Applied patch #1657 epoll and kqueue wrappers for the select module

The patch adds wrappers for the Linux epoll syscalls and the BSD kqueue syscalls. Thanks to Thomas Herve and the Twisted people for their support and help.
TODO: Finish documentation documentation

2 files changed, 355 insertions, 4 deletions

diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 4a97179..1368c78 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -7,10 +7,12 @@
 
 
 This module provides access to the :cfunc:`select` and :cfunc:`poll` functions
-available in most operating systems.  Note that on Windows, it only works for
-sockets; on other operating systems, it also works for other file types (in
-particular, on Unix, it works on pipes).  It cannot be used on regular files to
-determine whether a file has grown since it was last read.
+available in most operating systems, :cfunc:`epoll` available on Linux 2.5+ and
+:cfunc:`kqueue` available on most BSD.
+Note that on Windows, it only works for sockets; on other operating systems,
+it also works for other file types (in particular, on Unix, it works on pipes).
+It cannot be used on regular files to determine whether a file has grown since
+it was last read.
 
 The module defines the following:
 
@@ -22,6 +24,16 @@ The module defines the following:
    string, as would be printed by the C function :cfunc:`perror`.
 
 
+.. type:: epoll([sizehint=-1])
+
+   (Only supported on Linux 2.5.44 and newer.)  Returns an edge polling
+   object, which can be used as Edge or Level Triggered interface for I/O
+   events; see section :ref:`epoll-objects` below for the methods supported
+   by epolling objects.
+
+   .. versionadded:: 2.6
+
+
 .. function:: poll()
 
    (Not supported by all operating systems.)  Returns a polling object, which
@@ -30,6 +42,24 @@ The module defines the following:
    by polling objects.
 
 
+.. type:: kqueue()
+
+   (Only supported on BSD.)  Returns a kernel queue object
+   object; see section :ref:`kqueue-objects` below for the methods supported
+   by kqueue objects.
+
+   .. versionadded:: 2.6
+
+
+.. type:: kqueue(ident, filter=KQ_FILTER_READ, flags=KQ_ADD, fflags=0, data=0, udata=0)
+
+   (Only supported on BSD.)  Returns a kernel event object
+   object; see section :ref:`kevent-objects` below for the methods supported
+   by kqueue objects.
+
+   .. versionadded:: 2.6
+
+
 .. function:: select(iwtd, owtd, ewtd[, timeout])
 
    This is a straightforward interface to the Unix :cfunc:`select` system call.
@@ -67,6 +97,81 @@ The module defines the following:
       not handle file descriptors that don't originate from WinSock.
 
 
+.. _epoll-objects:
+
+Edge and Level Trigger Polling (epoll) Objects
+----------------------------------------------
+
+   http://linux.die.net/man/4/epoll
+
+   *eventmask*
+
+   +-----------------------+-----------------------------------------------+
+   | Constant              | Meaning                                       |
+   +=======================+===============================================+
+   | :const:`EPOLLIN`      | Available for read                            |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLOUT`     | Available for write                           |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLPRI`     | Urgent data for read                          |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLERR`     | Error condition happend on the assoc. fd      |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLHUP`     | Hang up happend on the assoc. fd              |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLET`      | Set Edge Trigger behavior, the default is     |
+   |                       | Level Trigger behavior                        |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLONESHOT` | Set one-shot behavior. After one event is     |
+   |                       | pulled out, the fd is internally disabled     |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLRDNORM`  | ???                                           |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLRDBAND`  | ???                                           |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLWRNORM`  | ???                                           |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLWRBAND`  | ???                                           |
+   +-----------------------+-----------------------------------------------+
+   | :const:`EPOLLMSG`     | ???                                           |
+   +-----------------------+-----------------------------------------------+
+
+
+.. method:: epoll.close()
+
+   Close the control file descriptor of the epoll object.
+
+
+.. method:: epoll.fileno()
+
+   Return the file descriptor number of the control fd.
+
+
+.. method:: epoll.fromfd(fd)
+
+   Create an epoll object from a given file descriptor.
+
+
+.. method:: epoll.register(fd[, eventmask])
+
+   Register a fd descriptor with the epoll object.
+
+
+.. method:: epoll.modify(fd, eventmask)
+
+   Modify a register file descriptor.
+
+
+.. method:: epoll.unregister(fd)
+
+   Remove a registered file descriptor from the epoll object.
+
+
+.. method:: epoll.poll([timeout=-1[, maxevents=-1]])
+
+   Wait for events. timeout in seconds (float)
+
+
 .. _poll-objects:
 
 Polling Objects
@@ -114,6 +219,16 @@ linearly scanned again. :cfunc:`select` is O(highest file descriptor), while
    the same effect as registering the descriptor exactly once.
 
 
+.. method:: poll.modify(fd, eventmask)
+
+   Modifies an already registered fd. This has the same effect as
+   :meth:`register(fd, eventmask)`.  Attempting to modify a file descriptor
+   that was never registered causes an :exc:`IOError` exception with errno
+   :const:`ENOENT` to be raised.
+
+   .. versionadded:: 2.6
+
+
 .. method:: poll.unregister(fd)
 
    Remove a file descriptor being tracked by a polling object.  Just like the
@@ -137,3 +252,184 @@ linearly scanned again. :cfunc:`select` is O(highest file descriptor), while
    returning. If *timeout* is omitted, negative, or :const:`None`, the call will
    block until there is an event for this poll object.
 
