diff --git a/include/gui/SensorEventQueue.h b/include/gui/SensorEventQueue.h
index 6581ae3..97dd391 100644
--- a/include/gui/SensorEventQueue.h
+++ b/include/gui/SensorEventQueue.h
@@ -42,7 +42,7 @@
 
 class ISensorEventConnection;
 class Sensor;
-class PollLoop;
+class Looper;
 
 // ----------------------------------------------------------------------------
 
@@ -69,11 +69,11 @@
     status_t disableSensor(int32_t handle) const;
 
 private:
-    sp<PollLoop> getPollLoop() const;
+    sp<Looper> getLooper() const;
     sp<ISensorEventConnection> mSensorEventConnection;
     sp<SensorChannel> mSensorChannel;
     mutable Mutex mLock;
-    mutable sp<PollLoop> mPollLoop;
+    mutable sp<Looper> mLooper;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h
index a06208a..d7e6254 100644
--- a/include/ui/InputDispatcher.h
+++ b/include/ui/InputDispatcher.h
@@ -25,7 +25,7 @@
 #include <utils/Timers.h>
 #include <utils/RefBase.h>
 #include <utils/String8.h>
-#include <utils/PollLoop.h>
+#include <utils/Looper.h>
 #include <utils/Pool.h>
 
 #include <stddef.h>
@@ -826,7 +826,7 @@
     Mutex mLock;
 
     Allocator mAllocator;
-    sp<PollLoop> mPollLoop;
+    sp<Looper> mLooper;
 
     EventEntry* mPendingEvent;
     Queue<EventEntry> mInboundQueue;
@@ -837,7 +837,7 @@
     void dispatchOnceInnerLocked(nsecs_t keyRepeatTimeout, nsecs_t keyRepeatDelay,
             nsecs_t* nextWakeupTime);
 
-    // Enqueues an inbound event.  Returns true if mPollLoop->wake() should be called.
+    // Enqueues an inbound event.  Returns true if mLooper->wake() should be called.
     bool enqueueInboundEventLocked(EventEntry* entry);
 
     // App switch latency optimization.
@@ -1010,7 +1010,7 @@
     void abortDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
             bool broken);
     void drainOutboundQueueLocked(Connection* connection, DispatchEntry* firstDispatchEntryToDrain);
-    static bool handleReceiveCallback(int receiveFd, int events, void* data);
+    static int handleReceiveCallback(int receiveFd, int events, void* data);
 
