libevent / libevent-book

Nick's libevent manual

1. BUILDING AND INSTALLATION

CMake (Unix)

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

See Documentation/Building#Building on Unix using CMake for more information.

CMake (Windows)

Install CMake: https://cmake.org/

md build && cd build
cmake -G "Visual Studio 10" ..   # Or use any generator you want to use. Run cmake --help for a list
cmake --build . --config Release # Or "start libevent.sln" and build with menu in Visual Studio.

See Documentation/Building#Building on Windows for more information.

Package Managers

You can download and install libevent using the vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install libevent

The libevent port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.

Autoconf

Note, since 2.2 it is deprecated

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

See Documentation/Building#Autoconf for more information.

2. USEFUL LINKS:

For the latest released version of Libevent, see the official website at https://libevent.org/ .

There's a pretty good work-in-progress manual up at http://www.wangafu.net/~nickm/libevent-book/ .

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

$ git clone https://github.com/libevent/libevent.git

You can browse the git repository online at:

https://github.com/libevent/libevent

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

Patches: https://github.com/libevent/libevent/pulls

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: https://github.com/libevent/libevent/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:

https://archives.seul.org/libevent/users/

3. ACKNOWLEDGMENTS

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

libevent-book's Issues

would someone translate this into Chinese version?

it is useful and I wanna take a try. Is it OK?

Set timer from signal callback warning - needs resolution

In nmathewson/libevent-book/blob/master/Ref4_event.txt under _constructing_signal_events there is a warning about setting timers from signal callback "It might not be supported".

I did a SIMPLE test and did not run into a problem, furthermore it would make sense for this to potentially be a problem in the signal handler itself, rather than the callback. I assume that the callback should be executing in the event-loop context and thus should be okay. In either case, IMO this should either go away or become more definitive, i.e. list cases, environments where it is not supported.

Thanks
-Nevo

Why named asynchronous IO?

In

https://github.com/nmathewson/libevent-book/blob/ab4dd1107bbfe419e94ccabbe9473b542173bccd/01_intro.txt#L5

why named asynchronous IO?

In my opinion, asynchronous IO is use like aio_write, aio_read , but libevent use like epoll , so there should use synchronous nonblocking IO

PDF does not build

Seems like there is a problem with asciidoc 8.6.3

  $ make pdf
  a2x -f pdf LibeventBook.txt
  a2x: ERROR: xmllint --nonet --noout --valid /Users/tcurdt/Desktop/libevent-book/LibeventBook.xml returned non-zero exit status 4
  make: *** [LibeventBook.pdf] Error 1

TOC link to Ref9 broken

Notice a broken link on http://www.wangafu.net/~nickm/libevent-book/TOC.html

• link:Ref8_listener.html[R8: Connection listeners: accepting TCP connections]
• link:Ref8_dns.html[R9: DNS for Libevent]
  ^^^^^^^^^^^
  Shall be Ref_9__dns.html ?

FD_SET(i, &readset)?

In file "01intro.txt"

/* Add all of the interesting fds to readset */
for (i=0; i < n_sockets; ++i) {
if (fd[i]>maxfd) maxfd = fd[i];
FD_SET(i, &readset);
}

Should it be FD_SET(fd[i], &readset)? I'm not sure about it.

address family not set in example

Here: https://github.com/nmathewson/libevent-book/blob/master/Ref6_bufferevent.txt#L271

The sockaddr_in is memset and the sin_addr and sin_port are set, but sin_family is not, leading to error 47 (Address family not supported by protocol family).

R4 needs more discussion of user-triggered events

The "Working with events" sections mentions user-triggered events, but then doesn't discuss a canonical way of having user-triggered events.

Can this be added?

Does « bufferevent_base_connect() » actually exists ?

Hey,

This bufferevent_base_connect() function is mentionned in the book around here https://github.com/nmathewson/libevent-book/blob/9e9e5242f6fcd4cc6bfe564c22756ab6f5ce5914/Ref6_bufferevent.txt#L296
I can not find any other occurence of it in the book or in the libevent api.
Should I be reading bufferevent_socket_connect() instead ?

Is return value of evutil_inet_pton() right?

Hi,

https://github.com/nmathewson/libevent-book/blob/6eb2799fdff4d53235d21dccca47ffc66513d250/Ref5_evutil.txt#L339-L340

I think that the following is right.

The return value from evutil_inet_pton() is 1 on success, -1 on invalid af, and 0 on invalid address format.

event_base_get_features() example code of Ref2

at line 241 of Ref2, the flag for O1 event notification shall be EV_FEATURE_O1 instead of EV_FEATURE_ET ?

if ((f & EV_FEATURE_ET))
    printf(" Edge-triggered events are supported.");
if ((f & EV_FEATURE_ET)) <- EV_FEATURE_O1 ?
    printf(" O(1) event notification is supported.");
if ((f & EV_FEATURE_FDS))