );
for (nn = 0; nn < MAX_THREADS; nn++) {
sem_post(&semaphore);
}
for ( nn = 0; nn < MAX_THREADS; nn++) {
void* result;
pthread_join(t[nn], &result);
if (result != (void*)t[nn]) {
printf("Thread %p joined but returned %p\n", (void*)t[nn], result);
}
}
if (sem_getvalue(&semaphore, &value) < 0) {
printf("Could not get semaphore value: %s\n", strerror(errno));
return 3;
}
if (value != 1) {
printf("Error: Semaphore value = %d\n", value);
return 4;
}
return 0;
}
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