#include <stdexcept> // std::exception, std::invalid_argument,
// std::runtime_error, std::bad_alloc
-/** @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 ;). I know @eventxx will work with @libevent 1.1 and 1.2 if you
- * use the @c event_base_free() fix (see \ref Status section for more details).
- *
- * 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://www.llucax.com.ar/~luca/repos/eventxx/">most up to date
- * sources</a> from the <a href="http://www.darcs.net/">darcs</a> repository.
- *
- * You can also take a look the the <a
- * href="http://auriga.wearlab.de/~alb/darcsweb/">darcsweb</a> interface to see
- * the <a href="http://www.llucax.com.ar/~luca/repos/darcsweb/?r=eventxx">latest
- * changes online</a> or subscribe to its
- * <a href="http://www.llucax.com.ar/~luca/repos/darcsweb/?r=eventxx;a=rss">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 simple, 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 has 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 are
- * 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, short 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 some more examples on the test directory of the distribution or
- * on the examples related page.
- *
- *
- * @section Status
- *
- * This library was not widely used yet, it lack some testing. Because templates
- * are not even compiled when they are not used, don't be surprised if you catch
- * a piece of code that don't even compiled yet because the lack of testing. The
- * library has no support for buffered events yet either. It doesn't support the
- * http stuff, and probably never will because that has nothing to do with event
- * handling.
- *
- * If you notice that when using @eventxx your program leaks some memory, don't
- * blame me, blame @libevent :) @libevent has a known bug on @c event_base_free()
- * that makes it assert always, so @c event_base_free() it's unusable, unless you
- * patch your libevent (for example, using this <a
- * href="http://monkeymail.org/archives/libevent-users/2006-April/000141.html">patch</a>
- * written by Mark D. Anderson, and who knows why it's not still applied. If you
- * do so, you can compile your programs with @c -DEVENT_BASE_FREE_FIX so
- * @c event_base_free() gets called in the eventxx::dispatcher @link
- * eventxx::dispatcher::~dispatcher() destructor @endlink.
- *
- * That said, I think it's still pretty usable anyways. If something is broken
- * it would be really easy to fix it because 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 ;).
- *
- * Patches to support buffered events are welcome too.
- *
- *
- * @author Leandro Lucarella <llucax+eventxx@gmail.com>
- *
- * @version 0.1
- *
- * @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://www.llucax.com.ar/~luca/repos/eventxx/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 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.
- */
-
/**
* Namespace for all symbols libevent C++ wrapper defines.
*/
};
-/// C function used as callback in the C API.
-typedef void (*ccallback_type)(int, short, void*);
-
-
/**
* Time used for timeout values.
*
* function objects (see eventxx::event, eventxx::timer and eventxx::signal
* templates). The former are just typedef'ed specialization of the later.
*
+ * A member function wrapper functor (eventxx::mem_cb) is also included,
+ * so you can use any member function (method) as an event handler.
+ *
+ * Please note that C-like function callback take a short as the type of event,
+ * while functors (or member functions) use eventxx::type.
+ *
* All events derive from a plain class (not template) eventxx::basic_event, one
* of the main utilities of it (besides containing common code ;) is to be used
* in STL containers.
*/
//@{
+
+/// C function used as callback in the C API.
+typedef void (*ccallback_type)(int, short, void*);
+
+
/**
* Type of events.
*
PERSIST = EV_PERSIST ///< Not really an event, is an event modifier.
};
+inline
+type operator| (const type& t1, const type& t2)
+{
+ int r = static_cast< int >(t1) | static_cast< int >(t2);
+ return static_cast< type >(r);
+}
+
+
/**
* Basic event from which all events derive.
*
* @param ev Type of events to monitor (see eventxx::type).
* @param handler Callback functor.
*/
- event(int fd, short ev, F& handler) throw()
+ event(int fd, type ev, F& handler) throw()
{
- event_set(this, fd, ev, &wrapper,
+ event_set(this, fd, static_cast< short >(ev), &wrapper,
reinterpret_cast< void* >(&handler));
}
F& handler = *reinterpret_cast< F* >(h);
// Hackish, but this way the handler can get a clean
// event type
- handler(fd, *reinterpret_cast< type* >(&ev));
+ handler(fd, static_cast< type >(ev));
}
}; // struct event< F >
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
*/
- event(int fd, short ev, ccallback_type handler, void* arg) throw()
+ event(int fd, type ev, ccallback_type handler, void* arg = 0) throw()
{
- event_set(this, fd, ev, handler, arg);
+ event_set(this, fd, static_cast< short >(ev), handler, arg);
}
protected:
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
*/
- timer(ccallback_type handler, void* arg) throw()
+ timer(ccallback_type handler, void* arg = 0) throw()
{
evtimer_set(this, handler, arg);
}
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
*/
- signal(int signum, ccallback_type handler, void* arg) throw()
+ signal(int signum, ccallback_type handler, void* arg = 0) throw()
{
signal_set(this, signum, handler, arg);
}
/// Shortcut to C-style signal handler.
typedef eventxx::signal< ccallback_type > csignal;
+/**
+ * Helper functor to use an arbitrary member function as an event handler.