     // Preempting input dispatch.
     bool preemptInputDispatchInnerLocked();
diff --git a/include/ui/InputTransport.h b/include/ui/InputTransport.h
index 82831e2..dc9e27a 100644
--- a/include/ui/InputTransport.h
+++ b/include/ui/InputTransport.h
@@ -33,7 +33,6 @@
 #include <semaphore.h>
 #include <ui/Input.h>
 #include <utils/Errors.h>
-#include <utils/PollLoop.h>
 #include <utils/Timers.h>
 #include <utils/RefBase.h>
 #include <utils/String8.h>
diff --git a/include/utils/Looper.h b/include/utils/Looper.h
new file mode 100644
index 0000000..92e4b0a
--- /dev/null
+++ b/include/utils/Looper.h
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef UTILS_LOOPER_H
+#define UTILS_LOOPER_H
+
+#include <utils/threads.h>
+#include <utils/RefBase.h>
+#include <utils/KeyedVector.h>
+
+#include <android/looper.h>
+
+/*
+ * Declare a concrete type for the NDK's looper forward declaration.
+ */
+struct ALooper {
+};
+
+namespace android {
+
+/**
+ * A polling loop that supports monitoring file descriptor events, optionally
+ * using callbacks.  The implementation uses epoll() internally.
+ *
+ * A looper can be associated with a thread although there is no requirement that it must be.
+ */
+class Looper : public ALooper, public RefBase {
+protected:
+    virtual ~Looper();
+
+public:
+    /**
+     * Creates a looper.
+     *
+     * If allowNonCallbaks is true, the looper will allow file descriptors to be
+     * registered without associated callbacks.  This assumes that the caller of
+     * pollOnce() is prepared to handle callback-less events itself.
+     */
+    Looper(bool allowNonCallbacks);
+
+    /**
+     * Returns whether this looper instance allows the registration of file descriptors
+     * using identifiers instead of callbacks.
+     */
+    bool getAllowNonCallbacks() const;
+
+    /**
+     * Waits for events to be available, with optional timeout in milliseconds.
+     * Invokes callbacks for all file descriptors on which an event occurred.
+     *
+     * If the timeout is zero, returns immediately without blocking.
+     * If the timeout is negative, waits indefinitely until an event appears.
+     *
+     * Returns ALOOPER_POLL_WAKE if the poll was awoken using wake() before
+     * the timeout expired and no callbacks were invoked and no other file
+     * descriptors were ready.
+     *
+     * Returns ALOOPER_POLL_CALLBACK if one or more callbacks were invoked.
+     *
+     * Returns ALOOPER_POLL_TIMEOUT if there was no data before the given
+     * timeout expired.
+     *
+     * Returns ALOOPER_POLL_ERROR if an error occurred.
+     *
+     * Returns a value >= 0 containing an identifier if its file descriptor has data
+     * and it has no callback function (requiring the caller here to handle it).
+     * In this (and only this) case outFd, outEvents and outData will contain the poll
+     * events and data associated with the fd, otherwise they will be set to NULL.
+     *
+     * This method does not return until it has finished invoking the appropriate callbacks
+     * for all file descriptors that were signalled.
+     */
+    int pollOnce(int timeoutMillis,
+            int* outFd = NULL, int* outEvents = NULL, void** outData = NULL);
+
+    /**
+     * Like pollOnce(), but performs all pending callbacks until all
+     * data has been consumed or a file descriptor is available with no callback.
+     * This function will never return ALOOPER_POLL_CALLBACK.
+     */
+    int pollAll(int timeoutMillis,
+            int* outFd = NULL, int* outEvents = NULL, void** outData = NULL);
+
+    /**
+     * Wakes the poll asynchronously.
+     *
+     * This method can be called on any thread.
+     * This method returns immediately.
+     */
+    void wake();
+
+    /**
+     * Adds a new file descriptor to be polled by the looper.
+     * If the same file descriptor was previously added, it is replaced.
+     *
+     * "fd" is the file descriptor to be added.
+     * "ident" is an identifier for this event, which is returned from ALooper_pollOnce().
+     * The identifier must be >= 0, or ALOOPER_POLL_CALLBACK if providing a non-NULL callback.
+     * "events" are the poll events to wake up on.  Typically this is ALOOPER_EVENT_INPUT.
+     * "callback" is the function to call when there is an event on the file descriptor.
+     * "data" is a private data pointer to supply to the callback.
+     *
+     * There are two main uses of this function:
+     *
+     * (1) If "callback" is non-NULL, then this function will be called when there is
+     * data on the file descriptor.  It should execute any events it has pending,
+     * appropriately reading from the file descriptor.  The 'ident' is ignored in this case.
+     *
+     * (2) If "callback" is NULL, the 'ident' will be returned by ALooper_pollOnce
+     * when its file descriptor has data available, requiring the caller to take
+     * care of processing it.
+     *
+     * Returns 1 if the file descriptor was added, 0 if the arguments were invalid.
+     *
+     * This method can be called on any thread.
+     * This method may block briefly if it needs to wake the poll.
+     */
+    int addFd(int fd, int ident,
+            int events, ALooper_callbackFunc callback, void* data = NULL);
+
+    /**
+     * Removes a previously added file descriptor from the looper.
+     *
+     * When this method returns, it is safe to close the file descriptor since the looper
+     * will no longer have a reference to it.  However, it is possible for the callback to
+     * already be running or for it to run one last time if the file descriptor was already
+     * signalled.  Calling code is responsible for ensuring that this case is safely handled.
+     * For example, if the callback takes care of removing itself during its own execution either
+     * by returning 0 or by calling this method, then it can be guaranteed to not be invoked
+     * again at any later time unless registered anew.
+     *
+     * Returns 1 if the file descriptor was removed, 0 if none was previously registered.
+     *
+     * This method can be called on any thread.
+     * This method may block briefly if it needs to wake the poll.
+     */
+    int removeFd(int fd);
+
+    /**
+     * Prepares a looper associated with the calling thread, and returns it.
+     * If the thread already has a looper, it is returned.  Otherwise, a new
+     * one is created, associated with the thread, and returned.
+     *
+     * The opts may be ALOOPER_PREPARE_ALLOW_NON_CALLBACKS or 0.
+     */
+    static sp<Looper> prepare(int opts);
+
+    /**
+     * Sets the given looper to be associated with the calling thread.
+     * If another looper is already associated with the thread, it is replaced.
+     *
+     * If "looper" is NULL, removes the currently associated looper.
+     */
+    static void setForThread(const sp<Looper>& looper);
+
+    /**
+     * Returns the looper associated with the calling thread, or NULL if
+     * there is not one.
+     */
+    static sp<Looper> getForThread();
+
+private:
+    struct Request {
+        int fd;
+        int ident;
+        ALooper_callbackFunc callback;
+        void* data;
+    };
+
+    struct Response {
+        int events;
+        Request request;
+    };
+
+    const bool mAllowNonCallbacks; // immutable
+
+    int mEpollFd; // immutable
+    int mWakeReadPipeFd;  // immutable
+    int mWakeWritePipeFd; // immutable
+
+    // Locked list of file descriptor monitoring requests.
+    Mutex mLock;
+    KeyedVector<int, Request> mRequests;
+
+    // This state is only used privately by pollOnce and does not require a lock since
+    // it runs on a single thread.
+    Vector<Response> mResponses;
+    size_t mResponseIndex;
+
+    int pollInner(int timeoutMillis);
+
+    static void threadDestructor(void *st);
+};
+
+} // namespace android
+
+#endif // UTILS_LOOPER_H
diff --git a/include/utils/PollLoop.h b/include/utils/PollLoop.h
deleted file mode 100644
index c2dfe5d..0000000
--- a/include/utils/PollLoop.h
+++ /dev/null
@@ -1,219 +0,0 @@
-/*
- * Copyright (C) 2010 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.
- */
-
-#ifndef UTILS_POLL_LOOP_H
-#define UTILS_POLL_LOOP_H
-
-#include <utils/Vector.h>
-#include <utils/threads.h>
-
-#include <sys/poll.h>
-
-#include <android/looper.h>
-
-struct ALooper : public android::RefBase {
-protected:
-    virtual ~ALooper() { }
-
-public:
-    ALooper() { }
-};
-
-namespace android {
-
-/**
- * A basic file descriptor polling loop based on poll() with callbacks.
- */
-class PollLoop : public ALooper {
-protected:
-    virtual ~PollLoop();
-
-public:
-    PollLoop(bool allowNonCallbacks);
-
-    /**
-     * A callback that it to be invoked when an event occurs on a file descriptor.
-     * Specifies the events that were triggered and the user data provided when the
-     * callback was set.
-     *
-     * Returns true if the callback should be kept, false if it should be removed automatically
-     * after the callback returns.
-     */
-    typedef bool (*Callback)(int fd, int events, void* data);
-
-    enum {
-        POLL_CALLBACK = ALOOPER_POLL_CALLBACK,
-        POLL_TIMEOUT = ALOOPER_POLL_TIMEOUT,
-        POLL_ERROR = ALOOPER_POLL_ERROR,
-    };
-    
-    /**
-     * Performs a single call to poll() with optional timeout in milliseconds.
-     * Invokes callbacks for all file descriptors on which an event occurred.
-     *
-     * If the timeout is zero, returns immediately without blocking.
-     * If the timeout is negative, waits indefinitely until awoken.
-     *
-     * Returns ALOOPER_POLL_CALLBACK if a callback was invoked.
-     *
-     * Returns ALOOPER_POLL_TIMEOUT if there was no data before the given
-     * timeout expired.
-     *
-     * Returns ALOPER_POLL_ERROR if an error occurred.
-     *
-     * Returns a value >= 0 containing a file descriptor if it has data
-     * and it has no callback function (requiring the caller here to handle it).
-     * In this (and only this) case outEvents and outData will contain the poll
-     * events and data associated with the fd.
-     *
-     * This method must only be called on the thread owning the PollLoop.
-     * This method blocks until either a file descriptor is signalled, a timeout occurs,
-     * or wake() is called.
-     * This method does not return until it has finished invoking the appropriate callbacks
-     * for all file descriptors that were signalled.
-     */
-    int32_t pollOnce(int timeoutMillis, int* outEvents = NULL, void** outData = NULL);
-
-    /**
-     * Wakes the loop asynchronously.
-     *
-     * This method can be called on any thread.
-     * This method returns immediately.
-     */
-    void wake();
-
-    /**
-     * Control whether this PollLoop instance allows using IDs instead
-     * of callbacks.
-     */
-    bool getAllowNonCallbacks() const;
-    
-    /**
-     * Sets the callback for a file descriptor, replacing the existing one, if any.
-     * It is an error to call this method with events == 0 or callback == NULL.
-     *
-     * Note that a callback can be invoked with the POLLERR, POLLHUP or POLLNVAL events
-     * even if it is not explicitly requested when registered.
-     *
-     * This method can be called on any thread.
-     * This method may block briefly if it needs to wake the poll loop.
-     */
-    void setCallback(int fd, int ident, int events, Callback callback, void* data = NULL);
-
-    /**
-     * Convenience for above setCallback when ident is not used.  In this case
-     * the ident is set to POLL_CALLBACK.
-     */
-    void setCallback(int fd, int events, Callback callback, void* data = NULL);
-    
-    /**
-     * Like setCallback(), but for the NDK callback function.
-     */
-    void setLooperCallback(int fd, int ident, int events, ALooper_callbackFunc* callback,
-            void* data);
-    
-    /**
-     * Removes the callback for a file descriptor, if one exists.
-     *
-     * When this method returns, it is safe to close the file descriptor since the poll loop
-     * will no longer have a reference to it.  However, it is possible for the callback to
-     * already be running or for it to run one last time if the file descriptor was already
-     * signalled.  Calling code is responsible for ensuring that this case is safely handled.
-     * For example, if the callback takes care of removing itself during its own execution either
-     * by returning false or calling this method, then it can be guaranteed to not be invoked
-     * again at any later time unless registered anew.
-     *
-     * This method can be called on any thread.
-     * This method may block briefly if it needs to wake the poll loop.
-     *
-     * Returns true if a callback was actually removed, false if none was registered.
-     */
-    bool removeCallback(int fd);
-
-    /**
-     * Set the given PollLoop to be associated with the
-     * calling thread.  There must be a 1:1 relationship between
-     * PollLoop and thread.
-     */
-    static void setForThread(const sp<PollLoop>& pollLoop);
-    
-    /**
-     * Return the PollLoop associated with the calling thread.
-     */
-    static sp<PollLoop> getForThread();
-    
-private:
-    struct RequestedCallback {
-        Callback callback;
-        ALooper_callbackFunc* looperCallback;
-        int ident;
-        void* data;
-    };
-
-    struct PendingCallback {
-        int fd;
-        int ident;
-        int events;
-        Callback callback;
-        ALooper_callbackFunc* looperCallback;
-        void* data;
-    };
-    
-    const bool mAllowNonCallbacks; // immutable
-
-    int mWakeReadPipeFd;  // immutable
-    int mWakeWritePipeFd; // immutable
-
-    // The lock guards state used to track whether there is a poll() in progress and whether
-    // there are any other threads waiting in wakeAndLock().  The condition variables
-    // are used to transfer control among these threads such that all waiters are
-    // serviced before a new poll can begin.
-    // The wakeAndLock() method increments mWaiters, wakes the poll, blocks on mAwake
-    // until mPolling becomes false, then decrements mWaiters again.
-    // The poll() method blocks on mResume until mWaiters becomes 0, then sets
-    // mPolling to true, blocks until the poll completes, then resets mPolling to false
-    // and signals mResume if there are waiters.
-    Mutex mLock;
-    bool mPolling;      // guarded by mLock
-    uint32_t mWaiters;  // guarded by mLock
-    Condition mAwake;   // guarded by mLock
-    Condition mResume;  // guarded by mLock
-
-    // The next two vectors are only mutated when mPolling is false since they must
-    // not be changed while the poll() system call is in progress.  To mutate these
-    // vectors, the poll() must first be awoken then the lock acquired.
-    Vector<struct pollfd> mRequestedFds;
-    Vector<RequestedCallback> mRequestedCallbacks;
-
-    // This state is only used privately by pollOnce and does not require a lock since
-    // it runs on a single thread.
-    Vector<PendingCallback> mPendingCallbacks;
-    Vector<PendingCallback> mPendingFds;
-    size_t mPendingFdsPos;
-    
-    void openWakePipe();
-    void closeWakePipe();
-
-    void setCallbackCommon(int fd, int ident, int events, Callback callback,
-            ALooper_callbackFunc* looperCallback, void* data);
-    ssize_t getRequestIndexLocked(int fd);
-    void wakeAndLock();
-    static void threadDestructor(void *st);
-};
-
-} // namespace android
-
-#endif // UTILS_POLL_LOOP_H
diff --git a/libs/gui/SensorEventQueue.cpp b/libs/gui/SensorEventQueue.cpp
index 7eb6da5..c3a9f22 100644
--- a/libs/gui/SensorEventQueue.cpp
+++ b/libs/gui/SensorEventQueue.cpp
@@ -21,7 +21,7 @@
 
 #include <utils/Errors.h>
 #include <utils/RefBase.h>
-#include <utils/PollLoop.h>
+#include <utils/Looper.h>
 
 #include <gui/Sensor.h>
 #include <gui/SensorChannel.h>
@@ -81,28 +81,28 @@
     return size;
 }
 
