Changes for 1.0#

Release 1.0.2#

  • Fix LifoQueue.peek() to return correct element. pull request #456. Patch by Christine Spang.

  • Upgrade to libev 4.19

  • Remove SSL3 entirely as default TLS protocol

  • Import socket on Windows (closes issue #459)

  • Fix C90 syntax error (pull request #449)

  • Add compatibility with Python 2.7.9’s SSL changes. issue #477.

Release 1.0.1#

  • Fix issue #423: Pool’s imap/imap_unordered could hang forever. Based on patch and test by Jianfei Wang.

Release 1.0 (Nov 26, 2013)#

  • pywsgi: Pass copy of error list instead of direct reference. Thanks to Jonathan Kamens, Matt Iversen.

  • Ignore the autogenerated doc/gevent.*.rst files. Patch by Matthias Urlichs.

  • Fix on Windows. Patch by Jeryn Mathew.

  • Remove (use gevent.wait).

Release 1.0rc3 (Sep 14, 2013)#

  • Fix issue #251: crash in gevent.core when accessing destroyed loop.

  • Fix issue #235: Replace self._threadpool.close() with self._threadpool.kill() in Patch by Jan-Philip Gehrcke.

  • Remove unused timeout from (issue #254). Patch by Saúl Ibarra Corretgé.

  • Rename’s argument to ‘callback’ (closes issue #244).

  • Fix parallel build (issue #193). Patch by Yichao Yu.

  • Fix issue #263: potential UnboundLocalError: ‘length’ in gevent.pywsgi.

  • Simplify (issue #239). Patch by Alex Gaynor.

  • pywsgi: allow Content-Length in GET requests (issue #264). Patch by 陈小玉.

  • documentation fixes (issue #281) [philipaconrad].

  • Fix old documentation about default blocking behavior of kill, killall (issue #306). Patch by Daniel Farina.

  • Fix issue #6: patch sys after thread. Patch by Anton Patrushev.

  • subprocess: fix check_output on Py2.6 and older (issue #265). Thanks to Marc Sibson for test.

  • Fix issue #302: “python -m gevent.monkey” now sets __file__ properly.

  • pywsgi: fix logging when bound on unix socket (issue #295). Thanks to Chris Meyers, Eugene Pankov.

  • pywsgi: readout request data to prevent ECONNRESET

  • Fix issue #303: ‘requestline’ AttributeError in pywsgi. Thanks to Neil Chintomby.

  • Fix issue #79: Properly handle HTTP versions. Patch by Luca Wehrstedt.

  • Fix issue #216: propagate errors raised by

Release 1.0rc2 (Dec 10, 2012)#

  • Fixed issue #210: callbacks were not run for non-default loop (bug introduced in 1.0rc1).

  • patch_all() no longer patches subprocess unless subprocess=True is passed.

  • Fixed AttributeError in hub.Waiter.

  • Fixed issue #181: make hidden imports visible to freezing tools like py2exe. Patch by Ralf Schmitt.

  • Fixed issue #202: periodically yield when running callbacks (sleep(0) cannot block the event loop now).

  • Fixed issue #204: os.tp_read/tp_write did not propogate errors to the caller.

  • Fixed issue #217: do not set SO_REUSEADDR on Windows.

  • Fixed bug in –module argument for gevent.monkey. Patch by Örjan Persson.

  • Remove warning from about mixing fork() and threads.

  • Cleaned up from code that was needed to support older greenlets. Patch by Saúl Ibarra Corretgé.

  • Allow for explicit default loop creation via get_hub(default=True). Patch by Jan-Philip Gehrcke.

Release 1.0rc1 (Oct 30, 2012)#

  • Fixed hub.switch() not to touch stacktrace when switching. greenlet restores the exception information correctly since version 0.3.2. gevent now requires greenlet >= 0.3.2

  • Added gevent.wait() and gevent.iwait(). This is like gevent.joinall() but supports more objects, including Greenlet, Event, Semaphore, Popen. Without arguments it waits for the event loop to finish (previously did that). will be removed before final release and gevent.joinall() might be deprecated.