+
+.. _kqueue-objects:
+
+Kqueue Objects
+--------------
+
+.. method:: kqueue.close()
+
+   Close the control file descriptor of the kqueue object.
+
+
+.. method:: kqueue.fileno()
+
+   Return the file descriptor number of the control fd.
+
+
+.. method:: epoll.fromfd(fd)
+
+   Create a kqueue object from a given file descriptor.
+
+
+.. method:: control(changelist, max_events=0[, timeout=None]) -> eventlist
+
+   Low level interface to kevent
+
+   - changelist must be an iterable of kevent object or None
+   - max_events must be 0 or a positive integer
+   - timeout in seconds (floats possible)
+
+
+.. _kevent-objects:
+
+Kevent Objects
+--------------
+
+   http://www.freebsd.org/cgi/man.cgi?query=kqueue&sektion=2
+
+   .. attribute:: ident
+
+   Value used to identify the event. The interpretation depends on the filter
+   but it's usually the file descriptor. In the constructor ident can either
+   be an int or an object with a fileno() function. kevent stores the integer
+   internally.
+
+   .. attribute:: filter
+
+   Name of the kernel filter
+
+   +---------------------------+---------------------------------------------+
+   | Constant                  | Meaning                                     |
+   +===========================+=============================================+
+   | :const:`KQ_FILTER_READ`   | Takes a descriptor and returns whenever     |
+   |                           | there is data available to read             |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_WRITE`  | Takes a descriptor and returns whenever     |
+   |                           | there is data available to read             |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_AIO`    | AIO requests                                |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_VNODE`  | Returns when one or more of the requested   |
+   |                           | events watched in *fflag* occurs            |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_PROC`   | Watch for events on a process id            |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_NETDEV` | Watch for events on a network device        |
+   |                           | [not available on Mac OS X]                 |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_SIGNAL` | Returns whenever the watched signal is      |
+   |                           | delivered to the process                    |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_FILTER_TIMER`  | Establishes an arbitrary timer              |
+   +---------------------------+---------------------------------------------+
+
+   .. attribute:: flags
+
+   Filter action
+
+   +---------------------------+---------------------------------------------+
+   | Constant                  | Meaning                                     |
+   +===========================+=============================================+
+   | :const:`KQ_EV_ADD`        | Adds or modifies an event                   |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_DELETE`     | Removes an event from the queue             |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_ENABLE`     | Permitscontrol() to returns the event       |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_DISABLE`    | Disablesevent                               |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_ONESHOT`    | Removes event after first occurence         |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_CLEAR`      | Reset the state after an event is retrieved |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_SYSFLAGS`   | internal event                              |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_FLAG1`      | internal event                              |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_EOF`        | Filter specific EOF condition               |
+   +---------------------------+---------------------------------------------+
+   | :const:`KQ_EV_ERROR`      | See return values                           |
+   +---------------------------+---------------------------------------------+
+
+
+   .. attribute:: fflags
+
+   Filter specific flags
+
+
+   *:const:`KQ_FILTER_READ` and  :const:`KQ_FILTER_WRITE` filter flags
+
+   +----------------------------+--------------------------------------------+
+   | Constant                   | Meaning                                    |
+   +============================+============================================+
+   | :const:`KQ_NOTE_LOWAT`     | low water mark of a socket buffer          |
+   +----------------------------+--------------------------------------------+
+
+
+   *:const:`KQ_FILTER_VNODE` filter flags*
+
+   +----------------------------+--------------------------------------------+
+   | Constant                   | Meaning                                    |
+   +============================+============================================+
+   | :const:`KQ_NOTE_DELETE`    | *unlink()* was called                      |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_WRITE`     | a write occured                            |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_EXTEND`    | the file was extended                      |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_ATTRIB`    | an attribute was changed                   |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_LINK`      | the link count has changed                 |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_RENAME`    | the file was renamed                       |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_REVOKE`    | access to the file was revoked             |
+   +----------------------------+--------------------------------------------+
+
+
+   *:const:`KQ_FILTER_PROC` filter flags*
+
+   +----------------------------+--------------------------------------------+
+   | Constant                   | Meaning                                    |
+   +============================+============================================+
+   | :const:`KQ_NOTE_EXIT`      | the process has exited                     |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_FORK`      | the process has called *fork()*            |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_EXEC`      | the process has executed a new process     |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_PCTRLMASK` | internal filter flag                       |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_PDATAMASK` | internal filter flag                       |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_TRACK`     | follow a process across *fork()*           |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_CHILD`     | returned on the child process for          |
+   |                            | *NOTE_TRACK*                               |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_TRACKERR`  | unable to attach to a child                |
+   +----------------------------+--------------------------------------------+
+
+   *:const:`KQ_FILTER_NETDEV` filter flags* [not available on Mac OS X]
+
+   +----------------------------+--------------------------------------------+
+   | Constant                   | Meaning                                    |
+   +============================+============================================+
+   | :const:`KQ_NOTE_LINKUP`    | link is up                                 |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_LINKDOWN`  | link is down                               |
+   +----------------------------+--------------------------------------------+
+   | :const:`KQ_NOTE_LINKINV`   | link state is invalid                      |
+   +----------------------------+--------------------------------------------+
+
+
+   .. attribute:: data
+
+   Filter specific data
+
+
+   .. attribute:: udata
+
+   User defined value
diff --git a/Doc/license.rst b/Doc/license.rst
index 89f379d..66a30e7 100644
--- a/Doc/license.rst
+++ b/Doc/license.rst
@@ -645,3 +645,58 @@ The :mod:`xmlrpclib` module contains the following notice::
    ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
    OF THIS SOFTWARE.
 
+
+test_epoll
+----------
+
+The :mod:`test_epoll` contains the following notice::
+
+  Copyright (c) 2001-2006 Twisted Matrix Laboratories.
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Select kqueue
+-------------
+
+The :mod:`select` and contains the following notice for the kqueue interface::
+
+  Copyright (c) 2000 Doug White, 2006 James Knight, 2007 Christian Heimes
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+  SUCH DAMAGE.