libevent  2.1.12
About: libevent is an event notification library. The libevent API provides a mechanism to execute a callback function when a specific event occurs on a file descriptor or after a timeout has been reached.
  Fossies Dox: libevent-2.1.12-stable.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  

libevent Documentation

Some Fossies usage hints in advance:

  1. To see the Doxygen generated documentation please click on one of the items in the steelblue colored "quick index" bar above or use the side panel at the left which displays a hierarchical tree-like index structure and is adjustable in width.
  2. If you want to search for something by keyword rather than browse for it you can use the client side search facility (using Javascript and DHTML) that provides live searching, i.e. the search results are presented and adapted as you type in the Search input field at the top right.
  3. Doxygen doesn't incorporate all member files but just a definable subset (basically the main project source code files that are written in a supported language). So to search and browse all member files you may visit the Fossies libevent-2.1.12-stable.tar.gz contents page and use the Fossies standard member browsing features (also with source code highlighting and additionally with optional code folding).

libevent logo

Appveyor Win32 Build Status Travis Build Status Coverage Status Join the chat at



 $ ./configure
 $ make
 $ make verify   # (optional)
 $ sudo make install

CMake (General)

The following Libevent specific CMake variables are as follows (the values being the default).

# Type of the library to build (SHARED or STATIC)
# Default is: SHARED for MSVC, otherwise BOTH

# Installation directory for CMake files

# Enable running gcov to get a test coverage report (only works with
# GCC/CLang). Make sure to enable -DCMAKE_BUILD_TYPE=Debug as well.

# Defines if Libevent should build without the benchmark executables

# Define if Libevent should build without support for a debug mode

# Define if Libevent should not allow replacing the mm functions

# Define if Libevent should build without support for OpenSSL encryption

# Disable the regress tests

# Disable sample files

# If tests should be compiled or not

# Define if Libevent should not be compiled with thread support

# Enables verbose debugging

# When cross compiling, forces running a test program that verifies that Kqueue
# works with pipes. Note that this requires you to manually run the test program
# on the the cross compilation target to verify that it works. See CMake
# documentation for try_run for more details

More variables can be found by running cmake -LAH <sourcedir_path>

CMake (Windows)

Install CMake:

 $ md build && cd build
 $ cmake -G "Visual Studio 10" ..   # Or whatever generator you want to use cmake --help for a list.
 $ start libevent.sln

CMake (Unix)

 $ mkdir build && cd build
 $ cmake ..     # Default to Unix Makefiles.
 $ make
 $ make verify  # (optional)



To build Libevent, type

 $ ./configure && make

(If you got Libevent from the git repository, you will first need to run the included "" script in order to generate the configure script.)

You can run the regression tests by running

 $ make verify

Install as root via

 $ make install

Before reporting any problems, please run the regression tests.

To enable low-level tracing, build the library as:

 $ CFLAGS=-DUSE_DEBUG ./configure [...]

Standard configure flags should work. In particular, see:

 --disable-shared          Only build static libraries.
 --prefix                  Install all files relative to this directory.

The configure script also supports the following flags:

 --enable-gcc-warnings     Enable extra compiler checking with GCC.
                           Don't let applications replace our memory
                           management functions.
 --disable-openssl         Disable support for OpenSSL encryption.
 --disable-thread-support  Don't support multithreaded environments.

CMake (Windows)

(Note that autoconf is currently the most mature and supported build environment for Libevent; the CMake instructions here are new and experimental, though they should be solid. We hope that CMake will still be supported in future versions of Libevent, and will try to make sure that happens.)

First of all install

To build Libevent using Microsoft Visual studio open the "Visual Studio Command prompt" and type:

$ cd <libevent source dir>
$ mkdir build && cd build
$ cmake -G "Visual Studio 10" ..   # Or whatever generator you want to use cmake --help for a list.
$ start libevent.sln

In the above, the ".." refers to the dir containing the Libevent source code. You can build multiple versions (with different compile time settings) from the same source tree by creating other build directories.

It is highly recommended to build "out of source" when using CMake instead of "in source" like the normal behaviour of autoconf for this reason.

