X-Git-Url: https://git.llucax.com/software/eventxx.git/blobdiff_plain/e6aa41369687b53303c73a390dc01276e0fa7d20..2be5a2e8f3eb90f2f6da62c0fd81c7e3b3e62f0c:/eventxx diff --git a/eventxx b/eventxx index ab72fbf..9ac878d 100644 --- a/eventxx +++ b/eventxx @@ -1,51 +1,10 @@ #ifndef _EVENTXX_HPP_ #define _EVENTXX_HPP_ -#include // timeval (hack -> event.h don't include it) +#include // timeval #include // 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 - * @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. */ @@ -60,7 +19,14 @@ namespace internal } -/// @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. + */ //@{ @@ -101,7 +67,7 @@ struct invalid_event: public std::invalid_argument, public exception * 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. @@ -127,17 +93,15 @@ struct invalid_priority: public std::invalid_argument, public exception //@} -/// 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. * @@ -186,9 +150,61 @@ struct time: ::timeval }; // 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 *reinterpret_cast< type* >(&r); +} + + /** * Basic event from which all events derive. * @@ -208,7 +224,7 @@ struct basic_event: internal::event * * @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); @@ -269,13 +285,14 @@ struct basic_event: internal::event /** * Generic event object. * - * This object stores all the information about an event, incluiding a callback + * 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 a short (the type of - * the fired event: EV_TIMEOUT, EV_SIGNAL, EV_READ, EV_WRITE). There is a - * 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. + * 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 > */ @@ -287,12 +304,13 @@ struct event: basic_event * 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. */ - event(int fd, short ev, F& handler) throw() + event(int fd, type ev, F& handler) throw() { - event_set(this, fd, ev, &wrapper, reinterpret_cast< void* >(&handler)); + event_set(this, fd, static_cast< short >(ev), &wrapper, + reinterpret_cast< void* >(&handler)); } protected: @@ -300,7 +318,9 @@ struct event: basic_event 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, *reinterpret_cast< type* >(&ev)); } }; // struct event< F > @@ -319,13 +339,13 @@ struct event< ccallback_type >: basic_event * 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. */ - 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: @@ -338,9 +358,12 @@ struct event< ccallback_type >: basic_event * 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). + * 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 > @@ -364,7 +387,7 @@ struct timer: event< 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 <> @@ -377,7 +400,7 @@ struct timer< ccallback_type >: event< ccallback_type > * @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); } @@ -389,10 +412,12 @@ struct timer< ccallback_type >: event< 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). + * (instead of a file descriptor being active). It's just a shortcut to: + * @code + * event(signum, eventxx::SIGNAL, handler); + * @endcode * - * @note This event always EV_PERSIST. + * @note This event always eventxx::PERSIST. * @see signal< ccallback_type > */ template < typename F > @@ -400,7 +425,7 @@ struct signal: event< F > { /** - * Creates a new singal event. + * Creates a new signal event. * * @param signum Signal number to monitor. * @param handler Callback functor. @@ -427,7 +452,7 @@ struct signal: event< F > /** * This is the specialization of eventxx::signal for C-style callbacks. * - * @note This event always EV_PERSIST. + * @note This event always eventxx::PERSIST. * @see signal */ template <> @@ -441,7 +466,7 @@ struct signal< ccallback_type >: event< ccallback_type > * @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); } @@ -468,6 +493,41 @@ typedef eventxx::timer< ccallback_type > ctimer; /// 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 //@} @@ -475,7 +535,15 @@ typedef eventxx::signal< ccallback_type > csignal; /** * 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 { @@ -488,7 +556,8 @@ struct dispatcher */ dispatcher() throw() { - _event_base = static_cast< internal::event_base* >(internal::event_init()); + _event_base = static_cast< internal::event_base* >( + internal::event_init()); } /** @@ -498,13 +567,15 @@ struct dispatcher */ 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 @@ -542,47 +613,50 @@ struct dispatcher if (priority != DEFAULT_PRIORITY && internal::event_priority_set(&e, priority)) throw invalid_priority(); - internal::event_add(&e, const_cast< time* >(&to)); // XXX HACK libevent don't use const + // 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. @@ -590,18 +664,20 @@ struct dispatcher * @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. @@ -609,9 +685,12 @@ struct dispatcher * @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)); } /** @@ -628,7 +707,8 @@ struct dispatcher { 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)); } /** @@ -643,7 +723,9 @@ struct dispatcher */ 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)); } /** @@ -667,14 +749,19 @@ struct dispatcher * - 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 EVLOOP_ONCE is specified, then just one event is - * processed, if EVLOOP_NONBLOCK is specified, then this + * @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); } @@ -684,10 +771,15 @@ struct dispatcher * * @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: @@ -696,13 +788,12 @@ struct dispatcher 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 - -} // namespace event +} // namespace eventxx #endif // _EVENTXX_HPP_