asyncio: Fix from Anthony Baire for CPython issue 19566 (replaces earlier fix).
diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py
index 9fced33..b611efd 100644
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
@@ -440,10 +440,13 @@
raise NotImplementedError()
- def set_loop(self, loop):
- """Reattach the watcher to another event loop.
+ def attach_loop(self, loop):
+ """Attach the watcher to an event loop.
- Note: loop may be None
+ If the watcher was previously attached to an event loop, then it is
+ first detached before attaching to the new loop.
+
+ Note: loop may be None.
"""
raise NotImplementedError()
@@ -467,15 +470,11 @@
class BaseChildWatcher(AbstractChildWatcher):
- def __init__(self, loop):
+ def __init__(self):
self._loop = None
- self._callbacks = {}
-
- self.set_loop(loop)
def close(self):
- self.set_loop(None)
- self._callbacks.clear()
+ self.attach_loop(None)
def _do_waitpid(self, expected_pid):
raise NotImplementedError()
@@ -483,7 +482,7 @@
def _do_waitpid_all(self):
raise NotImplementedError()
- def set_loop(self, loop):
+ def attach_loop(self, loop):
assert loop is None or isinstance(loop, events.AbstractEventLoop)
if self._loop is not None:
@@ -497,13 +496,6 @@
# during the switch.
self._do_waitpid_all()
- def remove_child_handler(self, pid):
- try:
- del self._callbacks[pid]
- return True
- except KeyError:
- return False
-
def _sig_chld(self):
try:
self._do_waitpid_all()
@@ -535,6 +527,14 @@
big number of children (O(n) each time SIGCHLD is raised)
"""
+ def __init__(self):
+ super().__init__()
+ self._callbacks = {}
+
+ def close(self):
+ self._callbacks.clear()
+ super().close()
+
def __enter__(self):
return self
@@ -547,6 +547,13 @@
# Prevent a race condition in case the child is already terminated.
self._do_waitpid(pid)
+ def remove_child_handler(self, pid):
+ try:
+ del self._callbacks[pid]
+ return True
+ except KeyError:
+ return False
+
def _do_waitpid_all(self):
for pid in list(self._callbacks):
@@ -592,17 +599,17 @@
There is no noticeable overhead when handling a big number of children
(O(1) each time a child terminates).
"""
- def __init__(self, loop):
+ def __init__(self):
+ super().__init__()
+ self._callbacks = {}
self._lock = threading.Lock()
self._zombies = {}
self._forks = 0
- # Call base class constructor last because it calls back into
- # the subclass (set_loop() calls _do_waitpid()).
- super().__init__(loop)
def close(self):
- super().close()
+ self._callbacks.clear()
self._zombies.clear()
+ super().close()
def __enter__(self):
with self._lock:
@@ -643,6 +650,13 @@
else:
callback(pid, returncode, *args)
+ def remove_child_handler(self, pid):
+ try:
+ del self._callbacks[pid]
+ return True
+ except KeyError:
+ return False
+
def _do_waitpid_all(self):
# Because of signal coalescing, we must keep calling waitpid() as
# long as we're able to reap a child.
@@ -687,25 +701,24 @@
def _init_watcher(self):
with events._lock:
if self._watcher is None: # pragma: no branch
+ self._watcher = SafeChildWatcher()
if isinstance(threading.current_thread(),
threading._MainThread):
- self._watcher = SafeChildWatcher(self._local._loop)
- else:
- self._watcher = SafeChildWatcher(None)
+ self._watcher.attach_loop(self._local._loop)
def set_event_loop(self, loop):
"""Set the event loop.
As a side effect, if a child watcher was set before, then calling
- .set_event_loop() from the main thread will call .set_loop(loop) on the
- child watcher.
+ .set_event_loop() from the main thread will call .attach_loop(loop) on
+ the child watcher.
"""
super().set_event_loop(loop)
if self._watcher is not None and \
isinstance(threading.current_thread(), threading._MainThread):
- self._watcher.set_loop(loop)
+ self._watcher.attach_loop(loop)
def get_child_watcher(self):
"""Get the child watcher