[ONOS-4668] Refactoring port statistic collector using SharedExecutor

- Add OpenFlowSwitchAdapter

Change-Id: I7bd9c61d8961bee18eca2c1ac0e5fca610e166e5

+/*
+ * Copyright 2015-present 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.onosproject.openflow.controller;
+
+import org.onosproject.net.Device;
+import org.projectfloodlight.openflow.protocol.OFFactory;
+import org.projectfloodlight.openflow.protocol.OFMessage;
+import org.projectfloodlight.openflow.protocol.OFPortDesc;
+
+import java.util.List;
+
+/**
+ * Test adapter for the OpenFlow switch interface.
+ */
+public class OpenFlowSwitchAdapter implements OpenFlowSwitch {
+    @Override
+    public void sendMsg(OFMessage msg) {
+
+    }
+
+    @Override
+    public void sendMsg(List<OFMessage> msgs) {
+
+    }
+
+    @Override
+    public void handleMessage(OFMessage fromSwitch) {
+
+    }
+
+    @Override
+    public void setRole(RoleState role) {
+
+    }
+
+    @Override
+    public RoleState getRole() {
+        return null;
+    }
+
+    @Override
+    public List<OFPortDesc> getPorts() {
+        return null;
+    }
+
+    @Override
+    public OFFactory factory() {
+        return null;
+    }
+
+    @Override
+    public String getStringId() {
+        return null;
+    }
+
+    @Override
+    public long getId() {
+        return 0;
+    }
+
+    @Override
+    public String manufacturerDescription() {
+        return null;
+    }
+
+    @Override
+    public String datapathDescription() {
+        return null;
+    }
+
+    @Override
+    public String hardwareDescription() {
+        return null;
+    }
+
+    @Override
+    public String softwareDescription() {
+        return null;
+    }
+
+    @Override
+    public String serialNumber() {
+        return null;
+    }
+
+    @Override
+    public boolean isConnected() {
+        return false;
+    }
+
+    @Override
+    public void disconnectSwitch() {
+
+    }
+
+    @Override
+    public void returnRoleReply(RoleState requested, RoleState response) {
+
+    }
+
+    @Override
+    public Device.Type deviceType() {
+        return null;
+    }
+
+    @Override
+    public String channelId() {
+        return null;
+    }
+}
\ No newline at end of file

 /*
- * Copyright 2014-present Open Networking Laboratory
+ * Copyright 2015-present 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.
@@ -38,6 +38,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.Timer;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
@@ -159,6 +160,8 @@ public class OpenFlowDeviceProvider extends AbstractProvider implements DevicePr
     label = "Frequency (in seconds) for polling switch Port statistics")
     private int portStatsPollFrequency = POLL_INTERVAL;
 
+    private final Timer timer = new Timer("onos-openflow-collector");
+
     private HashMap<Dpid, PortStatsCollector> collectors = Maps.newHashMap();
 
     /**
@@ -221,7 +224,7 @@ public class OpenFlowDeviceProvider extends AbstractProvider implements DevicePr
                 // disconnect to trigger switch-add later
                 sw.disconnectSwitch();
             }
-            PortStatsCollector psc = new PortStatsCollector(sw, portStatsPollFrequency);
+            PortStatsCollector psc = new PortStatsCollector(timer, sw, portStatsPollFrequency);
             psc.start();
             collectors.put(new Dpid(sw.getId()), psc);
         }
@@ -382,7 +385,7 @@ public class OpenFlowDeviceProvider extends AbstractProvider implements DevicePr
             providerService.deviceConnected(did, description);
             providerService.updatePorts(did, buildPortDescriptions(sw));
 
-            PortStatsCollector psc = new PortStatsCollector(sw, portStatsPollFrequency);
+            PortStatsCollector psc = new PortStatsCollector(timer, sw, portStatsPollFrequency);
             stopCollectorIfNeeded(collectors.put(dpid, psc));
             psc.start();
 

@@ -16,69 +16,87 @@
 
 package org.onosproject.provider.of.device.impl;
 
-import org.jboss.netty.util.HashedWheelTimer;
-import org.jboss.netty.util.Timeout;
-import org.jboss.netty.util.TimerTask;
-import org.onlab.util.Timer;
+import org.onlab.util.SharedExecutors;
 import org.onosproject.openflow.controller.OpenFlowSwitch;
 import org.onosproject.openflow.controller.RoleState;
 import org.projectfloodlight.openflow.protocol.OFPortStatsRequest;
 import org.projectfloodlight.openflow.types.OFPort;
 import org.slf4j.Logger;
 
-import java.util.concurrent.TimeUnit;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.concurrent.atomic.AtomicLong;
 
+import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
  * Sends Port Stats Request and collect the port statistics with a time interval.
  */
-public class PortStatsCollector implements TimerTask {
+public class PortStatsCollector {
 
-    // TODO: Refactoring is required using ScheduledExecutorService
-
-    private final HashedWheelTimer timer = Timer.getTimer();
-    private final OpenFlowSwitch sw;
     private final Logger log = getLogger(getClass());
+
+    private static final int SECONDS = 1000;
+
+    private OpenFlowSwitch sw;
+    private Timer timer;
+    private TimerTask task;
+
     private int refreshInterval;
     private final AtomicLong xidAtomic = new AtomicLong(1);
 
-    private Timeout timeout;
-    private volatile boolean stopped;
-
     /**
-     * Creates a PortStatsCollector object.
+     * Creates a port states collector object.
      *
-     * @param sw Open Flow switch
-     * @param interval time interval for collecting port statistic
+     * @param timer     timer to use for scheduling
+     * @param sw        switch to pull
+     * @param interval  interval for collecting port statistic
      */
-    public PortStatsCollector(OpenFlowSwitch sw, int interval) {
-        this.sw = sw;
+    PortStatsCollector(Timer timer, OpenFlowSwitch sw, int interval) {
+        this.timer = timer;
+        this.sw = checkNotNull(sw, "Null switch");
         this.refreshInterval = interval;
     }
 
-    @Override
-    public void run(Timeout to) throws Exception {
-        if (stopped || timeout.isCancelled()) {
-            return;
-        }
-        log.trace("Collecting stats for {}", sw.getStringId());
+    private class InternalTimerTask extends TimerTask {
 
+        @Override
+        public void run() {
             sendPortStatistic();
+        }
+    }
 
-        if (!stopped && !timeout.isCancelled()) {
-            log.trace("Scheduling stats collection in {} seconds for {}",
-                    this.refreshInterval, this.sw.getStringId());
-            timeout.getTimer().newTimeout(this, refreshInterval, TimeUnit.SECONDS);
+    /**
+     * Starts the port statistic collector.
+     */
+    public synchronized void start() {
+        log.info("Starting Port Stats collection thread for {}", sw.getStringId());
+        task = new InternalTimerTask();
+        SharedExecutors.getTimer().scheduleAtFixedRate(task, 1 * SECONDS,
+                                                       refreshInterval * SECONDS);
     }
+
+    /**
+     * Stops the port statistic collector.
+     */
+    public synchronized void stop() {
+        log.info("Stopping Port Stats collection thread for {}", sw.getStringId());
+        task.cancel();
+        task = null;
     }
 
-    synchronized void adjustPollInterval(int pollInterval) {
+    /**
+     * Adjusts poll interval of the port statistic collector and restart.
+     *
+     * @param pollInterval period of collecting port statistic
+     */
+    public synchronized void adjustPollInterval(int pollInterval) {
         this.refreshInterval = pollInterval;
-        // task.cancel();
-        // task = new InternalTimerTask();
-        // timer.scheduleAtFixedRate(task, pollInterval * SECONDS, pollInterval * 1000);
+        task.cancel();
+        task = new InternalTimerTask();
+        timer.scheduleAtFixedRate(task, refreshInterval * SECONDS,
+                                  refreshInterval * SECONDS);
     }
 
     /**
@@ -95,22 +113,4 @@ public class PortStatsCollector implements TimerTask {
                 .build();
         sw.sendMsg(statsRequest);
     }
-
-    /**
-     * Starts the collector.
-     */
-    public synchronized void start() {
-        log.info("Starting Port Stats collection thread for {}", sw.getStringId());
-        stopped = false;
-        timeout = timer.newTimeout(this, 1, TimeUnit.SECONDS);
-    }
-
-    /**
-     * Stops the collector.
-     */
-    public synchronized void stop() {
-        log.info("Stopping Port Stats collection thread for {}", sw.getStringId());
-        stopped = true;
-        timeout.cancel();
-    }
 }
\ No newline at end of file