test_threading.py 文件源码

def test_tstate_lock(self):
        # Test an implementation detail of Thread objects.
        started = _thread.allocate_lock()
        finish = _thread.allocate_lock()
        started.acquire()
        finish.acquire()
        def f():
            started.release()
            finish.acquire()
            time.sleep(0.01)
        # The tstate lock is None until the thread is started
        t = threading.Thread(target=f)
        self.assertIs(t._tstate_lock, None)
        t.start()
        started.acquire()
        self.assertTrue(t.is_alive())
        # The tstate lock can't be acquired when the thread is running
        # (or suspended).
        tstate_lock = t._tstate_lock
        self.assertFalse(tstate_lock.acquire(timeout=0), False)
        finish.release()
        # When the thread ends, the state_lock can be successfully
        # acquired.
        self.assertTrue(tstate_lock.acquire(timeout=5), False)
        # But is_alive() is still True:  we hold _tstate_lock now, which
        # prevents is_alive() from knowing the thread's end-of-life C code
        # is done.
        self.assertTrue(t.is_alive())
        # Let is_alive() find out the C code is done.
        tstate_lock.release()
        self.assertFalse(t.is_alive())
        # And verify the thread disposed of _tstate_lock.
        self.assertTrue(t._tstate_lock is None)