diff options
Diffstat (limited to 'Lib/test/test_asyncio/test_subprocess.py')
| -rw-r--r-- | Lib/test/test_asyncio/test_subprocess.py | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Lib/test/test_asyncio/test_subprocess.py b/Lib/test/test_asyncio/test_subprocess.py index 0e9e1ce..d0ab230 100644 --- a/Lib/test/test_asyncio/test_subprocess.py +++ b/Lib/test/test_asyncio/test_subprocess.py @@ -4,6 +4,7 @@ import asyncio import signal import sys import unittest +from unittest import mock from test import support if sys.platform != 'win32': from asyncio import unix_events @@ -161,6 +162,37 @@ class SubprocessMixin: self.loop.run_until_complete(proc.communicate(large_data)) self.loop.run_until_complete(proc.wait()) + def test_pause_reading(self): + @asyncio.coroutine + def test_pause_reading(): + limit = 100 + + code = '\n'.join(( + 'import sys', + 'sys.stdout.write("x" * %s)' % (limit * 2 + 1), + 'sys.stdout.flush()', + )) + proc = yield from asyncio.create_subprocess_exec( + sys.executable, '-c', code, + stdin=asyncio.subprocess.PIPE, + stdout=asyncio.subprocess.PIPE, + limit=limit, + loop=self.loop) + stdout_transport = proc._transport.get_pipe_transport(1) + stdout_transport.pause_reading = mock.Mock() + + yield from proc.wait() + + # The child process produced more than limit bytes of output, + # the stream reader transport should pause the protocol to not + # allocate too much memory. + return stdout_transport.pause_reading.called + + # Issue #22685: Ensure that the stream reader pauses the protocol + # when the child process produces too much data + called = self.loop.run_until_complete(test_pause_reading()) + self.assertTrue(called) + if sys.platform != 'win32': # Unix |