1 files changed, 95 insertions, 0 deletions
diff --git a/qpid/cpp/src/qpid/cluster/exp/CountdownTimer.h b/qpid/cpp/src/qpid/cluster/exp/CountdownTimer.h
new file mode 100644
index 0000000000..5d16ce6e10
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+++ b/qpid/cpp/src/qpid/cluster/exp/CountdownTimer.h
@@ -0,0 +1,95 @@
+#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;
+};
+
+
+}} // namespace qpid::cluster
+
+#endif  /*!QPID_CLUSTER_EXP_COUNTDOWNTIMER_H*/