#ifndef _EVENTXX_HPP_
#define _EVENTXX_HPP_
-#include <sys/types.h> // timeval (hack -> event.h don't include it)
+#include <sys/types.h> // timeval
#include <stdexcept> // std::exception, std::invalid_argument,
// std::runtime_error, std::bad_alloc
-/** @mainpage
- *
- * @section Introduction
- *
- * 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. Furthermore, libevent also support callbacks due to signals or
- * regular timeouts.
- *
- * libevent is meant to replace the event loop found in event driven network
- * servers. An application just needs to call dispatcher::dispatch() and then
- * add or remove events dynamically without having to change the event loop.
- *
- * Currently, libevent supports /dev/poll, kqueue(2), select(2), poll(2) and
- * epoll(4). It also has experimental support for real-time signals. The
- * internal event mechanism is completely independent of the exposed event API,
- * and a simple update of libevent can provide new functionality without having
- * to redesign the applications. As a result, Libevent allows for portable
- * application development and provides the most scalable event notification
- * mechanism available on an operating system. Libevent should compile on Linux,
- * *BSD, Mac OS X, Solaris and Windows.
- *
- * This is a simple, direct, one-header inline C++ wrapper for libevent.
- * It's designed to be as close to use to libevent without compromising modern
- * C++ programming techniques and efficiency (since all implementation is
- * trivial and inline, theoretically, it imposes no overhead at all).
- *
- *
- * @section Usage
- *
- * The best way to explain how this works is by examples. TODO
- *
- * @author Leandro Lucarella <llucarella@integratech.com.ar>
- * @version 0.1
- * @par License
- * This program is under the BOLA license (see
- * http://auriga.wearlab.de/~alb/bola/)
- *
- */
-
-
/**
* Namespace for all symbols libevent C++ wrapper defines.
*/
}
-/// @defgroup exceptions Exceptions
+/** @defgroup exceptions Exceptions
+ *
+ * eventxx makes a heavy use of exceptions. Each function has it's exceptions
+ * specified, so it's very easy to find out what exceptions to expect.
+ *
+ * Exceptions are mostly thrown when there is a programming error. So if you get
+ * an exception check your code.
+ */
//@{
* Invalid priority exception.
*
* This exception is thrown when passing an invalid priority to a function. This
- * usually means you don't have enought priority queues in your dispatcher, so
+ * usually means you don't have enough priority queues in your dispatcher, so
* you should have allocated more in the constructor.
*
* If you hit this exception, you probably got a programming error.
//@}
-/// Miscelaneous constants
+/// Miscellaneous constants
enum
{
- DEFAULT_PRIORITY = -1 ///< Default priority (the middle value)
+ DEFAULT_PRIORITY = -1, ///< Default priority (the middle value).
+ ONCE = EVLOOP_ONCE, ///< Loop just once.
+ NONBLOCK = EVLOOP_NONBLOCK ///< Don't block the event loop.
};
-/// C function used as callback in the C API.
-typedef void (*ccallback_type)(int, short, void*);
-
-
/**
* Time used for timeout values.
*
}; // struct time
-/// @defgroup events Events
+/** @defgroup events Events
+ *
+ * There are many ways to specify how to handle an event. You can use use the
+ * same plain functions callbacks (see eventxx::cevent, eventxx::ctimer and
+ * eventxx::csignal) like in C or the other kind of more advanced, stateful
+ * 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.
+ *
+ * Please see each class documentation for details and examples.
+ */
//@{
+
+/// C function used as callback in the C API.
+typedef void (*ccallback_type)(int, short, void*);
+
+
+/**
+ * Type of events.
+ *
+ * There are 4 kind of events: eventxx::TIMEOUT, eventxx::READ, eventxx::WRITE
+ * or eventxx::SIGNAL. eventxx::PERSIST is not an event, is an event modifier
+ * flag, that tells eventxx that this event should live until dispatcher::del()
+ * is called. You can use, for example:
+ * @code
+ * eventxx::event(fd, eventxx::READ | eventxx::PERSIST, ...);
+ * @endcode
+ */
+enum type
+{
+ TIMEOUT = EV_TIMEOUT, ///< Timeout event.
+ READ = EV_READ, ///< Read event.
+ WRITE = EV_WRITE, ///< Write event.
+ SIGNAL = EV_SIGNAL, ///< Signal event.
