ChangeLog

Tulip 3.4.4
===========

* Issue #234: Drop asyncio.JoinableQueue on Python 3.5 and newer


2015-02-04: Tulip 3.4.3
=======================

Major changes
-------------

* New SSL implementation using ssl.MemoryBIO. The new implementation requires
  Python 3.5 and newer, otherwise the legacy implementation is used.
* On Python 3.5 and newer usable, the ProactorEventLoop now supports SSL
  thanks to the new SSL implementation.
* Fix multiple resource leaks: close sockets on error, explicitly clear
  references, emit ResourceWarning when event loops and transports are not
  closed explicitly, etc.
* The proactor event loop is now much more reliable (no more known race
  condition).
* Enhance handling of task cancellation.

Changes of the asyncio API
--------------------------

* Export BaseEventLoop symbol in the asyncio namespace
* create_task(), call_soon(), call_soon_threadsafe(), call_later(),
  call_at() and run_in_executor() methods of BaseEventLoop now raise an
  exception if the event loop is closed.
* call_soon(), call_soon_threadsafe(), call_later(), call_at() and
  run_in_executor() methods of BaseEventLoop now raise an exception if the
  callback is a coroutine object.
* BaseEventLoopPolicy.get_event_loop() now always raises a RuntimeError
  if there is no event loop in the curren thread, instead of using an
  assertion (which can be disabld at runtime) and so raises an AssertionError.
* selectors: Selector.get_key() now raises an exception if the selector is
  closed.
* If wait_for() is cancelled, the waited task is also cancelled.
* _UnixSelectorEventLoop.add_signal_handler() now raises an exception if
  the callback is a coroutine object or a coroutine function. It also raises
  an exception if the event loop is closed.

Performances
------------

* sock_connect() doesn't check if the address is already resolved anymore.
  The check is only done in debug mode. Moreover, the check uses inet_pton()
  instead of getaddrinfo(), if inet_pton() is available, because getaddrinfo()
  is slow (around 10 us per call).

Debug
-----

* Better repr() of _ProactorBasePipeTransport, _SelectorTransport,
  _UnixReadPipeTransport and _UnixWritePipeTransport: add closed/closing
  status and the file descriptor
* Add repr(PipeHandle)
* PipeHandle destructor now emits a ResourceWarning is the pipe is not closed
  explicitly.
* In debug mode, call_at() method of BaseEventLoop now raises an exception
  if called from the wrong thread (not from the thread running the event
  loop). Before, it only raised an exception if current thread had an event
  loop.
* A ResourceWarning is now emitted when event loops and transports are
  destroyed before being closed.
* BaseEventLoop.call_exception_handler() now logs the traceback where
  the current handle was created (if no source_traceback was specified).
* BaseSubprocessTransport.close() now logs a warning when the child process is
  still running and the method kills it.

