Add m-esr52 at 52.6.0

13 files changed, 3012 insertions, 0 deletions

diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.cpp
new file mode 100644
index 000000000..7df72bf68
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.cpp
@@ -0,0 +1,193 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#include "GonkBufferItem.h"
+
+#include <ui/Fence.h>
+#include <ui/GraphicBuffer.h>
+
+#include <system/window.h>
+
+namespace android {
+
+GonkBufferItem::GonkBufferItem() :
+    mTransform(0),
+    mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE),
+    mTimestamp(0),
+    mIsAutoTimestamp(false),
+    mFrameNumber(0),
+    mSlot(INVALID_BUFFER_SLOT),
+    mIsDroppable(false),
+    mAcquireCalled(false),
+    mTransformToDisplayInverse(false) {
+    mCrop.makeInvalid();
+}
+
+GonkBufferItem::operator IGonkGraphicBufferConsumer::BufferItem() const {
+    IGonkGraphicBufferConsumer::BufferItem bufferItem;
+    bufferItem.mGraphicBuffer = mGraphicBuffer;
+    bufferItem.mFence = mFence;
+    bufferItem.mCrop = mCrop;
+    bufferItem.mTransform = mTransform;
+    bufferItem.mScalingMode = mScalingMode;
+    bufferItem.mTimestamp = mTimestamp;
+    bufferItem.mIsAutoTimestamp = mIsAutoTimestamp;
+    bufferItem.mFrameNumber = mFrameNumber;
+    bufferItem.mBuf = mSlot;
+    bufferItem.mIsDroppable = mIsDroppable;
+    bufferItem.mAcquireCalled = mAcquireCalled;
+    bufferItem.mTransformToDisplayInverse = mTransformToDisplayInverse;
+    return bufferItem;
+}
+
+size_t GonkBufferItem::getPodSize() const {
+    size_t c =  sizeof(mCrop) +
+            sizeof(mTransform) +
+            sizeof(mScalingMode) +
+            sizeof(mTimestamp) +
+            sizeof(mIsAutoTimestamp) +
+            sizeof(mFrameNumber) +
+            sizeof(mSlot) +
+            sizeof(mIsDroppable) +
+            sizeof(mAcquireCalled) +
+            sizeof(mTransformToDisplayInverse);
+    return c;
+}
+
+size_t GonkBufferItem::getFlattenedSize() const {
+    size_t c = 0;
+    if (mGraphicBuffer != 0) {
+        c += mGraphicBuffer->getFlattenedSize();
+        FlattenableUtils::align<4>(c);
+    }
+    if (mFence != 0) {
+        c += mFence->getFlattenedSize();
+        FlattenableUtils::align<4>(c);
+    }
+    return sizeof(int32_t) + c + getPodSize();
+}
+
+size_t GonkBufferItem::getFdCount() const {
+    size_t c = 0;
+    if (mGraphicBuffer != 0) {
+        c += mGraphicBuffer->getFdCount();
+    }
+    if (mFence != 0) {
+        c += mFence->getFdCount();
+    }
+    return c;
+}
+
+status_t GonkBufferItem::flatten(
+        void*& buffer, size_t& size, int*& fds, size_t& count) const {
+
+    // make sure we have enough space
+    if (count < GonkBufferItem::getFlattenedSize()) {
+        return NO_MEMORY;
+    }
+
+    // content flags are stored first
+    uint32_t& flags = *static_cast<uint32_t*>(buffer);
+
+    // advance the pointer
+    FlattenableUtils::advance(buffer, size, sizeof(uint32_t));
+
+    flags = 0;
+    if (mGraphicBuffer != 0) {
+        status_t err = mGraphicBuffer->flatten(buffer, size, fds, count);
+        if (err) return err;
+        size -= FlattenableUtils::align<4>(buffer);
+        flags |= 1;
+    }
+    if (mFence != 0) {
+        status_t err = mFence->flatten(buffer, size, fds, count);
+        if (err) return err;
+        size -= FlattenableUtils::align<4>(buffer);
+        flags |= 2;
+    }
+
+    // check we have enough space (in case flattening the fence/graphicbuffer lied to us)
+    if (size < getPodSize()) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::write(buffer, size, mCrop);
+    FlattenableUtils::write(buffer, size, mTransform);
+    FlattenableUtils::write(buffer, size, mScalingMode);
+    FlattenableUtils::write(buffer, size, mTimestamp);
+    FlattenableUtils::write(buffer, size, mIsAutoTimestamp);
+    FlattenableUtils::write(buffer, size, mFrameNumber);
+    FlattenableUtils::write(buffer, size, mSlot);
+    FlattenableUtils::write(buffer, size, mIsDroppable);
+    FlattenableUtils::write(buffer, size, mAcquireCalled);
+    FlattenableUtils::write(buffer, size, mTransformToDisplayInverse);
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferItem::unflatten(
+        void const*& buffer, size_t& size, int const*& fds, size_t& count) {
+
+    if (size < sizeof(uint32_t))
+        return NO_MEMORY;
+
+    uint32_t flags = 0;
+    FlattenableUtils::read(buffer, size, flags);
+
+    if (flags & 1) {
+        mGraphicBuffer = new GraphicBuffer();
+        status_t err = mGraphicBuffer->unflatten(buffer, size, fds, count);
+        if (err) return err;
+        size -= FlattenableUtils::align<4>(buffer);
+    }
+
+    if (flags & 2) {
+        mFence = new Fence();
+        status_t err = mFence->unflatten(buffer, size, fds, count);
+        if (err) return err;
+        size -= FlattenableUtils::align<4>(buffer);
+    }
+
+    // check we have enough space
+    if (size < getPodSize()) {
+        return NO_MEMORY;
+    }
+
+    FlattenableUtils::read(buffer, size, mCrop);
+    FlattenableUtils::read(buffer, size, mTransform);
+    FlattenableUtils::read(buffer, size, mScalingMode);
+    FlattenableUtils::read(buffer, size, mTimestamp);
+    FlattenableUtils::read(buffer, size, mIsAutoTimestamp);
+    FlattenableUtils::read(buffer, size, mFrameNumber);
+    FlattenableUtils::read(buffer, size, mSlot);
+    FlattenableUtils::read(buffer, size, mIsDroppable);
+    FlattenableUtils::read(buffer, size, mAcquireCalled);
+    FlattenableUtils::read(buffer, size, mTransformToDisplayInverse);
+
+    return NO_ERROR;
+}
+
+const char* GonkBufferItem::scalingModeName(uint32_t scalingMode) {
+    switch (scalingMode) {
+        case NATIVE_WINDOW_SCALING_MODE_FREEZE: return "FREEZE";
+        case NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW: return "SCALE_TO_WINDOW";
+        case NATIVE_WINDOW_SCALING_MODE_SCALE_CROP: return "SCALE_CROP";
+        default: return "Unknown";
+    }
+}
+
+} // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.h
new file mode 100644
index 000000000..b2d6d3068
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferItem.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERITEM_LL_H
+#define NATIVEWINDOW_GONKBUFFERITEM_LL_H
+
+#include "IGonkGraphicBufferConsumerLL.h"
+
+#include <ui/Rect.h>
+
+#include <utils/Flattenable.h>
+#include <utils/StrongPointer.h>
+
+namespace android {
+
+class Fence;
+class GraphicBuffer;
+
+class GonkBufferItem : public Flattenable<GonkBufferItem> {
+    friend class Flattenable<GonkBufferItem>;
+    size_t getPodSize() const;
+    size_t getFlattenedSize() const;
+    size_t getFdCount() const;
+    status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const;
+    status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count);
+
+    public:
+    // The default value of mBuf, used to indicate this doesn't correspond to a slot.
+    enum { INVALID_BUFFER_SLOT = -1 };
+    GonkBufferItem();
+    operator IGonkGraphicBufferConsumer::BufferItem() const;
+
+    static const char* scalingModeName(uint32_t scalingMode);
+
+    // mGraphicBuffer points to the buffer allocated for this slot, or is NULL
+    // if the buffer in this slot has been acquired in the past (see
+    // BufferSlot.mAcquireCalled).
+    sp<GraphicBuffer> mGraphicBuffer;
+
+    // mFence is a fence that will signal when the buffer is idle.
+    sp<Fence> mFence;
+
+    // mCrop is the current crop rectangle for this buffer slot.
+    Rect mCrop;
+
+    // mTransform is the current transform flags for this buffer slot.
+    // refer to NATIVE_WINDOW_TRANSFORM_* in <window.h>
+    uint32_t mTransform;
+
+    // mScalingMode is the current scaling mode for this buffer slot.
+    // refer to NATIVE_WINDOW_SCALING_* in <window.h>
+    uint32_t mScalingMode;
+
+    // mTimestamp is the current timestamp for this buffer slot. This gets
+    // to set by queueBuffer each time this slot is queued. This value
+    // is guaranteed to be monotonically increasing for each newly
+    // acquired buffer.
+    int64_t mTimestamp;
+
+    // mIsAutoTimestamp indicates whether mTimestamp was generated
+    // automatically when the buffer was queued.
+    bool mIsAutoTimestamp;
+
+    // mFrameNumber is the number of the queued frame for this slot.
+    uint64_t mFrameNumber;
+
+    // mSlot is the slot index of this buffer (default INVALID_BUFFER_SLOT).
+    int mSlot;
+
+    // mIsDroppable whether this buffer was queued with the
+    // property that it can be replaced by a new buffer for the purpose of
+    // making sure dequeueBuffer() won't block.
+    // i.e.: was the BufferQueue in "mDequeueBufferCannotBlock" when this buffer
+    // was queued.
+    bool mIsDroppable;
+
+    // Indicates whether this buffer has been seen by a consumer yet
+    bool mAcquireCalled;
+
+    // Indicates this buffer must be transformed by the inverse transform of the screen
+    // it is displayed onto. This is applied after mTransform.
+    bool mTransformToDisplayInverse;
+};
+
+} // namespace android
+
+#endif
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.cpp
new file mode 100644
index 000000000..1d7eb2702
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.cpp
@@ -0,0 +1,559 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#include <inttypes.h>
+
+#define LOG_TAG "GonkBufferQueueConsumer"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+//#define LOG_NDEBUG 0
+
+#include "GonkBufferItem.h"
+#include "GonkBufferQueueConsumer.h"
+#include "GonkBufferQueueCore.h"
+#include <gui/IConsumerListener.h>
+#include <gui/IProducerListener.h>
+
+namespace android {
+
+GonkBufferQueueConsumer::GonkBufferQueueConsumer(const sp<GonkBufferQueueCore>& core) :
+    mCore(core),
+    mSlots(core->mSlots),
+    mConsumerName() {}
+
+GonkBufferQueueConsumer::~GonkBufferQueueConsumer() {}
+
+status_t GonkBufferQueueConsumer::acquireBuffer(BufferItem* outBuffer,
+        nsecs_t expectedPresent) {
+    ATRACE_CALL();
+    Mutex::Autolock lock(mCore->mMutex);
+
+    // Check that the consumer doesn't currently have the maximum number of
+    // buffers acquired. We allow the max buffer count to be exceeded by one
+    // buffer so that the consumer can successfully set up the newly acquired
+    // buffer before releasing the old one.