+ 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.
*
*
* @return true if there is a pending event, false if not.
*/
- bool pending(short ev) const throw()
+ bool pending(type ev) const throw()
{
// HACK libevent don't use const
return event_pending(const_cast< basic_event* >(this), ev, 0);
*
* @param priority New event priority.
*
+ * @pre The event must be added to some dispatcher.
+ *
* @see dispatcher::dispatcher(int)
*/
void priority(int priority) const throw(invalid_event, invalid_priority)
/**
* Generic event object.
*
- * This object stores all the information about an event, incluiding a callback
- * functor, which is called then the event is fired. Then template parameter
- * must be a callable object (functor) that can take 2 parameters: an integer
- * (the file descriptor of the fired event) and a short (the type of event
- * fired: EV_TIMEOUT, EV_SIGNAL, EV_READ, EV_WRITE). There is an specialized
- * version of this class which takes as the template parameter a C function
- * with the ccallback_type signature, just like C libevent API does.
+ * This object stores all the information about an event, including a callback
+ * functor, which is called when the event is fired. The template parameter
+ * must be a functor (callable object or function) that can take 2 parameters:
+ * an integer (the file descriptor of the fired event) and an event::type (the
+ * type of event being fired).
+ * There is a specialized version of this class which takes as the template
+ * parameter a C function with the eventxx::ccallback_type signature, just like
+ * C @libevent API does.
*
* @see eventxx::event< ccallback_type >
*/
* Creates a new event.
*
* @param fd File descriptor to monitor for events.
- * @param ev Type of events to monitor.
+ * @param ev Type of events to monitor (see eventxx::type).
* @param handler Callback functor.
- * @param priority Priority of the event.
*/
- event(int fd, short ev, F& handler, int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ event(int fd, type ev, F& handler) throw()
{
- event_set(this, fd, ev, &wrapper, reinterpret_cast< void* >(&handler));
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
+ event_set(this, fd, static_cast< short >(ev), &wrapper,
+ reinterpret_cast< void* >(&handler));
}
protected:
static void wrapper(int fd, short ev, void* h)
{
F& handler = *reinterpret_cast< F* >(h);
- handler(fd, ev);
+ // Hackish, but this way the handler can get a clean
+ // event type
+ handler(fd, static_cast< type >(ev));
}
}; // struct event< F >
* Creates a new event.
*
* @param fd File descriptor to monitor for events.
- * @param ev Type of events to monitor.
+ * @param ev Type of events to monitor (see eventxx::type).
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
- * @param priority Priority of the event.
*/
- event(int fd, short ev, ccallback_type handler, void* arg,
- int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ event(int fd, type ev, ccallback_type handler, void* arg = 0) throw()
{
- event_set(this, fd, ev, handler, arg);
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
+ event_set(this, fd, static_cast< short >(ev), handler, arg);
}
protected:
* Timer event object.
*
* This is just a special case of event that is fired only when a timeout is
- * reached. It's just a shortcut to event(-1, 0, handler, priority).
+ * reached. It's just a shortcut to:
+ * @code
+ * event(-1, 0, handler);
+ * @endcode
*
- * @note This event can't EV_PERSIST.
+ * @note This event can't eventxx::PERSIST.
* @see timer< ccallback_type >
*/
template < typename F >
* Creates a new timer event.
*
* @param handler Callback functor.
- * @param priority Priority of the event.
*/
- timer(F& handler, int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ timer(F& handler) throw()
{
evtimer_set(this, &event< F >::wrapper,
reinterpret_cast< void* >(&handler));
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
}
}; // struct timer< F >
/**
* This is the specialization of eventxx::timer for C-style callbacks.
*
- * @note This event can't EV_PERSIST.
+ * @note This event can't eventxx::PERSIST.
* @see timer
*/
template <>
/**
* Creates a new timer event.
- *
+ *
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
- * @param priority Priority of the event.
*/
- timer(ccallback_type handler, void* arg, int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ timer(ccallback_type handler, void* arg = 0) throw()
{
evtimer_set(this, handler, arg);
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
}
}; // struct timer< ccallback_type >
* Signal event object.
*
* This is just a special case of event that is fired when a signal is raised
- * (instead of a file descriptor being active). It's just a shortcut to
- * event(signal, EV_SIGNAL, handler, priority).
