X-Git-Url: http://g0dil.de/git?a=blobdiff_plain;f=Scheduler%2FScheduler.hh;h=7f6682195e698f35a2545f0217d085c59cb579d0;hb=6159637c51fd562b2bf68a026a3946b2c84f4e0d;hp=a8dc456aed0469edb4052d98339fe717cf86c3d2;hpb=553781d9e9bce316dca24ac4f0c42e5613e849e0;p=senf.git diff --git a/Scheduler/Scheduler.hh b/Scheduler/Scheduler.hh index a8dc456..7f66821 100644 --- a/Scheduler/Scheduler.hh +++ b/Scheduler/Scheduler.hh @@ -1,9 +1,9 @@ // $Id$ // -// Copyright (C) 2006 -// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS) -// Kompetenzzentrum fuer Satelitenkommunikation (SatCom) -// Stefan Bund +// Copyright (C) 2006 +// Fraunhofer Institute for Open Communication Systems (FOKUS) +// Competence Center NETwork research (NET), St. Augustin, GERMANY +// Stefan Bund // // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by @@ -28,13 +28,11 @@ #define HH_Scheduler_ 1 // Custom includes -#include -#include -#include -#include -#include - -#include "Utils/MicroTime.hh" +#include "../Utils/Logger/SenfLog.hh" +#include "FdEvent.hh" +#include "TimerEvent.hh" +#include "SignalEvent.hh" +#include "../Utils/Logger/SenfLog.hh" //#include "scheduler.mpp" ///////////////////////////////hh.p//////////////////////////////////////// @@ -42,57 +40,153 @@ /** \brief SENF Project namespace */ namespace senf { - /** \brief Singleton class to manage the event loop - - This class manages a single select() type event loop. A customer of this class may register - any number of file descriptiors with this class and pass callback functions to be called on - input, output or error. This functions are specified using boost::function objects (See Boost.Function) - - The Scheduler is based on a generic handle representation. The only information needed from - a handle, is the intrinsic file descriptor. Any object for which the statement - \code - int fd = retrieve_filehandle(object); - \endcode - is valid and places the relevent file descriptor into fd can be used as a Handle type. There - is an implementation of retrieve_filehandle(int) within the library to handle explicit file - descrptors. The Socket library provides an - implementation of retrive_filehandle(FileHandle handle). If you want to support - some other handle type, just define an apropriate \c retrieve_filehandle function in - that types namespace. - - It is important to note, that for every combination of file descriptor and event, only a \e - single handler may be installed. Installing more handlers does not make sense. If you need - to distribute data to serveral interested parties, you must take care of this yourself. - - \todo Fix EventId parameter (probably to int) to allow |-ing without casting ... + /** \brief Visible scheduler interface + + The %scheduler singleton manages access to the %scheduler library. It provides access to + several event dispatchers: + \li File descriptor notifications + \li Timeouts + \li UNIX Signals + + The %scheduler is entered by calling it's process() member. This call will continue to run as + long as there is something to do, or until one of the handlers calls terminate(). The + %scheduler has 'something to do' as long as there is any file descriptor or timeout active. + + The %scheduler only provides low level primitive scheduling capability. Additional helpers + are defined on top of this functionality (e.g. ReadHelper or WriteHelper or the interval + timers of the PPI). + + + \section sched_handlers Specifying handlers + + All handlers are passed as generic Boost.Function objects. This allows + to pass any callable as a handler. Depending on the type of handler, some additional + arguments may be passed to the handler by the %scheduler. + + If you need to pass additional information to your handler, use Boost.Bind: + \code + // Handle callback function + void callback(UDPv4ClientSocketHandle handle, senf::Scheduler::EventId event) {..} + // Pass 'handle' as additional first argument to callback() + Scheduler::instance().add(handle, boost::bind(&callback, handle, _1), EV_READ) + // Timeout function + void timeout( int n) {..} + // Call timeout() handler with argument 'n' + Scheduler::instance().timeout(boost::bind(&timeout, n)) + \endcode + + To use member-functions as callbacks, use either Boost.Bind or senf::membind() + \code + // e.g. in Foo::Foo() constructor: + Scheduler::instance().add(handle_, senf::membind(&Foo::callback, this)), EV_READ) + \endcode + + The handler can also be identified by an arbitrary, user specified name. This name is used + in error messages to identify the failing handler. + + + \section sched_fd Registering file descriptors + + File descriptors are managed using add() or remove() + \code + Scheduler::instance().add(handle, &callback, EV_ALL); + Scheduler::instance().remove(handle); + \endcode + + The callback will be called with one additional argument. This argument is the event mask of + type EventId. This mask will tell, which of the registered events are signaled. The + additional flags EV_HUP