-sp<PollLoop> SensorEventQueue::getPollLoop() const
+sp<Looper> SensorEventQueue::getLooper() const
 {
     Mutex::Autolock _l(mLock);
-    if (mPollLoop == 0) {
-        mPollLoop = new PollLoop(true);
-        mPollLoop->setCallback(getFd(), getFd(), POLLIN, NULL, NULL);
+    if (mLooper == 0) {
+        mLooper = new Looper(true);
+        mLooper->addFd(getFd(), getFd(), ALOOPER_EVENT_INPUT, NULL, NULL);
     }
-    return mPollLoop;
+    return mLooper;
 }
 
 status_t SensorEventQueue::waitForEvent() const
 {
     const int fd = getFd();
-    sp<PollLoop> pollLoop(getPollLoop());
-    int32_t result = pollLoop->pollOnce(-1, NULL, NULL);
-    return (result == fd) ? NO_ERROR : -1;
+    sp<Looper> looper(getLooper());
+    int32_t result = looper->pollOnce(-1);
+    return (result == fd) ? status_t(NO_ERROR) : status_t(-1);
 }
 
 status_t SensorEventQueue::wake() const
 {
-    sp<PollLoop> pollLoop(getPollLoop());
-    pollLoop->wake();
+    sp<Looper> looper(getLooper());
+    looper->wake();
     return NO_ERROR;
 }
 
diff --git a/libs/ui/InputDispatcher.cpp b/libs/ui/InputDispatcher.cpp
index b8a26b0..48dea57 100644
--- a/libs/ui/InputDispatcher.cpp
+++ b/libs/ui/InputDispatcher.cpp
@@ -95,7 +95,7 @@
     mFocusedApplication(NULL),
     mCurrentInputTargetsValid(false),
     mInputTargetWaitCause(INPUT_TARGET_WAIT_CAUSE_NONE) {
-    mPollLoop = new PollLoop(false);
+    mLooper = new Looper(false);
 
     mInboundQueue.headSentinel.refCount = -1;
     mInboundQueue.headSentinel.type = EventEntry::TYPE_SENTINEL;
@@ -156,7 +156,7 @@
         timeoutMillis = 0;
     }
 
-    mPollLoop->pollOnce(timeoutMillis);
+    mLooper->pollOnce(timeoutMillis);
 }
 
 void InputDispatcher::dispatchOnceInnerLocked(nsecs_t keyRepeatTimeout,
@@ -1784,7 +1784,7 @@
     }
 }
 
-bool InputDispatcher::handleReceiveCallback(int receiveFd, int events, void* data) {
+int InputDispatcher::handleReceiveCallback(int receiveFd, int events, void* data) {
     InputDispatcher* d = static_cast<InputDispatcher*>(data);
 
     { // acquire lock
@@ -1794,24 +1794,24 @@
         if (connectionIndex < 0) {
             LOGE("Received spurious receive callback for unknown input channel.  "
                     "fd=%d, events=0x%x", receiveFd, events);
-            return false; // remove the callback
+            return 0; // remove the callback
         }
 
         nsecs_t currentTime = now();
 
         sp<Connection> connection = d->mConnectionsByReceiveFd.valueAt(connectionIndex);
-        if (events & (POLLERR | POLLHUP | POLLNVAL)) {
+        if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) {
             LOGE("channel '%s' ~ Consumer closed input channel or an error occurred.  "
                     "events=0x%x", connection->getInputChannelName(), events);
             d->abortDispatchCycleLocked(currentTime, connection, true /*broken*/);
             d->runCommandsLockedInterruptible();
-            return false; // remove the callback
+            return 0; // remove the callback
         }
 
-        if (! (events & POLLIN)) {
+        if (! (events & ALOOPER_EVENT_INPUT)) {
             LOGW("channel '%s' ~ Received spurious callback for unhandled poll event.  "
                     "events=0x%x", connection->getInputChannelName(), events);
-            return true;
+            return 1;
         }
 
         status_t status = connection->inputPublisher.receiveFinishedSignal();
@@ -1820,12 +1820,12 @@
                     connection->getInputChannelName(), status);
             d->abortDispatchCycleLocked(currentTime, connection, true /*broken*/);
             d->runCommandsLockedInterruptible();
-            return false; // remove the callback
+            return 0; // remove the callback
         }
 
         d->finishDispatchCycleLocked(currentTime, connection);
         d->runCommandsLockedInterruptible();
-        return true;
+        return 1;
     } // release lock
 }
 
@@ -1843,7 +1843,7 @@
     } // release lock
 
     if (needWake) {
-        mPollLoop->wake();
+        mLooper->wake();
     }
 }
 
@@ -1870,7 +1870,7 @@
     } // release lock
 
     if (needWake) {
-        mPollLoop->wake();
+        mLooper->wake();
     }
 }
 
@@ -2007,7 +2007,7 @@
     } // release lock
 
     if (needWake) {
-        mPollLoop->wake();
+        mLooper->wake();
     }
 }
 
@@ -2043,7 +2043,7 @@
     } // release lock
 
     if (needWake) {
-        mPollLoop->wake();
+        mLooper->wake();
     }
 
     int32_t injectionResult;
@@ -2294,7 +2294,7 @@
     } // release lock
 
     // Wake up poll loop since it may need to make new input dispatching choices.
-    mPollLoop->wake();
+    mLooper->wake();
 }
 
 void InputDispatcher::setFocusedApplication(const InputApplication* inputApplication) {
@@ -2317,7 +2317,7 @@
     } // release lock
 
     // Wake up poll loop since it may need to make new input dispatching choices.
-    mPollLoop->wake();
+    mLooper->wake();
 }
 
 void InputDispatcher::releaseFocusedApplicationLocked() {
@@ -2355,7 +2355,7 @@
 
     if (changed) {
         // Wake up poll loop since it may need to make new input dispatching choices.
-        mPollLoop->wake();
+        mLooper->wake();
     }
 }
 
@@ -2372,7 +2372,7 @@
 
     if (preemptedOne) {
         // Wake up the poll loop so it can get a head start dispatching the next event.
-        mPollLoop->wake();
+        mLooper->wake();
     }
 }
 
@@ -2495,7 +2495,7 @@
             mMonitoringChannels.push(inputChannel);
         }
 
-        mPollLoop->setCallback(receiveFd, POLLIN, handleReceiveCallback, this);
+        mLooper->addFd(receiveFd, 0, ALOOPER_EVENT_INPUT, handleReceiveCallback, this);
 
         runCommandsLockedInterruptible();
     } // release lock
@@ -2529,7 +2529,7 @@
             }
         }
 
-        mPollLoop->removeCallback(inputChannel->getReceivePipeFd());
+        mLooper->removeFd(inputChannel->getReceivePipeFd());
 
         nsecs_t currentTime = now();
         abortDispatchCycleLocked(currentTime, connection, true /*broken*/);
@@ -2539,7 +2539,7 @@
 
     // Wake the poll loop because removing the connection may have changed the current
     // synchronization state.
-    mPollLoop->wake();
+    mLooper->wake();
     return OK;
 }
 
diff --git a/libs/utils/Android.mk b/libs/utils/Android.mk
index 2e20268..eb75ed8 100644
--- a/libs/utils/Android.mk
+++ b/libs/utils/Android.mk
@@ -86,7 +86,7 @@
 	$(commonSources) \
 	BackupData.cpp \
 	BackupHelpers.cpp \
-	PollLoop.cpp
+	Looper.cpp
 
