Motivation for this PR (comment from @vstinner in bpo issue):
```
Warning seen o AMD64 Ubuntu Shared 3.x buildbot:
https://buildbot.python.org/all/#/builders/141/builds/2593
test_devnull_output (test.test_a=syncio.test_subprocess.SubprocessThreadedWatcherTests) ...
Warning -- threading_cleanup() failed to cleanup 1 threads (count: 1, dangling: 2)
```
The following implementation details for the new method are TBD:
1) Public vs private
2) Inclusion in `close()`
3) Name
4) Coroutine vs subroutine method
5) *timeout* parameter
If it's a private method, 3, 4, and 5 are significantly less important.
I started with the most minimal implementation that fixes the dangling threads without modifying the regression tests, which I think is particularly important. I typically try to avoid directly modifying existing tests as much as possible unless it's necessary to do so. However, I am open to changing any part of this.
https://bugs.python.org/issue38356
If waitpid() is called elsewhere, waitpid() call fails with
ChildProcessError: use return code 255 in this case, and log a
warning. It ensure that the pidfd file descriptor is closed if this
error occurs.
Capturing exceptions into names can lead to reference cycles though the __traceback__ attribute of the exceptions in some obscure cases that have been reported previously and fixed individually. As these variables are not used anyway, we can remove the binding to reduce the chances of creating reference cycles.
See for example GH-13135
* This just copies the docs from `StreamWriter` and `StreamReader`.
* Add docstring for asyncio functions.
https://bugs.python.org/issue36889
Automerge-Triggered-By: @asvetlov
This PR deprecate explicit loop parameters in all public asyncio APIs
This issues is split to be easier to review.
fourth step: queue.py
https://bugs.python.org/issue36373
This PR deprecate explicit loop parameters in all public asyncio APIs
This issues is split to be easier to review.
Third step: locks.py
https://bugs.python.org/issue36373
This PR deprecate explicit loop parameters in all public asyncio APIs
This issues is split to be easier to review.
Second step: streams.py
https://bugs.python.org/issue36373
Add BaseEventLoop.wait_executor_on_close attribute: true by default.
loop.close() now waits for the default executor to finish by default.
Set loop.wait_executor_on_close attribute to False to not wait for
the executor.
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
This PR proposes a solution to [bpo-35545](https://bugs.python.org/issue35545) by adding an optional `flowinfo` and `scopeid` to `asyncio.base_events._ipaddr_info` to carry the full address information into `_ipaddr_info` and avoid discarding IPv6 specific information.
Changelog entry & regression tests to come.
https://bugs.python.org/issue35545
When the future returned by shield is cancelled, its completion callback of the
inner future is not removed. This makes the callback list of inner inner future
grow each time a shield is created and cancelled.
This change unregisters the callback from the inner future when the outer
future is cancelled.
https://bugs.python.org/issue35125
*Moved from python/asyncio#493.*
This PR fixes issue python/asyncio#480, as explained in [this comment](https://github.com/python/asyncio/issues/480#issuecomment-278703828).
The `_SelectorDatagramTransport.sendto` method has to be modified ~~so `_sock.sendto` is used in all cases (because it is tricky to reliably tell if the socket is connected or not). Could that be an issue for connected sockets?~~ *EDIT* ... so `_sock.send` is used only if `_sock` is connected.
It also protects `socket.getsockname` against `OSError` in `_SelectorTransport`. This might happen on Windows if the socket is not connected (e.g. for UDP broadcasting).
https://bugs.python.org/issue31922
Added two keyword arguments, `delay` and `interleave`, to
`BaseEventLoop.create_connection`. Happy eyeballs is activated if
`delay` is specified.
We now have documentation for the new arguments. `staggered_race()` is in its own module, but not exported to the main asyncio package.
https://bugs.python.org/issue33530
asyncio.ProactorEventLoop now catchs and logs send errors when the
self-pipe is full: BaseProactorEventLoop._write_to_self() now catchs
and logs OSError exceptions, as done by
BaseSelectorEventLoop._write_to_self().
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.
* asyncio: __del__() keep reference to warnings.warn
The __del__() methods of asyncio classes now keep a strong reference
to the warnings.warn() to be able to display the ResourceWarning
warning in more cases. Ensure that the function remains available if
instances are destroyed late during Python shutdown (while module
symbols are cleared).
* Rename warn parameter to _warn
"_warn" name is a hint that it's not the regular warnings.warn()
function.
* _wait_for_handle(), _register() and _unregister() methods of
IocpProactor now raise an exception if closed
* Add "closed" to IocpProactor.__repr__()
* Simplify IocpProactor.close()
bpo-32622, bpo-35682: Fix asyncio.ProactorEventLoop.sendfile(): don't
attempt to set the result of an internal future if it's already done.
Fix asyncio _ProactorBasePipeTransport._force_close(): don't set the
result of _empty_waiter if it's already done.
The call to `_untrack_reader` is performed too soon, causing the protocol
to forget about the reader before `connection_lost` can run and feed the
EOF to the reader. See bpo-35065.
The waiting is pretty normal for any asyncio program, logging its time just adds
a noise to logs without any useful information provided.
https://bugs.python.org/issue34849
* Insert the warn in the asyncio.sleep when the loop argument is used
* Insert the warn in the asyncio.wait and asyncio.wait_for when the loop argument is used
* Better format of the code
* Add news file
* change calls for get_event_loop() to calls for get_running_loop()
* Change message to be more clear in News
* Improve the comments in test_tasks
Store a weak reference to stream readerfor breaking strong references
It breaks the strong reference loop between reader and protocol and allows to detect and close the socket if the stream is deleted (garbage collected)