// Custom includes
#include "../Utils/Logger/SenfLog.hh"
-#include "FdDispatcher.hh"
-#include "TimerDispatcher.hh"
-#include "SignalDispatcher.hh"
-#include "FileDispatcher.hh"
-#include "../Utils/Logger/SenfLog.hh"
+#include "FdEvent.hh"
+#include "TimerEvent.hh"
+#include "SignalEvent.hh"
//#include "scheduler.mpp"
///////////////////////////////hh.p////////////////////////////////////////
-/** \brief SENF Project namespace */
namespace senf {
- /** \brief Visible scheduler interface
+/** \brief The 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 API is comprised of two parts:
- 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.
+ \li Specific event classes, one for each type of event.
+ \li Some generic functions implemented in the \ref senf::scheduler namespace.
- 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).
+ Events are registered via the respective event class. The (global) functions are used to enter
+ the application main-loop or query for global information.
+ \autotoc
- \section sched_handlers Specifying handlers
- All handlers are passed as generic <a
- href="http://www.boost.org/doc/html/function.html">Boost.Function</a> 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.
+ \section sched_objects Event classes
- If you need to pass additional information to your handler, use <a
- href="http://www.boost.org/libs/bind/bind.html">Boost.Bind</a>:
- \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
+ Every event registration is represented by a class instance of an event specific class:
- To use member-functions as callbacks, use either <a
- href="http://www.boost.org/libs/bind/bind.html">Boost.Bind</a> or senf::membind()
- \code
- // e.g. in Foo::Foo() constructor:
- Scheduler::instance().add(handle_, senf::membind(&Foo::callback, this)), EV_READ)
- \endcode
+ \li senf::scheduler::FdEvent for file descriptor events
+ \li senf::scheduler::TimerEvent for single-shot deadline timer events
+ \li senf::scheduler::SignalEvent for UNIX signal events
- The handler can also be identified by an arbitrary, user specified name. This name is used
- in error messages to identify the failing handler.
+ These instance are owned and managed by the user of the scheduler \e not by the scheduler so the
+ RAII concept can be used.
+ \code
+ class SomeServer
+ {
+ SomeSocketHandle handle_;
+ senf::scheduler::FdEvent event_;
- \section sched_fd Registering file descriptors
+ public:
+ SomeServer(SomeSocketHandle handle)
+ : handle_ (handle),
+ event_ ("SomeServer handler", senf::membind(&SomeServer::readData, this),
+ handle, senf::scheduler::FdEvent::EV_READ)
+ {}
+
+ void readData(int events)
+ {
+ // read data from handle_, check for eof and so on.
+ }
+ };
+ \endcode
+
+ The event is defined as a class member variable. When the event member is initialized in the
+ constructor, the event is automatically registered (except if the optional \a initiallyEnabled
+ flag argument is set to \c false). The Destructor will automatically remove the event from the
+ scheduler and ensure, that no dead code is called accidentally.
+
+ The process is the same for the other event types or when registering multiple events. For
+ detailed information on the constructor arguments and other features see the event class
+ documentation referenced below.
+
+
+ \section sched_handlers Specifying handlers
+
+ All handlers are specified as generic <a
+ href="http://www.boost.org/doc/html/function.html">Boost.Function</a> 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 <a
+ href="http://www.boost.org/libs/bind/bind.html">Boost.Bind</a>:
+ \code
+ // Handle callback function
+ void callback(UDPv4ClientSocketHandle handle, senf::Scheduler::EventId event) {..}
+ // Pass 'handle' as additional first argument to callback()
+ senf::scheduler::FdEvent event ("name", boost::bind(&callback, handle, _1),
+ handle, senf::scheduler::FdEvent::EV_READ);
+ // Timeout function
+ void timeout( int n) {..}
+ // Call timeout() handler with argument 'n'
+ senf::scheduler::TimerEvent timer ("name", boost::bind(&timeout, n),
+ senf::ClockService::now() + senf::ClockService::seconds(1));
+ \endcode
+
+ To use member-functions as callbacks, use either <a
+ href="http://www.boost.org/libs/bind/bind.html">Boost.Bind</a> or senf::membind()
+ \code
+ // e.g. in Foo::Foo() constructor:
+ Foo::Foo()
+ : handle_ (...),
+ readevent_ ("Foo read", senf::membind(&Foo::callback, this),
+ handle_, senf::scheduler::FdEvent::EV_READ)
+ { ... }
+ \endcode
+
+ The handler is identified by an arbitrary, user specified name. This name is used in error
+ messages to identify the failing handler.
+
+ \todo Fix the file support to use threads (?) fork (?) and a pipe so it works reliably even
+ over e.g. NFS.
+ */
+namespace scheduler {
+
+ /** \brief Event handler main loop
- 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)
-
+ 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 if
+ \li a callback calls terminate()
+ \li the run queue becomes empty.
+ */
+ void process();
- \section sched_timers Registering timers
+ /** \brief Called by callbacks to terminate the main loop
- 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().
