X-Git-Url: https://git.llucax.com/software/eventxx.git/blobdiff_plain/f04d9717c849d448150e15d87bc3685af714694a..c91910cd7cf9a0fab1b015b67bc70e7468b9fa50:/eventxx?ds=sidebyside diff --git a/eventxx b/eventxx index 1f5f2f5..e2391b5 100644 --- a/eventxx +++ b/eventxx @@ -9,76 +9,78 @@ * * @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. + * @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 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. + * changes online or subscribe to its + * RSS + * feed to follow the development. * * * @section Usage * - * This wrapper was designed to be used just like libevent, but with C++ style - * syntax sugar (or poisson, depends on your point of view ;) and goodies. The - * main difference to libevent is you allways have to instance a + * 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. See eventxx::dispatcher documentation for - * more details. + * and makes things much more simpler, so I hope nobody complains about it ;). + * 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 + * 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 @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. + * @eventxx uses @ref exceptions to report errors. All functions have exception + * specifications, so it's easy to find out what to expect. See @ref 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). + * 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 ;). + * that this changes in the future (but use this knowledge with care, you have + * been warned ;). + * * * @section Example * @@ -92,7 +94,7 @@ * eventxx::dispatcher& d; * int i; * handler(eventxx::dispatcher& d): d(d), i(0) {} - * void operator() (int signum, short event) + * void operator() (int signum, eventxx::type event) * { * if (i < 5) std::cout << "keep going...\n"; * else @@ -122,31 +124,31 @@ * } * @endcode * - * You can see some more examples on the test directory of the distribution or - * on the examples related page. + * You can see 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 be surprissed 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. + * This library has not been widely used yet, so it lacks proper testing. + * Because templates are not even compiled when they are not used, don't be + * surprised if you catch a piece of code that doesn't compile. The library + * has no support for buffered events yet. It doesn't support the HTTP stuff, + * and probably never will because that has nothing to do with event handling. * - * 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 arround - * libevent. So, please try it out, and if you have any problems, + * 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() is 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 @c -DEVENTXX_EVENT_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 because @eventxx 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 ;). @@ -156,31 +158,37 @@ * * @author Leandro Lucarella * - * @version 0.1 + * @version 0.4 * * @par License * This program is under the BOLA license (see - * http://auriga.wearlab.de/~alb/bola/ for more info or the + * http://auriga.wearlab.de/~alb/bola/ for more details or read the * LICENSE - * file itself). + * file itself, it's very short and it basically says it's Public Domain). * */ /** @example c-way.cpp * - * This is a simple example ilustrating the usage with C-like callback + * This is a simple example illustrating the usage with C-like callback * functions. */ /** @example functor-way.cpp * - * This is a simple example ilustrating the usage with function object + * This is a simple example illustrating the usage with function object * callbacks. */ +/** @example wrapped-functor-way.cpp + * + * This is a simple example illustrating the usage with an arbitrary member + * function as an event handler callbacks. + */ + /** @example mixed-way.cpp * - * This is a simple example ilustrating the usage with a mix of C-like callbacks + * This is a simple example illustrating the usage with a mix of C-like callbacks * and function object callbacks. */ @@ -191,19 +199,24 @@ /** @example prio-test.cpp * - * This is a priotity usage example. + * This is a priority usage example. */ /** @example test-time.cpp * - * This is a timer usage example. + * This is a timer usage example ported from libevent. */ -/** @example test-weof.cpp +/** @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. @@ -271,7 +284,7 @@ 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. @@ -297,7 +310,7 @@ struct invalid_priority: public std::invalid_argument, public exception //@} -/// Miscelaneous constants +/// Miscellaneous constants enum { DEFAULT_PRIORITY = -1, ///< Default priority (the middle value). @@ -306,10 +319,6 @@ enum }; -/// C function used as callback in the C API. -typedef void (*ccallback_type)(int, short, void*); - - /** * Time used for timeout values. * @@ -366,6 +375,12 @@ 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 +389,11 @@ struct time: ::timeval */ //@{ + +/// C function used as callback in the C API. +typedef void (*ccallback_type)(int, short, void*); + + /** * Type of events. * @@ -394,6 +414,14 @@ 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 *reinterpret_cast< type* >(&r); +} + + /** * Basic event from which all events derive. * @@ -474,14 +502,14 @@ 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 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 +524,9 @@ 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)); } @@ -532,9 +560,9 @@ 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 +617,7 @@ 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); } @@ -614,7 +642,7 @@ struct signal: event< F > { /** - * Creates a new singal event. + * Creates a new signal event. * * @param signum Signal number to monitor. * @param handler Callback functor. @@ -655,7 +683,7 @@ 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 +710,41 @@ 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 //@} @@ -689,7 +752,7 @@ typedef eventxx::signal< ccallback_type > csignal; /** * Event dispatcher. * - * This class is the responsable for looping and dispatching events. Everytime + * 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 @@ -710,7 +773,8 @@ 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 +784,22 @@ 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 +#ifdef EVENTXX_BASE_FREE_FIX + /// 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()." +#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 " \ + "-DEVENTXX_EVENT_BASE_FREE_FIX to your compiler to make this message disappear " \ + "and really free the dispatcher memory using event_base_free()." #endif /** @@ -766,7 +836,8 @@ 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 +853,9 @@ 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 +871,8 @@ 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 +889,11 @@ 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 +908,12 @@ 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 +930,8 @@ 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 +946,9 @@ 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 +978,13 @@ 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 +994,11 @@ 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, @@ -919,7 +1008,7 @@ 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)); @@ -927,8 +1016,7 @@ struct dispatcher }; // struct dispatcher - -} // namespace event +} // namespace eventxx #endif // _EVENTXX_HPP_