Since Python 3.3, the C signal handler writes the signal number into the wakeup
file descriptor and then schedules the Python call using Py_AddPendingCall().
asyncio uses the wakeup file descriptor to wake up the event loop, and relies
on Py_AddPendingCall() to schedule the final callback with call_soon().
If the C signal handler is called in a thread different than the thread of the
event loop, the loop is awaken but Py_AddPendingCall() was not called yet. In
this case, the event loop has nothing to do and go to sleep again.
Py_AddPendingCall() is called while the event loop is sleeping again and so the
final callback is not scheduled immediatly.
This patch changes how asyncio handles signals. Instead of relying on
Py_AddPendingCall() and the wakeup file descriptor, asyncio now only relies on
the wakeup file descriptor. asyncio reads signal numbers from the wakeup file
descriptor to call its signal handler.
If you want to handle the BrokenPipeError, you can easily reimplement
communicate().
Add also a unit test to ensure that stdin.write() + stdin.drain() raises
BrokenPipeError.
* Tulip issue #184: Log subprocess events in debug mode
- Log stdin, stdout and stderr transports and protocols
- Log process identifier (pid)
- Log connection of pipes
- Log process exit
- Log Process.communicate() tasks: feed stdin, read stdout and stderr
- Add __repr__() method to many classes related to subprocesses
* Add BaseSubprocessTransport._pid attribute. Store the pid so it is still
accessible after the process exited. It's more convinient for debug.
* create_connection(): add the socket in the "connected to" debug log
* Clean up some docstrings and comments. Remove unused unimplemented
_read_from_self().
* Tulip issue #183: log socket events in debug mode
- Log most important socket events: socket connected, new client, connection
reset or closed by peer (EOF), etc.
- Log time elapsed in DNS resolution (getaddrinfo)
- Log pause/resume reading
- Log time of SSL handshake
- Log SSL handshake errors
- Add a __repr__() method to many classes
* Fix ProactorEventLoop() in debug mode. ProactorEventLoop._make_self_pipe()
doesn't call call_soon() directly because it checks for the current loop
which fails, because the method is called to build the event loop.
* Cleanup _ProactorReadPipeTransport constructor. Not need to set again
_read_fut attribute to None, it is already done in the base class.
- loop, waiters and active_count attributes are now private
- attach(), detach() and wakeup() methods are now private
The sockets attribute remains public.
* Tulip issue #182: Improve logs of BaseEventLoop._run_once()
- Don't log non-blocking poll
- Only log polling with a timeout if it gets events or if it timed out after
more than 1 second.
* Fix some pyflakes warnings: remove unused imports
Serhiy Storchaka
Senthil Kumaran
Antoine Pitrou
Victor Stinner
Raymond Hettinger
Benjamin Peterson
Mark Dickinson
Zachary Ware
Berker Peksag
Tal Einat
Terry Jan Reedy
Ned Deily