[WIP] Ensure recovery from BrokenPipeError

[krassowski]

References

Fixes part of #20, and maybe #274. Well, it does not work yet (if I remember correctly), but the tests might come in handy.

Code changes

User-facing changes

Backwards-incompatible changes

Chores

• linted
• tested
• documented
• changelog entry

[doodleEsc]

  183 class LspStdIoWriter(LspStdIoBase):
  184     """Language Server stdio Writer"""
  185
  186     async def write(self) -> None:
  187         """Write to a Language Server until it closes"""
  188         while not self.stream.closed:
  189             message = await self.queue.get()
  190             try:
  191                 body = message.encode("utf-8")
  192                 response = "Content-Length: {}\r\n\r\n{}".format(len(body), message)
  193                 await convert_yielded(self._write_one(response.encode("utf-8")))
  194             except BrokenPipeError:
  195                 #  self.queue.task_done()
  196                 # propagate broken pipe errors
  197                 raise
  198             except Exception:  # pragma: no cover
  199                 # catch other (hopefully mild) exceptions
  200                 self.log.exception("%s couldn't write message: %s", self, response)
  201             finally:
  202                 self.queue.task_done()
  203
  204     @run_on_executor
  205     def _write_one(self, message) -> None:
  206         self.stream.write(message)
  207         self.stream.flush()

Hi @krassowski , I delete the code at line 195 in stdio.py, and it works

1. self.queue.task_done() is called twice, and the BrokenPipeError will be covered by ValueError("task_done() called too many times").
2. The function _write_lsp does not catch BrokenPipeError，then the process will not be initialize again.

#563 #20 #274