diff --git a/src/main/java/com/android/volley/RequestQueue.java b/src/main/java/com/android/volley/RequestQueue.java
index 5c0e7af..4324590 100644
--- a/src/main/java/com/android/volley/RequestQueue.java
+++ b/src/main/java/com/android/volley/RequestQueue.java
@@ -19,9 +19,11 @@
 import android.os.Handler;
 import android.os.Looper;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
@@ -37,6 +39,12 @@
  */
 public class RequestQueue {
 
+    /** Callback interface for completed requests. */
+    public static interface RequestFinishedListener<T> {
+        /** Called when a request has finished processing. */
+        public void onRequestFinished(Request<T> request);
+    }
+
     /** Used for generating monotonically-increasing sequence numbers for requests. */
     private AtomicInteger mSequenceGenerator = new AtomicInteger();
 
@@ -86,6 +94,9 @@
     /** The cache dispatcher. */
     private CacheDispatcher mCacheDispatcher;
 
+    private List<RequestFinishedListener> mFinishedListeners =
+            new ArrayList<RequestFinishedListener>();
+
     /**
      * Creates the worker pool. Processing will not begin until {@link #start()} is called.
      *
@@ -261,11 +272,16 @@
      * <p>Releases waiting requests for <code>request.getCacheKey()</code> if
      *      <code>request.shouldCache()</code>.</p>
      */
-    void finish(Request<?> request) {
+    <T> void finish(Request<T> request) {
         // Remove from the set of requests currently being processed.
         synchronized (mCurrentRequests) {
             mCurrentRequests.remove(request);
         }
+        synchronized (mFinishedListeners) {
+          for (RequestFinishedListener<T> listener : mFinishedListeners) {
+            listener.onRequestFinished(request);
+          }
+        }
 
