X-Git-Url: https://git.llucax.com/software/eventxx.git/blobdiff_plain/e6aa41369687b53303c73a390dc01276e0fa7d20..e025da92de4fc21c84f30117de2bed7f3c579fb2:/eventxx diff --git a/eventxx b/eventxx index ab72fbf..5d13b3e 100644 --- a/eventxx +++ b/eventxx @@ -1,7 +1,7 @@ #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 @@ -9,10 +9,10 @@ * * @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. + * 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 @@ -27,24 +27,196 @@ * 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 + * 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 + * current + * release from the + * release + * directory or grab the + * most up to date + * sources from the darcs repository. + * + * You can also take a look the the darcsweb interface to see + * the latest + * changes online. + * * * @section Usage * - * The best way to explain how this works is by examples. TODO + * 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 * - * @author Leandro Lucarella * @version 0.1 + * * @par License - * This program is under the BOLA license (see - * http://auriga.wearlab.de/~alb/bola/) + * 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 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. @@ -60,7 +232,14 @@ 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 +280,7 @@ 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. @@ -127,10 +306,12 @@ 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. }; @@ -186,9 +367,42 @@ 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. + * + * 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. + */ //@{ +/** + * 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. +}; + /** * Basic event from which all events derive. * @@ -208,7 +422,7 @@ 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 +483,14 @@ 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 ccallback_type signature, just like C + * libevent API does. * * @see eventxx::event< ccallback_type > */ @@ -287,12 +502,13 @@ 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_set(this, fd, ev, &wrapper, reinterpret_cast< void* >(&handler)); + event_set(this, fd, ev, &wrapper, + reinterpret_cast< void* >(&handler)); } protected: @@ -300,7 +516,9 @@ 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 > @@ -319,7 +537,7 @@ 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. */ @@ -338,9 +556,12 @@ 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 +585,7 @@ 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 <> @@ -389,10 +610,12 @@ 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 +623,7 @@ 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 +650,7 @@ 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 <> @@ -475,7 +698,15 @@ 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 { @@ -506,6 +737,8 @@ struct dispatcher #ifdef EVENT_BASE_FREE_FIX ~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 /** @@ -549,14 +782,14 @@ struct dispatcher * 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); @@ -566,14 +799,14 @@ struct dispatcher * 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); } @@ -582,7 +815,7 @@ struct dispatcher * 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. @@ -590,7 +823,7 @@ 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), @@ -601,7 +834,7 @@ struct dispatcher * 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. @@ -609,7 +842,7 @@ 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 } @@ -667,11 +900,11 @@ 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. */ int dispatch(int flags = 0) // TODO throw(exception) @@ -687,16 +920,18 @@ struct dispatcher */ int exit(const time& to = time()) { - 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: internal::event_base* _event_base; template < typename F > - static void wrapper(int fd, short ev, void* h) + static void wrapper(int fd, type ev, void* h) { F& handler = *reinterpret_cast< F* >(h); - handler(fd, ev); + handler(fd, *reinterpret_cast< type* >(&ev)); } }; // struct dispatcher