51 lines
1.6 KiB
Python
51 lines
1.6 KiB
Python
from contextlib import suppress
|
|
from os import O_NONBLOCK, O_RDONLY, close
|
|
from os import open as osopen
|
|
from queue import Queue
|
|
from threading import Thread
|
|
|
|
from .terminate_process_on_failure import terminate_process_on_failure
|
|
|
|
|
|
class PipeWriterThread(Thread):
|
|
def __init__(self, pipe_path, stop_event):
|
|
super().__init__()
|
|
self._pipe_path = pipe_path
|
|
self._stop_event = stop_event
|
|
self._write_queue = Queue()
|
|
|
|
def write(self, message):
|
|
self._write_queue.put(message, block=False)
|
|
|
|
@terminate_process_on_failure
|
|
def run(self):
|
|
with self._open() as pipe:
|
|
while True:
|
|
message = self._write_queue.get(block=True)
|
|
if message is None:
|
|
self._stop_event.set()
|
|
break
|
|
try:
|
|
pipe.write(message + b'\n')
|
|
pipe.flush()
|
|
except BrokenPipeError:
|
|
try: # pipe was reopened, close() flushed the message
|
|
pipe.close()
|
|
except BrokenPipeError: # close() discarded the message
|
|
# TODO: a message is lost here, implement thread safe, blocking deque
|
|
pass
|
|
pipe = self._open()
|
|
|
|
def _open(self):
|
|
return open(self._pipe_path, 'wb')
|
|
|
|
def stop(self):
|
|
self.unblock()
|
|
self.join()
|
|
|
|
def unblock(self):
|
|
self._write_queue.put(None)
|
|
with suppress(OSError):
|
|
fd = osopen(self._pipe_path, O_RDONLY | O_NONBLOCK)
|
|
close(fd)
|