+ * (instead of a file descriptor being active). It's just a shortcut to:
+ * @code
+ * event(signum, eventxx::SIGNAL, handler);
+ * @endcode
*
- * @note This event allways EV_PERSIST.
+ * @note This event always eventxx::PERSIST.
* @see signal< ccallback_type >
*/
template < typename F >
{
/**
- * Creates a new singal event.
+ * Creates a new signal event.
*
* @param signum Signal number to monitor.
* @param handler Callback functor.
- * @param priority Priority of the event.
*/
- signal(int signum, F& handler, int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ signal(int signum, F& handler) throw()
{
signal_set(this, signum, &event< F >::wrapper,
reinterpret_cast< void* >(&handler));
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
}
/**
/**
* This is the specialization of eventxx::signal for C-style callbacks.
*
- * @note This event allways EV_PERSIST.
+ * @note This event always eventxx::PERSIST.
* @see signal
*/
template <>
* @param signum Signal number to monitor.
* @param handler C-style callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
- * @param priority Priority of the event.
*/
- signal(int signum, ccallback_type handler, void* arg,
- int priority = DEFAULT_PRIORITY)
- throw(invalid_priority)
+ signal(int signum, ccallback_type handler, void* arg = 0) throw()
{
signal_set(this, signum, handler, arg);
- if (priority != DEFAULT_PRIORITY
- && event_priority_set(this, priority))
- throw invalid_priority();
}
/**
* Event's signal number.
- *
+ *
* @return Event's signal number.
*/
int signum() const
/// 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
//@}
/**
* Event dispatcher.
*
- * This class is the responsable for looping and dispatching events.
+ * This class is the responsible for looping and dispatching events. Every time
+ * you need an event loop you should create an instance of this class.
+ *
+ * You can @link dispatcher::add add @endlink events to the dispatcher, and you
+ * can @link dispatcher::del remove @endlink them later or you can @link
+ * dispatcher::add_once add events to be processed just once @endlink. You can
+ * @link dispatcher::dispatch loop once or forever @endlink (well, of course you
+ * can break that forever removing all the events or by @link dispatcher::exit
+ * exiting the loop @endlink).
*/
struct dispatcher
{
/**
- * Creates a default dispatcher (with just 1 prioriority).
+ * Creates a default dispatcher (with just 1 priority).
*
* @see dispatcher(int) if you want to create a dispatcher with more
- * prioriorities.
+ * priorities.
*/
dispatcher() throw()
{
- _event_base = static_cast< internal::event_base* >(internal::event_init());
+ _event_base = static_cast< internal::event_base* >(
+ internal::event_init());
}
/**
- * Creates a dispatcher with npriorities prioriorities.
- *
+ * Creates a dispatcher with npriorities priorities.
+ *
* @param npriorities Number of priority queues to use.
*/
dispatcher(int npriorities) throw(std::bad_alloc)
{
- _event_base = static_cast< internal::event_base* >(internal::event_init());
+ _event_base = static_cast< internal::event_base* >(
+ internal::event_init());
if (!_event_base) throw std::bad_alloc();
// Can't fail because there is no way that it has active events
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); }
#endif
* Adds an event to the dispatcher.
*
* @param e Event to add.
+ * @param priority Priority of the event.
*/
- void add(basic_event& e) throw()
+ void add(basic_event& e, int priority = DEFAULT_PRIORITY)
+ throw(invalid_priority)
{
internal::event_base_set(_event_base, &e);
+ if (priority != DEFAULT_PRIORITY
+ && internal::event_priority_set(&e, priority))
+ throw invalid_priority();
internal::event_add(&e, 0);
}
/**
* Adds an event to the dispatcher with a timeout.
*
- * The event is fired when there is activity on e or when to is elapsed,
+ * The event is fired when there is activity on e or when to has elapsed,
* whatever come first.
*
* @param e Event to add.
* @param to Timeout.
+ * @param priority Priority of the event.
*/
- void add(basic_event& e, const time& to) throw()
+ void add(basic_event& e, const time& to,
+ int priority = DEFAULT_PRIORITY)
+ throw(invalid_priority)
{
internal::event_base_set(_event_base, &e);
- internal::event_add(&e, const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ if (priority != DEFAULT_PRIORITY
+ && internal::event_priority_set(&e, priority))
+ throw invalid_priority();
+ // XXX HACK libevent don't use const
+ internal::event_add(&e, const_cast< time* >(&to));
}
/**
* Adds a temporary event.