 ifeq ($(TARGET_OS),linux)
 LOCAL_LDLIBS += -lrt -ldl
diff --git a/libs/utils/Looper.cpp b/libs/utils/Looper.cpp
new file mode 100644
index 0000000..fd287da
--- /dev/null
+++ b/libs/utils/Looper.cpp
@@ -0,0 +1,368 @@
+//
+// Copyright 2010 The Android Open Source Project
+//
+// A looper implementation based on epoll().
+//
+#define LOG_TAG "Looper"
+
+//#define LOG_NDEBUG 0
+
+// Debugs poll and wake interactions.
+#define DEBUG_POLL_AND_WAKE 0
+
+// Debugs callback registration and invocation.
+#define DEBUG_CALLBACKS 0
+
+#include <cutils/log.h>
+#include <utils/Looper.h>
+#include <utils/Timers.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/epoll.h>
+
+
+namespace android {
+
+static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
+static bool gHaveTLS = false;
+static pthread_key_t gTLS = 0;
+
+// Hint for number of file descriptors to be associated with the epoll instance.
+static const int EPOLL_SIZE_HINT = 8;
+
+// Maximum number of file descriptors for which to retrieve poll events each iteration.
+static const int EPOLL_MAX_EVENTS = 16;
+
+Looper::Looper(bool allowNonCallbacks) :
+        mAllowNonCallbacks(allowNonCallbacks),
+        mResponseIndex(0) {
+    mEpollFd = epoll_create(EPOLL_SIZE_HINT);
+    LOG_ALWAYS_FATAL_IF(mEpollFd < 0, "Could not create epoll instance.  errno=%d", errno);
+
+    int wakeFds[2];
+    int result = pipe(wakeFds);
+    LOG_ALWAYS_FATAL_IF(result != 0, "Could not create wake pipe.  errno=%d", errno);
+
+    mWakeReadPipeFd = wakeFds[0];
+    mWakeWritePipeFd = wakeFds[1];
+
+    result = fcntl(mWakeReadPipeFd, F_SETFL, O_NONBLOCK);
+    LOG_ALWAYS_FATAL_IF(result != 0, "Could not make wake read pipe non-blocking.  errno=%d",
+            errno);
+
+    result = fcntl(mWakeWritePipeFd, F_SETFL, O_NONBLOCK);
+    LOG_ALWAYS_FATAL_IF(result != 0, "Could not make wake write pipe non-blocking.  errno=%d",
+            errno);
+
+    struct epoll_event eventItem;
+    eventItem.events = EPOLLIN;
+    eventItem.data.fd = mWakeReadPipeFd;
+    result = epoll_ctl(mEpollFd, EPOLL_CTL_ADD, mWakeReadPipeFd, & eventItem);
+    LOG_ALWAYS_FATAL_IF(result != 0, "Could not add wake read pipe to epoll instance.  errno=%d",
+            errno);
+}
+
+Looper::~Looper() {
+    close(mWakeReadPipeFd);
+    close(mWakeWritePipeFd);
+    close(mEpollFd);
+}
+
+void Looper::threadDestructor(void *st) {
+    Looper* const self = static_cast<Looper*>(st);
+    if (self != NULL) {
+        self->decStrong((void*)threadDestructor);
+    }
+}
+
+void Looper::setForThread(const sp<Looper>& looper) {
+    sp<Looper> old = getForThread(); // also has side-effect of initializing TLS
+
+    if (looper != NULL) {
+        looper->incStrong((void*)threadDestructor);
+    }
+
+    pthread_setspecific(gTLS, looper.get());
+
+    if (old != NULL) {
+        old->decStrong((void*)threadDestructor);
+    }
+}
+
+sp<Looper> Looper::getForThread() {
+    if (!gHaveTLS) {
+        pthread_mutex_lock(&gTLSMutex);
+        if (pthread_key_create(&gTLS, threadDestructor) != 0) {
+            pthread_mutex_unlock(&gTLSMutex);
+            return NULL;
+        }
+        gHaveTLS = true;
+        pthread_mutex_unlock(&gTLSMutex);
+    }
+
+    return (Looper*)pthread_getspecific(gTLS);
+}
+
+sp<Looper> Looper::prepare(int opts) {
+    bool allowNonCallbacks = opts & ALOOPER_PREPARE_ALLOW_NON_CALLBACKS;
+    sp<Looper> looper = Looper::getForThread();
+    if (looper == NULL) {
+        looper = new Looper(allowNonCallbacks);
+        Looper::setForThread(looper);
+    }
+    if (looper->getAllowNonCallbacks() != allowNonCallbacks) {
+        LOGW("Looper already prepared for this thread with a different value for the "
+                "ALOOPER_PREPARE_ALLOW_NON_CALLBACKS option.");
+    }
+    return looper;
+}
+
+bool Looper::getAllowNonCallbacks() const {
+    return mAllowNonCallbacks;
+}
+
+int Looper::pollOnce(int timeoutMillis, int* outFd, int* outEvents, void** outData) {
+    int result = 0;
+    for (;;) {
+        while (mResponseIndex < mResponses.size()) {
+            const Response& response = mResponses.itemAt(mResponseIndex++);
+            if (! response.request.callback) {
+#if DEBUG_POLL_AND_WAKE
+                LOGD("%p ~ pollOnce - returning signalled identifier %d: "
+                        "fd=%d, events=0x%x, data=%p", this,
+                        response.request.ident, response.request.fd,
+                        response.events, response.request.data);
+#endif
+                if (outFd != NULL) *outFd = response.request.fd;
+                if (outEvents != NULL) *outEvents = response.events;
+                if (outData != NULL) *outData = response.request.data;
+                return response.request.ident;
+            }
+        }
+
+        if (result != 0) {
+#if DEBUG_POLL_AND_WAKE
+            LOGD("%p ~ pollOnce - returning result %d", this, result);
+#endif
+            if (outFd != NULL) *outFd = 0;
+            if (outEvents != NULL) *outEvents = NULL;
+            if (outData != NULL) *outData = NULL;
+            return result;
+        }
+
+        result = pollInner(timeoutMillis);
+    }
+}
+
+int Looper::pollInner(int timeoutMillis) {
+#if DEBUG_POLL_AND_WAKE
+    LOGD("%p ~ pollOnce - waiting: timeoutMillis=%d", this, timeoutMillis);
+#endif
+    struct epoll_event eventItems[EPOLL_MAX_EVENTS];
+    int eventCount = epoll_wait(mEpollFd, eventItems, EPOLL_MAX_EVENTS, timeoutMillis);
+    if (eventCount < 0) {
+        if (errno != EINTR) {
+            LOGW("Poll failed with an unexpected error, errno=%d", errno);
+        }
+        return ALOOPER_POLL_ERROR;
+    }
+
+    if (eventCount == 0) {
+#if DEBUG_POLL_AND_WAKE
+        LOGD("%p ~ pollOnce - timeout", this);
+#endif
+        return ALOOPER_POLL_TIMEOUT;
+    }
+
+    int result = ALOOPER_POLL_WAKE;
+    mResponses.clear();
+    mResponseIndex = 0;
+
+#if DEBUG_POLL_AND_WAKE
+    LOGD("%p ~ pollOnce - handling events from %d fds", this, eventCount);
+#endif
+    { // acquire lock
+        AutoMutex _l(mLock);
+        for (int i = 0; i < eventCount; i++) {
+            int fd = eventItems[i].data.fd;
+            uint32_t epollEvents = eventItems[i].events;
+            if (fd == mWakeReadPipeFd) {
+                if (epollEvents & EPOLLIN) {
+#if DEBUG_POLL_AND_WAKE
+                    LOGD("%p ~ pollOnce - awoken", this);
+#endif
+                    char buffer[16];
+                    ssize_t nRead;
+                    do {
+                        nRead = read(mWakeReadPipeFd, buffer, sizeof(buffer));
+                    } while (nRead == sizeof(buffer));
+                } else {
+                    LOGW("Ignoring unexpected epoll events 0x%x on wake read pipe.", epollEvents);
+                }
+            } else {
+                ssize_t requestIndex = mRequests.indexOfKey(fd);
+                if (requestIndex >= 0) {
+                    int events = 0;
+                    if (epollEvents & EPOLLIN) events |= ALOOPER_EVENT_INPUT;
+                    if (epollEvents & EPOLLOUT) events |= ALOOPER_EVENT_OUTPUT;
+                    if (epollEvents & EPOLLERR) events |= ALOOPER_EVENT_ERROR;
+                    if (epollEvents & EPOLLHUP) events |= ALOOPER_EVENT_HANGUP;
+
+                    Response response;
+                    response.events = events;
+                    response.request = mRequests.valueAt(requestIndex);
+                    mResponses.push(response);
+                } else {
+                    LOGW("Ignoring unexpected epoll events 0x%x on fd %d that is "
+                            "no longer registered.", epollEvents, fd);
+                }
+            }
+        }
+    }
+
+    for (size_t i = 0; i < mResponses.size(); i++) {
+        const Response& response = mResponses.itemAt(i);
+        if (response.request.callback) {
+#if DEBUG_POLL_AND_WAKE || DEBUG_CALLBACKS
+            LOGD("%p ~ pollOnce - invoking callback: fd=%d, events=0x%x, data=%p", this,
+                    response.request.fd, response.events, response.request.data);
