asyncio, Tulip issue #136: Add get/set_debug() methods to BaseEventLoopTests.

Add also a PYTHONASYNCIODEBUG environment variable to debug coroutines since
Python startup, to be able to debug coroutines defined directly in the asyncio
module.

3 files changed, 30 insertions, 4 deletions

diff --git a/Doc/library/asyncio-dev.rst b/Doc/library/asyncio-dev.rst
index 90bae84..c5f0d1a 100644
--- a/Doc/library/asyncio-dev.rst
+++ b/Doc/library/asyncio-dev.rst
@@ -1,5 +1,7 @@
 .. currentmodule:: asyncio
 
+.. _asyncio-dev:
+
 Develop with asyncio
 ====================
 
@@ -81,10 +83,10 @@ Detect coroutine objects never scheduled
 When a coroutine function is called but not passed to :func:`async` or to the
 :class:`Task` constructor, it is not scheduled and it is probably a bug.
 
-To detect such bug, set :data:`asyncio.tasks._DEBUG` to ``True``. When the
-coroutine object is destroyed by the garbage collector, a log will be emitted
-with the traceback where the coroutine function was called. See the
-:ref:`asyncio logger <asyncio-logger>`.
+To detect such bug, set the environment variable :envvar:`PYTHONASYNCIODEBUG`
+to ``1``. When the coroutine object is destroyed by the garbage collector, a
+log will be emitted with the traceback where the coroutine function was called.
+See the :ref:`asyncio logger <asyncio-logger>`.
 
 The debug flag changes the behaviour of the :func:`coroutine` decorator. The
 debug flag value is only used when then coroutine function is defined, not when
diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index f056cac..04b182b 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -553,6 +553,22 @@ pool of processes). By default, an event loop uses a thread pool executor
    Set the default executor used by :meth:`run_in_executor`.
 
 
+Debug mode
+----------
+
+.. method:: BaseEventLoop.get_debug()
+
+   Get the debug mode (:class:`bool`) of the event loop.
+
+.. method:: BaseEventLoop.set_debug(enabled: bool)
+
+   Set the debug mode of the event loop.
+
+.. seealso::
+
+   The :ref:`Develop with asyncio <asyncio-dev>` section.
+
+
 Server
 ------
 
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 4807a36..0c3c203 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -614,6 +614,14 @@ conflict.
    .. versionadded:: 3.4
 
 
+.. envvar:: PYTHONASYNCIODEBUG
+
+   If this environment variable is set to a non-empty string, enable the debug
+   mode of the :mod:`asyncio` module.
+
+   .. versionadded:: 3.4
+
+
 Debug-mode variables
 ~~~~~~~~~~~~~~~~~~~~