// $Id$
//
-// Copyright (C) 2006
-// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
-// Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
-// Stefan Bund <stefan.bund@fokus.fraunhofer.de>
+// Copyright (C) 2006
+// Fraunhofer Institute for Open Communication Systems (FOKUS)
+// Competence Center NETwork research (NET), St. Augustin, GERMANY
+// Stefan Bund <g0dil@berlios.de>
//
// 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
#define HH_Scheduler_ 1
// Custom includes
-#include <map>
-#include <queue>
-#include <boost/function.hpp>
-#include <boost/utility.hpp>
-#include <boost/call_traits.hpp>
-
-#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////////////////////////////////////////
/** \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 <a
- href="http://www.boost.org/doc/html/function.html">Boost.Function</a>)
-
- 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 <a href="../../../Socket/doc/html/index.html">Socket library</a> provides an
- implementation of <tt>retrive_filehandle(FileHandle handle)</tt>. If you want to support
- some other handle type, just define an apropriate \c retrieve_filehandle function <em>in
- that types namespace</em>.
-
- 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 <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()
+ 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 <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
+
+ 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 <class Handle>
- struct GenericCallback {
- typedef boost::function<void (typename boost::call_traits<Handle>::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<void ()> TimerCallback;
+
+ /** \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;
///////////////////////////////////////////////////////////////////////////
///\name Structors and default members
// 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 <class Handle>
- void add(Handle const & handle,
- typename GenericCallback<Handle>::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 <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 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<void (EventId)> 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<int,EventSpec> FdTable;
- typedef std::priority_queue<TimerSpec> 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
\f
// 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:
projects / senf.git / blobdiff