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ftmemsim-valgrind/drd/tests/pth_inconsistent_cond_wait.c
Bart Van Assche c74a787450 Added more comments.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@8594
2008-09-09 18:18:26 +00:00

70 lines
1.6 KiB
C

/** Trigger two kinds of errors: once that condition variable s_cond is
* associated with two different mutexes (s_mutex1 and s_mutex2), and two
* times that pthread_cond_signal() is called without that the mutex
* associated with the condition variable is locked.
*/
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>
pthread_cond_t s_cond;
pthread_mutex_t s_mutex1;
pthread_mutex_t s_mutex2;
sem_t s_sem;
void* thread1(void* arg)
{
pthread_mutex_lock(&s_mutex1);
sem_post(&s_sem);
pthread_cond_wait(&s_cond, &s_mutex1);
pthread_mutex_unlock(&s_mutex1);
return 0;
}
void* thread2(void* arg)
{
pthread_mutex_lock(&s_mutex2);
sem_post(&s_sem);
pthread_cond_wait(&s_cond, &s_mutex2);
pthread_mutex_unlock(&s_mutex2);
return 0;
}
int main(int argc, char** argv)
{
pthread_t tid1;
pthread_t tid2;
/* Initialize synchronization objects. */
sem_init(&s_sem, 0, 0);
pthread_cond_init(&s_cond, 0);
pthread_mutex_init(&s_mutex1, 0);
pthread_mutex_init(&s_mutex2, 0);
/* Create two threads. */
pthread_create(&tid1, 0, &thread1, 0);
pthread_create(&tid2, 0, &thread2, 0);
/* Wait until both threads have called sem_post(). */
sem_wait(&s_sem);
sem_wait(&s_sem);
/* Wait until both threads are waiting inside pthread_cond_wait(). */
pthread_mutex_lock(&s_mutex1);
pthread_mutex_lock(&s_mutex2);
pthread_mutex_unlock(&s_mutex2);
pthread_mutex_unlock(&s_mutex1);
/* Signal s_cond twice. */
pthread_cond_signal(&s_cond);
pthread_cond_signal(&s_cond);
/* Join both threads. */
pthread_join(tid1, 0);
pthread_join(tid2, 0);
return 0;
}