+ 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.
+ */
+ void terminate();
+ /** \brief Return date/time of last event
- \section sched_signals Registering POSIX/UNIX signals
+ 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).
+ */
+ ClockService::clock_type eventTime();
- 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:
+ /** \brief Set task watchdog timeout */
+ void taskTimeout(unsigned ms);
- SENF_LOG_CLASS_AREA();
-
- ///////////////////////////////////////////////////////////////////////////
- // Types
-
- /** \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 file descriptor events */
- typedef boost::function<void (int)> FdCallback;
-
- /** \brief Callback type for timer events */
- typedef boost::function<void ()> SimpleCallback;
-
- /** \brief Callback type for signal events */
- typedef boost::function<void (siginfo_t const &)> SignalCallback;
-
- /** \brief Timer id type */
- typedef scheduler::TimerDispatcher::timer_id timer_id;
-
- ///////////////////////////////////////////////////////////////////////////
- ///\name Structors and default members
- ///@{
-
- // private default constructor
- // no copy constructor
- // no copy assignment
- // 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
- */
- static Scheduler & instance();
-
- ///@}
- ///////////////////////////////////////////////////////////////////////////
-
- ///\name File Descriptors
- ///\{
-
- template <class Handle>
- void add(std::string const & name, Handle const & handle, FdCallback const & cb,
- int eventMask = EV_ALL); ///< Add file handle event callback
- /**< add() will add a callback to the %scheduler. The
- callback 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
- registered for one of the events requested, the new
- handler will replace the old one.
- \param[in] name descriptive name to identify the
- callback.
- \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 \ref senf::Scheduler::EventId "EventId"
- designators. */
-
- template <class Handle>
- void add(Handle const & handle, FdCallback const & cb,
- int eventMask = EV_ALL); ///< Add file handle event callback
- /**< \see add() */
-
-
- template <class Handle>
- 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 \ref senf::Scheduler::EventId "EventId"
- designators. */
-
- ///\}
-
- ///\name Timeouts
- ///\{
-
- timer_id timeout(std::string const & name, ClockService::clock_type timeout,
- SimpleCallback const & cb);
- ///< Add timeout event
- /**< \returns timer id
- \param[in] name descriptive name to identify the
- callback.
- \param[in] timeout timeout in nanoseconds
- \param[in] cb callback to call after \a timeout
- milliseconds */
-
- timer_id timeout(ClockService::clock_type timeout, SimpleCallback const & cb);
- ///< Add timeout event
- /**< \see timeout() */
-
- void cancelTimeout(timer_id id); ///< Cancel timeout \a id
-
-#ifndef DOXYGEN
- ClockService::clock_type timeoutEarly() const;
- void timeoutEarly(ClockService::clock_type v);
-
- ClockService::clock_type timeoutAdjust() const;
- void timeoutAdjust(ClockService::clock_type v);
-#endif
+ /** \brief Current task watchdog timeout */
+ unsigned taskTimeout();
- ///\}
+ /** \brief Number of watchdog events */
+ unsigned hangCount();
- ///\name Signal handlers
- ///\{
+ /** \brief Restart scheduler
- void registerSignal(unsigned signal, SignalCallback const & cb);
- ///< Add signal handler
- /**< \param[in] signal signal number to register handler for
- \param[in] cb callback to call whenever \a signal is
- delivered. */
-
- void unregisterSignal(unsigned signal);
- ///< Remove signal handler for \a signal
-
- ///\}
-
- 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(). */
-
- 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. */
-
- 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;
-
- protected:
-
- private:
- Scheduler();
-
- void do_add(int fd, FdCallback const & cb, int eventMask = EV_ALL);
- void do_add(std::string const & name, int fd, FdCallback const & cb,
- int eventMask = EV_ALL);
- void do_remove(int fd, int eventMask);
-
- bool terminate_;
- scheduler::FdManager manager_;
- scheduler::FIFORunner runner_;
-
- scheduler::FdDispatcher fdDispatcher_;
- scheduler::TimerDispatcher timerDispatcher_;
- scheduler::SignalDispatcher signalDispatcher_;
- scheduler::FileDispatcher fileDispatcher_;
- };
-
- /** \brief Default file descriptor accessor
-
- retrieve_filehandle() provides the %scheduler with support for explicit file descriptors as
- file handle argument.
-
- \relates Scheduler
+ This call will restart all scheduler dispatchers (timers, signals, file descriptors). This
+ is necessary after a fork().
+ \warning This call will \e remove all registered events from the scheduler
*/
- int retrieve_filehandle(int fd);
+ void restart();
/** \brief %scheduler specific time source for Utils/Logger framework
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.
+
+ \code
+ senf::log::timeSource<senf::scheduler::LogTimeSource>();
+ \endcode
+
+ Using this information reduces the number of necessary ClockService::now() calls and thus
+ the number of system calls.
*/
- struct SchedulerLogTimeSource : public senf::log::TimeSource
+ struct LogTimeSource : 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
\f
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