1 files changed, 52 insertions, 0 deletions
diff --git a/framework/src/onos/utils/misc/src/main/java/org/onlab/util/Timer.java b/framework/src/onos/utils/misc/src/main/java/org/onlab/util/Timer.java
new file mode 100644
index 00000000..fe508839
--- /dev/null
+++ b/framework/src/onos/utils/misc/src/main/java/org/onlab/util/Timer.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+package org.onlab.util;
+
+import org.jboss.netty.util.HashedWheelTimer;
+
+/**
+ * Hashed-wheel timer singleton. Care must be taken to shutdown the timer
+ * only when the VM is ready to exit.
+ */
+public final class Timer {
+
+    private static volatile HashedWheelTimer timer;
+
+    // Ban public construction
+    private Timer() {
+    }
+
+    /**
+     * Returns the singleton hashed-wheel timer.
+     *
+     * @return hashed-wheel timer
+     */
+    public static HashedWheelTimer getTimer() {
+        if (Timer.timer == null) {
+            initTimer();
+        }
+        return Timer.timer;
+    }
+
+    private static synchronized  void initTimer() {
+        if (Timer.timer == null) {
+            HashedWheelTimer hwTimer = new HashedWheelTimer();
+            hwTimer.start();
+            Timer.timer = hwTimer;
+        }
+    }
+
+}