threading.Timer should be a class so that it can be derived

Doc/library/threading.rst

--- a/Doc/library/threading.rst
+++ b/Doc/library/threading.rst
@@ -21,7 +21,7 @@ The :mod:`dummy_threading` module is pro
    supported by this module.
 
 
-This module defines the following functions and objects:
+This module defines the following functions:
 
 
 .. function:: active_count()
@@ -30,16 +30,6 @@ This module defines the following functi
    count is equal to the length of the list returned by :func:`.enumerate`.
 
 
-.. function:: Condition()
-   :noindex:
-
-   A factory function that returns a new condition variable object. A condition
-   variable allows one or more threads to wait until they are notified by another
-   thread.
-
-   See :ref:`condition-objects`.
-
-
 .. function:: current_thread()
 
    Return the current :class:`Thread` object, corresponding to the caller's thread
@@ -67,89 +57,6 @@ This module defines the following functi
    and threads that have not yet been started.
 
 
-.. function:: Event()
-   :noindex:
-
-   A factory function that returns a new event object.  An event manages a flag
-   that can be set to true with the :meth:`~Event.set` method and reset to false
-   with the :meth:`clear` method.  The :meth:`wait` method blocks until the flag
-   is true.
-
-   See :ref:`event-objects`.
-
-
-.. class:: local
-
-   A class that represents thread-local data.  Thread-local data are data whose
-   values are thread specific.  To manage thread-local data, just create an
-   instance of :class:`local` (or a subclass) and store attributes on it::
-
-      mydata = threading.local()
-      mydata.x = 1
-
-   The instance's values will be different for separate threads.
-
-   For more details and extensive examples, see the documentation string of the
-   :mod:`_threading_local` module.
-
-
-.. function:: Lock()
-
-   A factory function that returns a new primitive lock object.  Once a thread has
-   acquired it, subsequent attempts to acquire it block, until it is released; any
-   thread may release it.
-
-   See :ref:`lock-objects`.
-
-
-.. function:: RLock()
-
-   A factory function that returns a new reentrant lock object. A reentrant lock
-   must be released by the thread that acquired it. Once a thread has acquired a
-   reentrant lock, the same thread may acquire it again without blocking; the
-   thread must release it once for each time it has acquired it.
-
-   See :ref:`rlock-objects`.
-
-
-.. function:: Semaphore(value=1)
-   :noindex:
-
-   A factory function that returns a new semaphore object.  A semaphore manages a
-   counter representing the number of :meth:`release` calls minus the number of
-   :meth:`acquire` calls, plus an initial value. The :meth:`acquire` method blocks
-   if necessary until it can return without making the counter negative.  If not
-   given, *value* defaults to 1.
-
-   See :ref:`semaphore-objects`.
-
-
-.. function:: BoundedSemaphore(value=1)
-
-   A factory function that returns a new bounded semaphore object.  A bounded
-   semaphore checks to make sure its current value doesn't exceed its initial
-   value.  If it does, :exc:`ValueError` is raised. In most situations semaphores
-   are used to guard resources with limited capacity.  If the semaphore is released
-   too many times it's a sign of a bug.  If not given, *value* defaults to 1.
-
-
-.. class:: Thread
-   :noindex:
-
-   A class that represents a thread of control.  This class can be safely
-   subclassed in a limited fashion.
-
-   See :ref:`thread-objects`.
-
-
-.. class:: Timer
-   :noindex:
-
-   A thread that executes a function after a specified interval has passed.
-
-   See :ref:`timer-objects`.
-
-
 .. function:: settrace(func)
 
    .. index:: single: trace function
@@ -198,7 +105,23 @@ This module also defines the following c
    .. versionadded:: 3.2
 
 
-Detailed interfaces for the objects are documented below.
+This module defines a number of classes.  Most of them are documented in detail
+later in this document.
+
+.. class:: local
+
+   A class that represents thread-local data.  Thread-local data are data whose
+   values are thread specific.  To manage thread-local data, just create an
+   instance of :class:`local` (or a subclass) and store attributes on it::
+
+      mydata = threading.local()
+      mydata.x = 1
+
+   The instance's values will be different for separate threads.
+
+   For more details and extensive examples, see the documentation string of the
+   :mod:`_threading_local` module.
+
 
 The design of this module is loosely based on Java's threading model. However,
 where Java makes locks and condition variables basic behavior of every object,
@@ -216,7 +139,8 @@ All of the methods described below are e
 Thread Objects
 --------------
 
-This class represents an activity that is run in a separate thread of control.
+The :class:`Thread` class represents an activity that is run in a separate
+thread of control.
 There are two ways to specify the activity: by passing a callable object to the
 constructor, or by overriding the :meth:`run` method in a subclass.  No other
 methods (except for the constructor) should be overridden in a subclass.  In
@@ -254,7 +178,7 @@ daemonic, and cannot be :meth:`join`\ ed
 impossible to detect the termination of alien threads.
 
 
-.. class:: Thread(group=None, target=None, name=None, args=(), kwargs={},
+.. class:: Thread(group=None, target=None, name=None, args=(), kwargs={}, \
                   verbose=None, *, daemon=None)
 
    This constructor should always be called with keyword arguments.  Arguments
@@ -287,6 +211,9 @@ impossible to detect the termination of 
    .. versionchanged:: 3.3
       Added the *daemon* argument.
 
