asyncio: add a note about (non) thread safety in each class

Doc/library/asyncio-eventloop.rst

@@ -22,6 +22,8 @@ It provides multiple facilities, amongst which:
 
    Base class of event loops.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
 Run an event loop
 -----------------
 
@@ -104,6 +106,9 @@ keywords to your callback, use :func:`functools.partial`. For example,
 
    Like :meth:`call_soon`, but thread safe.
 
+   See the :ref:`concurrency and multithreading <asyncio-multithreading>`
+   section of the documentation.
+
 
 .. _asyncio-delayed-calls:
 

Doc/library/asyncio-protocol.rst

@@ -23,6 +23,8 @@ then call the transport's methods for various purposes.
 subprocess pipes.  The methods available on a transport depend on
 the transport's kind.
 
+The transport classes are :ref:`not thread safe <asyncio-multithreading>`.
+
 
 BaseTransport
 -------------

Doc/library/asyncio-queue.rst

@@ -31,6 +31,8 @@ Queue
    be interrupted between calling :meth:`qsize` and doing an operation on the
    Queue.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
    .. versionchanged:: 3.4.3
       New :meth:`join` and :meth:`task_done` methods.
 

Doc/library/asyncio-stream.rst

@@ -85,6 +85,8 @@ StreamReader
 
 .. class:: StreamReader(limit=None, loop=None)
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
    .. method:: exception()
 
       Get the exception.
@@ -155,6 +157,8 @@ StreamWriter
    wait for flow control.  It also adds a transport attribute which references
    the :class:`Transport` directly.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
    .. attribute:: transport
 
       Transport.

Doc/library/asyncio-subprocess.rst

@@ -193,6 +193,9 @@ Process
      :meth:`~subprocess.Popen.wait` method of the :class:`~subprocess.Popen`
      class is implemented as a busy loop.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`. See also the
+   :ref:`Subprocess and threads <asyncio-subprocess-threads>` section.
+
    .. coroutinemethod:: wait()
 
       Wait for child process to terminate.  Set and return :attr:`returncode`
@@ -310,6 +313,8 @@ are limits:
   subprocesses from other threads. Call the :func:`get_child_watcher`
   function in the main thread to instantiate the child watcher.
 
+The :class:`asyncio.subprocess.Process` class is not thread safe.
+
 .. seealso::
 
    The :ref:`Concurrency and multithreading in asyncio

Doc/library/asyncio-task.rst

@@ -209,6 +209,8 @@ Future
      :func:`~concurrent.futures.as_completed` functions in the
      :mod:`concurrent.futures` package.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
    .. method:: cancel()
 
       Cancel the future and schedule callbacks.
@@ -375,6 +377,8 @@ Task
    Don't directly create :class:`Task` instances: use the :func:`async`
    function or the :meth:`BaseEventLoop.create_task` method.
 
+   This class is :ref:`not thread safe <asyncio-multithreading>`.
+
    .. classmethod:: all_tasks(loop=None)
 
       Return a set of all tasks for an event loop.