+    int numAcquiredBuffers = 0;
+    for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        if (mSlots[s].mBufferState == GonkBufferSlot::ACQUIRED) {
+            ++numAcquiredBuffers;
+        }
+    }
+    if (numAcquiredBuffers >= mCore->mMaxAcquiredBufferCount + 1) {
+        ALOGE("acquireBuffer: max acquired buffer count reached: %d (max %d)",
+                numAcquiredBuffers, mCore->mMaxAcquiredBufferCount);
+        return INVALID_OPERATION;
+    }
+
+    // Check if the queue is empty.
+    // In asynchronous mode the list is guaranteed to be one buffer deep,
+    // while in synchronous mode we use the oldest buffer.
+    if (mCore->mQueue.empty()) {
+        return NO_BUFFER_AVAILABLE;
+    }
+
+    GonkBufferQueueCore::Fifo::iterator front(mCore->mQueue.begin());
+
+    // If expectedPresent is specified, we may not want to return a buffer yet.
+    // If it's specified and there's more than one buffer queued, we may want
+    // to drop a buffer.
+    if (expectedPresent != 0) {
+        const int MAX_REASONABLE_NSEC = 1000000000ULL; // 1 second
+
+        // The 'expectedPresent' argument indicates when the buffer is expected
+        // to be presented on-screen. If the buffer's desired present time is
+        // earlier (less) than expectedPresent -- meaning it will be displayed
+        // on time or possibly late if we show it as soon as possible -- we
+        // acquire and return it. If we don't want to display it until after the
+        // expectedPresent time, we return PRESENT_LATER without acquiring it.
+        //
+        // To be safe, we don't defer acquisition if expectedPresent is more
+        // than one second in the future beyond the desired present time
+        // (i.e., we'd be holding the buffer for a long time).
+        //
+        // NOTE: Code assumes monotonic time values from the system clock
+        // are positive.
+
+        // Start by checking to see if we can drop frames. We skip this check if
+        // the timestamps are being auto-generated by Surface. If the app isn't
+        // generating timestamps explicitly, it probably doesn't want frames to
+        // be discarded based on them.
+        while (mCore->mQueue.size() > 1 && !mCore->mQueue[0].mIsAutoTimestamp) {
+            // If entry[1] is timely, drop entry[0] (and repeat). We apply an
+            // additional criterion here: we only drop the earlier buffer if our
+            // desiredPresent falls within +/- 1 second of the expected present.
+            // Otherwise, bogus desiredPresent times (e.g., 0 or a small
+            // relative timestamp), which normally mean "ignore the timestamp
+            // and acquire immediately", would cause us to drop frames.
+            //
+            // We may want to add an additional criterion: don't drop the
+            // earlier buffer if entry[1]'s fence hasn't signaled yet.
+            const BufferItem& bufferItem(mCore->mQueue[1]);
+            nsecs_t desiredPresent = bufferItem.mTimestamp;
+            if (desiredPresent < expectedPresent - MAX_REASONABLE_NSEC ||
+                    desiredPresent > expectedPresent) {
+                // This buffer is set to display in the near future, or
+                // desiredPresent is garbage. Either way we don't want to drop
+                // the previous buffer just to get this on the screen sooner.
+                ALOGV("acquireBuffer: nodrop desire=%" PRId64 " expect=%"
+                        PRId64 " (%" PRId64 ") now=%" PRId64,
+                        desiredPresent, expectedPresent,
+                        desiredPresent - expectedPresent,
+                        systemTime(CLOCK_MONOTONIC));
+                break;
+            }
+
+            ALOGV("acquireBuffer: drop desire=%" PRId64 " expect=%" PRId64
+                    " size=%zu",
+                    desiredPresent, expectedPresent, mCore->mQueue.size());
+            if (mCore->stillTracking(front)) {
+                // Front buffer is still in mSlots, so mark the slot as free
+                mSlots[front->mSlot].mBufferState = GonkBufferSlot::FREE;
+            }
+            mCore->mQueue.erase(front);
+            front = mCore->mQueue.begin();
+        }
+
+        // See if the front buffer is due
+        nsecs_t desiredPresent = front->mTimestamp;
+        if (desiredPresent > expectedPresent &&
+                desiredPresent < expectedPresent + MAX_REASONABLE_NSEC) {
+            ALOGV("acquireBuffer: defer desire=%" PRId64 " expect=%" PRId64
+                    " (%" PRId64 ") now=%" PRId64,
+                    desiredPresent, expectedPresent,
+                    desiredPresent - expectedPresent,
+                    systemTime(CLOCK_MONOTONIC));
+            return PRESENT_LATER;
+        }
+
+        ALOGV("acquireBuffer: accept desire=%" PRId64 " expect=%" PRId64 " "
+                "(%" PRId64 ") now=%" PRId64, desiredPresent, expectedPresent,
+                desiredPresent - expectedPresent,
+                systemTime(CLOCK_MONOTONIC));
+    }
+
+    int slot = front->mSlot;
+    //*outBuffer = *front;
+    outBuffer->mGraphicBuffer = mSlots[slot].mGraphicBuffer;
+    outBuffer->mFrameNumber = mSlots[slot].mFrameNumber;
+    outBuffer->mBuf = slot;
+    outBuffer->mFence = mSlots[slot].mFence;
+
+    ATRACE_BUFFER_INDEX(slot);
+
+    ALOGV("acquireBuffer: acquiring { slot=%d/%" PRIu64 " buffer=%p }",
+            slot, front->mFrameNumber, front->mGraphicBuffer->handle);
+    // If the front buffer is still being tracked, update its slot state
+    if (mCore->stillTracking(front)) {
+        mSlots[slot].mAcquireCalled = true;
+        mSlots[slot].mNeedsCleanupOnRelease = false;
+        mSlots[slot].mBufferState = GonkBufferSlot::ACQUIRED;
+        mSlots[slot].mFence = Fence::NO_FENCE;
+    }
+
+    // If the buffer has previously been acquired by the consumer, set
+    // mGraphicBuffer to NULL to avoid unnecessarily remapping this buffer
+    // on the consumer side
+    //if (outBuffer->mAcquireCalled) {
+    //    outBuffer->mGraphicBuffer = NULL;
+    //}
+
+    mCore->mQueue.erase(front);
+
+    // We might have freed a slot while dropping old buffers, or the producer
+    // may be blocked waiting for the number of buffers in the queue to
+    // decrease.
+    mCore->mDequeueCondition.broadcast();
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::detachBuffer(int slot) {
+    ATRACE_CALL();
+    ATRACE_BUFFER_INDEX(slot);
+    ALOGV("detachBuffer(C): slot %d", slot);
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("detachBuffer(C): GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    if (slot < 0 || slot >= GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+        ALOGE("detachBuffer(C): slot index %d out of range [0, %d)",
+                slot, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+        return BAD_VALUE;
+    } else if (mSlots[slot].mBufferState != GonkBufferSlot::ACQUIRED) {
+        ALOGE("detachBuffer(C): slot %d is not owned by the consumer "
+                "(state = %d)", slot, mSlots[slot].mBufferState);
+        return BAD_VALUE;
+    }
+
+    mCore->freeBufferLocked(slot);
+    mCore->mDequeueCondition.broadcast();
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::attachBuffer(int* outSlot,
+        const sp<android::GraphicBuffer>& buffer) {
+    ATRACE_CALL();
+
+    if (outSlot == NULL) {
+        ALOGE("attachBuffer(P): outSlot must not be NULL");
+        return BAD_VALUE;
+    } else if (buffer == NULL) {
+        ALOGE("attachBuffer(P): cannot attach NULL buffer");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    // Make sure we don't have too many acquired buffers and find a free slot
+    // to put the buffer into (the oldest if there are multiple).
+    int numAcquiredBuffers = 0;
+    int found = GonkBufferQueueCore::INVALID_BUFFER_SLOT;
+    for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        if (mSlots[s].mBufferState == GonkBufferSlot::ACQUIRED) {
+            ++numAcquiredBuffers;
+        } else if (mSlots[s].mBufferState == GonkBufferSlot::FREE) {
+            if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT ||
+                    mSlots[s].mFrameNumber < mSlots[found].mFrameNumber) {
+                found = s;
+            }
+        }
+    }
+
+    if (numAcquiredBuffers >= mCore->mMaxAcquiredBufferCount + 1) {
+        ALOGE("attachBuffer(P): max acquired buffer count reached: %d "
+                "(max %d)", numAcquiredBuffers,
+                mCore->mMaxAcquiredBufferCount);
+        return INVALID_OPERATION;
+    }
+    if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT) {
+        ALOGE("attachBuffer(P): could not find free buffer slot");
+        return NO_MEMORY;
+    }
+
+    *outSlot = found;
+    ATRACE_BUFFER_INDEX(*outSlot);
+    ALOGV("attachBuffer(C): returning slot %d", *outSlot);
+
+    mSlots[*outSlot].mGraphicBuffer = buffer;
+    mSlots[*outSlot].mBufferState = GonkBufferSlot::ACQUIRED;
+    mSlots[*outSlot].mAttachedByConsumer = true;
+    mSlots[*outSlot].mNeedsCleanupOnRelease = false;
+    mSlots[*outSlot].mFence = Fence::NO_FENCE;
+    mSlots[*outSlot].mFrameNumber = 0;
+
+    // mAcquireCalled tells GonkBufferQueue that it doesn't need to send a valid
+    // GraphicBuffer pointer on the next acquireBuffer call, which decreases
+    // Binder traffic by not un/flattening the GraphicBuffer. However, it
+    // requires that the consumer maintain a cached copy of the slot <--> buffer
+    // mappings, which is why the consumer doesn't need the valid pointer on
+    // acquire.
+    //
+    // The StreamSplitter is one of the primary users of the attach/detach
+    // logic, and while it is running, all buffers it acquires are immediately
+    // detached, and all buffers it eventually releases are ones that were
+    // attached (as opposed to having been obtained from acquireBuffer), so it
+    // doesn't make sense to maintain the slot/buffer mappings, which would
+    // become invalid for every buffer during detach/attach. By setting this to
+    // false, the valid GraphicBuffer pointer will always be sent with acquire
+    // for attached buffers.