+   .. versionchanged:: 3.3
+      ``Thread`` used to be a factory function rather than the class itself.

[ezio.melotti, 2011/09/17 20:49:11]

Something about this sentence sounds wrong to me.
IIUC in 3.2 Thread was a factory and _Thread was the real class, so saying "the
class itself" should be wrong because "itself" here refers to Thread (i.e. the
function) rather than _Thread (the class).  Using "a class" instead of "the
class itself" might be enough.

+
    .. method:: start()
 
       Start the thread's activity.
@@ -414,6 +341,16 @@ and may vary across implementations.
 All methods are executed atomically.
 
 
+.. class:: Lock()
+
+   The class implementing primitive lock objects.  Once a thread has acquired a
+   lock, subsequent attempts to acquire it block, until it is released; any
+   thread may release it.
+
+   .. versionchanged:: 3.3
+      ``Lock`` used to be a factory function rather than the class itself.
+
+
 .. method:: Lock.acquire(blocking=True, timeout=-1)
 
    Acquire a lock, blocking or non-blocking.
@@ -476,6 +413,17 @@ pair) resets the lock to unlocked and al
 :meth:`acquire` to proceed.
 
 
+.. class:: RLock()
+
+   This class implements reentrant lock objects.  A reentrant lock must be
+   released by the thread that acquired it.  Once a thread has acquired a
+   reentrant lock, the same thread may acquire it again without blocking; the
+   thread must release it once for each time it has acquired it.
+
+   .. versionchanged:: 3.3
+      ``RLock`` used to be a factory function rather than the class itself.
+
+
 .. method:: RLock.acquire(blocking=True, timeout=-1)
 
    Acquire a lock, blocking or non-blocking.
@@ -584,10 +532,16 @@ the call as often as necessary.
 
 .. class:: Condition(lock=None)
 
+   This class implements condition variable objects.  A condition variable
+   allows one or more threads to wait until they are notified by another thread.
+
    If the *lock* argument is given and not ``None``, it must be a :class:`Lock`
    or :class:`RLock` object, and it is used as the underlying lock.  Otherwise,
    a new :class:`RLock` object is created and used as the underlying lock.
 
+   .. versionchanged:: 3.3
+      ``Condition`` used to be a factory function rather than the class itself.
+
    .. method:: acquire(*args)
 
       Acquire the underlying lock. This method calls the corresponding method on
@@ -698,10 +652,19 @@ waiting until some other thread calls :m
 
 .. class:: Semaphore(value=1)
 
+   This class implements semaphore objects.  A semaphore manages a counter
+   representing the number of :meth:`release` calls minus the number of
+   :meth:`acquire` calls, plus an initial value.  The :meth:`acquire` method
+   blocks if necessary until it can return without making the counter negative.
+   If not given, *value* defaults to 1.
+
    The optional argument gives the initial *value* for the internal counter; it
    defaults to ``1``. If the *value* given is less than 0, :exc:`ValueError` is
    raised.
 
+   .. versionchanged:: 3.3
+      ``Semaphore`` used to be a factory function rather than the class itself.
+
    .. method:: acquire(blocking=True, timeout=None)
 
       Acquire a semaphore.
@@ -733,6 +696,19 @@ waiting until some other thread calls :m
       than zero again, wake up that thread.
 
 
+.. class:: BoundedSemaphore(value=1)
+
+   Class implementing bounded semaphore objects.  A bounded semaphore checks to
+   make sure its current value doesn't exceed its initial value.  If it does,
+   :exc:`ValueError` is raised. In most situations semaphores are used to guard
+   resources with limited capacity.  If the semaphore is released too many times
+   it's a sign of a bug.  If not given, *value* defaults to 1.
+
+   .. versionchanged:: 3.3
+      ``BoundedSemaphore`` used to be a factory function rather than the class
+      itself.
+
+
 .. _semaphore-examples:
 
 :class:`Semaphore` Example
@@ -744,7 +720,7 @@ you should use a bounded semaphore.  Bef
 main thread would initialize the semaphore::
 
    maxconnections = 5
-   ...
+   # ...
    pool_sema = BoundedSemaphore(value=maxconnections)
 
 Once spawned, worker threads call the semaphore's acquire and release methods
@@ -752,7 +728,7 @@ when they need to connect to the server:
 
    pool_sema.acquire()
    conn = connectdb()
-   ... use connection ...
+   # ... use connection ...
    conn.close()
    pool_sema.release()
 
@@ -775,7 +751,13 @@ An event object manages an internal flag
 
 .. class:: Event()
 
-   The internal flag is initially false.
+   Class implementing event objects.  An event manages a flag that can be set to
+   true with the :meth:`~Event.set` method and reset to false with the
+   :meth:`clear` method.  The :meth:`wait` method blocks until the flag is true.
+   The flag is initially false.
+
+   .. versionchanged:: 3.3
+      ``Event`` used to be a factory function rather than the class itself.
 
    .. method:: is_set()
 
@@ -838,6 +820,9 @@ For example::
    Create a timer that will run *function* with arguments *args* and  keyword
    arguments *kwargs*, after *interval* seconds have passed.
 
+   .. versionchanged:: 3.3
+      ``Timer`` used to be a factory function rather than the class itself.
+
    .. method:: cancel()
 
       Stop the timer, and cancel the execution of the timer's action.  This will