+ *
+ * With this wrapper, you can use any object method, which accepts the right
+ * parameters (int, short) and returns void, as an event handler. This way you
+ * don't have to overload the operator() which can be confusing depending on the
+ * context.
+ *
+ * You can see an usage example in the Examples Section.
+ */
+template < typename O, typename M >
+struct mem_cb
+{
+
+ /**
+ * Member function callback constructor.
+ *
+ * It expects to receive a class as the first parameter (O), and a
+ * member function (of that class O) as the second parameter.
+ *
+ * When this instance is called with fd and ev as function arguments,
+ * object.method(fd, ev) will be called.
+ *
+ * @param object Object to be used.
+ * @param method Method to be called.
+ */
+ mem_cb(O& object, M method) throw():
+ _object(object), _method(method) {}
+
+ void operator() (int fd, type ev) { (_object.*_method)(fd, ev); }
+ protected:
+ O& _object;
+ M _method;
+
+}; // struct mem_cb
//@}
internal::event_base_priority_init(_event_base, npriorities);
}
-#ifdef EVENT_BASE_FREE_FIX
+#ifndef EVENTXX_NO_EVENT_BASE_FREE
/// Free dispatcher resources, see @ref Status section for details.
~dispatcher() throw() { event_base_free(_event_base); }
-#else
-#warning "The dispatcher class *will* leak memory because of a libevent bug, " \
- "see http://www.mail-archive.com/libevent-users@monkey.org/msg00110.html " \
- "for more info an a patch. If you already have this patch, please " \
- "-DEVENT_BASE_FREE_FIX to your compiler to make this message disappear " \
- "and really free the dispatcher memory using event_base_free()."
#endif
/**
&& internal::event_priority_set(&e, priority))
throw invalid_priority();
// XXX HACK libevent don't use const
- internal::event_add(&e, const_cast< time* >(&to));
+ internal::event_add(&e, const_cast< time* >(&to));
}
/**
template < typename F >
void add_once(int fd, type ev, F& handler)
{
- internal::event_once(fd, ev, &dispatcher::wrapper< F >,
- reinterpret_cast< void* >(&handler), 0);
+ internal::event_once(fd, static_cast< short>(ev),
+ &dispatcher::wrapper< F >,
+ reinterpret_cast< void* >(&handler), 0);
}
/**
*/
void add_once(int fd, type ev, ccallback_type handler, void* arg)
{
- internal::event_once(fd, ev, handler, arg, 0);
+ internal::event_once(fd, static_cast< short >(ev), handler,
+ arg, 0);
}
/**
template < typename F >
void add_once(int fd, type ev, F& handler, const time& to)
{
- internal::event_once(fd, ev, &dispatcher::wrapper< F >,
- reinterpret_cast< void* >(&handler),
- // XXX HACK libevent don't use const
- const_cast< time* >(&to));
+ internal::event_once(fd, static_cast< short >(ev),
+ &dispatcher::wrapper< F >,
+ reinterpret_cast< void* >(&handler),
+ // XXX HACK libevent don't use const
+ const_cast< time* >(&to));
}
/**
void add_once(int fd, type ev, ccallback_type handler, void* arg,
const time& to)
{
- internal::event_once(fd, ev, handler, arg,
+ internal::event_once(fd, static_cast< short >(ev), handler, arg,
// XXX HACK libevent don't use const
const_cast< time* >(&to));
}
* @param flags If eventxx::ONCE is specified, then just one event is
* processed, if eventxx::NONBLOCK is specified, then this
* function returns even if there are no pending events.
+ *
+ * @return 0 if eventxx::NONBLOCK or eventxx::ONCE is set, 1 if there
+ * are no more events registered and EINTR if you use the
+ * @libevent's @c event_gotsig and return -1 in your
+ * @c event_sigcb callback.
*/
- int dispatch(int flags = 0) // TODO throw(exception)
+ int dispatch(int flags = 0) throw()
{
return internal::event_base_loop(_event_base, flags);
}
*
* @param to If a timeout is given, the loop exits after the specified
* time is elapsed.
+ *
+ * @return Not very well specified by @libevent :-/ that's why it
+ * doesn't throw an exception either.
*/
- int exit(const time& to = time())
+ int exit(const time& to = time()) throw() // TODO throw(exception)
{
// XXX HACK libevent don't use const
return internal::event_base_loopexit(_event_base,
protected:
internal::event_base* _event_base;
template < typename F >
- static void wrapper(int fd, type ev, void* h)
+ static void wrapper(int fd, short ev, void* h)
{
F& handler = *reinterpret_cast< F* >(h);
handler(fd, *reinterpret_cast< type* >(&ev));
}
-}; // struct dispatcher
+ private:
+ // Hide nonsense copy-constructor and operator=
+ dispatcher(const dispatcher&);
+ dispatcher& operator=(const dispatcher&);
+}; // struct dispatcher
-} // namespace event
+} // namespace eventxx
#endif // _EVENTXX_HPP_
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