[Python-checkins] bpo-38019: correctly handle pause/resume reading of closed asyncio unix pipe (GH-16472)

Sun Sep 29 08:19:15 EDT 2019

https://github.com/python/cpython/commit/1c3e4691bb41fa070d6f4836cb03005123e53e4b
commit: 1c3e4691bb41fa070d6f4836cb03005123e53e4b
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2019年09月29日T05:19:11-07:00
summary:
bpo-38019: correctly handle pause/resume reading of closed asyncio unix pipe (GH-16472)
(cherry picked from commit 58498bc7178608b1ab031994ca09c43889ce3e76)
Co-authored-by: Andrew Svetlov <andrew.svetlov at gmail.com>
files:
A Misc/NEWS.d/next/Library/2019-09-29-13-50-24.bpo-38019.6MoOE3.rst
M Lib/asyncio/unix_events.py
M Lib/test/test_asyncio/test_unix_events.py

diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py
index a0fc996d23a0..7034fc28d3e1 100644
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
@@ -431,6 +431,7 @@ def __init__(self, loop, pipe, protocol, waiter=None, extra=None):
 self._fileno = pipe.fileno()
 self._protocol = protocol
 self._closing = False
+ self._paused = False
 
 mode = os.fstat(self._fileno).st_mode
 if not (stat.S_ISFIFO(mode) or
@@ -492,10 +493,20 @@ def _read_ready(self):
 self._loop.call_soon(self._call_connection_lost, None)
 
 def pause_reading(self):
+ if self._closing or self._paused:
+ return
+ self._paused = True
 self._loop._remove_reader(self._fileno)
+ if self._loop.get_debug():
+ logger.debug("%r pauses reading", self)
 
 def resume_reading(self):
+ if self._closing or not self._paused:
+ return
+ self._paused = False
 self._loop._add_reader(self._fileno, self._read_ready)
+ if self._loop.get_debug():
+ logger.debug("%r resumes reading", self)
 
 def set_protocol(self, protocol):
 self._protocol = protocol
diff --git a/Lib/test/test_asyncio/test_unix_events.py b/Lib/test/test_asyncio/test_unix_events.py
index ec171fa83da3..66a6bc168031 100644
--- a/Lib/test/test_asyncio/test_unix_events.py
+++ b/Lib/test/test_asyncio/test_unix_events.py
@@ -722,6 +722,7 @@ def test_pause_reading(self, m_read):
 @mock.patch('os.read')
 def test_resume_reading(self, m_read):
 tr = self.read_pipe_transport()
+ tr.pause_reading()
 tr.resume_reading()
 self.loop.assert_reader(5, tr._read_ready)
 
@@ -776,6 +777,32 @@ def test__call_connection_lost_with_err(self):
 self.assertIsNone(tr._protocol)
 self.assertIsNone(tr._loop)
 
+ def test_pause_reading_on_closed_pipe(self):
+ tr = self.read_pipe_transport()
+ tr.close()
+ test_utils.run_briefly(self.loop)
+ self.assertIsNone(tr._loop)
+ tr.pause_reading()
+
+ def test_pause_reading_on_paused_pipe(self):
+ tr = self.read_pipe_transport()
+ tr.pause_reading()
+ # the second call should do nothing
+ tr.pause_reading()
+
+ def test_resume_reading_on_closed_pipe(self):
+ tr = self.read_pipe_transport()
+ tr.close()
+ test_utils.run_briefly(self.loop)
+ self.assertIsNone(tr._loop)
+ tr.resume_reading()
+
+ def test_resume_reading_on_paused_pipe(self):
+ tr = self.read_pipe_transport()
+ # the pipe is not paused
+ # resuming should do nothing
+ tr.resume_reading()
+
 
 class UnixWritePipeTransportTests(test_utils.TestCase):
 
diff --git a/Misc/NEWS.d/next/Library/2019-09-29-13-50-24.bpo-38019.6MoOE3.rst b/Misc/NEWS.d/next/Library/2019-09-29-13-50-24.bpo-38019.6MoOE3.rst
new file mode 100644
index 000000000000..aa5a23de2460
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-09-29-13-50-24.bpo-38019.6MoOE3.rst
@@ -0,0 +1 @@
+Correctly handle pause/resume reading of closed asyncio unix pipe.