         if (request.shouldCache()) {
             synchronized (mWaitingRequests) {
@@ -283,4 +299,19 @@
             }
         }
     }
+
+    public  <T> void addRequestFinishedListener(RequestFinishedListener<T> listener) {
+      synchronized (mFinishedListeners) {
+        mFinishedListeners.add(listener);
+      }
+    }
+
+    /**
+     * Remove a RequestFinishedListener. Has no effect if listener was not previously added.
+     */
+    public  <T> void removeRequestFinishedListener(RequestFinishedListener<T> listener) {
+      synchronized (mFinishedListeners) {
+        mFinishedListeners.remove(listener);
+      }
+    }
 }
diff --git a/src/main/java/com/android/volley/ServerError.java b/src/main/java/com/android/volley/ServerError.java
index 70a9fd5..97cb1c6 100644
--- a/src/main/java/com/android/volley/ServerError.java
+++ b/src/main/java/com/android/volley/ServerError.java
@@ -32,3 +32,4 @@
         super();
     }
 }
+
diff --git a/src/test/java/com/android/volley/RequestQueueIntegrationTest.java b/src/test/java/com/android/volley/RequestQueueIntegrationTest.java
new file mode 100644
index 0000000..a73435c
--- /dev/null
+++ b/src/test/java/com/android/volley/RequestQueueIntegrationTest.java
@@ -0,0 +1,207 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 com.android.volley;
+
+import com.android.volley.Request.Priority;
+import com.android.volley.RequestQueue.RequestFinishedListener;
+import com.android.volley.mock.MockRequest;
+import com.android.volley.mock.ShadowSystemClock;
+import com.android.volley.toolbox.NoCache;
+import com.android.volley.utils.ImmediateResponseDelivery;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+
+/**
+ * Integration tests for {@link RequestQueue}, that verify its behavior in conjunction with real dispatcher, queues and
+ * Requests. Network is mocked out
+ */
+@RunWith(RobolectricTestRunner.class)
+@Config(shadows = {ShadowSystemClock.class})
+public class RequestQueueIntegrationTest {
+
+    private ResponseDelivery mDelivery;
+    @Mock private Network mMockNetwork;
+
+    @Before public void setUp() throws Exception {
+        mDelivery = new ImmediateResponseDelivery();
+        initMocks(this);
+    }
+
+    @Test public void add_requestProcessedInCorrectOrder() throws Exception {
+        // Enqueue 2 requests with different cache keys, and different priorities. The second, higher priority request
+        // takes 20ms.
+        // Assert that first request is only handled after the first one has been parsed and delivered.
+        MockRequest lowerPriorityReq = new MockRequest();
+        MockRequest higherPriorityReq = new MockRequest();
+        lowerPriorityReq.setCacheKey("1");
+        higherPriorityReq.setCacheKey("2");
+        lowerPriorityReq.setPriority(Priority.LOW);
+        higherPriorityReq.setPriority(Priority.HIGH);
+
+        RequestFinishedListener listener = mock(RequestFinishedListener.class);
+        Answer<NetworkResponse> delayAnswer = new Answer<NetworkResponse>() {
+            @Override
+            public NetworkResponse answer(InvocationOnMock invocationOnMock) throws Throwable {
+                Thread.sleep(20);
+                return mock(NetworkResponse.class);
+            }
+        };
+        //delay only for higher request
+        when(mMockNetwork.performRequest(higherPriorityReq)).thenAnswer(delayAnswer);
+        when(mMockNetwork.performRequest(lowerPriorityReq)).thenReturn(mock(NetworkResponse.class));
+
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 1, mDelivery);
+        queue.addRequestFinishedListener(listener);
+        queue.add(lowerPriorityReq);
+        queue.add(higherPriorityReq);
+        queue.start();
+
+        // you cannot do strict order verification in combination with timeouts with mockito 1.9.5 :(
+        // as an alternative, first verify no requests have finished, while higherPriorityReq should be processing
+        verifyNoMoreInteractions(listener);
+        // verify higherPriorityReq goes through first
+        verify(listener, timeout(100)).onRequestFinished(higherPriorityReq);
+        // verify lowerPriorityReq goes last
+        verify(listener, timeout(10)).onRequestFinished(lowerPriorityReq);
+        queue.stop();
+    }
+
+    /**
+     * Asserts that requests with same cache key are processed in order.
+     *
+     * Needs to be an integration test because relies on complex interations between various queues
+     */
+    @Test public void add_dedupeByCacheKey() throws Exception {
+        // Enqueue 2 requests with the same cache key. The first request takes 20ms. Assert that the
+        // second request is only handled after the first one has been parsed and delivered.
+        Request req1 = new MockRequest();
+        Request req2 = new MockRequest();
+        RequestFinishedListener listener = mock(RequestFinishedListener.class);
+        Answer<NetworkResponse> delayAnswer = new Answer<NetworkResponse>() {
+            @Override
+            public NetworkResponse answer(InvocationOnMock invocationOnMock) throws Throwable {
+                Thread.sleep(20);
+                return mock(NetworkResponse.class);
+            }
+        };
+        //delay only for first
+        when(mMockNetwork.performRequest(req1)).thenAnswer(delayAnswer);
+        when(mMockNetwork.performRequest(req2)).thenReturn(mock(NetworkResponse.class));
+
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 3, mDelivery);
+        queue.addRequestFinishedListener(listener);
+        queue.add(req1);
+        queue.add(req2);
+        queue.start();
+
+        // you cannot do strict order verification with mockito 1.9.5 :(
+        // as an alternative, first verify no requests have finished, then verify req1 goes through
+        verifyNoMoreInteractions(listener);
+        verify(listener, timeout(100)).onRequestFinished(req1);
+        verify(listener, timeout(10)).onRequestFinished(req2);
+        queue.stop();
+    }
+
+    /**
+     * Verify RequestFinishedListeners are informed when requests are canceled
+     *
+     * Needs to be an integration test because relies on Request -> dispatcher -> RequestQueue interaction
+     */
+    @Test public void add_requestFinishedListenerCanceled() throws Exception {
+        RequestFinishedListener listener = mock(RequestFinishedListener.class);
+        Request request = new MockRequest();
+        Answer<NetworkResponse> delayAnswer = new Answer<NetworkResponse>() {
+            @Override
+            public NetworkResponse answer(InvocationOnMock invocationOnMock) throws Throwable {
+                Thread.sleep(200);
+                return mock(NetworkResponse.class);
+            }
+        };
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 1, mDelivery);
+
+        when(mMockNetwork.performRequest(request)).thenAnswer(delayAnswer);
+
+        queue.addRequestFinishedListener(listener);
+        queue.start();
+        queue.add(request);
+
+        request.cancel();
+        verify(listener, timeout(100)).onRequestFinished(request);
+        queue.stop();
+    }
+
+    /**
+     * Verify RequestFinishedListeners are informed when requests are successfully delivered
+     *
+     * Needs to be an integration test because relies on Request -> dispatcher -> RequestQueue interaction
+     */
+    @Test public void add_requestFinishedListenerSuccess() throws Exception {
+        NetworkResponse response = mock(NetworkResponse.class);
+        Request request = new MockRequest();
+        RequestFinishedListener listener = mock(RequestFinishedListener.class);
+        RequestFinishedListener listener2 = mock(RequestFinishedListener.class);
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 1, mDelivery);
+
+        queue.addRequestFinishedListener(listener);
+        queue.addRequestFinishedListener(listener2);
+        queue.start();
+        queue.add(request);
+
+        verify(listener, timeout(100)).onRequestFinished(request);
+        verify(listener2, timeout(100)).onRequestFinished(request);
+
+        queue.stop();
+    }
+
+    /**
+     * Verify RequestFinishedListeners are informed when request errors
+     *
+     * Needs to be an integration test because relies on Request -> dispatcher -> RequestQueue interaction
+     */
+    @Test public void add_requestFinishedListenerError() throws Exception {
+        RequestFinishedListener listener = mock(RequestFinishedListener.class);
+        Request request = new MockRequest();
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 1, mDelivery);
+
+        when(mMockNetwork.performRequest(request)).thenThrow(new VolleyError());
+
+        queue.addRequestFinishedListener(listener);
+        queue.start();
+        queue.add(request);
+
+        verify(listener, timeout(100)).onRequestFinished(request);
+        queue.stop();
+    }
+
+}
diff --git a/src/test/java/com/android/volley/RequestQueueTest.java b/src/test/java/com/android/volley/RequestQueueTest.java
index cc88d3b..bcf3ff2 100644
--- a/src/test/java/com/android/volley/RequestQueueTest.java
+++ b/src/test/java/com/android/volley/RequestQueueTest.java
@@ -16,114 +16,47 @@
 