*
* Adds a temporary event, without the need of instantiating a new event
- * object. Events added this way can't EV_PERSIST.
+ * object. Events added this way can't eventxx::PERSIST.
*
* @param fd File descriptor to monitor for events.
* @param ev Type of events to monitor.
* @param handler Callback function.
*/
template < typename F >
- void add_once(int fd, short ev, F& handler)
+ 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);
}
/**
* Adds a temporary event to with a C-style callback.
*
* Adds a temporary event, without the need of instantiating a new event
- * object. Events added this way can't EV_PERSIST.
+ * object. Events added this way can't eventxx::PERSIST.
*
* @param fd File descriptor to monitor for events.
* @param ev Type of events to monitor.
* @param handler Callback function.
* @param arg Arbitrary pointer to pass to the handler as argument.
*/
- void add_once(int fd, short ev, ccallback_type handler, void* arg)
+ 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);
}
/**
* Adds a temporary event.
*
* Adds a temporary event, without the need of instantiating a new event
- * object. Events added this way can't EV_PERSIST.
+ * object. Events added this way can't eventxx::PERSIST.
*
* @param fd File descriptor to monitor for events.
* @param ev Type of events to monitor.
* @param to Timeout.
*/
template < typename F >
- void add_once(int fd, short ev, F& handler, const time& to)
+ void add_once(int fd, type ev, F& handler, const time& to)
{
- internal::event_once(fd, ev, &dispatcher::wrapper< F >,
- reinterpret_cast< void* >(&handler),
- const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ 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));
}
/**
* Adds a temporary event with a C-style callback.
*
* Adds a temporary event, without the need of instantiating a new event
- * object. Events added this way can't EV_PERSIST.
+ * object. Events added this way can't eventxx::PERSIST.
*
* @param fd File descriptor to monitor for events.
* @param ev Type of events to monitor.
* @param arg Arbitrary pointer to pass to the handler as argument.
* @param to Timeout.
*/
- void add_once(int fd, short ev, ccallback_type handler, void* arg, const time& to)
+ void add_once(int fd, type ev, ccallback_type handler, void* arg,
+ const time& to)
{
- internal::event_once(fd, ev, handler, arg, const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ internal::event_once(fd, static_cast< short >(ev), handler, arg,
+ // XXX HACK libevent don't use const
+ const_cast< time* >(&to));
}
/**
{
internal::event_once(-1, EV_TIMEOUT, &dispatcher::wrapper< F >,
reinterpret_cast< void* >(&handler),
- const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ // XXX HACK libevent don't use const
+ const_cast< time* >(&to));
}
/**
*/
void add_once_timer(ccallback_type handler, void* arg, const time& to)
{
- internal::event_once(-1, EV_TIMEOUT, handler, arg, const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ // XXX HACK libevent don't use const
+ internal::event_once(-1, EV_TIMEOUT, handler, arg,
+ const_cast< time* >(&to));
}
/**
/**
* Main dispatcher loop.
*
- * This function takes the control of the program, waiting for event and
- * calling it's callbacks when they are fired. It only returns under
+ * This function takes the control of the program, waiting for an event
+ * and calling its callbacks when it's fired. It only returns under
* this conditions:
* - exit() was called.
* - All events were del()eted.
* - Another internal error.
- * - LOOP_ONCE flag was set.
- * - LOOP_NONBLOCK flag was set.
+ * - eventxx::ONCE flag was set.
+ * - eventxx::NONBLOCK flag was set.
+ *
+ * @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.
*
- * @param flags If EVLOOP_ONCE is specified, then just one event is
- * processed, if EVLOOP_NONBLOCK is specified, then this
- * function returns whenever as an event or not.
+ * @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);
}
/**
* Exit the dispatch() loop.
*
- * @param to If a timeout is given, the loop exits after to is passed.
+ * @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)
{
- return internal::event_base_loopexit(_event_base, const_cast< time* >(&to)); // XXX HACK libevent don't use const
+ // XXX HACK libevent don't use const
+ return internal::event_base_loopexit(_event_base,
+ const_cast< time* >(&to));
}
protected:
static void wrapper(int fd, short ev, void* h)
{
F& handler = *reinterpret_cast< F* >(h);
- handler(fd, ev);
+ 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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