/* Simple possible deadlock */
#include <pthread.h>
static pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t m2 = PTHREAD_MUTEX_INITIALIZER;
static void *t1(void *v)
{
pthread_mutex_lock(&m1);
pthread_mutex_lock(&m2);
pthread_mutex_unlock(&m1);
pthread_mutex_unlock(&m2);
return 0;
}
static void *t2(void *v)
{
pthread_mutex_lock(&m2);
pthread_mutex_lock(&m1);
pthread_mutex_unlock(&m1);
pthread_mutex_unlock(&m2);
return 0;
}
int main()
{
pthread_t a, b;
/* prevent spurious messages from the dynamic linker */
pthread_mutex_lock(&m1);
pthread_mutex_unlock(&m1);
pthread_create(&a, NULL, t1, NULL);
pthread_create(&b, NULL, t2, NULL);
pthread_join(a, NULL);
pthread_join(b, NULL);
return 0;
}