Method _enqueue_handlers

src/debugpy/common/messaging.py:1388–1415

Enqueues handlers for _run_handlers() to run. `what` is the Message being handled, and is used for logging purposes. If the background thread with _run_handlers() isn't running yet, starts it.

(self, what, *handlers)

            os._exit(1)

    def _enqueue_handlers(self, what, *handlers):
        """Enqueues handlers for _run_handlers() to run.

        `what` is the Message being handled, and is used for logging purposes.

        If the background thread with _run_handlers() isn't running yet, starts it.
        """

        with self:
            self._handler_queue.extend((what, handler) for handler in handlers)
            self._handlers_enqueued.notify_all()

            # If there is anything to handle, but there's no handler thread yet,
            # spin it up. This will normally happen only once, on the first call
            # to _enqueue_handlers(), and that thread will run all the handlers
            # for parsed messages. However, this can also happen is somebody calls
            # Request.on_response() - possibly concurrently from multiple threads -
            # after the channel has already been closed, and the initial handler
            # thread has exited. In this case, we spin up a new thread just to run
            # the enqueued response handlers, and it will exit as soon as it's out
            # of handlers to run.
            if len(self._handler_queue) and self._handler_thread is None:
                self._handler_thread = threading.Thread(
                    target=self._run_handlers,
                    name=f"{self} message handler",
                )
                hide_thread_from_debugger(self._handler_thread)
                self._handler_thread.start()

    def _run_handlers(self):
        """Runs enqueued handlers until the channel is closed, or until the handler