+    mSlots[*outSlot].mAcquireCalled = false;
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::releaseBuffer(int slot, uint64_t frameNumber,
+        const sp<Fence>& releaseFence) {
+    ATRACE_CALL();
+
+    if (slot < 0 || slot >= GonkBufferQueueDefs::NUM_BUFFER_SLOTS ||
+            releaseFence == NULL) {
+        return BAD_VALUE;
+    }
+
+    sp<IProducerListener> listener;
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+
+        // If the frame number has changed because the buffer has been reallocated,
+        // we can ignore this releaseBuffer for the old buffer
+        //if (frameNumber != mSlots[slot].mFrameNumber) {
+        //    return STALE_BUFFER_SLOT;
+        //}
+
+        // Make sure this buffer hasn't been queued while acquired by the consumer
+        GonkBufferQueueCore::Fifo::iterator current(mCore->mQueue.begin());
+        while (current != mCore->mQueue.end()) {
+            if (current->mSlot == slot) {
+                ALOGE("releaseBuffer: buffer slot %d pending release is "
+                        "currently queued", slot);
+                return BAD_VALUE;
+            }
+            ++current;
+        }
+
+        if (mSlots[slot].mBufferState == GonkBufferSlot::ACQUIRED) {
+            mSlots[slot].mFence = releaseFence;
+            mSlots[slot].mBufferState = GonkBufferSlot::FREE;
+            listener = mCore->mConnectedProducerListener;
+            ALOGV("releaseBuffer: releasing slot %d", slot);
+        } else if (mSlots[slot].mNeedsCleanupOnRelease) {
+            ALOGV("releaseBuffer: releasing a stale buffer slot %d "
+                    "(state = %d)", slot, mSlots[slot].mBufferState);
+            mSlots[slot].mNeedsCleanupOnRelease = false;
+            return STALE_BUFFER_SLOT;
+        } else {
+            ALOGV("releaseBuffer: attempted to release buffer slot %d "
+                    "but its state was %d", slot, mSlots[slot].mBufferState);
+            return BAD_VALUE;
+        }
+
+        mCore->mDequeueCondition.broadcast();
+    } // Autolock scope
+
+    // Call back without lock held
+    if (listener != NULL) {
+        listener->onBufferReleased();
+    }
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::connect(
+        const sp<IConsumerListener>& consumerListener, bool controlledByApp) {
+    ATRACE_CALL();
+
+    if (consumerListener == NULL) {
+        ALOGE("connect(C): consumerListener may not be NULL");
+        return BAD_VALUE;
+    }
+
+    ALOGV("connect(C): controlledByApp=%s",
+            controlledByApp ? "true" : "false");
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("connect(C): GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    mCore->mConsumerListener = consumerListener;
+    mCore->mConsumerControlledByApp = controlledByApp;
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::disconnect() {
+    ATRACE_CALL();
+
+    ALOGV("disconnect(C)");
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mConsumerListener == NULL) {
+        ALOGE("disconnect(C): no consumer is connected");
+        return BAD_VALUE;
+    }
+
+    mCore->mIsAbandoned = true;
+    mCore->mConsumerListener = NULL;
+    mCore->mQueue.clear();
+    mCore->freeAllBuffersLocked();
+    mCore->mDequeueCondition.broadcast();
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::getReleasedBuffers(uint64_t *outSlotMask) {
+    ATRACE_CALL();
+
+    if (outSlotMask == NULL) {
+        ALOGE("getReleasedBuffers: outSlotMask may not be NULL");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("getReleasedBuffers: GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    uint64_t mask = 0;
+    for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        if (!mSlots[s].mAcquireCalled) {
+            mask |= (1ULL << s);
+        }
+    }
+
+    // Remove from the mask queued buffers for which acquire has been called,
+    // since the consumer will not receive their buffer addresses and so must
+    // retain their cached information
+    GonkBufferQueueCore::Fifo::iterator current(mCore->mQueue.begin());
+    while (current != mCore->mQueue.end()) {
+        if (current->mAcquireCalled) {
+            mask &= ~(1ULL << current->mSlot);
+        }
+        ++current;
+    }
+
+    ALOGV("getReleasedBuffers: returning mask %#" PRIx64, mask);
+    *outSlotMask = mask;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::setDefaultBufferSize(uint32_t width,
+        uint32_t height) {
+    ATRACE_CALL();
+
+    if (width == 0 || height == 0) {
+        ALOGV("setDefaultBufferSize: dimensions cannot be 0 (width=%u "
+                "height=%u)", width, height);
+        return BAD_VALUE;
+    }
+
+    ALOGV("setDefaultBufferSize: width=%u height=%u", width, height);
+
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->mDefaultWidth = width;
+    mCore->mDefaultHeight = height;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::setDefaultMaxBufferCount(int bufferCount) {
+    ATRACE_CALL();
+    Mutex::Autolock lock(mCore->mMutex);
+    return mCore->setDefaultMaxBufferCountLocked(bufferCount);
+}
+
+status_t GonkBufferQueueConsumer::disableAsyncBuffer() {
+    ATRACE_CALL();
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mConsumerListener != NULL) {
+        ALOGE("disableAsyncBuffer: consumer already connected");
+        return INVALID_OPERATION;
+    }
+
+    ALOGV("disableAsyncBuffer");
+    mCore->mUseAsyncBuffer = false;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::setMaxAcquiredBufferCount(
+        int maxAcquiredBuffers) {
+    ATRACE_CALL();
+
+    if (maxAcquiredBuffers < 1 ||
+            maxAcquiredBuffers > GonkBufferQueueCore::MAX_MAX_ACQUIRED_BUFFERS) {
+        ALOGE("setMaxAcquiredBufferCount: invalid count %d",
+                maxAcquiredBuffers);
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mConnectedApi != GonkBufferQueueCore::NO_CONNECTED_API) {
+        ALOGE("setMaxAcquiredBufferCount: producer is already connected");
+        return INVALID_OPERATION;
+    }
+
+    ALOGV("setMaxAcquiredBufferCount: %d", maxAcquiredBuffers);
+    mCore->mMaxAcquiredBufferCount = maxAcquiredBuffers;
+    return NO_ERROR;
+}
+
+void GonkBufferQueueConsumer::setConsumerName(const String8& name) {
+    ATRACE_CALL();
+    ALOGV("setConsumerName: '%s'", name.string());
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->mConsumerName = name;
+    mConsumerName = name;
+}
+
+status_t GonkBufferQueueConsumer::setDefaultBufferFormat(uint32_t defaultFormat) {
+    ATRACE_CALL();
+    ALOGV("setDefaultBufferFormat: %u", defaultFormat);
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->mDefaultBufferFormat = defaultFormat;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::setConsumerUsageBits(uint32_t usage) {
+    ATRACE_CALL();
+    ALOGV("setConsumerUsageBits: %#x", usage);
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->mConsumerUsageBits = usage;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueConsumer::setTransformHint(uint32_t hint) {
+    ATRACE_CALL();
+    ALOGV("setTransformHint: %#x", hint);
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->mTransformHint = hint;
+    return NO_ERROR;
+}
+
+sp<NativeHandle> GonkBufferQueueConsumer::getSidebandStream() const {
+    return mCore->mSidebandStream;
+}
+
+void GonkBufferQueueConsumer::dumpToString(String8& result, const char* prefix) const {
+    mCore->dump(result, prefix);
+}
+
+already_AddRefed<GonkBufferSlot::TextureClient>
+GonkBufferQueueConsumer::getTextureClientFromBuffer(ANativeWindowBuffer* buffer)
+{
+    Mutex::Autolock _l(mCore->mMutex);
+    if (buffer == NULL) {
+        ALOGE("getSlotFromBufferLocked: encountered NULL buffer");
+        return nullptr;
+    }
+
+    for (int i = 0; i < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; i++) {
+        if (mSlots[i].mGraphicBuffer != NULL && mSlots[i].mGraphicBuffer->handle == buffer->handle) {
+            RefPtr<TextureClient> client(mSlots[i].mTextureClient);
+            return client.forget();
+        }
+    }
+    ALOGE("getSlotFromBufferLocked: unknown buffer: %p", buffer->handle);
+    return nullptr;
+}
+
+int
+GonkBufferQueueConsumer::getSlotFromTextureClientLocked(GonkBufferSlot::TextureClient* client) const
+{
+    if (client == NULL) {
+        ALOGE("getSlotFromBufferLocked: encountered NULL buffer");
+        return BAD_VALUE;
+    }
+
+    for (int i = 0; i < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; i++) {
+        if (mSlots[i].mTextureClient == client) {
+            return i;
+        }
+    }
+    ALOGE("getSlotFromBufferLocked: unknown TextureClient: %p", client);
+    return BAD_VALUE;
+}
+
+} // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.h
new file mode 100644
index 000000000..a97cfab42
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueConsumer.h
@@ -0,0 +1,173 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERQUEUECONSUMER_LL_H
+#define NATIVEWINDOW_GONKBUFFERQUEUECONSUMER_LL_H
+
+#include "GonkBufferQueueDefs.h"
+#include "IGonkGraphicBufferConsumerLL.h"
+
+namespace android {
+
+class GonkBufferQueueCore;
+
+class GonkBufferQueueConsumer : public BnGonkGraphicBufferConsumer {
+
+public:
+    GonkBufferQueueConsumer(const sp<GonkBufferQueueCore>& core);
+    virtual ~GonkBufferQueueConsumer();
+
+    // acquireBuffer attempts to acquire ownership of the next pending buffer in
+    // the GonkBufferQueue. If no buffer is pending then it returns
+    // NO_BUFFER_AVAILABLE. If a buffer is successfully acquired, the
+    // information about the buffer is returned in BufferItem.  If the buffer
+    // returned had previously been acquired then the BufferItem::mGraphicBuffer
+    // field of buffer is set to NULL and it is assumed that the consumer still
+    // holds a reference to the buffer.
+    //
+    // If expectedPresent is nonzero, it indicates the time when the buffer
+    // will be displayed on screen. If the buffer's timestamp is farther in the
+    // future, the buffer won't be acquired, and PRESENT_LATER will be
+    // returned.  The presentation time is in nanoseconds, and the time base
+    // is CLOCK_MONOTONIC.
+    virtual status_t acquireBuffer(BufferItem* outBuffer,
+            nsecs_t expectedPresent);
+
+    // See IGonkGraphicBufferConsumer::detachBuffer
+    virtual status_t detachBuffer(int slot);
+
+    // See IGonkGraphicBufferConsumer::attachBuffer
+    virtual status_t attachBuffer(int* slot, const sp<GraphicBuffer>& buffer);
+
+    // releaseBuffer releases a buffer slot from the consumer back to the
+    // GonkBufferQueue.  This may be done while the buffer's contents are still
+    // being accessed.  The fence will signal when the buffer is no longer
+    // in use. frameNumber is used to indentify the exact buffer returned.
+    //
+    // If releaseBuffer returns STALE_BUFFER_SLOT, then the consumer must free
+    // any references to the just-released buffer that it might have, as if it
+    // had received a onBuffersReleased() call with a mask set for the released
+    // buffer.
+    virtual status_t releaseBuffer(int slot, uint64_t frameNumber,
+            const sp<Fence>& releaseFence);
+
+    // connect connects a consumer to the GonkBufferQueue.  Only one
+    // consumer may be connected, and when that consumer disconnects the
+    // GonkBufferQueue is placed into the "abandoned" state, causing most
+    // interactions with the GonkBufferQueue by the producer to fail.