or EV_ERR (on hangup or error condition) may be set additionally. + + Only a single handler may be registered for any combination of file descriptor and event + (registering multiple callbacks for a single fd and event does not make sense). + + The %scheduler will accept any object as \a handle argument as long as retrieve_filehandle() + may be called on that object + \code + int fd = retrieve_filehandle(handle); + \endcode + to fetch the file handle given some abstract handle type. retrieve_filehandle() will be + found using ADL depending on the argument namespace. A default implementation is provided + for \c int arguments (file descriptors) + + + \section sched_timers Registering timers + + The %scheduler has very simple timer support. There is only one type of timer: A single-shot + deadline timer. More complex timers are built based on this. Timers are managed using + timeout() and cancelTimeout() + \code + int id = Scheduler::instance().timeout(Scheduler::instance().eventTime() + ClockService::milliseconds(100), + &callback); + Scheduler::instance().cancelTimeout(id); + \endcode + Timing is based on the ClockService, which provides a high resolution and strictly + monotonous time source which again is based on POSIX timers. Registering a timeout will fire + the callback when the target time is reached. The timer may be canceled by passing the + returned \a id to cancelTimeout(). + + + \section sched_signals Registering POSIX/UNIX signals + + The %scheduler also incorporates standard POSIX/UNIX signals. Signals registered with the + %scheduler will be handled \e synchronously within the event loop. + \code + Scheduler::instance().registerSignal(SIGUSR1, &callback); + Scheduler::instance().unregisterSignal(SIGUSR1); + \endcode + When registering a signal with the %scheduler, that signal will automatically be blocked so + it can be handled within the %scheduler. + + A registered signal does \e not count as 'something to do'. It is therefore not possible to + wait for signals \e only. + + \todo Change the Scheduler API to use RAII. Additionally, this will remove all dynamic + memory allocations from the scheduler. + \todo Fix the file support to use threads (?) fork (?) and a pipe so it works reliably even + over e.g. NFS. */ class Scheduler : boost::noncopyable { public: + + SENF_LOG_CLASS_AREA(); + /////////////////////////////////////////////////////////////////////////// // Types - /// \brief Types of file descriptor events */ - enum EventId { EV_NONE=0, - EV_READ=1, EV_PRIO=2, EV_WRITE=4, EV_HUP=8, EV_ERR=16, - EV_ALL=31 }; - - /** \brief Template typedef for Callback type - - This is a template typedef (which does not exist in C++) that is, a template class whose - sole member is a typedef symbol defining the callback type given the handle type. - - The Callback is any callable object taking a \c Handle and an \c EventId as argument. - */ - template - struct GenericCallback { - typedef boost::function::param_type, - EventId) > Callback; + /** \brief Types of file descriptor events + + These events are grouped into to classes: + \li Ordinary file descriptor events for which handlers may be registered. These are + EV_READ, EV_PRIO and EV_WRITE. EV_ALL is a combination of these three. + \li Error flags. These additional flags may be passed to a handler to pass an error + condition to the handler. + */ + enum EventId { + EV_NONE = 0 /**< No event */ + , EV_READ = scheduler::FdManager::EV_READ /**< File descriptor is readable */ + , EV_PRIO = scheduler::FdManager::EV_PRIO /**< File descriptor has OOB data */ + , EV_WRITE = scheduler::FdManager::EV_WRITE /**< File descriptor is writable */ + , EV_ALL = scheduler::FdManager::EV_READ + | scheduler::FdManager::EV_PRIO + | scheduler::FdManager::EV_WRITE /**< Used to register all events at once + (read/prio/write) */ + , EV_HUP = scheduler::FdManager::EV_HUP /**< Hangup condition on file handle */ + , EV_ERR = scheduler::FdManager::EV_ERR /**< Error condition on file handle */ }; - /** \brief Callback type for timer events */ - typedef boost::function TimerCallback; + + /** \brief Callback type for file descriptor events */ + typedef boost::function FdCallback; + + /** \brief Callback type for timer events */ + typedef boost::function SimpleCallback; + + /** \brief Callback type for signal events */ + typedef boost::function SignalCallback; /////////////////////////////////////////////////////////////////////////// ///\name Structors and default members @@ -104,132 +198,75 @@ namespace senf { // default destructor // no conversion constructors - /** \brief Return Scheduler instance - - This static member is used to access the singleton instance. This member is save to - return a correctly initialized Scheduler instance even if called at global construction - time - - \implementation This static member just defines the Scheduler as a static method - variable. The C++ standard then provides above guaratee. The instance will be - initialized the first