Stopping and restarting a proactor event loop on windows can lead to
spurious errors logged (ConnectionResetError while reading from the
self pipe). This fixes the issue by ensuring that we don't attempt
to start multiple copies of the self-pipe reading loop.
This will address the common mistake many asyncio users make:
an "except Exception" clause breaking Tasks cancellation.
In addition to this change, we stop inheriting asyncio.TimeoutError
and asyncio.InvalidStateError from their concurrent.futures.*
counterparts. There's no point for these exceptions to share the
inheritance chain.
In 3.9 we'll focus on implementing supervisors and cancel scopes,
which should allow better handling of all exceptions, including
SystemExit and KeyboardInterrupt
IocpProactor.close() now uses time to decide when to log: wait 1
second before the first log, then log every second. Log also the
number of seconds since close() was called.
* _wait_for_handle(), _register() and _unregister() methods of
IocpProactor now raise an exception if closed
* Add "closed" to IocpProactor.__repr__()
* Simplify IocpProactor.close()
* Convert asyncio/tasks.py to async/await
* Convert asyncio/queues.py to async/await
* Convert asyncio/test_utils.py to async/await
* Convert asyncio/base_subprocess.py to async/await
* Convert asyncio/subprocess.py to async/await
* Convert asyncio/streams.py to async/await
* Fix comments
* Convert asyncio/locks.py to async/await
* Convert asyncio.sleep to async def
* Add a comment
* Add missing news
* Convert stubs from AbstrctEventLoop to async functions
* Convert subprocess_shell/subprocess_exec
* Convert connect_read_pipe/connect_write_pip to async/await syntax
* Convert create_datagram_endpoint
* Convert create_unix_server/create_unix_connection
* Get rid of old style coroutines in unix_events.py
* Convert selector_events.py to async/await
* Convert wait_closed and create_connection
* Drop redundant line
* Convert base_events.py
* Code cleanup
* Drop redundant comments
* Fix indentation
* Add explicit tests for compatibility between old and new coroutines
* Convert windows event loop to use async/await
* Fix double awaiting of async function
* Convert asyncio/locks.py
* Improve docstring
* Convert tests to async/await
* Convert more tests
* Convert more tests
* Convert more tests
* Convert tests
* Improve test
* Remove asyncio.selectors and asyncio._overlapped symbols from the
namespace of the asyncio module
* Replace "from asyncio import selectors" with "import selectors"
* Replace "from asyncio import _overlapped" with "import _overlapped"
asyncio.selectors was added to support Python 3.3, which doesn't have
selectors in its standard library, and Python 3.4 in the same code
base. Same rationale for asyncio._overlapped. Python 3.3 reached its
end of life, and asyncio is no more maintained as a third party
module on PyPI.
Issue #23347: send_signal(), kill() and terminate() methods of
BaseSubprocessTransport now check if the transport was closed and if the
process exited.
Issue #23347: Refactor creation of subprocess transports. Changes on
BaseSubprocessTransport:
* Add a wait() method to wait until the child process exit
* The constructor now accepts an optional waiter parameter. The _post_init()
coroutine must not be called explicitly anymore. It makes subprocess
transports closer to other transports, and it gives more freedom if we want
later to change completly how subprocess transports are created.
* close() now kills the process instead of kindly terminate it: the child
process may ignore SIGTERM and continue to run. Call explicitly terminate()
and wait() if you want to kindly terminate the child process.
* close() now logs a warning in debug mode if the process is still running and
needs to be killed
* _make_subprocess_transport() is now fully asynchronous again: if the creation
of the transport failed, wait asynchronously for the process eixt. Before the
wait was synchronous. This change requires close() to *kill*, and not
terminate, the child process.
* Remove the _kill_wait() method, replaced with a more agressive close()
method. It fixes _make_subprocess_transport() on error.
BaseSubprocessTransport.close() calls the close() method of pipe transports,
whereas _kill_wait() closed directly pipes of the subprocess.Popen object
without unregistering file descriptors from the selector (which caused severe
bugs).
These changes simplifies the code of subprocess.py.
If ReadFile() fails with ERROR_BROKEN_PIPE, the operation is not pending: don't
register the overlapped.
I don't know if WSARecv() can fail with ERROR_BROKEN_PIPE. Since
Overlapped.WSARecv() already handled ERROR_BROKEN_PIPE, let me guess that it
has the same behaviour than ReadFile().
If UnregisterWaitEx() fais with ERROR_IO_PENDING, it doesn't mean that the wait
is unregistered yet. We still have to wait until the wait is cancelled.
Use a coroutine with asyncio.sleep() instead of call_later() to ensure that the
schedule call is cancelled.
Add also a unit test cancelling connect_pipe().
Overlapped.ConnectNamedPipe() now returns a boolean: True if the pipe is
connected (if ConnectNamedPipe() failed with ERROR_PIPE_CONNECTED), False if
the connection is in progress.
This change removes multiple hacks in IocpProactor.
Add _overlapped.ConnectPipe() which tries to connect to the pipe for
asynchronous I/O (overlapped): call CreateFile() in a loop until it doesn't
fail with ERROR_PIPE_BUSY. Use an increasing delay between 1 ms and 100 ms.
Remove Overlapped.WaitNamedPipeAndConnect() which is no more used.
This change fixes a race conditon related to _WaitHandleFuture.cancel() leading
to Python crash or "GetQueuedCompletionStatus() returned an unexpected event"
logs. Before, the overlapped object was destroyed too early, it was possible
that the wait completed whereas the overlapped object was already destroyed.
Sometimes, a different overlapped was allocated at the same address, leading to
unexpected completition.
_WaitHandleFuture.cancel() now waits until the wait is cancelled to clear its
reference to the overlapped object. To wait until the cancellation is done,
UnregisterWaitEx() is used with an event instead of UnregisterWait().
To wait for this event, a new _WaitCancelFuture class was added. It's a
simplified version of _WaitCancelFuture. For example, its cancel() method calls
UnregisterWait(), not UnregisterWaitEx(). _WaitCancelFuture should not be
cancelled.
The overlapped object is kept alive in _WaitHandleFuture until the wait is
unregistered.
Other changes:
* Add _overlapped.UnregisterWaitEx()
* Remove fast-path in IocpProactor.wait_for_handle() to immediatly set the
result if the wait already completed. I'm not sure that it's safe to
call immediatly UnregisterWaitEx() before the completion was signaled.
* Add IocpProactor._unregistered() to forget an overlapped which may never be
signaled, but may be signaled for the next loop iteration. It avoids to
block forever IocpProactor.close() if a wait was cancelled, and it may also
avoid some "... unexpected event ..." warnings.
Russell Keith-Magee
Thomas Grainger
Guido van Rossum
Dong Uk, Kang
Tony Solomonik
Alex Grönholm
Nikita Sobolev
Ben Darnell
Victor Stinner
Chris Jerdonek
Andrew Svetlov
Yury Selivanov
Victor Stinner
Vladimir Matveev
Victor Stinner
Antoine Pitrou
INADA Naoki
Yury Selivanov
Martin Panter