+#endif
+            int callbackResult = response.request.callback(
+                    response.request.fd, response.events, response.request.data);
+            if (callbackResult == 0) {
+                removeFd(response.request.fd);
+            }
+
+            result = ALOOPER_POLL_CALLBACK;
+        }
+    }
+    return result;
+}
+
+int Looper::pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outData) {
+    if (timeoutMillis <= 0) {
+        int result;
+        do {
+            result = pollOnce(timeoutMillis, outFd, outEvents, outData);
+        } while (result == ALOOPER_POLL_CALLBACK);
+        return result;
+    } else {
+        nsecs_t endTime = systemTime(SYSTEM_TIME_MONOTONIC)
+                + milliseconds_to_nanoseconds(timeoutMillis);
+
+        for (;;) {
+            int result = pollOnce(timeoutMillis, outFd, outEvents, outData);
+            if (result != ALOOPER_POLL_CALLBACK) {
+                return result;
+            }
+
+            nsecs_t timeoutNanos = endTime - systemTime(SYSTEM_TIME_MONOTONIC);
+            if (timeoutNanos <= 0) {
+                return ALOOPER_POLL_TIMEOUT;
+            }
+
+            timeoutMillis = int(nanoseconds_to_milliseconds(timeoutNanos + 999999LL));
+        }
+    }
+}
+
+void Looper::wake() {
+#if DEBUG_POLL_AND_WAKE
+    LOGD("%p ~ wake", this);
+#endif
+
+    ssize_t nWrite = write(mWakeWritePipeFd, "W", 1);
+    if (nWrite != 1) {
+        if (errno != EAGAIN) {
+            LOGW("Could not write wake signal, errno=%d", errno);
+        }
+    }
+}
+
+int Looper::addFd(int fd, int ident, int events, ALooper_callbackFunc callback, void* data) {
+#if DEBUG_CALLBACKS
+    LOGD("%p ~ addFd - fd=%d, ident=%d, events=0x%x, callback=%p, data=%p", this, fd, ident,
+            events, callback, data);
+#endif
+
+    int epollEvents = 0;
+    if (events & ALOOPER_EVENT_INPUT) epollEvents |= EPOLLIN;
+    if (events & ALOOPER_EVENT_OUTPUT) epollEvents |= EPOLLOUT;
+    if (events & ALOOPER_EVENT_ERROR) epollEvents |= EPOLLERR;
+    if (events & ALOOPER_EVENT_HANGUP) epollEvents |= EPOLLHUP;
+
+    if (epollEvents == 0) {
+        LOGE("Invalid attempt to set a callback with no selected poll events.");
+        return -1;
+    }
+
+    if (! callback) {
+        if (! mAllowNonCallbacks) {
+            LOGE("Invalid attempt to set NULL callback but not allowed for this looper.");
+            return -1;
+        }
+
+        if (ident < 0) {
+            LOGE("Invalid attempt to set NULL callback with ident <= 0.");
+            return -1;
+        }
+    }
+
+    { // acquire lock
+        AutoMutex _l(mLock);
+
+        Request request;
+        request.fd = fd;
+        request.ident = ident;
+        request.callback = callback;
+        request.data = data;
+
+        struct epoll_event eventItem;
+        eventItem.events = epollEvents;
+        eventItem.data.fd = fd;
+
+        ssize_t requestIndex = mRequests.indexOfKey(fd);
+        if (requestIndex < 0) {
+            int epollResult = epoll_ctl(mEpollFd, EPOLL_CTL_ADD, fd, & eventItem);
+            if (epollResult < 0) {
+                LOGE("Error adding epoll events for fd %d, errno=%d", fd, errno);
+                return -1;
+            }
+            mRequests.add(fd, request);
+        } else {
+            int epollResult = epoll_ctl(mEpollFd, EPOLL_CTL_MOD, fd, & eventItem);
+            if (epollResult < 0) {
+                LOGE("Error modifying epoll events for fd %d, errno=%d", fd, errno);
+                return -1;
+            }
+            mRequests.replaceValueAt(requestIndex, request);
+        }
+    } // release lock
+    return 1;
+}
+
+int Looper::removeFd(int fd) {
+#if DEBUG_CALLBACKS
+    LOGD("%p ~ removeFd - fd=%d", this, fd);
+#endif
+
+    { // acquire lock
+        AutoMutex _l(mLock);
+        ssize_t requestIndex = mRequests.indexOfKey(fd);
+        if (requestIndex < 0) {
+            return 0;
+        }
+
+        int epollResult = epoll_ctl(mEpollFd, EPOLL_CTL_DEL, fd, NULL);
+        if (epollResult < 0) {
+            LOGE("Error removing epoll events for fd %d, errno=%d", fd, errno);
+            return -1;
+        }
+
+        mRequests.removeItemsAt(requestIndex);
+    } // request lock
+    return 1;
+}
+
+} // namespace android
diff --git a/libs/utils/PollLoop.cpp b/libs/utils/PollLoop.cpp
deleted file mode 100644
index fe76cd0..0000000
--- a/libs/utils/PollLoop.cpp
+++ /dev/null
@@ -1,377 +0,0 @@
-//
-// Copyright 2010 The Android Open Source Project
-//
-// A select loop implementation.
-//
-#define LOG_TAG "PollLoop"
-
-//#define LOG_NDEBUG 0
-
-// Debugs poll and wake interactions.
-#define DEBUG_POLL_AND_WAKE 0
-
-// Debugs callback registration and invocation.
-#define DEBUG_CALLBACKS 0
-
-#include <cutils/log.h>
-#include <utils/PollLoop.h>
-
-#include <unistd.h>
-#include <fcntl.h>
-
-namespace android {
-
-static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
-static bool gHaveTLS = false;
-static pthread_key_t gTLS = 0;
-
-PollLoop::PollLoop(bool allowNonCallbacks) :
-        mAllowNonCallbacks(allowNonCallbacks), mPolling(false),
-        mWaiters(0), mPendingFdsPos(0) {
-    openWakePipe();
-}
-
-PollLoop::~PollLoop() {
-    closeWakePipe();
-}
-
-void PollLoop::threadDestructor(void *st) {
-    PollLoop* const self = static_cast<PollLoop*>(st);
-    if (self != NULL) {
-        self->decStrong((void*)threadDestructor);
-    }
-}
-
-void PollLoop::setForThread(const sp<PollLoop>& pollLoop) {
-    sp<PollLoop> old = getForThread();
-    
-    if (pollLoop != NULL) {
-        pollLoop->incStrong((void*)threadDestructor);
-    }
-    
-    pthread_setspecific(gTLS, pollLoop.get());
-    
-    if (old != NULL) {
-        old->decStrong((void*)threadDestructor);
-    }
-}
-    
-sp<PollLoop> PollLoop::getForThread() {
-    if (!gHaveTLS) {
-        pthread_mutex_lock(&gTLSMutex);
-        if (pthread_key_create(&gTLS, threadDestructor) != 0) {
-            pthread_mutex_unlock(&gTLSMutex);
-            return NULL;
-        }
-        gHaveTLS = true;
-        pthread_mutex_unlock(&gTLSMutex);
-    }
-    
-    return (PollLoop*)pthread_getspecific(gTLS);
-}
-
-void PollLoop::openWakePipe() {
-    int wakeFds[2];
-    int result = pipe(wakeFds);
-    LOG_ALWAYS_FATAL_IF(result != 0, "Could not create wake pipe.  errno=%d", errno);
-
-    mWakeReadPipeFd = wakeFds[0];
-    mWakeWritePipeFd = wakeFds[1];
-
-    result = fcntl(mWakeReadPipeFd, F_SETFL, O_NONBLOCK);
-    LOG_ALWAYS_FATAL_IF(result != 0, "Could not make wake read pipe non-blocking.  errno=%d",
-            errno);
-
-    result = fcntl(mWakeWritePipeFd, F_SETFL, O_NONBLOCK);
-    LOG_ALWAYS_FATAL_IF(result != 0, "Could not make wake write pipe non-blocking.  errno=%d",
-            errno);
-
-    // Add the wake pipe to the head of the request list with a null callback.
-    struct pollfd requestedFd;
-    requestedFd.fd = mWakeReadPipeFd;
-    requestedFd.events = POLLIN;
-    mRequestedFds.insertAt(requestedFd, 0);
-
-    RequestedCallback requestedCallback;
-    requestedCallback.callback = NULL;
-    requestedCallback.looperCallback = NULL;
-    requestedCallback.ident = 0;
-    requestedCallback.data = NULL;
-    mRequestedCallbacks.insertAt(requestedCallback, 0);
-}
-
-void PollLoop::closeWakePipe() {
-    close(mWakeReadPipeFd);
-    close(mWakeWritePipeFd);
-
-    // Note: We don't need to remove the poll structure or callback entry because this
-    //       method is currently only called by the destructor.
-}
-
-int32_t PollLoop::pollOnce(int timeoutMillis, int* outEvents, void** outData) {
-    // If there are still pending fds from the last call, dispatch those
-    // first, to avoid an earlier fd from starving later ones.
-    const size_t pendingFdsCount = mPendingFds.size();
-    if (mPendingFdsPos < pendingFdsCount) {
-        const PendingCallback& pending = mPendingFds.itemAt(mPendingFdsPos);
-        mPendingFdsPos++;
-        if (outEvents != NULL) *outEvents = pending.events;
