Attachment 152587 Details for Bug 217067 – test program for trying to reproduce pthread_cond_wait() hangs

test program for trying to reproduce pthread_cond_wait() hangs

futex.c (text/plain), 1.90 KB, created by Ernie Petrides on 2007-04-13 20:52:01 UTC

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Creator: Ernie Petrides

Created: 2007-04-13 20:52:01 UTC

Size: 1.90 KB

patch

obsolete

>/*
> * futex.c
> *
> * compile with:  cc -g -o futex futex.c -lpthread
> */
>
>#include <pthread.h>
>
>#define PADSIZ (1024 - 2 * sizeof(int) \
>	- sizeof(pthread_mutex_t) - sizeof(pthread_cond_t))
>
>struct synch {
>	int sem[2];
>	pthread_mutex_t mutex;
>	pthread_cond_t cond;
>	char pad[PADSIZ];
>};
>
>struct synch race =
>	{ 0, 0, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, "" };
>
>struct synch wake[4] = {
>	{ 0, 0, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, "" },
>	{ 0, 0, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, "" },
>	{ 0, 0, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, "" },
>	{ 0, 0, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, "" },
>};
>
>volatile int hung;
>
>void sleep_on_it(struct synch *p, int x)
>{
>	pthread_mutex_lock(&p->mutex);
>	while (p->sem <= 0)
>		pthread_cond_wait(&p->cond, &p->mutex);
>	p->sem[x]--;
>	pthread_mutex_unlock(&p->mutex);
>}
>
>void wake_it_up(struct synch *p, int x)
>{
>	pthread_mutex_lock(&p->mutex);
>	p->sem[x]++;
>	pthread_cond_signal(&p->cond);
>	pthread_mutex_unlock(&p->mutex);
>}
>
>void *consumer(void *arg)
>{
>	int x = ((struct synch *)arg != &wake[0]);
>
>	for (;;) {
>		sleep_on_it(&race, x);
>		hung = 0;
>		wake_it_up((struct synch *)arg + 0, 0);
>		wake_it_up((struct synch *)arg + 1, 0);
>	}
>}
>
>void *producer(void *arg)
>{
>	int x = ((struct synch *)arg != &wake[0]);
>
>	for (;;) {
>		wake_it_up(&race, x);
>		sleep_on_it((struct synch *)arg + 0, 0);
>		sleep_on_it((struct synch *)arg + 2, 0);
>	}
>}
>
>int main(int argc, char *argv[])
>{
>	pthread_t t1, t2, t3, t4;
>
>	pthread_create(&t1, NULL, consumer, (void *)&wake[0]);
>	pthread_create(&t2, NULL, consumer, (void *)&wake[2]);
>	pthread_create(&t3, NULL, producer, (void *)&wake[0]);
>	pthread_create(&t4, NULL, producer, (void *)&wake[1]);
>
>	do {
>		sleep(1);
>		if (hung++ == 0)
>			write(1, ".", 1);
>	} while (hung < 10);
>
>	write(1, "\nhung for 10 seconds at ", 24);
>	execl("/bin/date", "date", (char *)0);
>	write(1, "?\n", 2);
>	exit(0);
>}

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Attachments on bug 217067: 142001 | 145480 | 145684 | 145993 | 145994 | 145995 | 146161 | 146162 | 150237 | 152587 | 152592 | 161087 | 161088 | 161089 | 161090 | 161091 | 161092 | 161093 | 161094 | 161095