Bug fixes
---------

* windows_utils.socketpair() now reuses socket.socketpair() if available
  (Python 3.5 or newer).
* Fix IocpProactor.accept_pipe(): handle ERROR_PIPE_CONNECTED, it means
  that the pipe is connected. _overlapped.Overlapped.ConnectNamedPipe() now
  returns True on ERROR_PIPE_CONNECTED.
* Rewrite IocpProactor.connect_pipe() using polling to avoid tricky bugs
  if the connection is cancelled, instead of using QueueUserWorkItem() to run
  blocking code.
* Fix IocpProactor.recv(): handle BrokenPipeError, set the result to an empty
  string.
* Fix ProactorEventLoop.start_serving_pipe(): if a client connected while the
  server is closing, drop the client connection.
* Fix a tricky race condition when IocpProactor.wait_for_handle() is
  cancelled: wait until the wait is really cancelled before destroying the
  overlapped object. Unregister also the overlapped operation to not block
  in IocpProactor.close() before the wait will never complete.
* Fix _UnixSubprocessTransport._start(): make the write end of the stdin pipe
  non-inheritable.
* Set more attributes in the body of classes to avoid attribute errors in
  destructors if an error occurred in the constructor.
* Fix SubprocessStreamProtocol.process_exited(): close the transport
  and clear its reference to the transport.
* Fix SubprocessStreamProtocol.connection_made(): set the transport of
  stdout and stderr streams to respect reader buffer limits (stop reading when
  the buffer is full).
* Fix FlowControlMixin constructor: if the loop parameter is None, get the
  current event loop.
* Fix selectors.EpollSelector.select(): don't fail anymore if no file
  descriptor is registered.
* Fix _SelectorTransport: don't wakeup the waiter if it was cancelled
* Fix _SelectorTransport._call_connection_lost(): only call connection_lost()
  if connection_made() was already called.
* Fix BaseSelectorEventLoop._accept_connection(): close the transport on
  error. In debug mode, log errors (ex: SSL handshake failure) on the creation
  of the transport for incoming connection.
* Fix BaseProactorEventLoop.close(): stop the proactor before closing the
  event loop because stopping the proactor may schedule new callbacks, which
  is now forbidden when the event loop is closed.
* Fix wrap_future() to not use a free variable and so not keep a frame alive
  too long.
* Fix formatting of the "Future/Task exception was never retrieved" log: add
  a newline before the traceback.
* WriteSubprocessPipeProto.connection_lost() now clears its reference to the
  subprocess.Popen object.
* If the creation of a subprocess transport fails, the child process is killed
  and the event loop waits asynchronously for its completion.
* BaseEventLoop.run_until_complete() now consumes the exception to not log a
  warning when a BaseException like KeyboardInterrupt is raised and
  run_until_complete() is not a future (but a coroutine object).
* create_connection(), create_datagram_endpoint(), connect_read_pipe() and
  connect_write_pipe() methods of BaseEventLoop now close the transport on
  error.

Other changes
-------------

* Add tox.ini to run tests using tox.
* _FlowControlMixin constructor now requires an event loop.
* Embed asyncio/test_support.py to not depend on test.support of the system
  Python. For example, test.support is not installed by default on Windows.
* selectors.Selector.close() now clears its reference to the mapping object.
* _SelectorTransport and _UnixWritePipeTransport now only starts listening for
  read events after protocol.connection_made() has been called
* _SelectorTransport._fatal_error() now only logs ConnectionAbortedError
  in debug mode.
* BaseProactorEventLoop._loop_self_reading() now handles correctly
  CancelledError (just exit) and logs an error for other exceptions.
* _ProactorBasePipeTransport now clears explicitly references to read and
  write future and to the socket
* BaseSubprocessTransport constructor now calls the internal _connect_pipes()
  method (previously called _post_init()). The constructor now accepts an
  optional waiter parameter to notify when the transport is ready.
* send_signal(), terminate() and kill() methods of BaseSubprocessTransport now
  raise a ProcessLookupError if the process already exited.
* Add run_aiotest.py to run the aiotest test suite
* Add release.py script to build wheel packages on Windows and run unit tests


2014-09-30: Tulip 3.4.2
=======================

New shiny methods like create_task(), better documentation, much better debug
mode, better tests.

asyncio API
-----------

* Add BaseEventLoop.create_task() method: schedule a coroutine object.
  It allows other asyncio implementations to use their own Task class to
  change its behaviour.

* New BaseEventLoop methods:

  - create_task(): schedule a coroutine
  - get_debug()
  - is_closed()
  - set_debug()

* Add _FlowControlMixin.get_write_buffer_limits() method

* sock_recv(), sock_sendall(), sock_connect(), sock_accept() methods of
  SelectorEventLoop now raise an exception if the socket is blocking mode

* Include unix_events/windows_events symbols in asyncio.__all__.
  Examples: SelectorEventLoop, ProactorEventLoop, DefaultEventLoopPolicy.

* attach(), detach(), loop, active_count and waiters attributes of the Server
  class are now private

* BaseEventLoop: run_forever(), run_until_complete() now raises an exception if
  the event loop was closed

* close() now raises an exception if the event loop is running, because pending
  callbacks would be lost

* Queue now accepts a float for the maximum size.