-        if (outData != NULL) *outData = pending.data;
-        return pending.ident;
-    }
-
-    // Wait for wakeAndLock() waiters to run then set mPolling to true.
-    mLock.lock();
-    while (mWaiters != 0) {
-        mResume.wait(mLock);
-    }
-    mPolling = true;
-    mLock.unlock();
-
-    // Poll.
-    int32_t result;
-    size_t requestedCount = mRequestedFds.size();
-
-#if DEBUG_POLL_AND_WAKE
-    LOGD("%p ~ pollOnce - waiting on %d fds", this, requestedCount);
-    for (size_t i = 0; i < requestedCount; i++) {
-        LOGD("  fd %d - events %d", mRequestedFds[i].fd, mRequestedFds[i].events);
-    }
-#endif
-
-    int respondedCount = poll(mRequestedFds.editArray(), requestedCount, timeoutMillis);
-
-    if (respondedCount == 0) {
-        // Timeout
-#if DEBUG_POLL_AND_WAKE
-        LOGD("%p ~ pollOnce - timeout", this);
-#endif
-        result = POLL_TIMEOUT;
-        goto Done;
-    }
-
-    if (respondedCount < 0) {
-        // Error
-#if DEBUG_POLL_AND_WAKE
-        LOGD("%p ~ pollOnce - error, errno=%d", this, errno);
-#endif
-        if (errno != EINTR) {
-            LOGW("Poll failed with an unexpected error, errno=%d", errno);
-        }
-        result = POLL_ERROR;
-        goto Done;
-    }
-
-#if DEBUG_POLL_AND_WAKE
-    LOGD("%p ~ pollOnce - handling responses from %d fds", this, respondedCount);
-    for (size_t i = 0; i < requestedCount; i++) {
-        LOGD("  fd %d - events %d, revents %d", mRequestedFds[i].fd, mRequestedFds[i].events,
-                mRequestedFds[i].revents);
-    }
-#endif
-
-    // Process the poll results.
-    mPendingCallbacks.clear();
-    mPendingFds.clear();
-    mPendingFdsPos = 0;
-    if (outEvents != NULL) *outEvents = 0;
-    if (outData != NULL) *outData = NULL;
-    
-    result = POLL_CALLBACK;
-    for (size_t i = 0; i < requestedCount; i++) {
-        const struct pollfd& requestedFd = mRequestedFds.itemAt(i);
-
-        short revents = requestedFd.revents;
-        if (revents) {
-            const RequestedCallback& requestedCallback = mRequestedCallbacks.itemAt(i);
-            PendingCallback pending;
-            pending.fd = requestedFd.fd;
-            pending.ident = requestedCallback.ident;
-            pending.events = revents;
-            pending.callback = requestedCallback.callback;
-            pending.looperCallback = requestedCallback.looperCallback;
-            pending.data = requestedCallback.data;
-
-            if (pending.callback || pending.looperCallback) {
-                mPendingCallbacks.push(pending);
-            } else if (pending.fd != mWakeReadPipeFd) {
-                if (result == POLL_CALLBACK) {
-                    result = pending.ident;
-                    if (outEvents != NULL) *outEvents = pending.events;
-                    if (outData != NULL) *outData = pending.data;
-                } else {
-                    mPendingFds.push(pending);
-                }
-            } else {
-#if DEBUG_POLL_AND_WAKE
-                LOGD("%p ~ pollOnce - awoken", this);
-#endif
-                char buffer[16];
-                ssize_t nRead;
-                do {
-                    nRead = read(mWakeReadPipeFd, buffer, sizeof(buffer));
-                } while (nRead == sizeof(buffer));
-            }
-
-            respondedCount -= 1;
-            if (respondedCount == 0) {
-                break;
-            }
-        }
-    }
-
-Done:
-    // Set mPolling to false and wake up the wakeAndLock() waiters.
-    mLock.lock();
-    mPolling = false;
-    if (mWaiters != 0) {
-        mAwake.broadcast();
-    }
-    mLock.unlock();
-
-    if (result == POLL_CALLBACK || result >= 0) {
-        size_t pendingCount = mPendingCallbacks.size();
-        for (size_t i = 0; i < pendingCount; i++) {
-            const PendingCallback& pendingCallback = mPendingCallbacks.itemAt(i);
-#if DEBUG_POLL_AND_WAKE || DEBUG_CALLBACKS
-            LOGD("%p ~ pollOnce - invoking callback for fd %d", this, pendingCallback.fd);
-#endif
-
-            bool keep = true;
-            if (pendingCallback.callback != NULL) {
-                keep = pendingCallback.callback(pendingCallback.fd, pendingCallback.events,
-                        pendingCallback.data);
-            } else {
-                keep = pendingCallback.looperCallback(pendingCallback.fd, pendingCallback.events,
-                        pendingCallback.data) != 0;
-            }
-            if (! keep) {
-                removeCallback(pendingCallback.fd);
-            }
-        }
-    }
-
-#if DEBUG_POLL_AND_WAKE
-    LOGD("%p ~ pollOnce - done", this);
-#endif
-    return result;
-}
-
-void PollLoop::wake() {
-#if DEBUG_POLL_AND_WAKE
-    LOGD("%p ~ wake", this);
-#endif
-
-    ssize_t nWrite = write(mWakeWritePipeFd, "W", 1);
-    if (nWrite != 1) {
-        if (errno != EAGAIN) {
-            LOGW("Could not write wake signal, errno=%d", errno);
-        }
-    }
-}
-
-bool PollLoop::getAllowNonCallbacks() const {
-    return mAllowNonCallbacks;
-}
-
-void PollLoop::setCallback(int fd, int ident, int events, Callback callback, void* data) {
-    setCallbackCommon(fd, ident, events, callback, NULL, data);
-}
-
-void PollLoop::setCallback(int fd, int events, Callback callback, void* data) {
-    setCallbackCommon(fd, POLL_CALLBACK, events, callback, NULL, data);
-}
-
-void PollLoop::setLooperCallback(int fd, int ident, int events, ALooper_callbackFunc* callback,
-        void* data) {
-    setCallbackCommon(fd, ident, events, NULL, callback, data);
-}
-
-void PollLoop::setCallbackCommon(int fd, int ident, int events, Callback callback,
-        ALooper_callbackFunc* looperCallback, void* data) {
-
-#if DEBUG_CALLBACKS
-    LOGD("%p ~ setCallback - fd=%d, events=%d", this, fd, events);
-#endif
-
-    if (! events) {
-        LOGE("Invalid attempt to set a callback with no selected poll events.");
-        removeCallback(fd);
-        return;
-    }
-
-    if (! callback && ! looperCallback && ! mAllowNonCallbacks) {
-        LOGE("Invalid attempt to set NULL callback but not allowed.");
-        removeCallback(fd);
-        return;
-    }
-    
-    wakeAndLock();
-
-    struct pollfd requestedFd;
-    requestedFd.fd = fd;
-    requestedFd.events = events;
-
-    RequestedCallback requestedCallback;
-    requestedCallback.callback = callback;
-    requestedCallback.looperCallback = looperCallback;
-    requestedCallback.ident = ident;
-    requestedCallback.data = data;
-
-    ssize_t index = getRequestIndexLocked(fd);
-    if (index < 0) {
-        mRequestedFds.push(requestedFd);
-        mRequestedCallbacks.push(requestedCallback);
-    } else {
-        mRequestedFds.replaceAt(requestedFd, size_t(index));
-        mRequestedCallbacks.replaceAt(requestedCallback, size_t(index));
-    }
-
-    mLock.unlock();
-}
-
-bool PollLoop::removeCallback(int fd) {
-#if DEBUG_CALLBACKS
-    LOGD("%p ~ removeCallback - fd=%d", this, fd);
-#endif
-
-    wakeAndLock();
-
-    ssize_t index = getRequestIndexLocked(fd);
-    if (index >= 0) {
-        mRequestedFds.removeAt(size_t(index));
-        mRequestedCallbacks.removeAt(size_t(index));
-    }
-
-    mLock.unlock();
-    return index >= 0;
-}
-
-ssize_t PollLoop::getRequestIndexLocked(int fd) {
-    size_t requestCount = mRequestedFds.size();
-
-    for (size_t i = 0; i < requestCount; i++) {
-        if (mRequestedFds.itemAt(i).fd == fd) {
-            return i;
-        }
-    }
-
-    return -1;
-}
-
-void PollLoop::wakeAndLock() {
-    mLock.lock();
-
-    mWaiters += 1;
-    while (mPolling) {
-        wake();
-        mAwake.wait(mLock);
-    }
-
-    mWaiters -= 1;
-    if (mWaiters == 0) {
-        mResume.signal();
-    }
-}
-
-} // namespace android
diff --git a/libs/utils/tests/Android.mk b/libs/utils/tests/Android.mk
index 725de9c..00077ee 100644
--- a/libs/utils/tests/Android.mk
+++ b/libs/utils/tests/Android.mk
@@ -7,7 +7,7 @@
 # Build the unit tests.
 test_src_files := \
 	ObbFile_test.cpp \
-	PollLoop_test.cpp \
+	Looper_test.cpp \
 	String8_test.cpp
 
