evt-server - a simple, fast server framework for C

Overview
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evt-server simplifies writing network servers. It uses libevent to
watch for incoming connections, which can then be handled sequentially
or dispatched to multiple processors. The design is based on the server
in memcached, with a few beneficial modifications.

The goal is to make it unnecessary for people to think about pthreads,
libevent, or setting up servers with the painful BSD sockets API.


Usage
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Call evt_server_init() to set up the library (socktype may be
SOCK_STREAM for TCP, or SOCK_DGRAM for UDP). Write a callback that
handles incoming connections. You can use the helper functions listed
in evt-server.h as well as the ones in evt-core.h to get this done.

If you want to use threads to process accepted connections, separate
the logic from your first callback into two parts. The first accepts
incoming connections and calls evt_thread_dispatch() when it's done.
The second takes accepted connections and processes them (i.e does the
'real' I/O between the client and server). Register the first callback
with a call to evt_server_start(), and register the second one by
calling evt_server_threads(). At this point the server is running.

If you don't want to use threads, just write one callback that handles
everything sequentially and call evt_server_start().

Call evt_server_stop() if you want to stop the server and free the
internal data structures.


Benefits
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See test/evt_test.c. That's a complete, multithreaded server in
basically 15 lines of clear, simple C. On my laptop, it can handle a
flood of 10,000 connections without much difficulty (averaging 1,981
microseconds per 1KB transaction).


Bugs (comments and patches appreciated!)
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1. Windows hasn't been tested, though efforts have been made to
preserve portability.
2. evt-server does not serve you breakfast in bed, nor does it make you
a better AssaultCube player.


License
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Copyright (c) 2010 Vedant Kumar <vminch@gmail.com>

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.