  • Reimplemented loop.run_callback with a list and a single prepare watcher; this fixes the order of spawns and improves performance a little.

  • Fixes Semaphore/Lock not to init hub in __init__, so that it’s possible to have module-global locks without initializing the hub. This fixes monkey.patch_all() not to init the hub.

  • New implementation of callbacks that executes them in the order they were added. core.loop.callback is removed.

  • Fixed 2.5 compatibility.

  • Fixed crash on Windows when request ‘prev’ and ‘attr’ attributes of ‘stat’ watcher. The attribute access still fails, but now with an exception.

  • Added known_failures.txt that lists all the tests that fail. It can be used by via expected option. It’s used when running the test suite in travis.

  • Fixed socket, ssl and fileobject to not mask EBADF error - it is now propogated to the caller. Previously EBADF was converted to empty read/write. Thanks to Vitaly Kruglikov

  • Removed gevent.event.waitall()

  • Renamed FileObjectThreadPool -> FileObjectThread

  • Greenlet: Fixed issue #143: greenlet links are now executed in the order they were added

  • Synchronize access to FileObjectThread with Semaphore

  • EINVAL is no longer handled in fileobject.


  • Fixed issue #178: disable monkey patch

  • Fixed monkey.patch_thread() to patch threading._DummyThread to avoid leak in threading._active. Original patch by Wil Tan.

  • added Event=False argument to patch_all() and patch_thread

  • added patch_sys() which patches stdin, stdout, stderr with FileObjectThread wrappers. Experimental / buggy.

  • monkey patching everything no longer initializes the hub/event loop.


  • create_connection: do not lookup IPv6 address if IPv6 is unsupported. Patch by Ralf Schmitt.


  • Fixed issue #86: bytearray is now supported. Original patch by Aaron Westendorf.

  • Fixed issue #116: Multiline HTTP headers are now handled properly. Patch by Ralf Schmitt.


  • Fixed Windows compatibility. The wait() method now also supports ‘timeout’ argument on Windows.

  • Popen: Added rawlink() method, which makes Popen objects supported by gevent.wait(). Updated examples/

  • Fixed issue #148: read from errpipe_read in small chunks, to avoid trigger EINVAL issue on Mac OS X. Patch by Vitaly Kruglikov

  • Do os._exit() in “finally” section to avoid executing unrelated code. Patch by Vitaly Kruglikov.


  • improve getaddrinfo: For string ports (e.g. “http”) resolver_ares/getaddrinfo previously only checked either getservbyname(port, “tcp”) or getservbyname(port, “udp”), but never both. It now checks both of them.

  • now accepts strings as arguments

  • upgraded c-ares to cares-1_9_1-12-g805c736

  • it is now possible to configure resolver_ares directly with environ, like GEVENTARES_SERVERS


  • Renamed threadpool_read/write to tp_read/write.

  • Removed posix_read, posix_write.

  • Added nb_read, nb_write, make_nonblocking.


  • The system error is now raised immediately in main greenlet in all cases.

  • Dropped support for old greenlet versions (need >= 0.3.2 now)


  • allow ‘callback’ property of watcher to be set to None. “del w.callback” no longer works.

  • added missing ‘noinotify’ flag


  • gevent.thread: allocate_lock is now an alias for LockType/Semaphore. That way it does not fail when being used as class member.

  • Updated to start timeouts with ref=False.

  • pool: remove unused get_values() function

  • now recognizes GEVENTSETUP_EV_VERIFY env var which sets EV_VERIFY macro when compiling

  • Added a few micro benchmarks

  • stdlib tests that we care about are now included in greentest/2.x directories, so we don’t depend on them being installed system-wide

  • updated util/

  • the testrunner was completely rewritten.

Release 1.0b4 (Sep 6, 2012)#

  • Added gevent.os module with ‘read’ and ‘write’ functions. Patch by Geert Jansen.