+    // controlledByApp indicates whether the consumer is controlled by
+    // the application.
+    //
+    // consumerListener may not be NULL.
+    virtual status_t connect(const sp<IConsumerListener>& consumerListener,
+            bool controlledByApp);
+
+    // disconnect disconnects a consumer from the GonkBufferQueue. All
+    // buffers will be freed and the GonkBufferQueue is placed in the "abandoned"
+    // state, causing most interactions with the GonkBufferQueue by the producer to
+    // fail.
+    virtual status_t disconnect();
+
+    // getReleasedBuffers sets the value pointed to by outSlotMask to a bit mask
+    // indicating which buffer slots have been released by the GonkBufferQueue
+    // but have not yet been released by the consumer.
+    //
+    // This should be called from the onBuffersReleased() callback.
+    virtual status_t getReleasedBuffers(uint64_t* outSlotMask);
+
+    // setDefaultBufferSize is used to set the size of buffers returned by
+    // dequeueBuffer when a width and height of zero is requested.  Default
+    // is 1x1.
+    virtual status_t setDefaultBufferSize(uint32_t width, uint32_t height);
+
+    // setDefaultMaxBufferCount sets the default value for the maximum buffer
+    // count (the initial default is 2). If the producer has requested a
+    // buffer count using setBufferCount, the default buffer count will only
+    // take effect if the producer sets the count back to zero.
+    //
+    // The count must be between 2 and NUM_BUFFER_SLOTS, inclusive.
+    virtual status_t setDefaultMaxBufferCount(int bufferCount);
+
+    // disableAsyncBuffer disables the extra buffer used in async mode
+    // (when both producer and consumer have set their "isControlledByApp"
+    // flag) and has dequeueBuffer() return WOULD_BLOCK instead.
+    //
+    // This can only be called before connect().
+    virtual status_t disableAsyncBuffer();
+
+    // setMaxAcquiredBufferCount sets the maximum number of buffers that can
+    // be acquired by the consumer at one time (default 1).  This call will
+    // fail if a producer is connected to the GonkBufferQueue.
+    virtual status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers);
+
+    // setConsumerName sets the name used in logging
+    virtual void setConsumerName(const String8& name);
+
+    // setDefaultBufferFormat allows the GonkBufferQueue to create
+    // GraphicBuffers of a defaultFormat if no format is specified
+    // in dequeueBuffer.  Formats are enumerated in graphics.h; the
+    // initial default is HAL_PIXEL_FORMAT_RGBA_8888.
+    virtual status_t setDefaultBufferFormat(uint32_t defaultFormat);
+
+    // setConsumerUsageBits will turn on additional usage bits for dequeueBuffer.
+    // These are merged with the bits passed to dequeueBuffer.  The values are
+    // enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER; the default is 0.
+    virtual status_t setConsumerUsageBits(uint32_t usage);
+
+    // setTransformHint bakes in rotation to buffers so overlays can be used.
+    // The values are enumerated in window.h, e.g.
+    // NATIVE_WINDOW_TRANSFORM_ROT_90.  The default is 0 (no transform).
+    virtual status_t setTransformHint(uint32_t hint);
+
+    // Retrieve the sideband buffer stream, if any.
+    virtual sp<NativeHandle> getSidebandStream() const;
+
+    // dump our state in a String
+    virtual void dumpToString(String8& result, const char* prefix) const;
+
+    // Added by mozilla
+    virtual already_AddRefed<GonkBufferSlot::TextureClient> getTextureClientFromBuffer(ANativeWindowBuffer* buffer);
+
+    virtual int getSlotFromTextureClientLocked(GonkBufferSlot::TextureClient* client) const;
+
+    // Functions required for backwards compatibility.
+    // These will be modified/renamed in IGonkGraphicBufferConsumer and will be
+    // removed from this class at that time. See b/13306289.
+    virtual status_t consumerConnect(const sp<IConsumerListener>& consumer,
+            bool controlledByApp) {
+        return connect(consumer, controlledByApp);
+    }
+
+    virtual status_t consumerDisconnect() { return disconnect(); }
+
+    // End functions required for backwards compatibility
+
+private:
+    sp<GonkBufferQueueCore> mCore;
+
+    // This references mCore->mSlots. Lock mCore->mMutex while accessing.
+    GonkBufferQueueDefs::SlotsType& mSlots;
+
+    // This is a cached copy of the name stored in the GonkBufferQueueCore.
+    // It's updated during setConsumerName.
+    String8 mConsumerName;
+
+}; // class GonkBufferQueueConsumer
+
+} // namespace android
+
+#endif
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.cpp
new file mode 100644
index 000000000..9e8e337f6
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.cpp
@@ -0,0 +1,243 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#define LOG_TAG "GonkBufferQueueCore"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+//#define LOG_NDEBUG 0
+
+#include <inttypes.h>
+
+#include "GonkBufferItem.h"
+#include "GonkBufferQueueCore.h"
+#include <gui/IConsumerListener.h>
+#include <gui/IGraphicBufferAlloc.h>
+#include <gui/IProducerListener.h>
+#include <gui/ISurfaceComposer.h>
+#include <private/gui/ComposerService.h>
+
+#include <cutils/compiler.h>
+#include "mozilla/layers/GrallocTextureClient.h"
+#include "mozilla/layers/ImageBridgeChild.h"
+
+template <typename T>
+static inline T max(T a, T b) { return a > b ? a : b; }
+
+namespace android {
+
+static String8 getUniqueName() {
+    static volatile int32_t counter = 0;
+    return String8::format("unnamed-%d-%d", getpid(),
+            android_atomic_inc(&counter));
+}
+
+GonkBufferQueueCore::GonkBufferQueueCore(const sp<IGraphicBufferAlloc>& allocator) :
+    mAllocator(allocator),
+    mMutex(),
+    mIsAbandoned(false),
+    mConsumerControlledByApp(false),
+    mConsumerName(getUniqueName()),
+    mConsumerListener(),
+    mConsumerUsageBits(0),
+    mConnectedApi(NO_CONNECTED_API),
+    mConnectedProducerListener(),
+    mSlots(),
+    mQueue(),
+    mOverrideMaxBufferCount(0),
+    mDequeueCondition(),
+    mUseAsyncBuffer(true),
+    mDequeueBufferCannotBlock(false),
+    mDefaultBufferFormat(PIXEL_FORMAT_RGBA_8888),
+    mDefaultWidth(1),
+    mDefaultHeight(1),
+    mDefaultMaxBufferCount(2),
+    mMaxAcquiredBufferCount(1),
+    mBufferHasBeenQueued(false),
+    mFrameCounter(0),
+    mTransformHint(0),
+    mIsAllocating(false),
+    mIsAllocatingCondition()
+{
+    ALOGV("GonkBufferQueueCore");
+}
+
+GonkBufferQueueCore::~GonkBufferQueueCore() {}
+
+void GonkBufferQueueCore::dump(String8& result, const char* prefix) const {
+    Mutex::Autolock lock(mMutex);
+
+    String8 fifo;
+    Fifo::const_iterator current(mQueue.begin());
+    while (current != mQueue.end()) {
+        fifo.appendFormat("%02d:%p crop=[%d,%d,%d,%d], "
+                "xform=0x%02x, time=%#" PRIx64 ", scale=%s\n",
+                current->mSlot, current->mGraphicBuffer.get(),
+                current->mCrop.left, current->mCrop.top, current->mCrop.right,
+                current->mCrop.bottom, current->mTransform, current->mTimestamp,
+                GonkBufferItem::scalingModeName(current->mScalingMode));
+        ++current;
+    }
+
+    result.appendFormat("%s-GonkBufferQueue mMaxAcquiredBufferCount=%d, "
+            "mDequeueBufferCannotBlock=%d, default-size=[%dx%d], "
+            "default-format=%d, transform-hint=%02x, FIFO(%zu)={%s}\n",
+            prefix, mMaxAcquiredBufferCount, mDequeueBufferCannotBlock,
+            mDefaultWidth, mDefaultHeight, mDefaultBufferFormat, mTransformHint,
+            mQueue.size(), fifo.string());
+
+    // Trim the free buffers so as to not spam the dump
+    int maxBufferCount = 0;
+    for (int s = GonkBufferQueueDefs::NUM_BUFFER_SLOTS - 1; s >= 0; --s) {
+        const GonkBufferSlot& slot(mSlots[s]);
+        if (slot.mBufferState != GonkBufferSlot::FREE ||
+                slot.mGraphicBuffer != NULL) {
+            maxBufferCount = s + 1;
+            break;
+        }
+    }
+
+    for (int s = 0; s < maxBufferCount; ++s) {
+        const GonkBufferSlot& slot(mSlots[s]);
+        const sp<GraphicBuffer>& buffer(slot.mGraphicBuffer);
+        result.appendFormat("%s%s[%02d:%p] state=%-8s", prefix,
+                (slot.mBufferState == GonkBufferSlot::ACQUIRED) ? ">" : " ",
+                s, buffer.get(),
+                GonkBufferSlot::bufferStateName(slot.mBufferState));
+
+        if (buffer != NULL) {
+            result.appendFormat(", %p [%4ux%4u:%4u,%3X]", buffer->handle,
+                    buffer->width, buffer->height, buffer->stride,
+                    buffer->format);
+        }
+
+        result.append("\n");
+    }
+}
+
+int GonkBufferQueueCore::getMinUndequeuedBufferCountLocked(bool async) const {
+    // If dequeueBuffer is allowed to error out, we don't have to add an
+    // extra buffer.
+    if (!mUseAsyncBuffer) {
+        return mMaxAcquiredBufferCount;
+    }
+
+    if (mDequeueBufferCannotBlock || async) {
+        return mMaxAcquiredBufferCount + 1;
+    }
+
+    return mMaxAcquiredBufferCount;
+}
+
+int GonkBufferQueueCore::getMinMaxBufferCountLocked(bool async) const {
+    return getMinUndequeuedBufferCountLocked(async) + 1;
+}
+
+int GonkBufferQueueCore::getMaxBufferCountLocked(bool async) const {
+    int minMaxBufferCount = getMinMaxBufferCountLocked(async);
+
+    int maxBufferCount = max(mDefaultMaxBufferCount, minMaxBufferCount);
+    if (mOverrideMaxBufferCount != 0) {
+        assert(mOverrideMaxBufferCount >= minMaxBufferCount);
+        maxBufferCount = mOverrideMaxBufferCount;
+    }
+
+    // Any buffers that are dequeued by the producer or sitting in the queue
+    // waiting to be consumed need to have their slots preserved. Such buffers
+    // will temporarily keep the max buffer count up until the slots no longer
+    // need to be preserved.