 package com.android.volley;
 
-import com.android.volley.Request.Priority;
-import com.android.volley.mock.MockNetwork;
-import com.android.volley.mock.MockRequest;
+import com.android.volley.mock.ShadowSystemClock;
 import com.android.volley.toolbox.NoCache;
-import com.android.volley.utils.CacheTestUtils;
 import com.android.volley.utils.ImmediateResponseDelivery;
-
-import android.os.SystemClock;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Mock;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
-import org.robolectric.annotation.Implements;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-import java.util.concurrent.Semaphore;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+import static org.mockito.MockitoAnnotations.initMocks;
 
-// TODO: Resurrect these tests when we have something like a finish() observer.
-// They are really gross as-is and depend on a bunch of sleeping and whatnot.
-@Ignore
+/**
+ * Unit tests for RequestQueue, with all dependencies mocked out
+ */
 @RunWith(RobolectricTestRunner.class)
+@Config(shadows = {ShadowSystemClock.class})
 public class RequestQueueTest {
+
     private ResponseDelivery mDelivery;
+    @Mock private Network mMockNetwork;
 
     @Before public void setUp() throws Exception {
         mDelivery = new ImmediateResponseDelivery();
-    }
-
-    /**
-     * Make a list of requests with random priorities.
-     * @param count Number of requests to make
-     */
-    private List<MockRequest> makeRequests(int count) {
-        Request.Priority[] allPriorities = Request.Priority.values();
-        Random random = new Random();
-
-        List<MockRequest> requests = new ArrayList<MockRequest>();
-        for (int i = 0; i < count; i++) {
-            MockRequest request = new MockRequest();
-            Request.Priority priority = allPriorities[random.nextInt(allPriorities.length)];
-            request.setCacheKey(String.valueOf(i));
-            request.setPriority(priority);
-            requests.add(request);
-        }
-        return requests;
-    }
-
-    @Test public void add_requestProcessedInCorrectOrder() throws Exception {
-        int requestsToMake = 100;
-
-        OrderCheckingNetwork network = new OrderCheckingNetwork();
-        RequestQueue queue = new RequestQueue(new NoCache(), network, 1, mDelivery);
-
-        for (Request<?> request : makeRequests(requestsToMake)) {
-            queue.add(request);
-        }
-
-        network.setExpectedRequests(requestsToMake);
-        queue.start();
-        network.waitUntilExpectedDone(2000); // 2 seconds
-        queue.stop();
-    }
-
-    @Test public void add_dedupeByCacheKey() throws Exception {
-        OrderCheckingNetwork network = new OrderCheckingNetwork();
-        final AtomicInteger parsed = new AtomicInteger();
-        final AtomicInteger delivered = new AtomicInteger();
-        // Enqueue 2 requests with the same cache key. The first request takes 1.5s. Assert that the
-        // second request is only handled after the first one has been parsed and delivered.
-        DelayedRequest req1 = new DelayedRequest(1500, parsed, delivered);
-        DelayedRequest req2 = new DelayedRequest(0, parsed, delivered) {
-            @Override
-            protected Response<Object> parseNetworkResponse(NetworkResponse response) {
-                assertEquals(1, parsed.get());  // req1 must have been parsed.
-                assertEquals(1, delivered.get());  // req1 must have been parsed.
-                return super.parseNetworkResponse(response);
-            }
-        };
-        network.setExpectedRequests(2);
-        RequestQueue queue = new RequestQueue(new NoCache(), network, 3, mDelivery);
-        queue.add(req1);
-        queue.add(req2);
-        queue.start();
-        network.waitUntilExpectedDone(2000);
-        queue.stop();
+        initMocks(this);
     }
 
