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().
In debug mode, BaseEventLoop._run_once() now sets the
BaseEventLoop._current_handle attribute to the handle currently executed.
In release mode or when no handle is executed, the attribute is None.
BaseEventLoop.default_exception_handler() displays the traceback of the current
handle if available.
script_helper.assert_python_failure(). No such feature has ever existed,
thus it doesn't do what the comment claims. (It does add a 'without'
variable to the environment of the child process but that was not intended)
mode. Explicitly remove the PYTHONFAULTHANDLER environment variable before
launching a child interpreter when its presence would impact the test (the
reason -E was being used in the first place).
This enables running the test in an environment where other Python environment
variables must be set in order for things to run (such as using PYTHONHOME to
tell an embedded interpreter where it should think it lives).
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.
* Handle correctly CancelledError: just exit
* On error, log the exception and exit
Don't try to close the event loop, it is probably running and so it cannot be
closed.
Python subprocess failure assertion error messages for easier debugging.
Adds a unittest for test.script_helper to confirm that this code works as
it is otherwise uncovered by an already passing test suite that uses it. :)
Serhiy Storchaka
Berker Peksag
Victor Stinner
Benjamin Peterson
R David Murray
Senthil Kumaran
Vinay Sajip
Gregory P. Smith
Zachary Ware
Antoine Pitrou
Ned Deily