def _testPipeLoggerToPipe(self, test_string, loop=None):
"""
Test PipeLogger writing to a pipe connected to a PipeReader.
This verifies that PipeLogger does not deadlock when writing
to a pipe that's drained by a PipeReader running in the same
process (requires non-blocking write).
"""
producer = PopenProcess(proc=subprocess.Popen(
["bash", "-c", self._echo_cmd % test_string],
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT),
scheduler=loop)
pr, pw = os.pipe()
consumer = producer.pipe_reader = PipeLogger(
background=True,
input_fd=producer.proc.stdout,
log_file_path=os.fdopen(pw, 'wb', 0))
reader = _reader(pr, loop=loop)
yield producer.async_start()
content = yield reader
yield producer.async_wait()
yield consumer.async_wait()
self.assertEqual(producer.returncode, os.EX_OK)
self.assertEqual(consumer.returncode, os.EX_OK)
coroutine_return(content.decode('ascii', 'replace'))