* Process.communicate() now ignores BrokenPipeError and ConnectionResetError
  exceptions, as Popen.communicate() of the subprocess module


Performances
------------

* Optimize handling of cancelled timers


Debug
-----

* Future (and Task), CoroWrapper and Handle now remembers where they were
  created (new _source_traceback object), traceback displayed when errors are
  logged.

* On Python 3.4 and newer, Task destrutor now logs a warning if the task was
  destroyed while it was still pending. It occurs if the last reference
  to the task was removed, while the coroutine didn't finish yet.

* Much more useful events are logged:

  - Event loop closed
  - Network connection
  - Creation of a subprocess
  - Pipe lost
  - Log many errors previously silently ignored
  - SSL handshake failure
  - etc.

* BaseEventLoop._debug is now True if the envrionement variable
  PYTHONASYNCIODEBUG is set

* Log the duration of DNS resolution and SSL handshake

* Log a warning if a callback blocks the event loop longer than 100 ms
  (configurable duration)

* repr(CoroWrapper) and repr(Task) now contains the current status of the
  coroutine (running, done), current filename and line number, and filename and
  line number where the object was created

* Enhance representation (repr) of transports: add the file descriptor, status
  (idle, polling, writing, etc.), size of the write buffer, ...

* Add repr(BaseEventLoop)

* run_until_complete() doesn't log a warning anymore when called with a
  coroutine object which raises an exception.


Bugfixes
--------

* windows_utils.socketpair() now ensures that sockets are closed in case
  of error.

* Rewrite bricks of the IocpProactor() to make it more reliable

* IocpProactor destructor now closes it.

* _OverlappedFuture.set_exception() now cancels the overlapped operation.

* Rewrite _WaitHandleFuture:

  - cancel() is now able to signal the cancellation to the overlapped object
  - _unregister_wait() now catchs and logs exceptions

* PipeServer.close() (class used on Windows) now cancels the accept pipe
  future.

* Rewrite signal handling in the UNIX implementation of SelectorEventLoop:
  use the self-pipe to store pending signals instead of registering a
  signal handler calling directly _handle_signal(). The change fixes a
  race condition.

* create_unix_server(): close the socket on error.

* Fix wait_for()

* Rewrite gather()

* drain() is now a classic coroutine, no more special return value (empty
  tuple)

* Rewrite SelectorEventLoop.sock_connect() to handle correctly timeout

* Process data of the self-pipe faster to accept more pending events,
  especially signals written by signal handlers: the callback reads all pending
  data, not only a single byte

* Don't try to set the result of a Future anymore if it was cancelled
  (explicitly or by a timeout)

* CoroWrapper now works around CPython issue #21209: yield from & custom
  generator classes don't work together, issue with the send() method. It only
  affected asyncio in debug mode on Python older than 3.4.2


Misc changes
------------

* windows_utils.socketpair() now supports IPv6.

* Better documentation (online & docstrings): fill remaining XXX, more examples

* new asyncio.coroutines submodule, to ease maintenance with the trollius
  project: @coroutine, _DEBUG, iscoroutine() and iscoroutinefunction() have
  been moved from asyncio.tasks to asyncio.coroutines

* Cleanup code, ex: remove unused attribute (ex: _rawsock)

* Reuse os.set_blocking() of Python 3.5.

* Close explicitly the event loop in Tulip examples.

* runtests.py now mention if tests are running in release or debug mode.


2014-05-19: Tulip 3.4.1
=======================

2014-02-24: Tulip 0.4.1
=======================

2014-02-10: Tulip 0.3.1
=======================

* Add asyncio.subprocess submodule and the Process class.

2013-11-25: Tulip 0.2.1
=======================

* Add support of subprocesses using transports and protocols.

2013-10-22: Tulip 0.1.1
=======================

* First release.

Creation of the project
=======================

* 2013-10-14: The tulip package was renamed to asyncio.
* 2012-10-16: Creation of the Tulip project, started as mail threads on the
  python-ideas mailing list.