// NOTE: This file is in doxygen[1] format. Maybe you should try to run
//       doxygen to get a better looking documentation ;)
//
// [1] http://www.stack.nl/~dimitri/doxygen/

/** @mainpage

@section Introduction

@libevent is a popular API that provides a mechanism to execute a callback
function when a specific event occurs on a file descriptor or after a
timeout has been reached. Furthermore, @libevent also support callbacks due
to signals or regular timeouts.

@eventxx is a simple, direct, one-header inline C++ wrapper for @libevent.
Yes, it's just one header file, so if you want to use it you can just copy
the file to your project and you are set (well, you'll need to link to
@libevent too ;).

It's designed to be as close to use to @libevent (without compromising
modern C++ programming techniques) and efficient (since all implementation
is trivial and inline, theoretically, it imposes no overhead at all) as
possible.

Please, visit the @eventxx website for the latest version of this
documentation.

You can always get the <a
href="http://www.llucax.com.ar/~luca/eventxx/releases/eventxx.tar.gz">current
release</a> from the
<a href="http://www.llucax.com.ar/~luca/eventxx/releases/">release
directory</a> or grab the
<a href="http://git.llucax.com.ar/?p=software/eventxx.git;a=snapshot">most up
to date sources</a> from the <a href="http://git.or.cz/">git</a> repository.

You can also take a look the the <a
href="http://git.llucax.com.ar/?p=software/eventxx.git;a=summary">eventxx
gitweb</a> interface to see the latest changes online or subscribe to its
<a href="http://git.llucax.com.ar/?p=software/eventxx.git;a=atom">RSS
feed</a> to follow the development.


@section Usage

You probably should read @libevent documentation to get started or at least
just for reference, although @eventxx is pretty simple so you can jump right
into the \ref Example section (or the example list) and write a working
program without much trouble.

This wrapper was designed to be used just like @libevent, but with C++ style
syntax sugar (or poison, depends on your point of view ;) and goodies. The
main difference to libevent is you always have to instance a
eventxx::dispatcher to get an event loop. There is no implicit global event
loop. This adds just an extra line of code for single threaded applications
and makes things much more simpler, so I hope nobody complains about it ;).
See eventxx::dispatcher documentation for more details.

You can use use the same plain functions callbacks @libevent use or the other
kind of function objects (see @ref events section for details on event
types).

@eventxx uses @ref exceptions to report errors. All functions have exception
specifications, so it's easy to find out what to expect. See @ref exceptions
section for more detail.

A @c timespec abstraction is provided as eventxx::time for convenient
argument passing. Even more, it's a @c timespec itself, with some convenient
methods for accessing the attributes with pritier names. And even more,
@eventxx is such a direct mapping that all eventxx::event's are @libevent
event structs too, so theoretically you can pass a eventxx::event to
@libevent C functions without much trouble. eventxx::dispatcher is the only
class that is not derived from @libevent struct (@c event_base) because this
struct it's not defined on the libevent header (just declared).

Maybe you shouldn't know this implementation details to keep the abstraction,
but this is a basic design goal of this wrapper so there is not much chance
that this changes in the future (but use this knowledge with care, you have
been  warned ;).


@section Example

@code
#include <eventxx>
#include <iostream>
#include <csignal>

struct handler
{
	eventxx::dispatcher& d;
	int i;
	handler(eventxx::dispatcher& d): d(d), i(0) {}
	void operator() (int signum, eventxx::type event)
	{
		if (i < 5) std::cout << "keep going...\n";
		else
		{
			std::cout << "done!\n";
			d.exit();
		}
	}
};

void sighandler(int signum, short event, void* data)
{
	int& i = *static_cast< int* >(data);
	std::cout << ++i << " interrupts, ";
}

int main()
{
	eventxx::dispatcher d;
	handler h(d);
	eventxx::csignal sigev(SIGINT, sighandler, &h.i);
	eventxx::signal< handler > e(SIGINT, h);
	d.add(sigev);
	d.add(e);
	d.dispatch();
	return 0;
}
@endcode

You can see more examples on the test directory of the distribution or on the
examples related page.


@section Status

This library has not been widely used yet, but it's used in some serious
projects, so I think it's moderately stable now. The library has no support
for buffered events yet, but patches are welcome. It doesn't support the
HTTP stuff, and probably never will because that has nothing to do with
event handling.

@libevent had a memory leak before version 1.3b (before 1.2 it didn't even
had a way free that memory, from version 1.2 to 1.3a, if you tried to free
the memory the program @c abort() because a failed assertion). Because of
that, there is a way to disable the @link eventxx::dispatcher::~dispatcher()
dispatcher destructor @endlink (which calls the inexistent/broken
@c event_base_free() function). So if you use a @libevent version previous
to 1.3b, you have to compile your programs defining the
@c EVENTXX_NO_EVENT_BASE_FREE macro.

If something is broken it would be really easy to fix because @eventxx is
just a simple wrapper around @libevent. So, please try it out, and if you
have any problems, <a href="mailto:llucax+eventxx@gmail.com">drop me an
e-mail</a> and and I'll fix it ASAP (or provide a patch and you will be my
best friend ;).

If you use this library, please drop me an e-mail with your thoughts, or
simply saying "I use it", so I can keep track of how many people really use
it.

@author Leandro Lucarella <llucax+eventxx@gmail.com>

@version 0.7

@par License
This program is under the BOLA license (see
http://auriga.wearlab.de/~alb/bola/ for more details or read the
<a href="http://git.llucax.com.ar/?p=software/eventxx.git;a=blob_plain;f=LICENSE">LICENSE</a>
file itself, it's very short and it basically says it's Public Domain).

*/

/** @example c-way.cpp
This is a simple example illustrating the usage with C-like callback
functions.
*/

/** @example functor-way.cpp
This is a simple example illustrating the usage with function object
callbacks.
*/

/** @example wrapped-functor-way.cpp
This is a simple example illustrating the usage with an arbitrary member
function as an event handler callbacks.
*/

/** @example mixed-way.cpp
This is a simple example illustrating the usage with a mix of C-like callbacks
and function object callbacks.
*/

/** @example bench.cpp
This is a benchmark example, extracted from libevent and ported to eventxx.
*/

/** @example prio-test.cpp
This is a priority usage example.
*/

/** @example test-time.cpp
This is a timer usage example ported from libevent.
*/

/** @example test-eof.cpp
This is some kind of test of EOF ported from libevent.
*/

/** @example test-weof.cpp
Another test of EOF ported from libevent.
*/

/** @example trivial.cpp
This is the most trivial example.
*/