The "NMake Makefiles" CMake generator can be used to build entirely via the command line.

To get a list of settings available for the project you can type:

$ cmake -LH ..


CMake also provides a GUI that lets you specify the source directory and output (binary) directory that the build should be placed in.


For the latest released version of Libevent, see the official website at .

There's a pretty good work-in-progress manual up at .

For the latest development versions of Libevent, access our Git repository via

$ git clone

You can browse the git repository online at:

To report bugs, issues, or ask for new features:


OK, those are not really patches. You fork, modify, and hit the "Create Pull Request" button. You can still submit normal git patches via the mailing list.

Bugs, Features [RFC], and Issues:

Or you can do it via the mailing list.

There's also a libevent-users mailing list for talking about Libevent use and development:


The following people have helped with suggestions, ideas, code or fixing bugs:

  • Samy Al Bahra
  • Antony Antony
  • Jacob Appelbaum
  • Arno Bakker
  • Weston Andros Adamson
  • William Ahern
  • Ivan Andropov
  • Sergey Avseyev
  • Avi Bab
  • Joachim Bauch
  • Andrey Belobrov
  • Gilad Benjamini
  • Stas Bekman
  • Denis Bilenko
  • Julien Blache
  • Kevin Bowling
  • Tomash Brechko
  • Kelly Brock
  • Ralph Castain
  • Adrian Chadd
  • Lawnstein Chan
  • Shuo Chen
  • Ka-Hing Cheung
  • Andrew Cox
  • Paul Croome
  • George Danchev
  • Andrew Danforth
  • Ed Day
  • Christopher Davis
  • Mike Davis
  • Frank Denis
  • Antony Dovgal
  • Mihai Draghicioiu
  • Alexander Drozdov
  • Mark Ellzey
  • Shie Erlich
  • Leonid Evdokimov
  • Juan Pablo Fernandez
  • Christophe Fillot
  • Mike Frysinger
  • Remi Gacogne
  • Artem Germanov
  • Alexander von Gernler
  • Diego Giagio
  • Artur Grabowski
  • Diwaker Gupta
  • Kuldeep Gupta
  • Sebastian Hahn
  • Dave Hart
  • Greg Hazel
  • Nicholas Heath
  • Michael Herf
  • Savg He
  • Mark Heily
  • Maxime Henrion
  • Michael Herf
  • Greg Hewgill
  • Andrew Hochhaus
  • Aaron Hopkins
  • Tani Hosokawa
  • Jamie Iles
  • Xiuqiang Jiang
  • Claudio Jeker
  • Evan Jones
  • Marcin Juszkiewicz
  • George Kadianakis
  • Makoto Kato
  • Phua Keat
  • Azat Khuzhin
  • Alexander Klauer
  • Kevin Ko
  • Brian Koehmstedt
  • Marko Kreen
  • Ondřej Kuzník
  • Valery Kyholodov
  • Ross Lagerwall
  • Scott Lamb
  • Christopher Layne
  • Adam Langley
  • Graham Leggett
  • Volker Lendecke
  • Philip Lewis
  • Zhou Li
  • David Libenzi
  • Yan Lin
  • Moshe Litvin
  • Simon Liu
  • Mitchell Livingston
  • Hagne Mahre
  • Lubomir Marinov
  • Abilio Marques
  • Nicolas Martyanoff
  • Abel Mathew
  • Nick Mathewson
  • James Mansion
  • Nicholas Marriott
  • Andrey Matveev
  • Caitlin Mercer
  • Dagobert Michelsen
  • Andrea Montefusco
  • Mansour Moufid
  • Mina Naguib
  • Felix Nawothnig
  • Trond Norbye
