/* * mutex3.c * * Declare a static mutex object, lock it, trylock it, * and then unlock it again. * * Depends on API functions: * pthread_mutex_lock() * pthread_mutex_trylock() * pthread_mutex_unlock() */ #include "test.h" pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER; static int washere = 0; void * func(void * arg) { assert(pthread_mutex_trylock(&mutex1) == EBUSY); washere = 1; return 0; } int main() { pthread_t t; assert(pthread_mutex_lock(&mutex1) == 0); assert(pthread_create(&t, NULL, func, NULL) == 0); assert(pthread_join(t, NULL) == 0); assert(pthread_mutex_unlock(&mutex1) == 0); assert(washere == 1); return 0; }