  • Moved gevent.hub.fork to gevent.os module (it is still available as gevent.fork).

  • Fixed issue #148: Made fileobject handle EINVAL, which is randomly raised by on Mac OS X. Thanks to Mark Hingston.

  • Fixed issue #150: gevent.fileobject.SocketAdapter.sendall() could needlessly wait for write event on the descriptor. Original patch by Mark Hingston.

  • Fixed AttributeError in baseserver. In case of error, start() would call kill() which was renamed to close(). Thanks to Vitaly Kruglikov.

Release 1.0b3 (Jul 27, 2012)#

  • New gevent.subprocess module

  • New gevent.fileobject module

  • Fixed ThreadPool to discard references of the objects passed to it (function, arguments) asap. Previously they could be stored for unlimited time until the thread gets a new job.

  • Fixed issue #138: gevent.pool.Pool().imap_unordered hangs with an empty iterator. Thanks to exproxus.

  • Fixed issue #127: could raise TypeError in certain cases. Thanks to Johan Mjones.

  • Fixed socket.makefile() to keep the timeout setting of the socket instance. Thanks to Colin Marc.

  • Added ‘copy()’ method to queues.

  • The ‘nochild’ event loop config option is removed. The install_sigchld offer more flexible way of enabling child watchers.

  • core: all watchers except for ‘child’ now accept new ‘priority’ keyword argument

  • gevent.Timeout accepts new arguments: ‘ref’ and ‘priority’. The default priority for Timeout is -1.

  • Hub.wait() uses Waiter now instead of raw switching

  • Updated libev to the latest CVS version

  • Made pywsgi to raise an AssertionError if non-zero content-length is passed to start_response(204/304) or if non-empty body is attempted to be written for 304/204 response

  • Removed pywsgi feature to capitalize the passed headers.

  • Fixed util/ to work on python3.2 (issue #123). Patch by Alexandre Kandalintsev.

  • Added ‘closed’ readonly property to socket.

  • Added ‘ref’ read/write property to socket.

  • now parses CARES_EMBED and LIBEV_EMBED parameters, in addition to EMBED.

  • gevent.reinit() and gevent.fork() only reinit hub if it was created and do not create it themselves

  • Fixed not to add libev and c-ares to include dirs in non-embed mode. Patch by Ralf Schmitt.

  • Renamed util/ to util/

  • now saves more information about the system; the stat printing functionality is moved to a separate util/ script.

Release 1.0b2 (Apr 11, 2012)#

Major and backward-incompatible changes:

  • Made the threadpool-based resolver the default. To enable the ares-based resolver, set GEVENT_RESOLVER=ares env var.

  • Added support for child watchers (not available on Windows).

    • Libev loop now reaps all children by default.

    • If NOCHILD flag is passed to the loop, child watchers and child reaping are disabled.

  • Renamed gevent.coros to gevent.lock. The gevent.coros is still available but deprecated.

  • Added ‘stat’ watchers to loop.

  • The now recognizes gevent_embed env var. When set to “no”, bundled c-ares and libev are ignored.

  • Added optional ‘ref’ argument to sleep(). When ref=false, the watchers created by sleep() do not hold from exiting.

  • ThreadPool now calls Hub.handle_error for exceptions in worker threads.

  • ThreadPool got new method: apply_e.

  • Added new extension module gevent._util and moved gevent.core.set_exc_info function there.

  • Added new extension module gevent._semaphore. It contains Semaphore class which is imported by gevent.lock as gevent.lock.Semaphore. Providing Semaphore in extension module ensures that trace function set with settrace will not be called during __exit__. Thanks to Ralf Schmitt.

  • It is now possible to kill or pre-spawn threads in ThreadPool by setting its ‘size’ property.


  • Make sure the default loop cannot be destroyed more than once, thus crashing the process.

  • Make Hub.destroy() method not to destroy the default loop, unless destroy_loop is True. Non-default loops are still destroyed by default.

