test_locks.py 文件源码

def run_deadlock_avoidance_test(self, create_deadlock):
        NLOCKS = 10
        locks = [self.LockType(str(i)) for i in range(NLOCKS)]
        pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
        if create_deadlock:
            NTHREADS = NLOCKS
        else:
            NTHREADS = NLOCKS - 1
        barrier = threading.Barrier(NTHREADS)
        results = []
        def _acquire(lock):
            """Try to acquire the lock. Return True on success, False on deadlock."""
            try:
                lock.acquire()
            except self.DeadlockError:
                return False
            else:
                return True
        def f():
            a, b = pairs.pop()
            ra = _acquire(a)
            barrier.wait()
            rb = _acquire(b)
            results.append((ra, rb))
            if rb:
                b.release()
            if ra:
                a.release()
        lock_tests.Bunch(f, NTHREADS).wait_for_finished()
        self.assertEqual(len(results), NTHREADS)
        return results