     @Test public void cancelAll_onlyCorrectTag() throws Exception {
-        MockNetwork network = new MockNetwork();
-        RequestQueue queue = new RequestQueue(new NoCache(), network, 3, mDelivery);
+        RequestQueue queue = new RequestQueue(new NoCache(), mMockNetwork, 0, mDelivery);
         Object tagA = new Object();
         Object tagB = new Object();
-        MockRequest req1 = new MockRequest();
-        req1.setTag(tagA);
-        MockRequest req2 = new MockRequest();
-        req2.setTag(tagB);
-        MockRequest req3 = new MockRequest();
-        req3.setTag(tagA);
-        MockRequest req4 = new MockRequest();
-        req4.setTag(tagA);
+        Request req1 = mock(Request.class);
+        when(req1.getTag()).thenReturn(tagA);
+        Request req2 = mock(Request.class);
+        when(req2.getTag()).thenReturn(tagB);
+        Request req3 = mock(Request.class);
+        when(req3.getTag()).thenReturn(tagA);
+        Request req4 = mock(Request.class);
+        when(req4.getTag()).thenReturn(tagA);
 
         queue.add(req1); // A
         queue.add(req2); // B
@@ -131,75 +64,9 @@
         queue.cancelAll(tagA);
         queue.add(req4); // A
 
-        assertTrue(req1.cancel_called); // A cancelled
-        assertFalse(req2.cancel_called); // B not cancelled
-        assertTrue(req3.cancel_called); // A cancelled
-        assertFalse(req4.cancel_called); // A added after cancel not cancelled
+        verify(req1).cancel(); // A cancelled
+        verify(req3).cancel(); // A cancelled
+        verify(req2, never()).cancel(); // B not cancelled
+        verify(req4, never()).cancel(); // A added after cancel not cancelled
     }
-
-    private class OrderCheckingNetwork implements Network {
-        private Priority mLastPriority = Priority.IMMEDIATE;
-        private int mLastSequence = -1;
-        private Semaphore mSemaphore;
-
-        public void setExpectedRequests(int expectedRequests) {
-            // Leave one permit available so the waiter can find it.
-            expectedRequests--;
-            mSemaphore = new Semaphore(-expectedRequests);
-        }
-
-        public void waitUntilExpectedDone(long timeout)
-                throws InterruptedException, TimeoutError {
-            if (mSemaphore.tryAcquire(timeout, TimeUnit.MILLISECONDS) == false) {
-                throw new TimeoutError();
-            }
-        }
-
-        @Override
-        public NetworkResponse performRequest(Request<?> request) {
-            Priority thisPriority = request.getPriority();
-            int thisSequence = request.getSequence();
-
-            int priorityDiff = thisPriority.compareTo(mLastPriority);
-
-            // Should never experience a higher priority after a lower priority
-            assertFalse(priorityDiff > 0);
-
-            // If we're not transitioning to a new priority block, check sequence numbers
-            if (priorityDiff == 0) {
-                assertTrue(thisSequence > mLastSequence);
-            }
-            mLastSequence = thisSequence;
-            mLastPriority = thisPriority;
-
-            mSemaphore.release();
-            return new NetworkResponse(new byte[16]);
-        }
-    }
-
-    private class DelayedRequest extends Request<Object> {
-        private final long mDelayMillis;
-        private final AtomicInteger mParsedCount;
-        private final AtomicInteger mDeliveredCount;
-
-        public DelayedRequest(long delayMillis, AtomicInteger parsed, AtomicInteger delivered) {
-            super(Request.Method.GET, "http://buganizer/", null);
-            mDelayMillis = delayMillis;
-            mParsedCount = parsed;
-            mDeliveredCount = delivered;
-        }
-
-        @Override
-        protected Response<Object> parseNetworkResponse(NetworkResponse response) {
-            mParsedCount.incrementAndGet();
-            SystemClock.sleep(mDelayMillis);
-            return Response.success(new Object(), CacheTestUtils.makeRandomCacheEntry(null));
-        }
-
-        @Override
-        protected void deliverResponse(Object response) {
-            mDeliveredCount.incrementAndGet();
-        }
-    }
-
 }
diff --git a/src/test/java/com/android/volley/mock/ShadowSystemClock.java b/src/test/java/com/android/volley/mock/ShadowSystemClock.java
new file mode 100644
index 0000000..f2697cc
--- /dev/null
+++ b/src/test/java/com/android/volley/mock/ShadowSystemClock.java
@@ -0,0 +1,11 @@
+package com.android.volley.mock;
+
+import android.os.SystemClock;
+import org.robolectric.annotation.Implements;
+
+@Implements(value = SystemClock.class, callThroughByDefault = true)
+public class ShadowSystemClock {
+    public static long elapsedRealtime() {
+        return 0;
+    }
+}