X-Git-Url: https://git.llucax.com/software/eventxx.git/blobdiff_plain/d8f5a98473b01893208ed1fececff69ba76297a2..ab96e110f2d5754fc1d9822db3506d58a0929122:/eventxx diff --git a/eventxx b/eventxx index 66e94ea..2aeb0d0 100644 --- a/eventxx +++ b/eventxx @@ -5,210 +5,6 @@ #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. 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. - * - * 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). - * - * Please, visit the eventxx - * website for the latest documentation. - * - * You can always get - * the most up to date sources from the - * darcs. - * - * You can also take a look the the darcsweb interface to see - * the latest - * changes online. - * - * - * @section Usage - * - * 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. See eventxx::dispatcher documentation for - * more details. - * - * You can use use the same plain functions callbacks or the other kind of - * function objects (see @link events @endlink section for details on event - * types). - * - * eventxx uses @link exceptions @endlink to report errors. All functions has - * exception specifications, so it's easy to find out what to expect. See - * exceptions section for more detail. - * - * A timespec abstraction is provided in eventxx::time for convenient argument - * passing. Even more, it's a timespec itself, with some convenient methods for - * accessing the timespec attributes in a more C++ way. 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 (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 - * #include - * #include - * - * 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 used, you can't be surprised if you catch - * a piece of code that didn't got 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 this lib leaks memory, don't blame me, blame libevent :) - * libevent has a known bug on event_base_free() that makes it assert always, so - * event_base_free() it's unusable, unless you patch your libevent (for example, - * using this patch - * written by Mark D. Anderson and who knows why it's not still applied. If you - * do so, you can compile your programs with -DEVENT_BASE_FREE_FIX so - * event_base_free() gets called. - * - * That said, I think it's 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, - * drop me an - * e-mail 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 - * - * @version 0.1 - * - * @par License - * This program is under the BOLA license (see - * http://auriga.wearlab.de/~alb/bola/ for more info or the - * LICENSE - * file itself). - * - */ - -/** @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. - */ - -/** @example test-weof.cpp - * - * This is some kind of test of EOF ported from libevent. - */ - -/** @example trivial.cpp - * - * This is the most trivial example. - */ - /** * Namespace for all symbols libevent C++ wrapper defines. */ @@ -306,10 +102,6 @@ enum }; -/// C function used as callback in the C API. -typedef void (*ccallback_type)(int, short, void*); - - /** * Time used for timeout values. * @@ -366,6 +158,12 @@ struct time: ::timeval * 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. @@ -374,6 +172,11 @@ struct time: ::timeval */ //@{ + +/// C function used as callback in the C API. +typedef void (*ccallback_type)(int, short, void*); + + /** * Type of events. * @@ -394,6 +197,14 @@ enum type 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. * @@ -480,8 +291,8 @@ struct basic_event: internal::event * 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 ccallback_type signature, just like C - * libevent API does. + * parameter a C function with the eventxx::ccallback_type signature, just like + * C @libevent API does. * * @see eventxx::event< ccallback_type > */ @@ -496,9 +307,9 @@ struct event: basic_event * @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)); } @@ -509,7 +320,7 @@ struct event: basic_event 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 > @@ -532,9 +343,9 @@ struct event< ccallback_type >: basic_event * @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: @@ -589,7 +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); } @@ -655,7 +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); } @@ -682,6 +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 //@} @@ -710,7 +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()); } /** @@ -720,16 +567,16 @@ 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); } -#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 /** @@ -766,7 +613,8 @@ 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)); } /** @@ -782,8 +630,9 @@ struct dispatcher 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); } /** @@ -799,7 +648,8 @@ struct dispatcher */ 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); } /** @@ -816,9 +666,11 @@ struct dispatcher 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), - 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)); } /** @@ -833,9 +685,12 @@ struct dispatcher * @param arg Arbitrary pointer to pass to the handler as argument. * @param to Timeout. */ - void add_once(int fd, type 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)); } /** @@ -852,7 +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)); } /** @@ -867,7 +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)); } /** @@ -897,8 +755,13 @@ struct dispatcher * @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); } @@ -908,8 +771,11 @@ 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) { // XXX HACK libevent don't use const return internal::event_base_loopexit(_event_base, @@ -919,16 +785,20 @@ struct dispatcher 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_