Added PeriodicTimer interface for periodic tasks that need cluster synchronization.

The ManagementAgent's periodic prociessing uses PeriodicTimer.
PeriodicTimerImpl is the default implementation for stand-alone
brokers, simple wrapper for sys::Timer.


git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@903866 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 156 insertions, 0 deletions

diff --git a/cpp/src/qpid/sys/PeriodicTimer.h b/cpp/src/qpid/sys/PeriodicTimer.h
new file mode 100644
index 0000000000..290ffb6218
--- /dev/null
+++ b/cpp/src/qpid/sys/PeriodicTimer.h
@@ -0,0 +1,56 @@
+#ifndef QPID_SYS_PERIODICTIMER_H
+#define QPID_SYS_PERIODICTIMER_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 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.
+ *
+ */
+
+#include "Timer.h"
+#include <boost/function.hpp>
+
+namespace qpid {
+namespace sys {
+
+/**
+ * Interface of a timer for periodic tasks that should be synchronized
+ * across all brokers in a periodic. The standalone broker
+ * implementation simply wraps qpid::sys::Timer. The clustered broker
+ * implementation synchronizes execution of periodic tasks on all
+ * periodic members.
+ */
+class PeriodicTimer
+{
+  public:
+    typedef boost::function<void()> Task;
+
+    QPID_COMMON_EXTERN virtual ~PeriodicTimer() {}
+
+    /**
+     * Add a named task to be executed at the given period.
+     *
+     * The task registered under the same name will be executed on
+     * all brokers at the given period.
+     */
+    virtual void add(const Task& task, Duration period, const std::string& taskName) = 0;
+
+};
+}} // namespace qpid::sys
+
+#endif  /*!QPID_SYS_PERIODICTIMER_H*/
diff --git a/cpp/src/qpid/sys/PeriodicTimerImpl.cpp b/cpp/src/qpid/sys/PeriodicTimerImpl.cpp
new file mode 100644
index 0000000000..e2a6dccf3e
--- /dev/null
+++ b/cpp/src/qpid/sys/PeriodicTimerImpl.cpp
@@ -0,0 +1,49 @@
+/*
+ *
+ * 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.
+ *
+ */
+#include "PeriodicTimerImpl.h"
+
+namespace qpid {
+namespace sys {
+
+PeriodicTimerImpl::PeriodicTimerImpl(Timer& t) : timer(t) {}
+
+struct PeriodicTimerImpl::TaskImpl : public TimerTask {
+    Timer& timer;
+    Task task;
+
+    TaskImpl(Timer& timer_, const Task& task_, Duration period) :
+        TimerTask(period), timer(timer_), task(task_) {}
+
+    void fire() {
+        task();
+        setupNextFire();
+        timer.add(this);
+    }
+};
+
+void PeriodicTimerImpl::add(
+    const Task& task, Duration period, const std::string& /*taskName*/
+)
+{
+    timer.add(new TaskImpl(timer, task, period));
+}
+
+}} // namespace qpid::sys
diff --git a/cpp/src/qpid/sys/PeriodicTimerImpl.h b/cpp/src/qpid/sys/PeriodicTimerImpl.h
new file mode 100644
index 0000000000..51ce0ffdf9
--- /dev/null
+++ b/cpp/src/qpid/sys/PeriodicTimerImpl.h
@@ -0,0 +1,45 @@
+#ifndef QPID_SYS_PERIODICTIMERIMPL_H
+#define QPID_SYS_PERIODICTIMERIMPL_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 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.
+ *
+ */
+
+#include "PeriodicTimer.h"
+
+namespace qpid {
+namespace sys {
+
+/**
+ * Standalone broker implementation of PeriodicTimer.
+ */
+class PeriodicTimerImpl : public PeriodicTimer
+{
+  public:
+    PeriodicTimerImpl(Timer& timer);
+    void add(const Task& task, Duration period, const std::string& taskName);
+
+  private:
+    struct TaskImpl;
+    Timer& timer;
+};
+}} // namespace qpid::sys
+
+#endif  /*!QPID_SYS_PERIODICTIMER_H*/
diff --git a/cpp/src/qpid/sys/Timer.h b/cpp/src/qpid/sys/Timer.h
index 5748503841..303d44a299 100644
--- a/cpp/src/qpid/sys/Timer.h
+++ b/cpp/src/qpid/sys/Timer.h
@@ -69,6 +69,12 @@ protected:
 bool operator<(const boost::intrusive_ptr<TimerTask>& a,
                 const boost::intrusive_ptr<TimerTask>& b);
 
+/**
+   A timer to trigger tasks that are local to one broker.
+
+   For periodic tasks that should be synchronized across all brokers
+   in a cluster, use qpid::sys::PeriodicTimer.
+ */
 class Timer : private Runnable {
     qpid::sys::Monitor monitor;
     std::priority_queue<boost::intrusive_ptr<TimerTask> > tasks;