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Diffstat (limited to 'qpid/cpp/src/qpid/sys/Timer.h')
-rw-r--r-- | qpid/cpp/src/qpid/sys/Timer.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/qpid/cpp/src/qpid/sys/Timer.h b/qpid/cpp/src/qpid/sys/Timer.h new file mode 100644 index 0000000000..6281e08913 --- /dev/null +++ b/qpid/cpp/src/qpid/sys/Timer.h @@ -0,0 +1,166 @@ +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * + */ +#ifndef sys_Timer +#define sys_Timer + +#include "qpid/sys/TimerWarnings.h" +#include "qpid/sys/Monitor.h" +#include "qpid/sys/Mutex.h" +#include "qpid/sys/Thread.h" +#include "qpid/sys/Runnable.h" +#include "qpid/RefCounted.h" +#include "qpid/CommonImportExport.h" +#include <memory> +#include <queue> + +#include <boost/intrusive_ptr.hpp> + +namespace qpid { +namespace sys { + +class Timer; + +class TimerTask : public RefCounted { + friend class Timer; + friend class TimerTaskCallbackScope; + friend bool operator<(const boost::intrusive_ptr<TimerTask>&, + const boost::intrusive_ptr<TimerTask>&); + + std::string name; + AbsTime sortTime; + Duration period; + AbsTime nextFireTime; + qpid::sys::Monitor stateMonitor; + enum {WAITING, CALLING, CANCELLED} state; + + bool prepareToFire(); + void finishFiring(); + bool readyToFire() const; + void fireTask(); + + public: + /** Create a periodic TimerTask + * + * This TimerTask type will trigger after the specified duration + * and can also be retriggered again after the same duration + * by using setupNextFire() after it has been fired. + * + * Before it has been triggered you can use restart() to push off + * triggering the TimerTask by the specified duration. + */ + QPID_COMMON_EXTERN TimerTask(Duration period, const std::string& name); + + /** Create a TimerTask that fires at a given absolute time + * + * This is a once only Timer and cannot be restarted after it has fired. + */ + QPID_COMMON_EXTERN TimerTask(AbsTime fireTime, const std::string& name); + + QPID_COMMON_EXTERN virtual ~TimerTask(); + + /** Adjust a periodic TimerTask for next firing time + * + * Called after a TimerTask has been triggered - probably in the fire() + * callback function itself. This will set up a TimerTask for the next + * triggering. + * + * Note that the TimerTask will need to be added again to the Timer. + */ + QPID_COMMON_EXTERN void setupNextFire(); + + /** Restart a TimerTask so to delay it being firing + * + * This can be called either with the TimerTask already added to a Timer + * or after the task has been triggered. It has the effect of delaying + * the task triggering by the initially specified duration. + */ + QPID_COMMON_EXTERN void restart(); + + /** Cancel a TimerTask so that it is no longer triggered + * + * After cancelling the only thing you can do nothing further + * with a TimerTask. + * + * The Timer will delete the cancelled TimerTask. + */ + QPID_COMMON_EXTERN void cancel(); + + std::string getName() const { return name; } + + protected: + // Must be overridden with callback + virtual void fire() = 0; +}; + +// For the priority_queue order +bool operator<(const boost::intrusive_ptr<TimerTask>& a, + const boost::intrusive_ptr<TimerTask>& b); + +class Timer : private Runnable { + qpid::sys::Monitor monitor; + std::priority_queue<boost::intrusive_ptr<TimerTask> > tasks; + qpid::sys::Thread runner; + bool active; + + // Runnable interface + void run(); + + public: + QPID_COMMON_EXTERN Timer(); + QPID_COMMON_EXTERN virtual ~Timer(); + + /** Add an TimerTask to the Timer queue + * + * Once a TimerTask has been triggered by (calling its fire() function) + * the TimerTask is no longer on the Timer queue and needs to be added again. + * + * Note that TimerTasks must never be added more than once to a Timer + * and must never be added simultaneuosly to multiple Timers. + */ + QPID_COMMON_EXTERN virtual void add(boost::intrusive_ptr<TimerTask> task); + + /** Start the Timer + * + * This will start a new thread that runs the Timer and the fire callbacks. + */ + QPID_COMMON_EXTERN virtual void start(); + + /** Stop the Timer + * + * This will stop the Timer and its thread. + */ + QPID_COMMON_EXTERN virtual void stop(); + + protected: + QPID_COMMON_EXTERN virtual void fire(boost::intrusive_ptr<TimerTask> task); + + // Allow derived classes to change the late/overran thresholds. + Duration late; + Duration overran; + Duration lateCancel; + TimerWarnings warn; +}; + + +}} + + +#endif |