+    for (int s = maxBufferCount; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        GonkBufferSlot::BufferState state = mSlots[s].mBufferState;
+        if (state == GonkBufferSlot::QUEUED || state == GonkBufferSlot::DEQUEUED) {
+            maxBufferCount = s + 1;
+        }
+    }
+
+    return maxBufferCount;
+}
+
+status_t GonkBufferQueueCore::setDefaultMaxBufferCountLocked(int count) {
+    const int minBufferCount = 2;
+    if (count < minBufferCount || count > GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+        ALOGV("setDefaultMaxBufferCount: invalid count %d, should be in "
+                "[%d, %d]",
+                count, minBufferCount, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+        return BAD_VALUE;
+    }
+
+    ALOGV("setDefaultMaxBufferCount: setting count to %d", count);
+    mDefaultMaxBufferCount = count;
+    mDequeueCondition.broadcast();
+
+    return NO_ERROR;
+}
+
+void GonkBufferQueueCore::freeBufferLocked(int slot) {
+    ALOGV("freeBufferLocked: slot %d", slot);
+
+    if (mSlots[slot].mTextureClient) {
+        mSlots[slot].mTextureClient->ClearRecycleCallback();
+        // release TextureClient in ImageBridge thread
+        RefPtr<TextureClientReleaseTask> task =
+          MakeAndAddRef<TextureClientReleaseTask>(mSlots[slot].mTextureClient);
+        mSlots[slot].mTextureClient = NULL;
+        ImageBridgeChild::GetSingleton()->GetMessageLoop()->PostTask(task.forget());
+    }
+    mSlots[slot].mGraphicBuffer.clear();
+    if (mSlots[slot].mBufferState == GonkBufferSlot::ACQUIRED) {
+        mSlots[slot].mNeedsCleanupOnRelease = true;
+    }
+    mSlots[slot].mBufferState = GonkBufferSlot::FREE;
+    mSlots[slot].mFrameNumber = UINT32_MAX;
+    mSlots[slot].mAcquireCalled = false;
+
+    // Destroy fence as GonkBufferQueue now takes ownership
+    mSlots[slot].mFence = Fence::NO_FENCE;
+}
+
+void GonkBufferQueueCore::freeAllBuffersLocked() {
+    ALOGW_IF(!mQueue.isEmpty(),
+            "freeAllBuffersLocked called but mQueue is not empty");
+    mQueue.clear();
+    mBufferHasBeenQueued = false;
+    for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        freeBufferLocked(s);
+    }
+}
+
+bool GonkBufferQueueCore::stillTracking(const GonkBufferItem* item) const {
+    const GonkBufferSlot& slot = mSlots[item->mSlot];
+
+    ALOGV("stillTracking: item { slot=%d/%" PRIu64 " buffer=%p } "
+            "slot { slot=%d/%" PRIu64 " buffer=%p }",
+            item->mSlot, item->mFrameNumber,
+            (item->mGraphicBuffer.get() ? item->mGraphicBuffer->handle : 0),
+            item->mSlot, slot.mFrameNumber,
+            (slot.mGraphicBuffer.get() ? slot.mGraphicBuffer->handle : 0));
+
+    // Compare item with its original buffer slot. We can check the slot as
+    // the buffer would not be moved to a different slot by the producer.
+    return (slot.mGraphicBuffer != NULL) &&
+           (item->mGraphicBuffer->handle == slot.mGraphicBuffer->handle);
+}
+
+void GonkBufferQueueCore::waitWhileAllocatingLocked() const {
+    ATRACE_CALL();
+    while (mIsAllocating) {
+        mIsAllocatingCondition.wait(mMutex);
+    }
+}
+
+} // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.h
new file mode 100644
index 000000000..936e11686
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueCore.h
@@ -0,0 +1,251 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERQUEUECORE_LL_H
+#define NATIVEWINDOW_GONKBUFFERQUEUECORE_LL_H
+
+#include "GonkBufferQueueDefs.h"
+#include "GonkBufferSlot.h"
+
+#include <utils/Condition.h>
+#include <utils/Mutex.h>
+#include <utils/NativeHandle.h>
+#include <utils/RefBase.h>
+#include <utils/String8.h>
+#include <utils/StrongPointer.h>
+#include <utils/Trace.h>
+#include <utils/Vector.h>
+
+#include "mozilla/layers/TextureClient.h"
+
+#define ATRACE_BUFFER_INDEX(index)
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+using namespace mozilla::layers;
+
+namespace android {
+
+class GonkBufferItem;
+class IConsumerListener;
+class IGraphicBufferAlloc;
+class IProducerListener;
+
+class GonkBufferQueueCore : public virtual RefBase {
+
+    friend class GonkBufferQueueProducer;
+    friend class GonkBufferQueueConsumer;
+
+public:
+    // Used as a placeholder slot number when the value isn't pointing to an
+    // existing buffer.
+    enum { INVALID_BUFFER_SLOT = -1 }; // TODO: Extract from IGBC::BufferItem
+
+    // We reserve two slots in order to guarantee that the producer and
+    // consumer can run asynchronously.
+    enum { MAX_MAX_ACQUIRED_BUFFERS = GonkBufferQueueDefs::NUM_BUFFER_SLOTS - 2 };
+
+    // The default API number used to indicate that no producer is connected
+    enum { NO_CONNECTED_API = 0 };
+
+    typedef Vector<GonkBufferItem> Fifo;
+    typedef mozilla::layers::TextureClient TextureClient;
+
+    // GonkBufferQueueCore manages a pool of gralloc memory slots to be used by
+    // producers and consumers. allocator is used to allocate all the needed
+    // gralloc buffers.
+    GonkBufferQueueCore(const sp<IGraphicBufferAlloc>& allocator = NULL);
+    virtual ~GonkBufferQueueCore();
+
+private:
+    // Dump our state in a string
+    void dump(String8& result, const char* prefix) const;
+
+    int getSlotFromTextureClientLocked(TextureClient* client) const;
+
+    // getMinUndequeuedBufferCountLocked returns the minimum number of buffers
+    // that must remain in a state other than DEQUEUED. The async parameter
+    // tells whether we're in asynchronous mode.
+    int getMinUndequeuedBufferCountLocked(bool async) const;
+
+    // getMinMaxBufferCountLocked returns the minimum number of buffers allowed
+    // given the current GonkBufferQueue state. The async parameter tells whether
+    // we're in asynchonous mode.
+    int getMinMaxBufferCountLocked(bool async) const;
+
+    // getMaxBufferCountLocked returns the maximum number of buffers that can be
+    // allocated at once. This value depends on the following member variables:
+    //
+    //     mDequeueBufferCannotBlock
+    //     mMaxAcquiredBufferCount
+    //     mDefaultMaxBufferCount
+    //     mOverrideMaxBufferCount
+    //     async parameter
+    //
+    // Any time one of these member variables is changed while a producer is
+    // connected, mDequeueCondition must be broadcast.
+    int getMaxBufferCountLocked(bool async) const;
+
+    // setDefaultMaxBufferCountLocked sets the maximum number of buffer slots
+    // that will be used if the producer does not override the buffer slot
+    // count. The count must be between 2 and NUM_BUFFER_SLOTS, inclusive. The
+    // initial default is 2.
+    status_t setDefaultMaxBufferCountLocked(int count);
+
+    // freeBufferLocked frees the GraphicBuffer and sync resources for the
+    // given slot.
+    void freeBufferLocked(int slot);
+
+    // freeAllBuffersLocked frees the GraphicBuffer and sync resources for
+    // all slots.
+    void freeAllBuffersLocked();
+
+    // stillTracking returns true iff the buffer item is still being tracked
+    // in one of the slots.
+    bool stillTracking(const GonkBufferItem* item) const;
+
+    // waitWhileAllocatingLocked blocks until mIsAllocating is false.
+    void waitWhileAllocatingLocked() const;
+
+    // mAllocator is the connection to SurfaceFlinger that is used to allocate
+    // new GraphicBuffer objects.
+    sp<IGraphicBufferAlloc> mAllocator;
+
+    // mMutex is the mutex used to prevent concurrent access to the member
+    // variables of GonkBufferQueueCore objects. It must be locked whenever any
+    // member variable is accessed.
+    mutable Mutex mMutex;
+
+    // mIsAbandoned indicates that the GonkBufferQueue will no longer be used to
+    // consume image buffers pushed to it using the IGraphicBufferProducer
+    // interface. It is initialized to false, and set to true in the
+    // consumerDisconnect method. A GonkBufferQueue that is abandoned will return
+    // the NO_INIT error from all IGraphicBufferProducer methods capable of
+    // returning an error.
+    bool mIsAbandoned;
+
+    // mConsumerControlledByApp indicates whether the connected consumer is
+    // controlled by the application.
+    bool mConsumerControlledByApp;
+
+    // mConsumerName is a string used to identify the GonkBufferQueue in log
+    // messages. It is set by the IGraphicBufferConsumer::setConsumerName
+    // method.
+    String8 mConsumerName;
+
+    // mConsumerListener is used to notify the connected consumer of
+    // asynchronous events that it may wish to react to. It is initially
+    // set to NULL and is written by consumerConnect and consumerDisconnect.
+    sp<IConsumerListener> mConsumerListener;
+
+    // mConsumerUsageBits contains flags that the consumer wants for
+    // GraphicBuffers.
+    uint32_t mConsumerUsageBits;
+
+    // mConnectedApi indicates the producer API that is currently connected
+    // to this GonkBufferQueue. It defaults to NO_CONNECTED_API, and gets updated
+    // by the connect and disconnect methods.
+    int mConnectedApi;
+
+    // mConnectedProducerToken is used to set a binder death notification on
+    // the producer.
+    sp<IProducerListener> mConnectedProducerListener;
+
+    // mSlots is an array of buffer slots that must be mirrored on the producer
+    // side. This allows buffer ownership to be transferred between the producer
+    // and consumer without sending a GraphicBuffer over Binder. The entire
+    // array is initialized to NULL at construction time, and buffers are
+    // allocated for a slot when requestBuffer is called with that slot's index.
+    GonkBufferQueueDefs::SlotsType mSlots;
+
+    // mQueue is a FIFO of queued buffers used in synchronous mode.
+    Fifo mQueue;
+
+    // mOverrideMaxBufferCount is the limit on the number of buffers that will
+    // be allocated at one time. This value is set by the producer by calling
+    // setBufferCount. The default is 0, which means that the producer doesn't
+    // care about the number of buffers in the pool. In that case,
+    // mDefaultMaxBufferCount is used as the limit.
+    int mOverrideMaxBufferCount;
+
+    // mDequeueCondition is a condition variable used for dequeueBuffer in
+    // synchronous mode.
+    mutable Condition mDequeueCondition;
+
+    // mUseAsyncBuffer indicates whether an extra buffer is used in async mode
+    // to prevent dequeueBuffer from blocking.
+    bool mUseAsyncBuffer;
+
+    // mDequeueBufferCannotBlock indicates whether dequeueBuffer is allowed to
+    // block. This flag is set during connect when both the producer and
+    // consumer are controlled by the application.
