source: source/ariba/utility/system/SystemQueue.h @ 5289

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// [License]

#ifndef SYSTEMQUEUE_H_
#define SYSTEMQUEUE_H_

#include <vector>
#include <cassert>
#include "SystemEvent.h"
#include "SystemEventListener.h"
#include "ariba/utility/logging/Logging.h"
#include <boost/date_time.hpp>
#include <boost/cstdint.hpp>

#ifdef UNDERLAY_OMNET
  #include <csimplemodule.h>
  #include <cmessage.h>
  #include <macros.h>
#else
  #include <boost/thread/mutex.hpp>
  #include <boost/thread/thread.hpp>
  #include <boost/thread/condition_variable.hpp>
  #include <boost/utility.hpp>
  #include <boost/bind.hpp>
#endif

using std::vector;
using boost::posix_time::ptime;

namespace ariba {
namespace utility {

/**
 * This class implements a simple system event queue to allow
 * a simulation of cooperative multitasking. It also allows
 * events to be scheduled from other tasks. This allows
 * dispatching asynchronous tasks.
 *
 * @author Christoph Mayer, Sebastian Mies
 */

#ifndef UNDERLAY_OMNET
class SystemQueue : private boost::noncopyable {
#else
class SystemQueue : public cSimpleModule {
#endif
        
        use_logging_h(SystemQueue);
        friend class EnterMethod;
public:
        /**
         * Get the SystemQueue singleton instance.
         */
        static SystemQueue& instance() {
                static SystemQueue _inst;
                return _inst;
        }

#ifdef UNDERLAY_OMNET
        /**
         * Prevent deletion of this module
         * by implementing the virtual method
         * and doing nothing in it
         */
        virtual void deleteModule(){}
#endif

        /**
         * This methods schedules a given event.
         *
         * @param The event to be scheduled
         * @param The delay in milli-seconds
         */
        void scheduleEvent( const SystemEvent& event, uint32_t delay = 0 );

        /**
         * Starts the processing and waiting for events.
         * Use <code>cancel()</code> to end system queue processing and
         * <code>isEmpty()</code> to check wheter the queue is empty.
         */
        void run();

        /**
         * Cancels the system queue and ends the processing after the
         * currently processed event is processed.
         *
         * This method is thread-safe.
         */
        void cancel();

        /**
         * Check wheter this queue has items or not.
         *
         * @return True, if this queue is empty.
         */
        bool isEmpty();

        /**
         * Is the system queue already started and running?
         *
         * @return True, if the system queue is running.
         */
        bool isRunning();

protected:

        /**
         * Aqcuire the mutex
         */
        void enterMethod();

        /**
         * Leave the mutex
         */
        void leaveMethod();

        /**
         * Constructs a system queue.
         */
        SystemQueue();

        /**
         * Destroys the system queue. Beware that all events
         * are canceled
         */
        ~SystemQueue();

#ifdef UNDERLAY_OMNET
        virtual void handleMessage( cMessage* msg );
#endif

private:

#ifndef UNDERLAY_OMNET
        typedef vector<SystemEvent> EventQueue;

        //********************************************************

        class QueueThread {
        public:
                QueueThread(QueueThread* _transferQueue = NULL);
                virtual ~QueueThread();
                void run();
                void cancel();
                bool isEmpty();
                void insert( const SystemEvent& event, uint32_t delay );
                void enter();
                void leave();

        protected:
                virtual void onItemInserted( const SystemEvent& event ) = 0;
                virtual void onNextQueueItem( const SystemEvent& event ) = 0;
                QueueThread* transferQueue;
                EventQueue eventsQueue;
                boost::mutex queueMutex;
        private:
                boost::thread* queueThread;
                static void threadFunc( QueueThread* obj );
                boost::condition_variable itemsAvailable;
                volatile bool running;
        }; // class QueueThread

        //********************************************************

        class QueueThreadDirect : public QueueThread {
        public:
                QueueThreadDirect();
                ~QueueThreadDirect();
        protected:
                virtual void onItemInserted( const SystemEvent& event );
                virtual void onNextQueueItem( const SystemEvent& event );
        }; // class QueueThreadDirect

        //********************************************************

        class QueueThreadDelay : public QueueThread {
        public:
                QueueThreadDelay(QueueThread* _transferQueue = NULL);
                ~QueueThreadDelay();
        protected:
                virtual void onItemInserted( const SystemEvent& event );
                virtual void onNextQueueItem( const SystemEvent& event );
        private:
                volatile bool isSleeping;
                ptime sleepStart;
                boost::mutex sleepMutex;
                boost::condition_variable sleepCond;
        }; // class QueueThreadDelay

        //********************************************************

        QueueThreadDirect directScheduler;
        QueueThreadDelay delayScheduler;
        volatile bool systemQueueRunning;
#endif

}; // class SystemQueue

#ifdef UNDERLAY_OMNET

        //
        // the system queue must be a singleton in simulations, too.
        // and to include it in the simulation the module is defined
        // as submodule in every SpoVNet host. Therefore we hack the
        // Define_Module (see omnet/includes/macros.h) the way we need
        // it with our singleton ...
        //
        // this is the macro definition from macros.h
        //
        // #define Define_Module(CLASSNAME) \
        //   static cModule *CLASSNAME##__create() {return new CLASSNAME();} \
        //   EXECUTE_ON_STARTUP(CLASSNAME##__mod, modtypes.instance()->add(new cModuleType(#CLASSNAME,#CLASSNAME,(ModuleCreateFunc)CLASSNAME##__create));)
        //
        // and this is how we do it :)
        //

        static cModule* SystemQueue__create() {
                return &SystemQueue::instance();
        }

        EXECUTE_ON_STARTUP(SystemQueue__mod, modtypes.instance()->add(new cModuleType("SystemQueue","SystemQueue",(ModuleCreateFunc)SystemQueue__create));)

#endif

}} // spovnet, common

#endif /* SYSTEMQUEUE_H_ */