asyncio.docs: Improve wordings; add a note to the Coroutines section. Issue #20706

4 files changed, 49 insertions, 38 deletions

diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index 88fe35e..2e48d30 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -102,7 +102,8 @@ Run an event loop
 
    Run until the :class:`Future` is done.
 
-   If the argument is a coroutine, it is wrapped in a :class:`Task`.
+   If the argument is a :ref:`coroutine <coroutine>`, it is wrapped
+   in a :class:`Task`.
 
    Return the Future's result, or raise its exception.
 
@@ -207,7 +208,7 @@ Creating connections
    socket type :py:data:`~socket.SOCK_STREAM`.  *protocol_factory* must be a
    callable returning a :ref:`protocol <asyncio-protocol>` instance.
 
-   This method returns a :ref:`coroutine object <coroutine>` which will try to
+   This method is a :ref:`coroutine <coroutine>` which will try to
    establish the connection in the background.  When successful, the
    coroutine returns a ``(transport, protocol)`` pair.
 
@@ -274,7 +275,7 @@ Creating connections
    :py:data:`~socket.AF_INET6` depending on *host* (or *family* if specified),
    socket type :py:data:`~socket.SOCK_DGRAM`.
 
-   This method returns a :ref:`coroutine object <coroutine>` which will try to
+   This method is a :ref:`coroutine <coroutine>` which will try to
    establish the connection in the background.  When successful, the
    coroutine returns a ``(transport, protocol)`` pair.
 
@@ -288,7 +289,7 @@ Creating connections
    family is used to communicate between processes on the same machine
    efficiently.
 
-   This method returns a :ref:`coroutine object <coroutine>` which will try to
+   This method is a :ref:`coroutine <coroutine>` which will try to
    establish the connection in the background.  When successful, the
    coroutine returns a ``(transport, protocol)`` pair.
 
@@ -302,8 +303,8 @@ Creating listening connections
 
 .. method:: BaseEventLoop.create_server(protocol_factory, host=None, port=None, \*, family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE, sock=None, backlog=100, ssl=None, reuse_address=None)
 
-   A :ref:`coroutine function <coroutine>` which creates a TCP server bound to host and
-   port.
+   A :ref:`coroutine <coroutine>` method which creates a TCP server bound to
+   host and port.
 
    The return value is a :class:`AbstractServer` object which can be used to stop
    the service.
@@ -332,8 +333,6 @@ Creating listening connections
    expire. If not specified will automatically be set to True on
    UNIX.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
-
    .. seealso::
 
       The function :func:`start_server` creates a (:class:`StreamReader`,
@@ -380,7 +379,7 @@ Low-level socket operations
    representing the data received.  The maximum amount of data to be received
    at once is specified by *nbytes*.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    .. seealso::
 
@@ -392,9 +391,9 @@ Low-level socket operations
    This method continues to send data from *data* until either all data has
    been sent or an error occurs.  ``None`` is returned on success.  On error,
    an exception is raised, and there is no way to determine how much data, if
-   any, was successfully sent.
+   any, was successfully processed by the receiving end of the connection.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    .. seealso::
 
@@ -410,7 +409,7 @@ Low-level socket operations
    :py:data:`~socket.AF_INET` and :py:data:`~socket.AF_INET6` address families.
    Use :meth:`getaddrinfo` to resolve the hostname asynchronously.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    .. seealso::
 
@@ -427,7 +426,7 @@ Low-level socket operations
    and *address* is the address bound to the socket on the other end of the
    connection.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    .. seealso::
 
@@ -440,13 +439,13 @@ Resolve host name
 
 .. method:: BaseEventLoop.getaddrinfo(host, port, \*, family=0, type=0, proto=0, flags=0)
 
-   Similar to the :meth:`socket.getaddrinfo`  function, but return a
-   :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`, similar to
+   :meth:`socket.getaddrinfo` function but non-blocking.
 
 .. method:: BaseEventLoop.getnameinfo(sockaddr, flags=0)
 
-   Similar to the :meth:`socket.getnameinfo`  function, but return a
-   :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`, similar to
+   :meth:`socket.getnameinfo` function but non-blocking.
 
 
 Running subprocesses
@@ -472,7 +471,7 @@ Run subprocesses asynchronously using the :mod:`subprocess` module.
 
    XXX
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    See the constructor of the :class:`subprocess.Popen` class for parameters.
 
@@ -480,7 +479,7 @@ Run subprocesses asynchronously using the :mod:`subprocess` module.
 
    XXX
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
    See the constructor of the :class:`subprocess.Popen` class for parameters.
 
@@ -493,7 +492,7 @@ Run subprocesses asynchronously using the :mod:`subprocess` module.
    Return pair (transport, protocol), where transport support
    :class:`ReadTransport` interface.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
 .. method:: BaseEventLoop.connect_write_pipe(protocol_factory, pipe)
 
@@ -504,7 +503,7 @@ Run subprocesses asynchronously using the :mod:`subprocess` module.
    Return pair (transport, protocol), where transport support
    :class:`WriteTransport` interface.
 
-   This method returns a :ref:`coroutine object <coroutine>`.
+   This method is a :ref:`coroutine <coroutine>`.
 
 .. seealso::
 
@@ -549,6 +548,8 @@ pool of processes). By default, an event loop uses a thread pool executor
    *executor* is a :class:`~concurrent.futures.Executor` instance,
    the default executor is used if *executor* is ``None``.
 
+   This method is a :ref:`coroutine <coroutine>`.
+
 .. method:: BaseEventLoop.set_default_executor(executor)
 
    Set the default executor used by :meth:`run_in_executor`.
@@ -633,7 +634,7 @@ Server
 
    .. method:: wait_closed()
 
-      Coroutine to wait until service is closed.
+      A :ref:`coroutine <coroutine>` to wait until service is closed.
 