+    bool mDequeueBufferCannotBlock;
+
+    // mDefaultBufferFormat can be set so it will override the buffer format
+    // when it isn't specified in dequeueBuffer.
+    uint32_t mDefaultBufferFormat;
+
+    // mDefaultWidth holds the default width of allocated buffers. It is used
+    // in dequeueBuffer if a width and height of 0 are specified.
+    int mDefaultWidth;
+
+    // mDefaultHeight holds the default height of allocated buffers. It is used
+    // in dequeueBuffer if a width and height of 0 are specified.
+    int mDefaultHeight;
+
+    // mDefaultMaxBufferCount is the default limit on the number of buffers that
+    // will be allocated at one time. This default limit is set by the consumer.
+    // The limit (as opposed to the default limit) may be overriden by the
+    // producer.
+    int mDefaultMaxBufferCount;
+
+    // mMaxAcquiredBufferCount is the number of buffers that the consumer may
+    // acquire at one time. It defaults to 1, and can be changed by the consumer
+    // via setMaxAcquiredBufferCount, but this may only be done while no
+    // producer is connected to the GonkBufferQueue. This value is used to derive
+    // the value returned for the MIN_UNDEQUEUED_BUFFERS query to the producer.
+    int mMaxAcquiredBufferCount;
+
+    // mBufferHasBeenQueued is true once a buffer has been queued. It is reset
+    // when something causes all buffers to be freed (e.g., changing the buffer
+    // count).
+    bool mBufferHasBeenQueued;
+
+    // mFrameCounter is the free running counter, incremented on every
+    // successful queueBuffer call and buffer allocation.
+    uint64_t mFrameCounter;
+
+    // mTransformHint is used to optimize for screen rotations.
+    uint32_t mTransformHint;
+
+    // mSidebandStream is a handle to the sideband buffer stream, if any
+    sp<NativeHandle> mSidebandStream;
+
+    // mIsAllocating indicates whether a producer is currently trying to allocate buffers (which
+    // releases mMutex while doing the allocation proper). Producers should not modify any of the
+    // FREE slots while this is true. mIsAllocatingCondition is signaled when this value changes to
+    // false.
+    bool mIsAllocating;
+
+    // mIsAllocatingCondition is a condition variable used by producers to wait until mIsAllocating
+    // becomes false.
+    mutable Condition mIsAllocatingCondition;
+}; // class GonkBufferQueueCore
+
+} // namespace android
+
+#endif
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueDefs.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueDefs.h
new file mode 100644
index 000000000..60085706f
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueDefs.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_BUFFERQUEUECOREDEFS_H
+#define NATIVEWINDOW_BUFFERQUEUECOREDEFS_H
+
+#include "GonkBufferSlot.h"
+
+namespace android {
+    class GonkBufferQueueCore;
+
+    namespace GonkBufferQueueDefs {
+        // GonkBufferQueue will keep track of at most this value of buffers.
+        // Attempts at runtime to increase the number of buffers past this
+        // will fail.
+        enum { NUM_BUFFER_SLOTS = 64 };
+
+        typedef GonkBufferSlot SlotsType[NUM_BUFFER_SLOTS];
+    } // namespace GonkBufferQueueDefs
+} // namespace android
+
+#endif
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.cpp
new file mode 100644
index 000000000..649d06bee
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#define LOG_TAG "GonkBufferQueue"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+#define LOG_NDEBUG 0
+
+#include "GonkBufferQueue.h"
+#include "GonkBufferQueueConsumer.h"
+#include "GonkBufferQueueCore.h"
+#include "GonkBufferQueueProducer.h"
+
+namespace android {
+
+GonkBufferQueue::ProxyConsumerListener::ProxyConsumerListener(
+        const wp<ConsumerListener>& consumerListener):
+        mConsumerListener(consumerListener) {}
+
+GonkBufferQueue::ProxyConsumerListener::~ProxyConsumerListener() {}
+
+#if ANDROID_VERSION == 21
+void GonkBufferQueue::ProxyConsumerListener::onFrameAvailable() {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        listener->onFrameAvailable();
+    }
+}
+#else
+void GonkBufferQueue::ProxyConsumerListener::onFrameAvailable(const ::android::BufferItem& item) {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        listener->onFrameAvailable(item);
+    }
+}
+
+void GonkBufferQueue::ProxyConsumerListener::onFrameReplaced(const ::android::BufferItem& item) {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        listener->onFrameReplaced(item);
+    }
+}
+#endif
+
+void GonkBufferQueue::ProxyConsumerListener::onBuffersReleased() {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        listener->onBuffersReleased();
+    }
+}
+
+void GonkBufferQueue::ProxyConsumerListener::onSidebandStreamChanged() {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        listener->onSidebandStreamChanged();
+    }
+}
+
+void GonkBufferQueue::createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
+        sp<IGonkGraphicBufferConsumer>* outConsumer,
+        const sp<IGraphicBufferAlloc>& allocator) {
+    LOG_ALWAYS_FATAL_IF(outProducer == NULL,
+            "GonkBufferQueue: outProducer must not be NULL");
+    LOG_ALWAYS_FATAL_IF(outConsumer == NULL,
+            "GonkBufferQueue: outConsumer must not be NULL");
+
+    sp<GonkBufferQueueCore> core(new GonkBufferQueueCore(allocator));
+    LOG_ALWAYS_FATAL_IF(core == NULL,
+            "GonkBufferQueue: failed to create GonkBufferQueueCore");
+
+    sp<IGraphicBufferProducer> producer(new GonkBufferQueueProducer(core));
+    LOG_ALWAYS_FATAL_IF(producer == NULL,
+            "GonkBufferQueue: failed to create GonkBufferQueueProducer");
+
+    sp<IGonkGraphicBufferConsumer> consumer(new GonkBufferQueueConsumer(core));
+    LOG_ALWAYS_FATAL_IF(consumer == NULL,
+            "GonkBufferQueue: failed to create GonkBufferQueueConsumer");
+
+    *outProducer = producer;
+    *outConsumer = consumer;
+}
+
+}; // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.h
new file mode 100644
index 000000000..b1b4e06b5
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueLL.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERQUEUE_LL_H
+#define NATIVEWINDOW_GONKBUFFERQUEUE_LL_H
+
+#include "GonkBufferQueueDefs.h"
+#include "IGonkGraphicBufferConsumerLL.h"
+#include <gui/IGraphicBufferProducer.h>
+#include <gui/IConsumerListener.h>
+
+// These are only required to keep other parts of the framework with incomplete
+// dependencies building successfully
+#include <gui/IGraphicBufferAlloc.h>
+
+namespace android {
+
+class GonkBufferQueue {
+public:
+    // GonkBufferQueue will keep track of at most this value of buffers.
+    // Attempts at runtime to increase the number of buffers past this will fail.
+    enum { NUM_BUFFER_SLOTS = GonkBufferQueueDefs::NUM_BUFFER_SLOTS };
+    // Used as a placeholder slot# when the value isn't pointing to an existing buffer.
+    enum { INVALID_BUFFER_SLOT = IGonkGraphicBufferConsumer::BufferItem::INVALID_BUFFER_SLOT };
+    // Alias to <IGonkGraphicBufferConsumer.h> -- please scope from there in future code!
+    enum {
+        NO_BUFFER_AVAILABLE = IGonkGraphicBufferConsumer::NO_BUFFER_AVAILABLE,
+        PRESENT_LATER = IGonkGraphicBufferConsumer::PRESENT_LATER,
+    };
+
+    // When in async mode we reserve two slots in order to guarantee that the
+    // producer and consumer can run asynchronously.
+    enum { MAX_MAX_ACQUIRED_BUFFERS = NUM_BUFFER_SLOTS - 2 };
+
+    // for backward source compatibility
+    typedef ::android::ConsumerListener ConsumerListener;
+    typedef IGonkGraphicBufferConsumer::BufferItem BufferItem;
+
+    // ProxyConsumerListener is a ConsumerListener implementation that keeps a weak
+    // reference to the actual consumer object.  It forwards all calls to that
+    // consumer object so long as it exists.
+    //
+    // This class exists to avoid having a circular reference between the
+    // GonkBufferQueue object and the consumer object.  The reason this can't be a weak
+    // reference in the GonkBufferQueue class is because we're planning to expose the
+    // consumer side of a GonkBufferQueue as a binder interface, which doesn't support
+    // weak references.
+    class ProxyConsumerListener : public BnConsumerListener {
+    public:
+        ProxyConsumerListener(const wp<ConsumerListener>& consumerListener);
+        virtual ~ProxyConsumerListener();
+#if ANDROID_VERSION == 21
+        virtual void onFrameAvailable();
+#else
+        virtual void onFrameAvailable(const ::android::BufferItem& item);
+        virtual void onFrameReplaced(const ::android::BufferItem& item);
+#endif
+        virtual void onBuffersReleased();
+        virtual void onSidebandStreamChanged();
+    private:
+        // mConsumerListener is a weak reference to the IConsumerListener.  This is
+        // the raison d'etre of ProxyConsumerListener.
+        wp<ConsumerListener> mConsumerListener;
+    };
+
+    // GonkBufferQueue manages a pool of gralloc memory slots to be used by
+    // producers and consumers. allocator is used to allocate all the
+    // needed gralloc buffers.
+    static void createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
+            sp<IGonkGraphicBufferConsumer>* outConsumer,
+            const sp<IGraphicBufferAlloc>& allocator = NULL);
+
+private:
+    GonkBufferQueue(); // Create through createBufferQueue
+};
+
+// ----------------------------------------------------------------------------
+}; // namespace android
+
+#endif // NATIVEWINDOW_GONKBUFFERQUEUE_LL_H
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.cpp
new file mode 100644
index 000000000..d3436756f
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.cpp
@@ -0,0 +1,886 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#include <inttypes.h>
+
+#define LOG_TAG "GonkBufferQueueProducer"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+//#define LOG_NDEBUG 0
+
+#include "GonkBufferItem.h"
+#include "GonkBufferQueueCore.h"
+#include "GonkBufferQueueProducer.h"
+#include <gui/IConsumerListener.h>
+#include <gui/IGraphicBufferAlloc.h>
+#include <gui/IProducerListener.h>
+
+#include <cutils/compiler.h>
+#include <utils/Log.h>
+#include <utils/Trace.h>
+
+#include "mozilla/layers/GrallocTextureClient.h"
+#include "mozilla/layers/ImageBridgeChild.h"
+#include "mozilla/layers/TextureClient.h"
+
+namespace android {
+
+GonkBufferQueueProducer::GonkBufferQueueProducer(const sp<GonkBufferQueueCore>& core) :
+    mCore(core),
+    mSlots(core->mSlots),
+    mConsumerName(),
+    mSynchronousMode(true),
+    mStickyTransform(0) {}
+
+GonkBufferQueueProducer::~GonkBufferQueueProducer() {}
+
+status_t GonkBufferQueueProducer::requestBuffer(int slot, sp<GraphicBuffer>* buf) {
+    ATRACE_CALL();
+    ALOGV("requestBuffer: slot %d", slot);
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("requestBuffer: GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    if (slot < 0 || slot >= GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+        ALOGE("requestBuffer: slot index %d out of range [0, %d)",
+                slot, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+        return BAD_VALUE;
+    } else if (mSlots[slot].mBufferState != GonkBufferSlot::DEQUEUED) {
+        ALOGE("requestBuffer: slot %d is not owned by the producer "
+                "(state = %d)", slot, mSlots[slot].mBufferState);
+        return BAD_VALUE;
+    }
+
+    mSlots[slot].mRequestBufferCalled = true;
+    *buf = mSlots[slot].mGraphicBuffer;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::setBufferCount(int bufferCount) {
+    ATRACE_CALL();
+    ALOGV("setBufferCount: count = %d", bufferCount);
+
+    sp<IConsumerListener> listener;
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+        mCore->waitWhileAllocatingLocked();
+
+        if (mCore->mIsAbandoned) {
+            ALOGE("setBufferCount: GonkBufferQueue has been abandoned");
+            return NO_INIT;
+        }
+
+        if (bufferCount > GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+            ALOGE("setBufferCount: bufferCount %d too large (max %d)",
+                    bufferCount, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+            return BAD_VALUE;
+        }
+
+        // There must be no dequeued buffers when changing the buffer count.