  • loop: Removed properties from loop: fdchangecnt, timercnt, asynccnt.

  • loop: Added properties: sigfd, origflags, origflags_int

  • loop: The EVFLAG_NOENV is now always passed to libev. Thus LIBEV_FLAGS env variable is no longer checked. Use GEVENT_BACKEND.


  • Check that the argument of link() is callable. Raise TypeError when it’s not.

  • Fixed TypeError in baseserver when parsing an address.

  • Pool: made add() and discard() usable by external users. Thanks to Danil Eremeev.

  • When specifying a class to import, it is now possible to use format path/

  • pywsgi: Made sure format_request() does not fail if ‘status’ attribute is not set yet

  • pywsgi: Added REMOTE_PORT variable to the environment.


  • now shows how to use to implement graceful shutdown of a server.

  • Changed execute() to return rowcount.

  • Added fetchall() and fetchiter() methods.

Developer utilities:

  • When building, CYTHON env variable can be used to specify Cython executable to use.

  • util/ now recongizes –fast and –revert options. Previous –rsync option is removed.

  • Added util/ which automates building/testing/making binaries on Windows VM.

  • Fixed typos in exception handling code in

  • Fixed patching unittest.runner on Python2.7. This caused the details of test cases run lost.

  • Made kill the whole process group after test is done.

Release 1.0b1 (Jan 10, 2012)#

Backward-incompatible changes:

  • Removed “link to greenlet” feature of Greenlet.

  • If greenlet module older than 0.3.2 is used, then greenlet.GreenletExit.__bases__ is monkey patched to derive from BaseException and not Exception. That way gevent.GreenletExit is always derived from BaseException, regardless of installed greenlet version.

  • Some code supporting Python 2.4 has been removed.

Release highlights:

  • Added thread pool: gevent.threadpool.ThreadPool.

  • Added thread pool-based resolver. Enable with GEVENT_RESOLVER=thread.

  • Added UDP server: gevent.server.DatagramServer

  • A “configure” is now run on libev. This fixes a problem of ‘kqueue’ not being available on Mac OS X.

  • Gevent recognizes some environment variables now:

    • GEVENT_BACKEND allows passing argument to loop, e.g. “GEVENT_BACKEND=select” for force select backend

    • GEVENT_RESOLVER allows choosing resolver class.

    • GEVENT_THREADPOOL allows choosing thread pool class.

  • Added new examples: portforwarder,,,

  • Fixed non-embedding build. To build against system libev, remove or rename ‘libev’ directory. To build against system c-ares, remove or rename ‘c-ares’. Thanks to Örjan Persson.


  • gevent.joinall() method now accepts optional ‘count’ keyword.

  • gevent.fork() only calls reinit() in the child process now.

  • now returns False when exiting because of timeout or event (previous None).

  • Hub got a new method: destroy().

  • Hub got a new property: threadpool.


  • Fixed issue #104: made ares_host_result pickable. Thanks to Shaun Cutts.


  • Removed unused deprecated ‘wfile’ property from WSGIHandler

  • Fixed issue #92: raise IOError on truncated POST requests.

  • Fixed issue #93: do not sent multiple “100 continue” responses


  • Fixed issue #97: the timer watcher now calls ev_now_update() in start() and again() unless ‘update’ keyword is passed and set to False.

  • add set_syserr_cb() function; it’s used by gevent internally.

  • gevent now installs syserr callback using libev’s set_syserr_cb. This callback is called when libev encounters an error it cannot recover from. The default action is to print a message and abort. With the callback installed, a SystemError() is now raised in the main greenlet.

  • renamed ‘backend_fd’ property to ‘fileno()’ method. (not available if you build gevent against system libev)

  • added ‘asynccnt’ property (not available if you build gevent against system libev)

  • made loop.__repr__ output a bit more compact

  • the watchers check the arguments for validness now (previously invalid argument would crash libev).