  • Linus Nordberg
  • Richard Nyberg
  • Jon Oberheide
  • John Ohl
  • Phil Oleson
  • Alexey Ozeritsky
  • Dave Pacheco
  • Derrick Pallas
  • Tassilo von Parseval
  • Catalin Patulea
  • Patrick Pelletier
  • Simon Perreault
  • Dan Petro
  • Pierre Phaneuf
  • Amarin Phaosawasdi
  • Ryan Phillips
  • Dimitre Piskyulev
  • Pavel Plesov
  • Jon Poland
  • Roman Puls
  • Nate R
  • Robert Ransom
  • Balint Reczey
  • Bert JW Regeer
  • Nate Rosenblum
  • Peter Rosin
  • Maseeb Abdul Qadir
  • Wang Qin
  • Alex S
  • Gyepi Sam
  • Hanna Schroeter
  • Ralf Schmitt
  • Mike Smellie
  • Steve Snyder
  • Nir Soffer
  • Dug Song
  • Dongsheng Song
  • Hannes Sowa
  • Joakim Soderberg
  • Joseph Spadavecchia
  • Kevin Springborn
  • Harlan Stenn
  • Andrew Sweeney
  • Ferenc Szalai
  • Brodie Thiesfield
  • Jason Toffaletti
  • Brian Utterback
  • Gisle Vanem
  • Bas Verhoeven
  • Constantine Verutin
  • Colin Watt
  • Zack Weinberg
  • Jardel Weyrich
  • Jay R. Wren
  • Zack Weinberg
  • Mobai Zhang
  • Alejo
  • Alex
  • Taral
  • propanbutan
  • masksqwe
  • mmadia
  • yangacer
  • Andrey Skriabin
  • billsegall
  • Bill Vaughan
  • Christopher Wiley
  • David Paschich
  • Ed Schouten
  • Eduardo Panisset
  • Jan Heylen
  • jer-gentoo
  • Joakim Söderberg
  • kirillDanshin
  • lzmths
  • Marcus Sundberg
  • Mark Mentovai
  • Mattes D
  • Matyas Dolak
  • Neeraj Badlani
  • Nick Mathewson
  • Rainer Keller
  • Seungmo Koo
  • Thomas Bernard
  • Xiao Bao Clark
  • zeliard
  • Zonr Chang
  • Kurt Roeckx
  • Seven
  • Simone Basso
  • Vlad Shcherban
  • Tim Hentenaar
  • Breaker
  • johnsonlee
  • Philip Prindeville
  • Vis Virial
  • Andreas Gustafsson
  • Andrey Okoshkin
  • an-tao
  • baixiangcpp
  • Bernard Spil
  • Bogdan Harjoc
  • Carlo Marcelo Arenas Belón
  • David Benjamin
  • David Disseldorp
  • Dmitry Alimov
  • Dominic Chen
  • dpayne
  • ejurgensen
  • Fredrik Strupe
  • Gonçalo Ribeiro
  • James Synge
  • Jan Beich
  • Jesse Fang
  • Jiri Luznicky
  • José Luis Millán
  • Kiyoshi Aman
  • Leo Zhang
  • lightningkay
  • Luke Dashjr
  • Marcin Szewczyk
  • Maximilian Brunner
  • Maya Rashish
  • Murat Demirten
  • Nathan French
  • Nikolay Edigaryev
  • Philip Herron
  • Redfoxmoon
  • stenn
  • SuckShit
  • The Gitter Badger
  • tim-le
  • Vincent JARDIN
  • Xiang Zhang
  • Xiaozhou Liu
  • yongqing.jiao
  • Enji Cooper
  • linxiaohui
  • Seong-Joong Kim
  • Tobias Stoeckmann
  • Yury Korzhetsky
  • zhuizhuhaomeng
  • Pierce Lopez
  • yuangongji
  • Keith Smiley
  • jeremyerb
  • Fabrice Fontaine
  • wenyg
  • Aleksandr-Melnikov
  • ayuseleznev
  • chenguolong
  • Dimo Markov
  • dota17
  • fanquake
  • Jan Kasiak
  • Kamil Rytarowski
  • Mario Emmenlauer
  • Michael Davidsaver
  • mohuang
  • Nick Grifka
  • Nicolas J. Bouliane
  • Paul Osborne
  • Philip Homburg
  • Wataru Ashihara
  • William A Rowe Jr
  • yangyongsheng

If we have forgotten your name, please contact us.