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/*
* Copyright (C) 2019 Intel Corporation. All rights reserved.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*/
#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
static pthread_mutex_t mutex;
static pthread_cond_t cond;
static sem_t *sem;
static void *
thread(void *arg)
{
int *num = (int *)arg;
pthread_mutex_lock(&mutex);
printf("thread start \n");
for (int i = 0; i < 10; i++) {
*num = *num + 1;
printf("num: %d\n", *num);
}
pthread_cond_signal(&cond);
pthread_mutex_unlock(&mutex);
sem_post(sem);
printf("thread exit \n");
return NULL;
}
int
main(int argc, char *argv[])
{
pthread_t tid;
int num = 0, ret = -1;
if (pthread_mutex_init(&mutex, NULL) != 0) {
printf("Failed to init mutex.\n");
return -1;
}
if (pthread_cond_init(&cond, NULL) != 0) {
printf("Failed to init cond.\n");
goto fail1;
}
// O_CREAT and S_IRGRPS_IRGRP | S_IWGRP on linux (glibc), initial value is 0
if (!(sem = sem_open("tessstsem", 0100, 0x10 | 0x20, 0))) {
printf("Failed to open sem. %p\n", sem);
goto fail2;
}
pthread_mutex_lock(&mutex);
if (pthread_create(&tid, NULL, thread, &num) != 0) {
printf("Failed to create thread.\n");
pthread_mutex_unlock(&mutex);
goto fail3;
}
printf("cond wait start\n");
pthread_cond_wait(&cond, &mutex);
pthread_mutex_unlock(&mutex);
printf("cond wait success.\n");
if (sem_wait(sem) != 0) {
printf("Failed to wait sem.\n");
}
else {
printf("sem wait success.\n");
}
if (pthread_join(tid, NULL) != 0) {
printf("Failed to join thread.\n");
}
ret = 0;
fail3:
sem_close(sem);
sem_unlink("tessstsem");
fail2:
pthread_cond_destroy(&cond);
fail1:
pthread_mutex_destroy(&mutex);
return ret;
}
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