 
 Handle
diff --git a/Doc/library/asyncio-stream.rst b/Doc/library/asyncio-stream.rst
index 76b6643..4543af4 100644
--- a/Doc/library/asyncio-stream.rst
+++ b/Doc/library/asyncio-stream.rst
@@ -30,7 +30,7 @@ Stream functions
    :class:`StreamReaderProtocol` classes, just copy the code -- there's really
    nothing special here except some convenience.)
 
-   This function returns a :ref:`coroutine object <coroutine>`.
+   This function is a :ref:`coroutine <coroutine>`.
 
 .. function:: start_server(client_connected_cb, host=None, port=None, \*, loop=None, limit=None, **kwds)
 
@@ -56,7 +56,7 @@ Stream functions
    The return value is the same as :meth:`~BaseEventLoop.create_server()`, i.e.
    a :class:`AbstractServer` object which can be used to stop the service.
 
-   This function returns a :ref:`coroutine object <coroutine>`.
+   This function is a :ref:`coroutine <coroutine>`.
 
 .. function:: open_unix_connection(path=None, \*, loop=None, limit=None, **kwds)
 
@@ -66,7 +66,7 @@ Stream functions
    See :func:`open_connection` for information about return value and other
    details.
 
-   This function returns a :ref:`coroutine object <coroutine>`.
+   This function is a :ref:`coroutine <coroutine>`.
 
    Availability: UNIX.
 
@@ -77,7 +77,7 @@ Stream functions
    See :func:`start_server` for information about return value and other
    details.
 
-   This function returns a :ref:`coroutine object <coroutine>`.
+   This function is a :ref:`coroutine <coroutine>`.
 
    Availability: UNIX.
 
@@ -116,7 +116,7 @@ StreamReader
       If the EOF was received and the internal buffer is empty,
       return an empty ``bytes`` object.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: readline()
 
@@ -128,7 +128,7 @@ StreamReader
       If the EOF was received and the internal buffer is empty,
       return an empty ``bytes`` object.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: readexactly(n)
 
@@ -137,7 +137,7 @@ StreamReader
       :attr:`IncompleteReadError.partial` attribute of the exception contains
       the partial read bytes.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: at_eof()
 
diff --git a/Doc/library/asyncio-sync.rst b/Doc/library/asyncio-sync.rst
index 19e49ff..de38131 100644
--- a/Doc/library/asyncio-sync.rst
+++ b/Doc/library/asyncio-sync.rst
@@ -124,7 +124,7 @@ Event
       Otherwise, block until another coroutine calls :meth:`set` to set the
       flag to true, then return ``True``.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
 
 Condition
@@ -175,7 +175,7 @@ Condition
       condition variable in another coroutine.  Once awakened, it re-acquires
       the lock and returns ``True``.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: wait_for(predicate)
 
@@ -184,7 +184,7 @@ Condition
       The predicate should be a callable which result will be interpreted as a
       boolean value. The final predicate value is the return value.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
 
 Semaphores
@@ -217,7 +217,7 @@ Semaphore
       until some other coroutine has called :meth:`release` to make it larger
       than ``0``, and then return ``True``.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: locked()
 
@@ -279,7 +279,7 @@ Queue
 
       If you yield from :meth:`get()`, wait until a item is available.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: get_nowait()
 
@@ -295,7 +295,7 @@ Queue
       If you yield from ``put()``, wait until a free slot is available before
       adding item.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: put_nowait(item)
 
@@ -350,7 +350,7 @@ JoinableQueue
       it is complete.  When the count of unfinished tasks drops to zero,
       :meth:`join` unblocks.
 
-      This method returns a :ref:`coroutine object <coroutine>`.
+      This method is a :ref:`coroutine <coroutine>`.
 
    .. method:: task_done()
 
diff --git a/Doc/library/asyncio-task.rst b/Doc/library/asyncio-task.rst
index e7ef172..4e5526e 100644
--- a/Doc/library/asyncio-task.rst
+++ b/Doc/library/asyncio-task.rst
@@ -64,6 +64,14 @@ Coroutines (and tasks) can only run when the event loop is running.
     message is logged. See :ref:`Detect coroutines never scheduled
     <asyncio-coroutine-not-scheduled>`.
 
+.. note::
+
+    In this documentation, some methods are documented as coroutines,
+    even if they are plain Python functions returning a :class:`Future`.
+    This is intentional to have a freedom of tweaking the implementation
+    of these functions in the future. If such a function is needed to be
+    used in a callback-style code, wrap its result with :func:`async`.
+
 
 .. _asyncio-hello-world-coroutine:
 
@@ -440,7 +448,7 @@ Task functions
 
 .. function:: sleep(delay, result=None, \*, loop=None)
 
-   Create a :ref:`coroutine object <coroutine>` that completes after a given
+   Create a :ref:`coroutine <coroutine>` that completes after a given
    time (in seconds).  If *result* is provided, it is produced to the caller
    when the coroutine completes.
 
@@ -505,7 +513,7 @@ Task functions
    |                             | futures finish or are cancelled.       |
    +-----------------------------+----------------------------------------+
 
-   This function returns a :ref:`coroutine object <coroutine>`.
+   This function is a :ref:`coroutine <coroutine>`.
 
    Usage::
 
@@ -529,6 +537,8 @@ Task functions
    cancels the task and raises :exc:`TimeoutError`. To avoid the task
    cancellation, wrap it in :func:`shield`.
 
+   This function is a :ref:`coroutine <coroutine>`.
+
    Usage::
 
         result = yield from asyncio.wait_for(fut, 60.0)