test_threading.py 文件源码

def test_frame_tstate_tracing(self):
        # Issue #14432: Crash when a generator is created in a C thread that is
        # destroyed while the generator is still used. The issue was that a
        # generator contains a frame, and the frame kept a reference to the
        # Python state of the destroyed C thread. The crash occurs when a trace
        # function is setup.

        def noop_trace(frame, event, arg):
            # no operation
            return noop_trace

        def generator():
            while 1:
                yield "generator"

        def callback():
            if callback.gen is None:
                callback.gen = generator()
            return next(callback.gen)
        callback.gen = None

        old_trace = sys.gettrace()
        sys.settrace(noop_trace)
        try:
            # Install a trace function
            threading.settrace(noop_trace)

            # Create a generator in a C thread which exits after the call
            _testcapi.call_in_temporary_c_thread(callback)

            # Call the generator in a different Python thread, check that the
            # generator didn't keep a reference to the destroyed thread state
            for test in range(3):
                # The trace function is still called here
                callback()
        finally:
            sys.settrace(old_trace)