 shared_libraries := \
diff --git a/libs/utils/tests/Looper_test.cpp b/libs/utils/tests/Looper_test.cpp
new file mode 100644
index 0000000..afc92f8
--- /dev/null
+++ b/libs/utils/tests/Looper_test.cpp
@@ -0,0 +1,433 @@
+//
+// Copyright 2010 The Android Open Source Project
+//
+
+#include <utils/Looper.h>
+#include <utils/Timers.h>
+#include <utils/StopWatch.h>
+#include <gtest/gtest.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "TestHelpers.h"
+
+// # of milliseconds to fudge stopwatch measurements
+#define TIMING_TOLERANCE_MS 25
+
+namespace android {
+
+class DelayedWake : public DelayedTask {
+    sp<Looper> mLooper;
+
+public:
+    DelayedWake(int delayMillis, const sp<Looper> looper) :
+        DelayedTask(delayMillis), mLooper(looper) {
+    }
+
+protected:
+    virtual void doTask() {
+        mLooper->wake();
+    }
+};
+
+class DelayedWriteSignal : public DelayedTask {
+    Pipe* mPipe;
+
+public:
+    DelayedWriteSignal(int delayMillis, Pipe* pipe) :
+        DelayedTask(delayMillis), mPipe(pipe) {
+    }
+
+protected:
+    virtual void doTask() {
+        mPipe->writeSignal();
+    }
+};
+
+class CallbackHandler {
+public:
+    void setCallback(const sp<Looper>& looper, int fd, int events) {
+        looper->addFd(fd, 0, events, staticHandler, this);
+    }
+
+protected:
+    virtual ~CallbackHandler() { }
+
+    virtual int handler(int fd, int events) = 0;
+
+private:
+    static int staticHandler(int fd, int events, void* data) {
+        return static_cast<CallbackHandler*>(data)->handler(fd, events);
+    }
+};
+
+class StubCallbackHandler : public CallbackHandler {
+public:
+    int nextResult;
+    int callbackCount;
+
+    int fd;
+    int events;
+
+    StubCallbackHandler(int nextResult) : nextResult(nextResult),
+            callbackCount(0), fd(-1), events(-1) {
+    }
+
+protected:
+    virtual int handler(int fd, int events) {
+        callbackCount += 1;
+        this->fd = fd;
+        this->events = events;
+        return nextResult;
+    }
+};
+
+class LooperTest : public testing::Test {
+protected:
+    sp<Looper> mLooper;
+
+    virtual void SetUp() {
+        mLooper = new Looper(true);
+    }
+
+    virtual void TearDown() {
+        mLooper.clear();
+    }
+};
+
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndNotAwoken_WaitsForTimeout) {
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(100);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal timeout";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndAwokenBeforeWaiting_ImmediatelyReturns) {
+    mLooper->wake();
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(1000);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. zero because wake() was called before waiting";
+    EXPECT_EQ(ALOOPER_POLL_WAKE, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because loop was awoken";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndAwokenWhileWaiting_PromptlyReturns) {
+    sp<DelayedWake> delayedWake = new DelayedWake(100, mLooper);
+    delayedWake->run();
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(1000);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal wake delay";
+    EXPECT_EQ(ALOOPER_POLL_WAKE, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because loop was awoken";
+}
+
+TEST_F(LooperTest, PollOnce_WhenZeroTimeoutAndNoRegisteredFDs_ImmediatelyReturns) {
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(0);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should be approx. zero";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+}
+
+TEST_F(LooperTest, PollOnce_WhenZeroTimeoutAndNoSignalledFDs_ImmediatelyReturns) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(0);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should be approx. zero";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+    EXPECT_EQ(0, handler.callbackCount)
+            << "callback should not have been invoked because FD was not signalled";
+}
+
+TEST_F(LooperTest, PollOnce_WhenZeroTimeoutAndSignalledFD_ImmediatelyInvokesCallbackAndReturns) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+
+    ASSERT_EQ(OK, pipe.writeSignal());
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(0);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should be approx. zero";
+    EXPECT_EQ(ALOOPER_POLL_CALLBACK, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because FD was signalled";
+    EXPECT_EQ(1, handler.callbackCount)
+            << "callback should be invoked exactly once";
+    EXPECT_EQ(pipe.receiveFd, handler.fd)
+            << "callback should have received pipe fd as parameter";
+    EXPECT_EQ(ALOOPER_EVENT_INPUT, handler.events)
+            << "callback should have received ALOOPER_EVENT_INPUT as events";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndNoSignalledFDs_WaitsForTimeoutAndReturns) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(100);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal timeout";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+    EXPECT_EQ(0, handler.callbackCount)
+            << "callback should not have been invoked because FD was not signalled";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndSignalledFDBeforeWaiting_ImmediatelyInvokesCallbackAndReturns) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+
+    pipe.writeSignal();
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(100);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should be approx. zero";
+    EXPECT_EQ(ALOOPER_POLL_CALLBACK, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because FD was signalled";
+    EXPECT_EQ(1, handler.callbackCount)
+            << "callback should be invoked exactly once";
+    EXPECT_EQ(pipe.receiveFd, handler.fd)
+            << "callback should have received pipe fd as parameter";
+    EXPECT_EQ(ALOOPER_EVENT_INPUT, handler.events)
+            << "callback should have received ALOOPER_EVENT_INPUT as events";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonZeroTimeoutAndSignalledFDWhileWaiting_PromptlyInvokesCallbackAndReturns) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+    sp<DelayedWriteSignal> delayedWriteSignal = new DelayedWriteSignal(100, & pipe);
+
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+    delayedWriteSignal->run();
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(1000);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal signal delay";
+    EXPECT_EQ(ALOOPER_POLL_CALLBACK, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because FD was signalled";
+    EXPECT_EQ(1, handler.callbackCount)
+            << "callback should be invoked exactly once";
+    EXPECT_EQ(pipe.receiveFd, handler.fd)
+            << "callback should have received pipe fd as parameter";
+    EXPECT_EQ(ALOOPER_EVENT_INPUT, handler.events)
+            << "callback should have received ALOOPER_EVENT_INPUT as events";
+}
+
+TEST_F(LooperTest, PollOnce_WhenCallbackAddedThenRemoved_CallbackShouldNotBeInvoked) {
+    Pipe pipe;
+    StubCallbackHandler handler(true);
+
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+    pipe.writeSignal(); // would cause FD to be considered signalled
+    mLooper->removeFd(pipe.receiveFd);
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(100);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal timeout because FD was no longer registered";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+    EXPECT_EQ(0, handler.callbackCount)
+            << "callback should not be invoked";
+}
+
+TEST_F(LooperTest, PollOnce_WhenCallbackReturnsFalse_CallbackShouldNotBeInvokedAgainLater) {
+    Pipe pipe;
+    StubCallbackHandler handler(false);
+
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    // First loop: Callback is registered and FD is signalled.
+    pipe.writeSignal();
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(0);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal zero because FD was already signalled";
+    EXPECT_EQ(ALOOPER_POLL_CALLBACK, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because FD was signalled";
+    EXPECT_EQ(1, handler.callbackCount)
+            << "callback should be invoked";
+
+    // Second loop: Callback is no longer registered and FD is signalled.
+    pipe.writeSignal();
+
+    stopWatch.reset();
+    result = mLooper->pollOnce(0);
+    elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. equal zero because timeout was zero";
+    EXPECT_EQ(ALOOPER_POLL_TIMEOUT, result)
+            << "pollOnce result should be ALOOPER_POLL_TIMEOUT";
+    EXPECT_EQ(1, handler.callbackCount)
+            << "callback should not be invoked this time";
+}
+
+TEST_F(LooperTest, PollOnce_WhenNonCallbackFdIsSignalled_ReturnsIdent) {
+    const int expectedIdent = 5;
+    void* expectedData = this;
+
+    Pipe pipe;
+
+    pipe.writeSignal();
+    mLooper->addFd(pipe.receiveFd, expectedIdent, ALOOPER_EVENT_INPUT, NULL, expectedData);
+
+    StopWatch stopWatch("pollOnce");
+    int fd;
+    int events;
+    void* data;
+    int result = mLooper->pollOnce(100, &fd, &events, &data);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should be approx. zero";
+    EXPECT_EQ(expectedIdent, result)
+            << "pollOnce result should be the ident of the FD that was signalled";
+    EXPECT_EQ(pipe.receiveFd, fd)
+            << "pollOnce should have returned the received pipe fd";
+    EXPECT_EQ(ALOOPER_EVENT_INPUT, events)
+            << "pollOnce should have returned ALOOPER_EVENT_INPUT as events";
+    EXPECT_EQ(expectedData, data)
+            << "pollOnce should have returned the data";
+}
+
+TEST_F(LooperTest, AddFd_WhenCallbackAdded_ReturnsOne) {
+    Pipe pipe;
+    int result = mLooper->addFd(pipe.receiveFd, 0, ALOOPER_EVENT_INPUT, NULL, NULL);
+
+    EXPECT_EQ(1, result)
+            << "addFd should return 1 because FD was added";
+}
+
+TEST_F(LooperTest, AddFd_WhenEventsIsZero_ReturnsError) {
+    Pipe pipe;
+    int result = mLooper->addFd(pipe.receiveFd, 0, 0, NULL, NULL);
+
+    EXPECT_EQ(-1, result)
+            << "addFd should return -1 because arguments were invalid";
+}
+
+TEST_F(LooperTest, AddFd_WhenIdentIsNegativeAndCallbackIsNull_ReturnsError) {
+    Pipe pipe;
+    int result = mLooper->addFd(pipe.receiveFd, -1, ALOOPER_EVENT_INPUT, NULL, NULL);
+
+    EXPECT_EQ(-1, result)
+            << "addFd should return -1 because arguments were invalid";
+}
+
+TEST_F(LooperTest, AddFd_WhenNoCallbackAndAllowNonCallbacksIsFalse_ReturnsError) {
+    Pipe pipe;
+    sp<Looper> looper = new Looper(false /*allowNonCallbacks*/);
+    int result = looper->addFd(pipe.receiveFd, 0, 0, NULL, NULL);
+
+    EXPECT_EQ(-1, result)
+            << "addFd should return -1 because arguments were invalid";
+}
+
+TEST_F(LooperTest, RemoveFd_WhenCallbackNotAdded_ReturnsZero) {
+    int result = mLooper->removeFd(1);
+
+    EXPECT_EQ(0, result)
+            << "removeFd should return 0 because FD not registered";
+}
+
+TEST_F(LooperTest, RemoveFd_WhenCallbackAddedThenRemovedTwice_ReturnsOnceFirstTimeAndReturnsZeroSecondTime) {
+    Pipe pipe;
+    StubCallbackHandler handler(false);
+    handler.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+
+    // First time.
+    int result = mLooper->removeFd(pipe.receiveFd);
+
+    EXPECT_EQ(1, result)
+            << "removeFd should return 1 first time because FD was registered";
+
+    // Second time.
+    result = mLooper->removeFd(pipe.receiveFd);
+
+    EXPECT_EQ(0, result)
+            << "removeFd should return 0 second time because FD was no longer registered";
+}
+
+TEST_F(LooperTest, PollOnce_WhenCallbackAddedTwice_OnlySecondCallbackShouldBeInvoked) {
+    Pipe pipe;
+    StubCallbackHandler handler1(true);
