testcases/open_posix_testsuite/conformance/interfaces/pthread_cond_signal/1-1.c

/*
 * Copyright (c) 2002, Intel Corporation. All rights reserved.
 * Created by:  bing.wei.liu REMOVE-THIS AT intel DOT com
 * This file is licensed under the GPL license.  For the full content
 * of this license, see the COPYING file at the top level of this
 * source tree.

 * Test that pthread_cond_signal()
 *   shall unblock at least one of the threads currently blocked on
 *   the specified condition variable cond.
 */


#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include "posixtest.h"

#define THREAD_NUM  3

struct testdata {
	pthread_mutex_t mutex;
	pthread_cond_t cond;
} td;

pthread_t thread[THREAD_NUM];

int start_num = 0;
int waken_num = 0;

/* Alarm handler */
void alarm_handler(int signo)
{
	int i;
	printf("Error: failed to wakeup all threads\n");
	for (i = 0; i < THREAD_NUM; i++) {	/* cancel threads */
		pthread_cancel(thread[i]);
	}

	exit(PTS_UNRESOLVED);
}

void *thr_func(void *arg)
{
	int rc;
	pthread_t self = pthread_self();

	if (pthread_mutex_lock(&td.mutex) != 0) {
		fprintf(stderr, "[Thread 0x%p] failed to acquire the mutex\n",
			(void *)self);
		exit(PTS_UNRESOLVED);
	}
	start_num++;
	fprintf(stderr, "[Thread 0x%p] started and locked the mutex\n",
		(void *)self);

	fprintf(stderr, "[Thread 0x%p] is waiting for the cond\n",
		(void *)self);
	rc = pthread_cond_wait(&td.cond, &td.mutex);
	if (rc != 0) {
		fprintf(stderr, "pthread_cond_wait return %d\n", rc);
		exit(PTS_UNRESOLVED);
	}
	waken_num++;
	fprintf(stderr,
		"[Thread 0x%p] was wakened and acquired the mutex again\n",
		(void *)self);

	if (pthread_mutex_unlock(&td.mutex) != 0) {
		fprintf(stderr, "[Thread 0x%p] failed to release the mutex\n",
			(void *)self);
		exit(PTS_UNRESOLVED);
	}
	fprintf(stderr, "[Thread 0x%p] released the mutex\n", (void *)self);
	return NULL;
}

int main(void)
{
	int i, rc;
	struct sigaction act;

	if (pthread_mutex_init(&td.mutex, NULL) != 0) {
		fprintf(stderr, "Fail to initialize mutex\n");
		return PTS_UNRESOLVED;
	}
	if (pthread_cond_init(&td.cond, NULL) != 0) {
		fprintf(stderr, "Fail to initialize cond\n");
		return PTS_UNRESOLVED;
	}

	for (i = 0; i < THREAD_NUM; i++) {	/* create THREAD_NUM threads */
		if (pthread_create(&thread[i], NULL, thr_func, NULL) != 0) {
			fprintf(stderr, "Fail to create thread[%d]\n", i);
			exit(PTS_UNRESOLVED);
		}
	}
	while (start_num < THREAD_NUM)	/* waiting for all threads started */
		usleep(100);

	/* Acquire the mutex to make sure that all waiters are currently
	   blocked on pthread_cond_wait */
	if (pthread_mutex_lock(&td.mutex) != 0) {
		fprintf(stderr, "Main: Fail to acquire mutex\n");
		exit(PTS_UNRESOLVED);
	}
	if (pthread_mutex_unlock(&td.mutex) != 0) {
		fprintf(stderr, "Main: Fail to release mutex\n");
		exit(PTS_UNRESOLVED);
	}

	/* signal once and check if at least one waiter is wakened */
	fprintf(stderr, "[Main thread] signals a condition\n");
	rc = pthread_cond_signal(&td.cond);
	if (rc != 0) {
		fprintf(stderr,
			"[Main thread] failed to signal the condition\n");
		exit(PTS_UNRESOLVED);
	}
	sleep(1);
	if (waken_num <= 0) {
		fprintf(stderr, "[Main thread] but no waiters were wakened\n");
		printf("Test FAILED\n");
		/* Cancel the threads */
		for (i = 0; i < THREAD_NUM; i++) {	/* cancel threads */
			pthread_cancel(thread[i]);
		}
		exit(PTS_FAIL);
	}
	fprintf(stderr, "[Main thread] %d waiters were wakened\n", waken_num);

	/* Setup alarm handler */
	act.sa_handler = alarm_handler;
	act.sa_flags = 0;
	sigemptyset(&act.sa_mask);
	sigaction(SIGALRM, &act, 0);
	alarm(5);

	/* loop to wake up the rest threads */
	for (i = 1; i < THREAD_NUM; i++) {
		fprintf(stderr,
			"[Main thread] signals to wake up the next thread\n");
		if (pthread_cond_signal(&td.cond) != 0) {
			fprintf(stderr,
				"Main failed to signal the condition\n");
			exit(PTS_UNRESOLVED);
		}
		usleep(100);
	}

	/* join all secondary threads */
	for (i = 0; i < THREAD_NUM; i++) {
		if (pthread_join(thread[i], NULL) != 0) {
			fprintf(stderr, "Fail to join thread[%d]\n", i);
			exit(PTS_UNRESOLVED);
		}
	}
	printf("Test PASSED\n");
	return PTS_PASS;
}