time, the code flow passes the variable declaration found in - the instance() body. - */ + /** \brief Return %scheduler instance + + This static member is used to access the singleton instance. This member is save to + return a correctly initialized %scheduler instance even if called at global construction + time + */ static Scheduler & instance(); ///@} /////////////////////////////////////////////////////////////////////////// - template - void add(Handle const & handle, - typename GenericCallback::Callback const & cb, - int eventMask = EV_ALL); ///< Add file handle event callback - /**< add() will add a callback to the Scheduler. The - callbeck will be called for the given type of event on - the given arbitrary file-descriptor or - handle-like object. If there already is a Callback - register ed for one of the events requested, the new - handler will replace the old one. - \param[in] handle file descriptor or handle providing - the Handle interface defined above. - \param[in] cb callback - \param[in] eventMask arbitrary combination via '|' - operator of EventId designators. */ - template - void remove(Handle const & handle, int eventMask = EV_ALL); ///< Remove event callback - /**< remove() will remove any callback registered for any of - the given events on the given file descriptor or handle - like object. - \param[in] handle file descriptor or handle providing - the Handle interface defined above. - \param[in] eventMask arbitrary combination via '|' - operator of EventId designators. */ - - void timeout(unsigned long timeout, TimerCallback const & cb); ///< Add timeout event - /**< \param[in] timeout timeout in milliseconds - \param[in] cb callback to call after \a timeout - milliseconds - \todo Return some kind of handle/pointer and add - support to update or revoke a timeout */ - void process(); ///< Event handler main loop /**< This member must be called at some time to enter the - event handler main loop. Only while this function is - running any events are handled. The call will return - only, if any callback calls terminate(). */ + event handler main loop. Only while this function is + running any events are handled. The call will return + only, if any callback calls terminate(). */ + void terminate(); ///< Called by callbacks to terminate the main loop /**< This member may be called by any callback to tell the - main loop to terminate. The main loop will return to - it's caller after the currently running callback - returns. */ + main loop to terminate. The main loop will return to + it's caller after the currently running callback + returns. */ + + ClockService::clock_type eventTime() const; ///< Return date/time of last event + /**< This is the timestamp, the last event has been + signaled. This is the real time at which the event is + delivered \e not the time it should have been delivered + (in the case of timers). */ + + void taskTimeout(unsigned ms); + unsigned taskTimeout() const; + unsigned hangCount() const; + + void restart(); protected: private: - typedef boost::function SimpleCallback; - Scheduler(); - - void do_add(int fd, SimpleCallback const & cb, int eventMask = EV_ALL); - void do_remove(int fd, int eventMask = EV_ALL); - - /** \brief Descriptor event specification - \internal */ - struct EventSpec - { - SimpleCallback cb_read; - SimpleCallback cb_prio; - SimpleCallback cb_write; - SimpleCallback cb_hup; - SimpleCallback cb_err; - - int epollMask() const; - }; - - /** \brief Timer event specification - \internal */ - struct TimerSpec - { - TimerSpec() : timeout(), cb() {} - TimerSpec(unsigned long long timeout_, TimerCallback cb_) - : timeout(timeout_), cb(cb_) {} - - bool operator< (TimerSpec const & other) const - { return timeout > other.timeout; } - - unsigned long long timeout; - TimerCallback cb; - }; - - typedef std::map FdTable; - typedef std::priority_queue TimerQueue; - FdTable fdTable_; - TimerQueue timerQueue_; - int epollFd_; bool terminate_; }; - /** \brief Default file descriptor accessor - - retrieve_filehandle() provides the Scheduler with support for explicit file descriptors as - file handle argument. + /** \brief %scheduler specific time source for Utils/Logger framework - \relates Scheduler + This time source may be used to provide timing information for log messages within the + Utils/Logger framework. This time source will use Scheduler::eventTime() to provide timing + information. */ - int retrieve_filehandle(int fd); + struct SchedulerLogTimeSource : public senf::log::TimeSource + { + senf::log::time_type operator()() const; + }; } ///////////////////////////////hh.e//////////////////////////////////////// #include "Scheduler.cci" //#include "Scheduler.ct" -#include "Scheduler.cti" +//#include "Scheduler.cti" #endif // Local Variables: // mode: c++ -// c-file-style: "senf" // fill-column: 100 +// c-file-style: "senf" +// indent-tabs-mode: nil +// ispell-local-dictionary: "american" +// compile-command: "scons -u test" +// comment-column: 40 // End: