diff --git a/src/test/java/net/onrc/onos/core/flowprogrammer/FlowPusherTest.java b/src/test/java/net/onrc/onos/core/flowprogrammer/FlowPusherTest.java
index be7834c..1c25e75 100644
--- a/src/test/java/net/onrc/onos/core/flowprogrammer/FlowPusherTest.java
+++ b/src/test/java/net/onrc/onos/core/flowprogrammer/FlowPusherTest.java
@@ -41,515 +41,517 @@
 import org.openflow.protocol.factory.BasicFactory;
 
 public class FlowPusherTest {
-	private FlowPusher pusher;
-	private FloodlightContext context;
-	private FloodlightModuleContext modContext;
-	private BasicFactory factory;
-	private OFMessageDamper damper;
-	private IFloodlightProviderService flProviderService;
-	private IThreadPoolService threadPoolService;
+    private FlowPusher pusher;
+    private FloodlightContext context;
+    private FloodlightModuleContext modContext;
+    private BasicFactory factory;
+    private OFMessageDamper damper;
+    private IFloodlightProviderService flProviderService;
+    private IThreadPoolService threadPoolService;
 
-	/**
-	 * Test single OFMessage is correctly sent to single switch via MessageDamper.
-	 */
-	@Test
-	public void testAddMessage() {
-		beginInitMock();
-		
-		OFMessage msg = EasyMock.createMock(OFMessage.class);
-		EasyMock.expect(msg.getXid()).andReturn(1).anyTimes();
-		EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-		EasyMock.replay(msg);
-		
-		IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-		EasyMock.expect(sw.getId()).andReturn((long)1).anyTimes();
-		sw.flush();
-		EasyMock.expectLastCall().once();
-		EasyMock.replay(sw);
-		
-		try {
-			EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
-				.andReturn(true).once();
-		} catch (IOException e1) {
-			fail("Failed in OFMessageDamper#write()");
-		}
-		
-		endInitMock();
-		initPusher(1);
-		
-		boolean add_result = pusher.add(sw, msg);
-		assertTrue(add_result);
-		
-		try {
-			// wait until message is processed.
-			Thread.sleep(1000);
-		} catch (InterruptedException e) {
-			fail("Failed in Thread.sleep()");
-		}
-		EasyMock.verify(msg);
-		EasyMock.verify(sw);
-		verifyAll();
-		
-		pusher.stop();
-	}
-	
-	/**
-	 * Test bunch of OFMessages are correctly sent to single switch via MessageDamper.
-	 */
-	@Test
-	public void testMassiveAddMessage() {
-		final int NUM_MSG = 10000;
-		
-		beginInitMock();
+    /**
+     * Test single OFMessage is correctly sent to single switch via MessageDamper.
+     */
+    @Test
+    public void testAddMessage() {
+        beginInitMock();
 
-		IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-		EasyMock.expect(sw.getId()).andReturn((long)1).anyTimes();
-		sw.flush();
-		EasyMock.expectLastCall().atLeastOnce();
-		EasyMock.replay(sw);
-		
-		List<OFMessage> messages = new ArrayList<OFMessage>();
-		
-		for (int i = 0; i < NUM_MSG; ++i) {
-			OFMessage msg = EasyMock.createMock(OFMessage.class);
-			EasyMock.expect(msg.getXid()).andReturn(i).anyTimes();
-			EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-			EasyMock.replay(msg);
-			messages.add(msg);
-			
-			try {
-				EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
-					.andReturn(true).once();
-			} catch (IOException e1) {
-				fail("Failed in OFMessageDamper#write()");
-			}
-		}
-		
-		endInitMock();
-		initPusher(1);
-		
-		for (OFMessage msg : messages) {
-			boolean add_result = pusher.add(sw, msg);
-			assertTrue(add_result);
-		}
-		
-		try {
-			// wait until message is processed.
-			Thread.sleep(5000);
-		} catch (InterruptedException e) {
-			fail("Failed in Thread.sleep()");
-		}
-		
-		for (OFMessage msg : messages) {
-			EasyMock.verify(msg);
-		}
-		EasyMock.verify(sw);
-		verifyAll();
-		
-		pusher.stop();
-	}
-	
-	/**
-	 * Test bunch of OFMessages are correctly sent to multiple switches with single threads.
-	 */
-	@Test
-	public void testMultiSwitchAddMessage() {
-		final int NUM_SWITCH = 10;
-		final int NUM_MSG = 100;	// messages per thread
-		
-		beginInitMock();
+        OFMessage msg = EasyMock.createMock(OFMessage.class);
+        EasyMock.expect(msg.getXid()).andReturn(1).anyTimes();
+        EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+        EasyMock.replay(msg);
 
-		Map<IOFSwitch, List<OFMessage>> sw_map = new HashMap<IOFSwitch, List<OFMessage>>();
-		for (int i = 0; i < NUM_SWITCH; ++i) {
-			IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-			EasyMock.expect(sw.getId()).andReturn((long)i).anyTimes();
-			sw.flush();
-			EasyMock.expectLastCall().atLeastOnce();
-			EasyMock.replay(sw);
-			
-			List<OFMessage> messages = new ArrayList<OFMessage>();
-			
-			for (int j = 0; j < NUM_MSG; ++j) {
-				OFMessage msg = EasyMock.createMock(OFMessage.class);
-				EasyMock.expect(msg.getXid()).andReturn(j).anyTimes();
-				EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-				EasyMock.replay(msg);
-				messages.add(msg);
-				
-				try {
-					EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
-						.andReturn(true).once();
-				} catch (IOException e1) {
-					fail("Failed in OFMessageDamper#write()");
-				}
-			}
-			sw_map.put(sw, messages);
-		}
-		
-		endInitMock();
-		initPusher(1);
-		
-		for (IOFSwitch sw : sw_map.keySet()) {
-			for (OFMessage msg : sw_map.get(sw)) {
-				boolean add_result = pusher.add(sw, msg);
-				assertTrue(add_result);
-			}
-		}
-		
-		try {
-			// wait until message is processed.
-			Thread.sleep(1000);
-		} catch (InterruptedException e) {
-			fail("Failed in Thread.sleep()");
-		}
-		
-		for (IOFSwitch sw : sw_map.keySet()) {
-			for (OFMessage msg : sw_map.get(sw)) {
-				EasyMock.verify(msg);
-			}
-			
-			EasyMock.verify(sw);
-		}
-		verifyAll();
+        IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+        EasyMock.expect(sw.getId()).andReturn((long) 1).anyTimes();
+        sw.flush();
+        EasyMock.expectLastCall().once();
+        EasyMock.replay(sw);
 
-		pusher.stop();
-	}
-	
-	/**
-	 * Test bunch of OFMessages are correctly sent to multiple switches using multiple threads.
-	 */
-	@Test
-	public void testMultiThreadedAddMessage() {
-		final int NUM_THREAD = 10;
-		final int NUM_MSG = 100;	// messages per thread
-		
-		beginInitMock();
+        try {
+            EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
+                    .andReturn(true).once();
+        } catch (IOException e1) {
+            fail("Failed in OFMessageDamper#write()");
+        }
 
-		Map<IOFSwitch, List<OFMessage>> sw_map = new HashMap<IOFSwitch, List<OFMessage>>();
-		for (int i = 0; i < NUM_THREAD; ++i) {
-			IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-			EasyMock.expect(sw.getId()).andReturn((long)i).anyTimes();
-			sw.flush();
-			EasyMock.expectLastCall().atLeastOnce();
-			EasyMock.replay(sw);
-			
-			List<OFMessage> messages = new ArrayList<OFMessage>();
-			
-			for (int j = 0; j < NUM_MSG; ++j) {
-				OFMessage msg = EasyMock.createMock(OFMessage.class);
-				EasyMock.expect(msg.getXid()).andReturn(j).anyTimes();
-				EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-				EasyMock.replay(msg);
-				messages.add(msg);
-				
-				try {
-					EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
-						.andReturn(true).once();
-				} catch (IOException e1) {
-					fail("Failed in OFMessageDamper#write()");
-				}
-			}
-			sw_map.put(sw, messages);
-		}
-		
-		endInitMock();
-		initPusher(NUM_THREAD);
-		
-		for (IOFSwitch sw : sw_map.keySet()) {
-			for (OFMessage msg : sw_map.get(sw)) {
-				boolean add_result = pusher.add(sw, msg);
-				assertTrue(add_result);
-			}
-		}
-		
-		try {
-			// wait until message is processed.
-			Thread.sleep(1000);
-		} catch (InterruptedException e) {
-			fail("Failed in Thread.sleep()");
-		}
-		
-		for (IOFSwitch sw : sw_map.keySet()) {
-			for (OFMessage msg : sw_map.get(sw)) {
-				EasyMock.verify(msg);
-			}
-			
-			EasyMock.verify(sw);
-		}
-		verifyAll();
+        endInitMock();
+        initPusher(1);
 
-		pusher.stop();
-	}
-	
-	private long barrierTime = 0;
-	/**
-	 * Test rate limitation of messages works correctly.
-	 */
-	@Test
-	public void testRateLimitedAddMessage() {
-		final long LIMIT_RATE = 100; // [bytes/ms]
-		final int NUM_MSG = 1000;
-		
-		// Accuracy of FlowPusher's rate calculation can't be measured by unit test
-		// because switch doesn't return BARRIER_REPLY.
-		// In unit test we use approximate way to measure rate. This value is 
-		// acceptable margin of measured rate.
-		final double ACCEPTABLE_RATE = LIMIT_RATE * 1.2;
-		
-		beginInitMock();
+        boolean add_result = pusher.add(sw, msg);
+        assertTrue(add_result);
 
-		IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-		EasyMock.expect(sw.getId()).andReturn((long)1).anyTimes();
-		sw.flush();
-		EasyMock.expectLastCall().atLeastOnce();
-		prepareBarrier(sw);
-		EasyMock.replay(sw);
-		
-		List<OFMessage> messages = new ArrayList<OFMessage>();
-		
-		for (int i = 0; i < NUM_MSG; ++i) {
-			OFMessage msg = EasyMock.createMock(OFMessage.class);
-			EasyMock.expect(msg.getXid()).andReturn(1).anyTimes();
-			EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-			EasyMock.expect(msg.getLengthU()).andReturn(100).anyTimes();
-			EasyMock.replay(msg);
-			messages.add(msg);
-			
-			try {
-				EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
-					.andReturn(true).once();
-			} catch (IOException e) {
-				fail("Failed in OFMessageDamper#write()");
-			}
-		}
-		
-		try {
-			EasyMock.expect(damper.write(EasyMock.eq(sw), (OFMessage)EasyMock.anyObject(), EasyMock.eq(context)))
-				.andAnswer(new IAnswer<Boolean>() {
-					@Override
-					public Boolean answer() throws Throwable {
-						OFMessage msg = (OFMessage)EasyMock.getCurrentArguments()[1];
-						if (msg.getType() == OFType.BARRIER_REQUEST) {
-							barrierTime = System.currentTimeMillis();
-						}
-						return true;
-					}
-				}).once();
-		} catch (IOException e1) {
-			fail("Failed in OFMessageDamper#write()");
-		}
+        try {
+            // wait until message is processed.
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            fail("Failed in Thread.sleep()");
+        }
+        EasyMock.verify(msg);
+        EasyMock.verify(sw);
+        verifyAll();
 
-		endInitMock();
-		initPusher(1);
-		
-		pusher.createQueue(sw);
-		pusher.setRate(sw, LIMIT_RATE);
-		
-		long beginTime = System.currentTimeMillis();
-		for (OFMessage msg : messages) {
-			boolean add_result = pusher.add(sw, msg);
-			assertTrue(add_result);
-		}
-		
-		pusher.barrierAsync(sw);
+        pusher.stop();
+    }
 
-		try {
-			do {
-				Thread.sleep(1000);
-			} while (barrierTime == 0);
-		} catch (InterruptedException e) {
-			fail("Failed to sleep");
-		}
-		
-		double measured_rate = NUM_MSG * 100 /  (barrierTime - beginTime);
-		assertTrue(measured_rate < ACCEPTABLE_RATE);
-		
-		for (OFMessage msg : messages) {
-			EasyMock.verify(msg);
-		}
-		EasyMock.verify(sw);
-		verifyAll();
+    /**
+     * Test bunch of OFMessages are correctly sent to single switch via MessageDamper.
+     */
+    @Test
+    public void testMassiveAddMessage() {
+        final int NUM_MSG = 10000;
 
-		pusher.stop();
-	}
+        beginInitMock();
 
-	/**
-	 * Test barrier message is correctly sent to a switch.
-	 */
-	@Test
-	public void testBarrierMessage() {
-		beginInitMock();
-		
-		IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-		EasyMock.expect(sw.getId()).andReturn((long)1).anyTimes();
-		sw.flush();
-		EasyMock.expectLastCall().atLeastOnce();
-		prepareBarrier(sw);
-		EasyMock.replay(sw);
+        IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+        EasyMock.expect(sw.getId()).andReturn((long) 1).anyTimes();
+        sw.flush();
+        EasyMock.expectLastCall().atLeastOnce();
+        EasyMock.replay(sw);
 
-		try {
-			EasyMock.expect(damper.write(EasyMock.eq(sw), (OFMessage)EasyMock.anyObject(), EasyMock.eq(context)))
-				.andReturn(true).once();
-		} catch (IOException e1) {
-			fail("Failed in OFMessageDamper#write()");
-		}
+        List<OFMessage> messages = new ArrayList<OFMessage>();
 
-		endInitMock();
-		initPusher(1);
+        for (int i = 0; i < NUM_MSG; ++i) {
+            OFMessage msg = EasyMock.createMock(OFMessage.class);
+            EasyMock.expect(msg.getXid()).andReturn(i).anyTimes();
+            EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+            EasyMock.replay(msg);
+            messages.add(msg);
 
-		OFBarrierReplyFuture future = pusher.barrierAsync(sw);
-		
-		assertNotNull(future);
-		
-		try {
-			Thread.sleep(1000);
-		} catch (InterruptedException e) {
-			fail("Failed to sleep");
-		}
-		
-		verifyAll();
+            try {
+                EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
+                        .andReturn(true).once();
+            } catch (IOException e1) {
+                fail("Failed in OFMessageDamper#write()");
+            }
+        }
 
-		pusher.stop();
-	}
-	
-	static final int XID_TO_VERIFY = 100;
-	static final long DPID_TO_VERIFY = 10;
-	/**
-	 * Test FlowObject is correctly converted to message and is sent to a switch.
-	 */
-	@SuppressWarnings("unchecked")
-	@Test
-	public void testAddFlow() {
-		// instantiate required objects
-		FlowEntry flowEntry1 = new FlowEntry();
-		flowEntry1.setDpid(new Dpid(DPID_TO_VERIFY));
-		flowEntry1.setFlowId(new FlowId(1));
-		flowEntry1.setInPort(new Port((short) 1));
-		flowEntry1.setOutPort(new Port((short) 11));
-		flowEntry1.setFlowEntryId(new FlowEntryId(1));
-		flowEntry1.setFlowEntryMatch(new FlowEntryMatch());
-		flowEntry1.setFlowEntryActions(new FlowEntryActions());
-		flowEntry1.setFlowEntryErrorState(new FlowEntryErrorState());
-		flowEntry1.setFlowEntryUserState(FlowEntryUserState.FE_USER_ADD);
-		
-		beginInitMock();
-		
-		OFFlowMod msg = EasyMock.createMock(OFFlowMod.class);
-		EasyMock.expect(msg.setIdleTimeout(EasyMock.anyShort())).andReturn(msg);
-		EasyMock.expect(msg.setHardTimeout(EasyMock.anyShort())).andReturn(msg);
-		EasyMock.expect(msg.setPriority(EasyMock.anyShort())).andReturn(msg);
-		EasyMock.expect(msg.setBufferId(EasyMock.anyInt())).andReturn(msg);
-		EasyMock.expect(msg.setCookie(EasyMock.anyLong())).andReturn(msg);
-		EasyMock.expect(msg.setCommand(EasyMock.anyShort())).andReturn(msg);
-		EasyMock.expect(msg.setMatch(EasyMock.anyObject(OFMatch.class))).andReturn(msg);
-		EasyMock.expect(msg.setActions((List<OFAction>)EasyMock.anyObject())).andReturn(msg);
-		EasyMock.expect(msg.setLengthU(EasyMock.anyShort())).andReturn(msg);
-		EasyMock.expect(msg.setOutPort(EasyMock.anyShort())).andReturn(msg).atLeastOnce();
-		EasyMock.expect(msg.getXid()).andReturn(XID_TO_VERIFY).anyTimes();
-		EasyMock.expect(msg.getType()).andReturn(OFType.FLOW_MOD).anyTimes();
-		EasyMock.expect(msg.getLength()).andReturn((short)100).anyTimes();
-		EasyMock.replay(msg);
-		
-		EasyMock.expect(factory.getMessage(EasyMock.eq(OFType.FLOW_MOD))).andReturn(msg);
+        endInitMock();
+        initPusher(1);
 
-		IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
-		EasyMock.expect(sw.getId()).andReturn(DPID_TO_VERIFY).anyTimes();
-		EasyMock.expect(sw.getStringId()).andReturn("1").anyTimes();
-		sw.flush();
-		EasyMock.expectLastCall().once();
-		
-		try {
-			EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.anyObject(OFMessage.class), EasyMock.eq(context)))
-				.andAnswer(new IAnswer<Boolean>() {
-					@Override
-					public Boolean answer() throws Throwable {
-						OFMessage msg = (OFMessage)EasyMock.getCurrentArguments()[1];
-						if (msg.getType() == OFType.FLOW_MOD) {
-							assertEquals(msg.getXid(), XID_TO_VERIFY);
-						}
-						return true;
-					}
-				}).atLeastOnce();
-		} catch (IOException e1) {
-			fail("Failed in OFMessageDamper#write()");
-		}
-		
-		EasyMock.replay(sw);
-		
-		endInitMock();
-		initPusher(1);
+        for (OFMessage msg : messages) {
+            boolean add_result = pusher.add(sw, msg);
+            assertTrue(add_result);
+        }
 
-		pusher.pushFlowEntry(sw, flowEntry1);
-		
-		try {
-			Thread.sleep(1000);
-		} catch (InterruptedException e) {
-			fail("Failed to sleep");
-		}
-		
-		EasyMock.verify(sw);
-		verifyAll();
+        try {
+            // wait until message is processed.
+            Thread.sleep(5000);
+        } catch (InterruptedException e) {
+            fail("Failed in Thread.sleep()");
+        }
 
-		pusher.stop();
-	}
-	
-	private void beginInitMock() {
-		context = EasyMock.createMock(FloodlightContext.class);
-		modContext = EasyMock.createMock(FloodlightModuleContext.class);
-		factory = EasyMock.createMock(BasicFactory.class);
-		damper = EasyMock.createMock(OFMessageDamper.class);
-		flProviderService = EasyMock.createMock(IFloodlightProviderService.class);
-		threadPoolService = EasyMock.createMock(IThreadPoolService.class);
-		
-		EasyMock.expect(modContext.getServiceImpl(EasyMock.eq(IThreadPoolService.class)))
-			.andReturn(threadPoolService).once();
-		EasyMock.expect(modContext.getServiceImpl(EasyMock.eq(IFloodlightProviderService.class)))
-			.andReturn(flProviderService).once();
-		flProviderService.addOFMessageListener(EasyMock.eq(OFType.BARRIER_REPLY),
-				(FlowPusher) EasyMock.anyObject());
-		EasyMock.expectLastCall().once();
-		
-		ScheduledExecutorService executor = EasyMock.createMock(ScheduledExecutorService.class);
-		EasyMock.expect(executor.schedule((Runnable)EasyMock.anyObject(), EasyMock.anyLong(),
-				(TimeUnit)EasyMock.anyObject())).andReturn(null).once();
-		EasyMock.replay(executor);
-		EasyMock.expect(threadPoolService.getScheduledExecutor()).andReturn(executor).anyTimes();
-	}
-	
-	private void endInitMock() {
-		EasyMock.replay(threadPoolService);
-		EasyMock.replay(flProviderService);
-		EasyMock.replay(damper);
-		EasyMock.replay(factory);
-		EasyMock.replay(modContext);
-		EasyMock.replay(context);
-	}
-	
-	private void verifyAll() {
-		EasyMock.verify(threadPoolService);
-		EasyMock.verify(flProviderService);
-		EasyMock.verify(damper);
-		EasyMock.verify(factory);
-		EasyMock.verify(modContext);
-		EasyMock.verify(context);
-	}
-		
-	private void initPusher(int num_thread) {
-		pusher = new FlowPusher(num_thread);
-		pusher.init(context, modContext, factory, damper);
-		pusher.start();
-	}
-	
-	private void prepareBarrier(IOFSwitch sw) {
-		OFBarrierRequest req = EasyMock.createMock(OFBarrierRequest.class);
-		req.setXid(EasyMock.anyInt());
-		EasyMock.expectLastCall().once();
-		EasyMock.expect(req.getXid()).andReturn(1).anyTimes();
-		EasyMock.expect(req.getType()).andReturn(OFType.BARRIER_REQUEST).anyTimes();
-		EasyMock.expect(req.getLength()).andReturn((short)100).anyTimes();
-		EasyMock.replay(req);
-		EasyMock.expect(factory.getMessage(EasyMock.eq(OFType.BARRIER_REQUEST))).andReturn(req).anyTimes();
-		EasyMock.expect(sw.getNextTransactionId()).andReturn(1);
-	}
-	
+        for (OFMessage msg : messages) {
+            EasyMock.verify(msg);
+        }
+        EasyMock.verify(sw);
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    /**
+     * Test bunch of OFMessages are correctly sent to multiple switches with single threads.
+     */
+    @Test
+    public void testMultiSwitchAddMessage() {
+        final int NUM_SWITCH = 10;
+        final int NUM_MSG = 100;    // messages per thread
+
+        beginInitMock();
+
+        Map<IOFSwitch, List<OFMessage>> sw_map = new HashMap<IOFSwitch, List<OFMessage>>();
+        for (int i = 0; i < NUM_SWITCH; ++i) {
+            IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+            EasyMock.expect(sw.getId()).andReturn((long) i).anyTimes();
+            sw.flush();
+            EasyMock.expectLastCall().atLeastOnce();
+            EasyMock.replay(sw);
+
+            List<OFMessage> messages = new ArrayList<OFMessage>();
+
+            for (int j = 0; j < NUM_MSG; ++j) {
+                OFMessage msg = EasyMock.createMock(OFMessage.class);
+                EasyMock.expect(msg.getXid()).andReturn(j).anyTimes();
+                EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+                EasyMock.replay(msg);
+                messages.add(msg);
+
+                try {
+                    EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
+                            .andReturn(true).once();
+                } catch (IOException e1) {
+                    fail("Failed in OFMessageDamper#write()");
+                }
+            }
+            sw_map.put(sw, messages);
+        }
+
+        endInitMock();
+        initPusher(1);
+
+        for (IOFSwitch sw : sw_map.keySet()) {
+            for (OFMessage msg : sw_map.get(sw)) {
+                boolean add_result = pusher.add(sw, msg);
+                assertTrue(add_result);
+            }
+        }
+
+        try {
+            // wait until message is processed.
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            fail("Failed in Thread.sleep()");
+        }
+
+        for (IOFSwitch sw : sw_map.keySet()) {
+            for (OFMessage msg : sw_map.get(sw)) {
+                EasyMock.verify(msg);
+            }
+
+            EasyMock.verify(sw);
+        }
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    /**
+     * Test bunch of OFMessages are correctly sent to multiple switches using multiple threads.
+     */
+    @Test
+    public void testMultiThreadedAddMessage() {
+        final int NUM_THREAD = 10;
+        final int NUM_MSG = 100;    // messages per thread
+
+        beginInitMock();
+
+        Map<IOFSwitch, List<OFMessage>> sw_map = new HashMap<IOFSwitch, List<OFMessage>>();
+        for (int i = 0; i < NUM_THREAD; ++i) {
+            IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+            EasyMock.expect(sw.getId()).andReturn((long) i).anyTimes();
+            sw.flush();
+            EasyMock.expectLastCall().atLeastOnce();
+            EasyMock.replay(sw);
+
+            List<OFMessage> messages = new ArrayList<OFMessage>();
+
+            for (int j = 0; j < NUM_MSG; ++j) {
+                OFMessage msg = EasyMock.createMock(OFMessage.class);
+                EasyMock.expect(msg.getXid()).andReturn(j).anyTimes();
+                EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+                EasyMock.replay(msg);
+                messages.add(msg);
+
+                try {
+                    EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
+                            .andReturn(true).once();
+                } catch (IOException e1) {
+                    fail("Failed in OFMessageDamper#write()");
+                }
+            }
+            sw_map.put(sw, messages);
+        }
+
+        endInitMock();
+        initPusher(NUM_THREAD);
+
+        for (IOFSwitch sw : sw_map.keySet()) {
+            for (OFMessage msg : sw_map.get(sw)) {
+                boolean add_result = pusher.add(sw, msg);
+                assertTrue(add_result);
+            }
+        }
+
+        try {
+            // wait until message is processed.
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            fail("Failed in Thread.sleep()");
+        }
+
+        for (IOFSwitch sw : sw_map.keySet()) {
+            for (OFMessage msg : sw_map.get(sw)) {
+                EasyMock.verify(msg);
+            }
+
+            EasyMock.verify(sw);
+        }
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    private long barrierTime = 0;
+
+    /**
+     * Test rate limitation of messages works correctly.
+     */
+    @Test
+    public void testRateLimitedAddMessage() {
+        final long LIMIT_RATE = 100; // [bytes/ms]
+        final int NUM_MSG = 1000;
+
+        // Accuracy of FlowPusher's rate calculation can't be measured by unit test
+        // because switch doesn't return BARRIER_REPLY.
+        // In unit test we use approximate way to measure rate. This value is
+        // acceptable margin of measured rate.
+        final double ACCEPTABLE_RATE = LIMIT_RATE * 1.2;
+
+        beginInitMock();
+
+        IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+        EasyMock.expect(sw.getId()).andReturn((long) 1).anyTimes();
+        sw.flush();
+        EasyMock.expectLastCall().atLeastOnce();
+        prepareBarrier(sw);
+        EasyMock.replay(sw);
+
+        List<OFMessage> messages = new ArrayList<OFMessage>();
+
+        for (int i = 0; i < NUM_MSG; ++i) {
+            OFMessage msg = EasyMock.createMock(OFMessage.class);
+            EasyMock.expect(msg.getXid()).andReturn(1).anyTimes();
+            EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+            EasyMock.expect(msg.getLengthU()).andReturn(100).anyTimes();
+            EasyMock.replay(msg);
+            messages.add(msg);
+
+            try {
+                EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.eq(msg), EasyMock.eq(context)))
+                        .andReturn(true).once();
+            } catch (IOException e) {
+                fail("Failed in OFMessageDamper#write()");
+            }
+        }
+
+        try {
+            EasyMock.expect(damper.write(EasyMock.eq(sw), (OFMessage) EasyMock.anyObject(), EasyMock.eq(context)))
+                    .andAnswer(new IAnswer<Boolean>() {
+                        @Override
+                        public Boolean answer() throws Throwable {
+                            OFMessage msg = (OFMessage) EasyMock.getCurrentArguments()[1];
+                            if (msg.getType() == OFType.BARRIER_REQUEST) {
+                                barrierTime = System.currentTimeMillis();
+                            }
+                            return true;
+                        }
+                    }).once();
+        } catch (IOException e1) {
+            fail("Failed in OFMessageDamper#write()");
+        }
+
+        endInitMock();
+        initPusher(1);
+
+        pusher.createQueue(sw);
+        pusher.setRate(sw, LIMIT_RATE);
+
+        long beginTime = System.currentTimeMillis();
+        for (OFMessage msg : messages) {
+            boolean add_result = pusher.add(sw, msg);
+            assertTrue(add_result);
+        }
+
+        pusher.barrierAsync(sw);
+
+        try {
+            do {
+                Thread.sleep(1000);
+            } while (barrierTime == 0);
+        } catch (InterruptedException e) {
+            fail("Failed to sleep");
+        }
+
+        double measured_rate = NUM_MSG * 100 / (barrierTime - beginTime);
+        assertTrue(measured_rate < ACCEPTABLE_RATE);
+
+        for (OFMessage msg : messages) {
+            EasyMock.verify(msg);
+        }
+        EasyMock.verify(sw);
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    /**
+     * Test barrier message is correctly sent to a switch.
+     */
+    @Test
+    public void testBarrierMessage() {
+        beginInitMock();
+
+        IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+        EasyMock.expect(sw.getId()).andReturn((long) 1).anyTimes();
+        sw.flush();
+        EasyMock.expectLastCall().atLeastOnce();
+        prepareBarrier(sw);
+        EasyMock.replay(sw);
+
+        try {
+            EasyMock.expect(damper.write(EasyMock.eq(sw), (OFMessage) EasyMock.anyObject(), EasyMock.eq(context)))
+                    .andReturn(true).once();
+        } catch (IOException e1) {
+            fail("Failed in OFMessageDamper#write()");
+        }
+
+        endInitMock();
+        initPusher(1);
+
+        OFBarrierReplyFuture future = pusher.barrierAsync(sw);
+
+        assertNotNull(future);
+
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            fail("Failed to sleep");
+        }
+
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    static final int XID_TO_VERIFY = 100;
+    static final long DPID_TO_VERIFY = 10;
+
+    /**
+     * Test FlowObject is correctly converted to message and is sent to a switch.
+     */
+    @SuppressWarnings("unchecked")
+    @Test
+    public void testAddFlow() {
+        // instantiate required objects
+        FlowEntry flowEntry1 = new FlowEntry();
+        flowEntry1.setDpid(new Dpid(DPID_TO_VERIFY));
+        flowEntry1.setFlowId(new FlowId(1));
+        flowEntry1.setInPort(new Port((short) 1));
+        flowEntry1.setOutPort(new Port((short) 11));
+        flowEntry1.setFlowEntryId(new FlowEntryId(1));
+        flowEntry1.setFlowEntryMatch(new FlowEntryMatch());
+        flowEntry1.setFlowEntryActions(new FlowEntryActions());
+        flowEntry1.setFlowEntryErrorState(new FlowEntryErrorState());
+        flowEntry1.setFlowEntryUserState(FlowEntryUserState.FE_USER_ADD);
+
+        beginInitMock();
+
+        OFFlowMod msg = EasyMock.createMock(OFFlowMod.class);
+        EasyMock.expect(msg.setIdleTimeout(EasyMock.anyShort())).andReturn(msg);
+        EasyMock.expect(msg.setHardTimeout(EasyMock.anyShort())).andReturn(msg);
+        EasyMock.expect(msg.setPriority(EasyMock.anyShort())).andReturn(msg);
+        EasyMock.expect(msg.setBufferId(EasyMock.anyInt())).andReturn(msg);
+        EasyMock.expect(msg.setCookie(EasyMock.anyLong())).andReturn(msg);
+        EasyMock.expect(msg.setCommand(EasyMock.anyShort())).andReturn(msg);
+        EasyMock.expect(msg.setMatch(EasyMock.anyObject(OFMatch.class))).andReturn(msg);
+        EasyMock.expect(msg.setActions((List<OFAction>) EasyMock.anyObject())).andReturn(msg);
+        EasyMock.expect(msg.setLengthU(EasyMock.anyShort())).andReturn(msg);
+        EasyMock.expect(msg.setOutPort(EasyMock.anyShort())).andReturn(msg).atLeastOnce();
+        EasyMock.expect(msg.getXid()).andReturn(XID_TO_VERIFY).anyTimes();
+        EasyMock.expect(msg.getType()).andReturn(OFType.FLOW_MOD).anyTimes();
+        EasyMock.expect(msg.getLength()).andReturn((short) 100).anyTimes();
+        EasyMock.replay(msg);
+
+        EasyMock.expect(factory.getMessage(EasyMock.eq(OFType.FLOW_MOD))).andReturn(msg);
+
+        IOFSwitch sw = EasyMock.createMock(IOFSwitch.class);
+        EasyMock.expect(sw.getId()).andReturn(DPID_TO_VERIFY).anyTimes();
+        EasyMock.expect(sw.getStringId()).andReturn("1").anyTimes();
+        sw.flush();
+        EasyMock.expectLastCall().once();
+
+        try {
+            EasyMock.expect(damper.write(EasyMock.eq(sw), EasyMock.anyObject(OFMessage.class), EasyMock.eq(context)))
+                    .andAnswer(new IAnswer<Boolean>() {
+                        @Override
+                        public Boolean answer() throws Throwable {
+                            OFMessage msg = (OFMessage) EasyMock.getCurrentArguments()[1];
+                            if (msg.getType() == OFType.FLOW_MOD) {
+                                assertEquals(msg.getXid(), XID_TO_VERIFY);
+                            }
+                            return true;
+                        }
+                    }).atLeastOnce();
+        } catch (IOException e1) {
+            fail("Failed in OFMessageDamper#write()");
+        }
+
+        EasyMock.replay(sw);
+
+        endInitMock();
+        initPusher(1);
+
+        pusher.pushFlowEntry(sw, flowEntry1);
+
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            fail("Failed to sleep");
+        }
+
+        EasyMock.verify(sw);
+        verifyAll();
+
+        pusher.stop();
+    }
+
+    private void beginInitMock() {
+        context = EasyMock.createMock(FloodlightContext.class);
+        modContext = EasyMock.createMock(FloodlightModuleContext.class);
+        factory = EasyMock.createMock(BasicFactory.class);
+        damper = EasyMock.createMock(OFMessageDamper.class);
+        flProviderService = EasyMock.createMock(IFloodlightProviderService.class);
+        threadPoolService = EasyMock.createMock(IThreadPoolService.class);
+
+        EasyMock.expect(modContext.getServiceImpl(EasyMock.eq(IThreadPoolService.class)))
+                .andReturn(threadPoolService).once();
+        EasyMock.expect(modContext.getServiceImpl(EasyMock.eq(IFloodlightProviderService.class)))
+                .andReturn(flProviderService).once();
+        flProviderService.addOFMessageListener(EasyMock.eq(OFType.BARRIER_REPLY),
+                (FlowPusher) EasyMock.anyObject());
+        EasyMock.expectLastCall().once();
+
+        ScheduledExecutorService executor = EasyMock.createMock(ScheduledExecutorService.class);
+        EasyMock.expect(executor.schedule((Runnable) EasyMock.anyObject(), EasyMock.anyLong(),
+                (TimeUnit) EasyMock.anyObject())).andReturn(null).once();
+        EasyMock.replay(executor);
+        EasyMock.expect(threadPoolService.getScheduledExecutor()).andReturn(executor).anyTimes();
+    }
+
+    private void endInitMock() {
+        EasyMock.replay(threadPoolService);
+        EasyMock.replay(flProviderService);
+        EasyMock.replay(damper);
+        EasyMock.replay(factory);
+        EasyMock.replay(modContext);
+        EasyMock.replay(context);
+    }
+
+    private void verifyAll() {
+        EasyMock.verify(threadPoolService);
+        EasyMock.verify(flProviderService);
+        EasyMock.verify(damper);
+        EasyMock.verify(factory);
+        EasyMock.verify(modContext);
+        EasyMock.verify(context);
+    }
+
+    private void initPusher(int num_thread) {
+        pusher = new FlowPusher(num_thread);
+        pusher.init(context, modContext, factory, damper);
+        pusher.start();
+    }
+
+    private void prepareBarrier(IOFSwitch sw) {
+        OFBarrierRequest req = EasyMock.createMock(OFBarrierRequest.class);
+        req.setXid(EasyMock.anyInt());
+        EasyMock.expectLastCall().once();
+        EasyMock.expect(req.getXid()).andReturn(1).anyTimes();
+        EasyMock.expect(req.getType()).andReturn(OFType.BARRIER_REQUEST).anyTimes();
+        EasyMock.expect(req.getLength()).andReturn((short) 100).anyTimes();
+        EasyMock.replay(req);
+        EasyMock.expect(factory.getMessage(EasyMock.eq(OFType.BARRIER_REQUEST))).andReturn(req).anyTimes();
+        EasyMock.expect(sw.getNextTransactionId()).andReturn(1);
+    }
+
 }