  • The ‘async’ watcher now has send() method;

  • fixed time() function

  • libev has been upgraded to latest CVS version.

  • libev has been patched to use send()/recv() for evpipe on windows when libev_vfd.h is in effect


  • Slightly improved compatibility with stdlib’s socket in some error cases.


  • Fixed close() method not to reference any globals

  • Fixed issue #115: _dummy gets unexpected Timeout arg

  • Removed _fileobject used for python 2.4 compatibility in

  • Fixed issue #94: fallback to buffer if memoryview fails in _get_memory on python 2.7


  • Removed patch_httplib()

  • Fixed issue #112: threading._sleep is not patched. Thanks to David LaBissoniere.

  • Added get_unpatched() function. However, it is slightly broken at the moment.


  • make ‘locals()’ not spew out __builtin__.__dict__ in backdoor

  • add optional banner argument to BackdoorServer


  • add server.DatagramServer;

  • StreamServer: ‘ssl_enabled’ is now a read-only property

  • servers no longer have ‘kill’ method; it has been renamed to ‘close’.

  • listeners can now be configured as strings, e.g. ‘:80’ or 80

  • modify baseserver.BaseServer in such a way that makes it a good base class for both StreamServer and DatagramServer

  • BaseServer no longer accepts ‘backlog’ parameter. It is now done by StreamServer.

  • BaseServer implements start_accepting() and stop_accepting() methods

  • BaseServer now implements “temporarily stop accepting” strategy

  • BaseServer now has _do_read method which does everything except for actually calling accept()/recvfrom()

  • pre_start() method is renamed to init_socket()

  • renamed _stopped_event to _stop_event

  • ‘started’ is now a read-only property (which actually reports state of _stop_event)

  • post_stop() method is removed

  • close() now sets _stop_event(), thus setting ‘started’ to False, thus causing serve_forever() to exit

  • _tcp_listener() function is moved from to

  • added ‘fatal_errors’ class attribute which is a tuple of all errnos that should kill the server


  • Semaphore: add _start_notify() method

  • Semaphore: avoid copying list of links; rawlink() no longer schedules notification

Release 1.0a3 (Sep 15, 2011)#

Added ‘ref’ property to all watchers. Settings it to False make watcher call ev_unref/ev_ref appropriately so that this watcher does not prevent from exiting. Made resolver_ares.Resolver use ‘ref’ property for internal watcher.

In all servers, method “kill” was renamed to “close”. The old name is available as deprecated alias.

Added a few properties to the loop: backend_fd, fdchangecnt, timercnt.

Upgraded c-ares to 1.7.5+patch.

Fixed getaddrinfo to return results in the order (::1, IPv4, IPv6).

Fixed getaddrinfo() to handle integer of string type. Thanks to kconor.

Fixed gethostbyname() to handle ‘’ (empty string).

Fixed getaddrinfo() to convert UnicodeEncodeError into error(‘Int or String expected’).

Fixed getaddrinfo() to uses the lowest 16 bits of passed port integer similar to built-in _socket.

Fixed getnameinfo() to call getaddrinfo() to process arguments similar to built-in _socket.

Fixed gethostbyaddr() to use getaddrinfo() to process arguments.

version_info is now a 5-tuple.

Added handle_system_error() method to Hub (used internally).

Fixed Hub’s run() method to never exit. This prevent inappropriate switches into parent greenlet.

Fixed Hub.join() to return True if Hub was already dead.

Added ‘event’ argument to Hub.join().

Added run() function to gevent top level package.

Fixed Greenlet.start() to exit silently if greenlet was already started rather than raising AssertionError.

Fixed Greenlet.start() not to schedule another switch if greenlet is already dead.

Fixed gevent.signal() to spawn Greenlet instead of raw greenlet. Also it’ll switch into the new greenlet immediately instead of scheduling additional callback.

