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#ifndef QPID_CLUSTER_EXP_COUNTDOWNTIMER_H
#define QPID_CLUSTER_EXP_COUNTDOWNTIMER_H
/*
*
* 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 countdown. 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.
*
*/
#include "qpid/sys/Timer.h"
#include <boost/function.hpp>
namespace qpid {
namespace cluster {
/** Manage the CountdownTimeout */
class CountdownTimer {
public:
/**
* Resettable count-down timer for a fixed interval.
*@param cb callback when countdown expires.
*@param t Timer to use for countdown.
*@param d duration of countdown.
*/
CountdownTimer(boost::function<void()> cb, sys::Timer& t, sys::Duration d)
: task(new Task(*this, d)), timerRunning(false), callback(cb), timer(t) {}
~CountdownTimer() { stop(); }
/** Start the countdown if not already started. */
void start() {
sys::Mutex::ScopedLock l(lock);
if (!timerRunning) {
timerRunning = true;
task->restart();
timer.add(task);
}
}
/** Stop the countdown if not already stopped. */
void stop() {
sys::Mutex::ScopedLock l(lock);
if (timerRunning) {
timerRunning = false;
task->cancel();
}
}
private:
class Task : public sys::TimerTask {
CountdownTimer& parent;
public:
Task(CountdownTimer& ct, const sys::Duration& d) :
TimerTask(d, "CountdownTimer::Task"), parent(ct) {}
void fire() { parent.fire(); }
};
// Called when countdown expires.
void fire() {
bool doCallback = false;
{
sys::Mutex::ScopedLock l(lock);
doCallback = timerRunning;
timerRunning = false;
}
if (doCallback) callback();
}
sys::Mutex lock;
boost::intrusive_ptr<Task> task;
bool timerRunning;
boost::function<void()> callback;
sys::Timer& timer;
sys::Duration duration;
};
}} // namespace qpid::cluster
#endif /*!QPID_CLUSTER_EXP_COUNTDOWNTIMER_H*/
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