+    StubCallbackHandler handler2(true);
+
+    handler1.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT);
+    handler2.setCallback(mLooper, pipe.receiveFd, ALOOPER_EVENT_INPUT); // replace it
+    pipe.writeSignal(); // would cause FD to be considered signalled
+
+    StopWatch stopWatch("pollOnce");
+    int result = mLooper->pollOnce(100);
+    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
+
+    ASSERT_EQ(OK, pipe.readSignal())
+            << "signal should actually have been written";
+    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
+            << "elapsed time should approx. zero because FD was already signalled";
+    EXPECT_EQ(ALOOPER_POLL_CALLBACK, result)
+            << "pollOnce result should be ALOOPER_POLL_CALLBACK because FD was signalled";
+    EXPECT_EQ(0, handler1.callbackCount)
+            << "original handler callback should not be invoked because it was replaced";
+    EXPECT_EQ(1, handler2.callbackCount)
+            << "replacement handler callback should be invoked";
+}
+
+
+} // namespace android
diff --git a/libs/utils/tests/PollLoop_test.cpp b/libs/utils/tests/PollLoop_test.cpp
deleted file mode 100644
index 02f1808..0000000
--- a/libs/utils/tests/PollLoop_test.cpp
+++ /dev/null
@@ -1,370 +0,0 @@
-//
-// Copyright 2010 The Android Open Source Project
-//
-
-#include <utils/PollLoop.h>
-#include <utils/Timers.h>
-#include <utils/StopWatch.h>
-#include <gtest/gtest.h>
-#include <unistd.h>
-#include <time.h>
-
-#include "TestHelpers.h"
-
-// # of milliseconds to fudge stopwatch measurements
-#define TIMING_TOLERANCE_MS 25
-
-namespace android {
-
-class DelayedWake : public DelayedTask {
-    sp<PollLoop> mPollLoop;
-
-public:
-    DelayedWake(int delayMillis, const sp<PollLoop> pollLoop) :
-        DelayedTask(delayMillis), mPollLoop(pollLoop) {
-    }
-
-protected:
-    virtual void doTask() {
-        mPollLoop->wake();
-    }
-};
-
-class DelayedWriteSignal : public DelayedTask {
-    Pipe* mPipe;
-
-public:
-    DelayedWriteSignal(int delayMillis, Pipe* pipe) :
-        DelayedTask(delayMillis), mPipe(pipe) {
-    }
-
-protected:
-    virtual void doTask() {
-        mPipe->writeSignal();
-    }
-};
-
-class CallbackHandler {
-public:
-    void setCallback(const sp<PollLoop>& pollLoop, int fd, int events) {
-        pollLoop->setCallback(fd, events, staticHandler, this);
-    }
-
-protected:
-    virtual ~CallbackHandler() { }
-
-    virtual bool handler(int fd, int events) = 0;
-
-private:
-    static bool staticHandler(int fd, int events, void* data) {
-        return static_cast<CallbackHandler*>(data)->handler(fd, events);
-    }
-};
-
-class StubCallbackHandler : public CallbackHandler {
-public:
-    bool nextResult;
-    int callbackCount;
-
-    int fd;
-    int events;
-
-    StubCallbackHandler(bool nextResult) : nextResult(nextResult),
-            callbackCount(0), fd(-1), events(-1) {
-    }
-
-protected:
-    virtual bool handler(int fd, int events) {
-        callbackCount += 1;
-        this->fd = fd;
-        this->events = events;
-        return nextResult;
-    }
-};
-
-class PollLoopTest : public testing::Test {
-protected:
-    sp<PollLoop> mPollLoop;
-
-    virtual void SetUp() {
-        mPollLoop = new PollLoop(false);
-    }
-
-    virtual void TearDown() {
-        mPollLoop.clear();
-    }
-};
-
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndNotAwoken_WaitsForTimeoutAndReturnsFalse) {
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(100);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal timeout";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndAwokenBeforeWaiting_ImmediatelyReturnsTrue) {
-    mPollLoop->wake();
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(1000);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. zero because wake() was called before waiting";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because loop was awoken";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndAwokenWhileWaiting_PromptlyReturnsTrue) {
-    sp<DelayedWake> delayedWake = new DelayedWake(100, mPollLoop);
-    delayedWake->run();
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(1000);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal wake delay";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because loop was awoken";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenZeroTimeoutAndNoRegisteredFDs_ImmediatelyReturnsFalse) {
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(0);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should be approx. zero";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenZeroTimeoutAndNoSignalledFDs_ImmediatelyReturnsFalse) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(0);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should be approx. zero";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-    EXPECT_EQ(0, handler.callbackCount)
-            << "callback should not have been invoked because FD was not signalled";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenZeroTimeoutAndSignalledFD_ImmediatelyInvokesCallbackAndReturnsTrue) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-
-    ASSERT_EQ(OK, pipe.writeSignal());
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(0);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should be approx. zero";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because FD was signalled";
-    EXPECT_EQ(1, handler.callbackCount)
-            << "callback should be invoked exactly once";
-    EXPECT_EQ(pipe.receiveFd, handler.fd)
-            << "callback should have received pipe fd as parameter";
-    EXPECT_EQ(POLL_IN, handler.events)
-            << "callback should have received POLL_IN as events";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndNoSignalledFDs_WaitsForTimeoutAndReturnsFalse) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(100);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal timeout";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-    EXPECT_EQ(0, handler.callbackCount)
-            << "callback should not have been invoked because FD was not signalled";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndSignalledFDBeforeWaiting_ImmediatelyInvokesCallbackAndReturnsTrue) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-
-    pipe.writeSignal();
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(100);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should be approx. zero";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because FD was signalled";
-    EXPECT_EQ(1, handler.callbackCount)
-            << "callback should be invoked exactly once";
-    EXPECT_EQ(pipe.receiveFd, handler.fd)
-            << "callback should have received pipe fd as parameter";
-    EXPECT_EQ(POLL_IN, handler.events)
-            << "callback should have received POLL_IN as events";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenNonZeroTimeoutAndSignalledFDWhileWaiting_PromptlyInvokesCallbackAndReturnsTrue) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-    sp<DelayedWriteSignal> delayedWriteSignal = new DelayedWriteSignal(100, & pipe);
-
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-    delayedWriteSignal->run();
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(1000);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal signal delay";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because FD was signalled";
-    EXPECT_EQ(1, handler.callbackCount)
-            << "callback should be invoked exactly once";
-    EXPECT_EQ(pipe.receiveFd, handler.fd)
-            << "callback should have received pipe fd as parameter";
-    EXPECT_EQ(POLL_IN, handler.events)
-            << "callback should have received POLL_IN as events";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenCallbackAddedThenRemoved_CallbackShouldNotBeInvoked) {
-    Pipe pipe;
-    StubCallbackHandler handler(true);
-
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-    pipe.writeSignal(); // would cause FD to be considered signalled
-    mPollLoop->removeCallback(pipe.receiveFd);
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(100);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(100, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal timeout because FD was no longer registered";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-    EXPECT_EQ(0, handler.callbackCount)
-            << "callback should not be invoked";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenCallbackReturnsFalse_CallbackShouldNotBeInvokedAgainLater) {
-    Pipe pipe;
-    StubCallbackHandler handler(false);
-
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    // First loop: Callback is registered and FD is signalled.
-    pipe.writeSignal();
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(0);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal zero because FD was already signalled";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because FD was signalled";
-    EXPECT_EQ(1, handler.callbackCount)
-            << "callback should be invoked";
-
-    // Second loop: Callback is no longer registered and FD is signalled.
-    pipe.writeSignal();
-
-    stopWatch.reset();
-    result = mPollLoop->pollOnce(0);
-    elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. equal zero because timeout was zero";
-    EXPECT_EQ(result, PollLoop::POLL_TIMEOUT)
-            << "pollOnce result should be POLL_TIMEOUT";
-    EXPECT_EQ(1, handler.callbackCount)
-            << "callback should not be invoked this time";
-}
-
-TEST_F(PollLoopTest, RemoveCallback_WhenCallbackNotAdded_ReturnsFalse) {
-    bool result = mPollLoop->removeCallback(1);
-
-    EXPECT_FALSE(result)
-            << "removeCallback should return false because FD not registered";
-}
-
-TEST_F(PollLoopTest, RemoveCallback_WhenCallbackAddedThenRemovedTwice_ReturnsTrueFirstTimeAndReturnsFalseSecondTime) {
-    Pipe pipe;
-    StubCallbackHandler handler(false);
-    handler.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-
-    // First time.
-    bool result = mPollLoop->removeCallback(pipe.receiveFd);
-
-    EXPECT_TRUE(result)
-            << "removeCallback should return true first time because FD was registered";
-
-    // Second time.
-    result = mPollLoop->removeCallback(pipe.receiveFd);
-
-    EXPECT_FALSE(result)
-            << "removeCallback should return false second time because FD was no longer registered";
-}
-
-TEST_F(PollLoopTest, PollOnce_WhenCallbackAddedTwice_OnlySecondCallbackShouldBeInvoked) {
-    Pipe pipe;
-    StubCallbackHandler handler1(true);
-    StubCallbackHandler handler2(true);
-
-    handler1.setCallback(mPollLoop, pipe.receiveFd, POLL_IN);
-    handler2.setCallback(mPollLoop, pipe.receiveFd, POLL_IN); // replace it
-    pipe.writeSignal(); // would cause FD to be considered signalled
-
-    StopWatch stopWatch("pollOnce");
-    int32_t result = mPollLoop->pollOnce(100);
-    int32_t elapsedMillis = ns2ms(stopWatch.elapsedTime());
-
-    ASSERT_EQ(OK, pipe.readSignal())
-            << "signal should actually have been written";
-    EXPECT_NEAR(0, elapsedMillis, TIMING_TOLERANCE_MS)
-            << "elapsed time should approx. zero because FD was already signalled";
-    EXPECT_EQ(result, PollLoop::POLL_CALLBACK)
-            << "pollOnce result should be POLL_CALLBACK because FD was signalled";
-    EXPECT_EQ(0, handler1.callbackCount)
-            << "original handler callback should not be invoked because it was replaced";
-    EXPECT_EQ(1, handler2.callbackCount)
-            << "replacement handler callback should be invoked";
-}
-
-
-} // namespace android