Do monkey patch create_connection() as gevent’s version works better with gevent.socket.socket than the standard create_connection.

pywsgi: make sure we don’t try to read more requests if socket operation failed with EPIPE

pywsgi: if we failed to send the reply, change ‘status’ to socket error so that the logs mention the error.

Release 1.0a2 (Aug 2, 2011)#

Fixed a bug in gevent.queue.Channel class. (Thanks to Alexey Borzenkov)

Release 1.0a1 (Aug 2, 2011)#

Backward-incompatible changes:

  • Dropped support for Python 2.4.

  • Queue(0) is now equivalent to an unbound queue and raises DeprecationError. Use gevent.queue.Channel if you need a channel.

  • Deprecated ability to pass a greenlet instance to, Greenlet.link_value() and Greenlet.link_exception().

  • All of gevent.core has been rewritten and the interface is not compatible.

  • SystemExit and SystemError now kill the whole process instead of printing a traceback.

  • Removed deprecated util.lazy_property property.

  • Removed gevent.dns module.

  • Removed deprecated gevent.sslold module

  • Removed deprecated gevent.rawgreenlet module

  • Removed deprecated name GreenletSet which used to be alias for Group.

  • gevent.wsgi is now a deprecated alias for gevent.pywsgi.

Release highlights:

  • The gevent.core module now wraps libev’s API and is not compatible with gevent 0.x.

  • Added a concept of pluggable event loops. By default gevent.core.loop is used, which is a wrapper around libev.

  • Added a concept of pluggable name resolvers. By default a resolver based on c-ares library is used.

  • Added support for multiple OS threads, each new thread will get its own Hub instance with its own event loop.

  • The release now includes and embeds the dependencies: libev and c-ares.

  • The standard signal works now as expected.

  • The unhandled errors are now handled uniformely by Hub.handle_error function.

  • Added gevent.queue.Channel class to gevent.queue module. It is equivalent to Queue(0) in gevent 0.x, which is deprecated now.

  • Added method peek to gevent.queue.Queue class.

  • Added idle function which blocks until the event loop is idle.

  • Added a way to gracefully shutdown the application by waiting for all outstanding greenlets/servers/watchers: Hub.join.

  • Added new gevent.ares C extension which wraps c-ares and provides asynchronous DNS resolver.

  • Added new gevent.resolver_ares module provides synchronous API on top of gevent.ares.

The gevent.socket module:

  • DNS functions now use c-ares library rather than libevent-dns. This fixes a number of problems with name resolving:

    • Fix issue #2: DNS resolver no longer breaks after fork(). You still need to call gevent.fork() (os.fork is monkey patched with it if monkey.patch_all() was called).

    • DNS resolver no longer ignores /etc/resolv.conf and /etc/hosts.

  • The following functions were added to socket module

    • gethostbyname_ex

    • getnameinfo

    • gethostbyaddr

    • getfqdn

  • Removed undocumented bind_and_listen and tcp_listener

The gevent.hub.Hub object:

  • Added join method which waits until the event loop exits or optional timeout expires.

  • Added wait method which waits until a watcher has got an event.

  • Added handle_error method which is called by all of gevent in case of unhandled exception.

  • Added print_exception method which is called by handle_error to print the exception traceback.

The Greenlet objects:

  • Added __nonzero__ implementation that returns True after greenlet was started until it’s dead. Previously greenlet was False after start() until it was first switched to.

The gevent.pool module:

  • It is now possible to add raw greenlets to the pool.

  • The map and imap methods now start yielding the results as soon as possible.

  • The imap_unordered no longer swallows an exception raised while iterating its argument.


  • gevent.sleep(<negative value>) no longer raises an exception, instead it does sleep(0).

  • Added method clear to internal Waiter class.

  • Removed wait method from internal Waiter class.

  • The WSGIServer now sets max_accept to 1 if wsgi.multiprocessing is set to True`

  • Added gevent.monkey.patch_module() function that monkey patches module using __implements__ list provided by gevent module. All of gevent modules that replace stdlib module now have __implements__ attribute.