+        for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+            if (mSlots[s].mBufferState == GonkBufferSlot::DEQUEUED) {
+                ALOGE("setBufferCount: buffer owned by producer");
+                return BAD_VALUE;
+            }
+        }
+
+        if (bufferCount == 0) {
+            mCore->mOverrideMaxBufferCount = 0;
+            mCore->mDequeueCondition.broadcast();
+            return NO_ERROR;
+        }
+
+        const int minBufferSlots = mCore->getMinMaxBufferCountLocked(false);
+        if (bufferCount < minBufferSlots) {
+            ALOGE("setBufferCount: requested buffer count %d is less than "
+                    "minimum %d", bufferCount, minBufferSlots);
+            return BAD_VALUE;
+        }
+
+        // Here we are guaranteed that the producer doesn't have any dequeued
+        // buffers and will release all of its buffer references. We don't
+        // clear the queue, however, so that currently queued buffers still
+        // get displayed.
+        mCore->freeAllBuffersLocked();
+        mCore->mOverrideMaxBufferCount = bufferCount;
+        mCore->mDequeueCondition.broadcast();
+        listener = mCore->mConsumerListener;
+    } // Autolock scope
+
+    // Call back without lock held
+    if (listener != NULL) {
+        listener->onBuffersReleased();
+    }
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::waitForFreeSlotThenRelock(const char* caller,
+        bool async, int* found, status_t* returnFlags) const {
+    bool tryAgain = true;
+    while (tryAgain) {
+        if (mCore->mIsAbandoned) {
+            ALOGE("%s: GonkBufferQueue has been abandoned", caller);
+            return NO_INIT;
+        }
+
+        const int maxBufferCount = mCore->getMaxBufferCountLocked(async);
+        if (async && mCore->mOverrideMaxBufferCount) {
+            // FIXME: Some drivers are manually setting the buffer count
+            // (which they shouldn't), so we do this extra test here to
+            // handle that case. This is TEMPORARY until we get this fixed.
+            if (mCore->mOverrideMaxBufferCount < maxBufferCount) {
+                ALOGE("%s: async mode is invalid with buffer count override",
+                        caller);
+                return BAD_VALUE;
+            }
+        }
+
+        // Free up any buffers that are in slots beyond the max buffer count
+        //for (int s = maxBufferCount; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        //    assert(mSlots[s].mBufferState == GonkBufferSlot::FREE);
+        //    if (mSlots[s].mGraphicBuffer != NULL) {
+        //        mCore->freeBufferLocked(s);
+        //        *returnFlags |= RELEASE_ALL_BUFFERS;
+        //    }
+        //}
+
+        // Look for a free buffer to give to the client
+        *found = GonkBufferQueueCore::INVALID_BUFFER_SLOT;
+        int dequeuedCount = 0;
+        int acquiredCount = 0;
+        for (int s = 0; s < maxBufferCount; ++s) {
+            switch (mSlots[s].mBufferState) {
+                case GonkBufferSlot::DEQUEUED:
+                    ++dequeuedCount;
+                    break;
+                case GonkBufferSlot::ACQUIRED:
+                    ++acquiredCount;
+                    break;
+                case GonkBufferSlot::FREE:
+                    // We return the oldest of the free buffers to avoid
+                    // stalling the producer if possible, since the consumer
+                    // may still have pending reads of in-flight buffers
+                    if (*found == GonkBufferQueueCore::INVALID_BUFFER_SLOT ||
+                            mSlots[s].mFrameNumber < mSlots[*found].mFrameNumber) {
+                        *found = s;
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        // Producers are not allowed to dequeue more than one buffer if they
+        // did not set a buffer count
+        if (!mCore->mOverrideMaxBufferCount && dequeuedCount) {
+            ALOGE("%s: can't dequeue multiple buffers without setting the "
+                    "buffer count", caller);
+            return INVALID_OPERATION;
+        }
+
+        // See whether a buffer has been queued since the last
+        // setBufferCount so we know whether to perform the min undequeued
+        // buffers check below
+        if (mCore->mBufferHasBeenQueued) {
+            // Make sure the producer is not trying to dequeue more buffers
+            // than allowed
+            const int newUndequeuedCount =
+                maxBufferCount - (dequeuedCount + 1);
+            const int minUndequeuedCount =
+                mCore->getMinUndequeuedBufferCountLocked(async);
+            if (newUndequeuedCount < minUndequeuedCount) {
+                ALOGE("%s: min undequeued buffer count (%d) exceeded "
+                        "(dequeued=%d undequeued=%d)",
+                        caller, minUndequeuedCount,
+                        dequeuedCount, newUndequeuedCount);
+                return INVALID_OPERATION;
+            }
+        }
+
+        // If we disconnect and reconnect quickly, we can be in a state where
+        // our slots are empty but we have many buffers in the queue. This can
+        // cause us to run out of memory if we outrun the consumer. Wait here if
+        // it looks like we have too many buffers queued up.
+        bool tooManyBuffers = mCore->mQueue.size()
+                            > static_cast<size_t>(maxBufferCount);
+        if (tooManyBuffers) {
+            ALOGV("%s: queue size is %zu, waiting", caller,
+                    mCore->mQueue.size());
+        }
+
+        // If no buffer is found, or if the queue has too many buffers
+        // outstanding, wait for a buffer to be acquired or released, or for the
+        // max buffer count to change.
+        tryAgain = (*found == GonkBufferQueueCore::INVALID_BUFFER_SLOT) ||
+                   tooManyBuffers;
+        if (tryAgain) {
+            // Return an error if we're in non-blocking mode (producer and
+            // consumer are controlled by the application).
+            // However, the consumer is allowed to briefly acquire an extra
+            // buffer (which could cause us to have to wait here), which is
+            // okay, since it is only used to implement an atomic acquire +
+            // release (e.g., in GLConsumer::updateTexImage())
+            if (mCore->mDequeueBufferCannotBlock &&
+                    (acquiredCount <= mCore->mMaxAcquiredBufferCount)) {
+                return WOULD_BLOCK;
+            }
+            mCore->mDequeueCondition.wait(mCore->mMutex);
+        }
+    } // while (tryAgain)
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::dequeueBuffer(int *outSlot,
+        sp<android::Fence> *outFence, bool async,
+        uint32_t width, uint32_t height, uint32_t format, uint32_t usage) {
+    ATRACE_CALL();
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+        mConsumerName = mCore->mConsumerName;
+    } // Autolock scope
+
+    ALOGV("dequeueBuffer: async=%s w=%u h=%u format=%#x, usage=%#x",
+            async ? "true" : "false", width, height, format, usage);
+
+    if ((width && !height) || (!width && height)) {
+        ALOGE("dequeueBuffer: invalid size: w=%u h=%u", width, height);
+        return BAD_VALUE;
+    }
+
+    status_t returnFlags = NO_ERROR;
+    // Reset slot
+    *outSlot = GonkBufferQueueCore::INVALID_BUFFER_SLOT;
+
+    bool attachedByConsumer = false;
+
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+        mCore->waitWhileAllocatingLocked();
+
+        if (format == 0) {
+            format = mCore->mDefaultBufferFormat;
+        }
+
+        // Enable the usage bits the consumer requested
+        usage |= mCore->mConsumerUsageBits;
+
+        int found;
+        status_t status = waitForFreeSlotThenRelock("dequeueBuffer", async,
+                &found, &returnFlags);
+        if (status != NO_ERROR) {
+            return status;
+        }
+
+        // This should not happen
+        if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT) {
+            ALOGE("dequeueBuffer: no available buffer slots");
+            return -EBUSY;
+        }
+
+        *outSlot = found;
+
+        attachedByConsumer = mSlots[found].mAttachedByConsumer;
+
+        const bool useDefaultSize = !width && !height;
+        if (useDefaultSize) {
+            width = mCore->mDefaultWidth;
+            height = mCore->mDefaultHeight;
+        }
+
+        mSlots[found].mBufferState = GonkBufferSlot::DEQUEUED;
+
+        const sp<GraphicBuffer>& buffer(mSlots[found].mGraphicBuffer);
+        if ((buffer == NULL) ||
+                (static_cast<uint32_t>(buffer->width) != width) ||
+                (static_cast<uint32_t>(buffer->height) != height) ||
+                (static_cast<uint32_t>(buffer->format) != format) ||
+                ((static_cast<uint32_t>(buffer->usage) & usage) != usage))
+        {
+            mSlots[found].mAcquireCalled = false;
+            mSlots[found].mGraphicBuffer = NULL;
+            mSlots[found].mRequestBufferCalled = false;
+            mSlots[found].mFence = Fence::NO_FENCE;
+
+            if (mSlots[found].mTextureClient) {
+                mSlots[found].mTextureClient->ClearRecycleCallback();
+                // release TextureClient in ImageBridge thread
+                RefPtr<TextureClientReleaseTask> task =
+                  MakeAndAddRef<TextureClientReleaseTask>(mSlots[found].mTextureClient);
+                mSlots[found].mTextureClient = NULL;
+                ImageBridgeChild::GetSingleton()->GetMessageLoop()->PostTask(task.forget());
+            }
+
+            returnFlags |= BUFFER_NEEDS_REALLOCATION;
+        }
+
+        if (CC_UNLIKELY(mSlots[found].mFence == NULL)) {
+            ALOGE("dequeueBuffer: about to return a NULL fence - "
+                    "slot=%d w=%d h=%d format=%u",
+                    found, buffer->width, buffer->height, buffer->format);
+        }
+
+        *outFence = mSlots[found].mFence;
+        mSlots[found].mFence = Fence::NO_FENCE;
+    } // Autolock scope
+
+    if (returnFlags & BUFFER_NEEDS_REALLOCATION) {
+        RefPtr<LayersIPCChannel> allocator = ImageBridgeChild::GetSingleton();
