There is a race condition in create_connection() used with wait_for() to have a
timeout. sock_connect() registers the file descriptor of the socket to be
notified of write event (if connect() raises BlockingIOError). When
create_connection() is cancelled with a TimeoutError, sock_connect() coroutine
gets the exception, but it doesn't unregister the file descriptor for write
event. create_connection() gets the TimeoutError and closes the socket.
If you call again create_connection(), the new socket will likely gets the same
file descriptor, which is still registered in the selector. When sock_connect()
calls add_writer(), it tries to modify the entry instead of creating a new one.
This issue was originally reported in the Trollius project, but the bug comes
from Tulip in fact (Trollius is based on Tulip):
https://bitbucket.org/enovance/trollius/issue/15/after-timeouterror-on-wait_for
This change fixes the race condition. It also makes sock_connect() more
reliable (and portable) is sock.connect() raises an InterruptedError.
* PipeServer.close() now cancels the "accept pipe" future which cancels the
overlapped operation.
* Fix _SelectorTransport.__repr__() if the transport was closed
* Fix debug log in BaseEventLoop.create_connection(): get the socket object
from the transport because SSL transport closes the old socket and creates a
new SSL socket object. Remove also the _SelectorSslTransport._rawsock
attribute: it contained the closed socket (not very useful) and it was not
used.
* Issue #22063: socket operations (sock_recv, sock_sendall, sock_connect,
sock_accept) of the proactor event loop don't raise an exception in debug
mode if the socket are in blocking mode. Overlapped operations also work on
blocking sockets.
* Fix unit tests in debug mode: mock a non-blocking socket for socket
operations which now raise an exception if the socket is blocking.
* _fatal_error() method of _UnixReadPipeTransport and _UnixWritePipeTransport
now log all exceptions in debug mode
* Don't log expected errors in unit tests
* Tulip issue 200: _WaitHandleFuture._unregister_wait() now catchs and logs
exceptions.
* Tulip issue 200: Log errors in debug mode instead of simply ignoring them.
* Tulip issue #196: IocpProactor._poll() clears the reference to the
overlapped operation when the operation is done. It would be better to clear
the reference in a new _OverlappedFuture.set_result() method, but it cannot
be done yet because of a weird bug.
* BaseSelectorEventLoop._write_to_self() now logs errors in debug mode.
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.
* 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 #181: Faster create_connection(). Call directly
waiter.set_result() in the constructor of _ProactorBasePipeTransport and
_SelectorSocketTransport, instead of using of delaying the call with
call_soon().
- Cleanup iscoroutine()
available bytes from the "self pipe", not only a single byte. This change
reduces the risk of having the pipe full and so getting the innocuous
"BlockingIOError: [Errno 11] Resource temporarily unavailable" message.
Add BaseEventLoop._closed attribute and use it to check if the event loop was
closed or not, instead of checking different attributes in each subclass of
BaseEventLoop.
run_forever() and run_until_complete() methods now raise a RuntimeError('Event loop is
closed') exception if the event loop was closed.
BaseProactorEventLoop.close() now also cancels "accept futures".
* Issue #159: Fix windows_utils.socketpair()
- Use "127.0.0.1" (IPv4) or "::1" (IPv6) host instead of "localhost", because
"localhost" may be a different IP address
- Reject also invalid arguments: only AF_INET/AF_INET6 with SOCK_STREAM (and
proto=0) are supported
* Reject add/remove reader/writer when event loop is closed.
* Fix ResourceWarning warnings
Major changes:
- StreamReader.readexactly() now raises an IncompleteReadError if the
end of stream is reached before we received enough bytes, instead of
returning less bytes than requested.
- Unit tests use the main asyncio module instead of submodules like events
- _UnixWritePipeTransport now also supports character devices, as
_UnixReadPipeTransport. Patch written by Jonathan Slenders.
- Export more symbols: BaseEventLoop, BaseProactorEventLoop,
BaseSelectorEventLoop, Queue and Queue sublasses, Empty, Full
between the resolution of the BaseEventLoop.time() method and the resolution of
the selector. The granuarility is used in the scheduler to round time and
deadline.
Victor Stinner
Andrew Svetlov
Guido van Rossum
Yury Selivanov
Christian Heimes
Guido van Rossum
Antoine Pitrou