threadutil.py 文件源码

def _async_raise(tid, exctype):
    """raises the exception, performs cleanup if needed"""
    if not inspect.isclass(exctype):
        raise TypeError("Only types can be raised (not instances)")

    if not issubclass(exctype, BaseException):
        raise ValueError("Only sub classes of BaseException can be raised")

    # PyThreadState_SetAsyncExc requires GIL to be held
    gil_state = ctypes.pythonapi.PyGILState_Ensure()
    try:
        res = ctypes.pythonapi.PyThreadState_SetAsyncExc(ctypes.c_long(tid),
                                                         ctypes.py_object(exctype))
        if res == 0:
            # The thread is likely dead already.
            raise InvalidThreadIdError(tid)

        elif res != 1:
            # If more than one threads are affected (WTF?), we're in trouble, and
            # we try our best to revert the effect, although this may not work.
            ctypes.pythonapi.PyThreadState_SetAsyncExc(ctypes.c_long(tid), None)

            raise AsyncRaiseError("PyThreadState_SetAsyncExc failed", res)

    finally:
        ctypes.pythonapi.PyGILState_Release(gil_state)