+        usage |= GraphicBuffer::USAGE_HW_TEXTURE;
+        GrallocTextureData* texData = GrallocTextureData::Create(IntSize(width,height), format,
+                                                                 gfx::BackendType::NONE,
+                                                                 usage, allocator);
+        if (!texData) {
+            ALOGE("dequeueBuffer: failed to alloc gralloc buffer");
+            return -ENOMEM;
+        }
+        RefPtr<TextureClient> textureClient = TextureClient::CreateWithData(
+            texData, TextureFlags::RECYCLE | TextureFlags::DEALLOCATE_CLIENT, allocator);
+
+        sp<GraphicBuffer> graphicBuffer = texData->GetGraphicBuffer();
+
+        { // Autolock scope
+            Mutex::Autolock lock(mCore->mMutex);
+
+            if (mCore->mIsAbandoned) {
+                ALOGE("dequeueBuffer: GonkBufferQueue has been abandoned");
+                return NO_INIT;
+            }
+
+            mSlots[*outSlot].mFrameNumber = UINT32_MAX;
+            mSlots[*outSlot].mGraphicBuffer = graphicBuffer;
+            mSlots[*outSlot].mTextureClient = textureClient;
+        } // Autolock scope
+    }
+
+    if (attachedByConsumer) {
+        returnFlags |= BUFFER_NEEDS_REALLOCATION;
+    }
+
+    ALOGV("dequeueBuffer: returning slot=%d/%" PRIu64 " buf=%p flags=%#x",
+            *outSlot,
+            mSlots[*outSlot].mFrameNumber,
+            mSlots[*outSlot].mGraphicBuffer->handle, returnFlags);
+
+    return returnFlags;
+}
+
+status_t GonkBufferQueueProducer::detachBuffer(int slot) {
+    ATRACE_CALL();
+    ATRACE_BUFFER_INDEX(slot);
+    ALOGV("detachBuffer(P): slot %d", slot);
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("detachBuffer(P): GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    if (slot < 0 || slot >= GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+        ALOGE("detachBuffer(P): slot index %d out of range [0, %d)",
+                slot, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+        return BAD_VALUE;
+    } else if (mSlots[slot].mBufferState != GonkBufferSlot::DEQUEUED) {
+        ALOGE("detachBuffer(P): slot %d is not owned by the producer "
+                "(state = %d)", slot, mSlots[slot].mBufferState);
+        return BAD_VALUE;
+    } else if (!mSlots[slot].mRequestBufferCalled) {
+        ALOGE("detachBuffer(P): buffer in slot %d has not been requested",
+                slot);
+        return BAD_VALUE;
+    }
+
+    mCore->freeBufferLocked(slot);
+    mCore->mDequeueCondition.broadcast();
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::detachNextBuffer(sp<GraphicBuffer>* outBuffer,
+        sp<Fence>* outFence) {
+    ATRACE_CALL();
+
+    if (outBuffer == NULL) {
+        ALOGE("detachNextBuffer: outBuffer must not be NULL");
+        return BAD_VALUE;
+    } else if (outFence == NULL) {
+        ALOGE("detachNextBuffer: outFence must not be NULL");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->waitWhileAllocatingLocked();
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("detachNextBuffer: GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    // Find the oldest valid slot
+    int found = GonkBufferQueueCore::INVALID_BUFFER_SLOT;
+    for (int s = 0; s < GonkBufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+        if (mSlots[s].mBufferState == GonkBufferSlot::FREE &&
+                mSlots[s].mGraphicBuffer != NULL) {
+            if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT ||
+                    mSlots[s].mFrameNumber < mSlots[found].mFrameNumber) {
+                found = s;
+            }
+        }
+    }
+
+    if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT) {
+        return NO_MEMORY;
+    }
+
+    ALOGV("detachNextBuffer detached slot %d", found);
+
+    *outBuffer = mSlots[found].mGraphicBuffer;
+    *outFence = mSlots[found].mFence;
+    mCore->freeBufferLocked(found);
+
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::attachBuffer(int* outSlot,
+        const sp<android::GraphicBuffer>& buffer) {
+    ATRACE_CALL();
+
+    if (outSlot == NULL) {
+        ALOGE("attachBuffer(P): outSlot must not be NULL");
+        return BAD_VALUE;
+    } else if (buffer == NULL) {
+        ALOGE("attachBuffer(P): cannot attach NULL buffer");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock lock(mCore->mMutex);
+    mCore->waitWhileAllocatingLocked();
+
+    status_t returnFlags = NO_ERROR;
+    int found;
+    // TODO: Should we provide an async flag to attachBuffer? It seems
+    // unlikely that buffers which we are attaching to a GonkBufferQueue will
+    // be asynchronous (droppable), but it may not be impossible.
+    status_t status = waitForFreeSlotThenRelock("attachBuffer(P)", false,
+            &found, &returnFlags);
+    if (status != NO_ERROR) {
+        return status;
+    }
+
+    // This should not happen
+    if (found == GonkBufferQueueCore::INVALID_BUFFER_SLOT) {
+        ALOGE("attachBuffer(P): no available buffer slots");
+        return -EBUSY;
+    }
+
+    *outSlot = found;
+    ATRACE_BUFFER_INDEX(*outSlot);
+    ALOGV("attachBuffer(P): returning slot %d flags=%#x",
+            *outSlot, returnFlags);
+
+    mSlots[*outSlot].mGraphicBuffer = buffer;
+    mSlots[*outSlot].mBufferState = GonkBufferSlot::DEQUEUED;
+    mSlots[*outSlot].mFence = Fence::NO_FENCE;
+    mSlots[*outSlot].mRequestBufferCalled = true;
+
+    return returnFlags;
+}
+
+status_t GonkBufferQueueProducer::setSynchronousMode(bool enabled) {
+    ALOGV("setSynchronousMode: enabled=%d", enabled);
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("setSynchronousMode: BufferQueue has been abandoned!");
+        return NO_INIT;
+    }
+
+    if (mSynchronousMode != enabled) {
+        mSynchronousMode = enabled;
+        mCore->mDequeueCondition.broadcast();
+    }
+    return OK;
+}
+
+status_t GonkBufferQueueProducer::queueBuffer(int slot,
+        const QueueBufferInput &input, QueueBufferOutput *output) {
+    ATRACE_CALL();
+
+    int64_t timestamp;
+    bool isAutoTimestamp;
+    Rect crop;
+    int scalingMode;
+    uint32_t transform;
+    uint32_t stickyTransform;
+    bool async;
+    sp<Fence> fence;
+    input.deflate(&timestamp, &isAutoTimestamp, &crop, &scalingMode, &transform,
+            &async, &fence, &stickyTransform);
+
+    if (fence == NULL) {
+        ALOGE("queueBuffer: fence is NULL");
+        // Temporary workaround for b/17946343: soldier-on instead of returning an error. This
+        // prevents the client from dying, at the risk of visible corruption due to hwcomposer
+        // reading the buffer before the producer is done rendering it. Unless the buffer is the
+        // last frame of an animation, the corruption will be transient.
+        fence = Fence::NO_FENCE;
+        // return BAD_VALUE;
+    }
+
+    switch (scalingMode) {
+        case NATIVE_WINDOW_SCALING_MODE_FREEZE:
+        case NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW:
+        case NATIVE_WINDOW_SCALING_MODE_SCALE_CROP:
+        case NATIVE_WINDOW_SCALING_MODE_NO_SCALE_CROP:
+            break;
+        default:
+            ALOGE("queueBuffer: unknown scaling mode %d", scalingMode);
+            return BAD_VALUE;
+    }
+
+    GonkBufferItem item;
+    sp<IConsumerListener> listener;
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+
+        if (mCore->mIsAbandoned) {
+            ALOGE("queueBuffer: GonkBufferQueue has been abandoned");
+            return NO_INIT;
+        }
+
+        const int maxBufferCount = mCore->getMaxBufferCountLocked(async);
+        if (async && mCore->mOverrideMaxBufferCount) {
+            // FIXME: Some drivers are manually setting the buffer count
+            // (which they shouldn't), so we do this extra test here to
+            // handle that case. This is TEMPORARY until we get this fixed.
+            if (mCore->mOverrideMaxBufferCount < maxBufferCount) {
+                ALOGE("queueBuffer: async mode is invalid with "
+                        "buffer count override");
+                return BAD_VALUE;
+            }
+        }
+
+        if (slot < 0 || slot >= maxBufferCount) {
+            ALOGE("queueBuffer: slot index %d out of range [0, %d)",
+                    slot, maxBufferCount);
+            return BAD_VALUE;
+        } else if (mSlots[slot].mBufferState != GonkBufferSlot::DEQUEUED) {
+            ALOGE("queueBuffer: slot %d is not owned by the producer "
+                    "(state = %d)", slot, mSlots[slot].mBufferState);
+            return BAD_VALUE;
+        } else if (!mSlots[slot].mRequestBufferCalled) {
+            ALOGE("queueBuffer: slot %d was queued without requesting "
+                    "a buffer", slot);
+            return BAD_VALUE;
+        }
+
+        ALOGV("queueBuffer: slot=%d/%" PRIu64 " time=%" PRIu64
+                " crop=[%d,%d,%d,%d] transform=%#x scale=%s",
+                slot, mCore->mFrameCounter + 1, timestamp,
+                crop.left, crop.top, crop.right, crop.bottom,
+                transform, GonkBufferItem::scalingModeName(scalingMode));
+
+        const sp<GraphicBuffer>& graphicBuffer(mSlots[slot].mGraphicBuffer);
+        Rect bufferRect(graphicBuffer->getWidth(), graphicBuffer->getHeight());
+        Rect croppedRect;
+        crop.intersect(bufferRect, &croppedRect);
+        if (croppedRect != crop) {
+            ALOGE("queueBuffer: crop rect is not contained within the "
+                    "buffer in slot %d", slot);
+            return BAD_VALUE;
+        }
+
+        mSlots[slot].mFence = fence;
+        mSlots[slot].mBufferState = GonkBufferSlot::QUEUED;
+        ++mCore->mFrameCounter;
+        mSlots[slot].mFrameNumber = mCore->mFrameCounter;
+
+        item.mAcquireCalled = mSlots[slot].mAcquireCalled;
+        item.mGraphicBuffer = mSlots[slot].mGraphicBuffer;
+        item.mCrop = crop;
+        item.mTransform = transform & ~NATIVE_WINDOW_TRANSFORM_INVERSE_DISPLAY;
+        item.mTransformToDisplayInverse =
+                bool(transform & NATIVE_WINDOW_TRANSFORM_INVERSE_DISPLAY);
+        item.mScalingMode = scalingMode;
+        item.mTimestamp = timestamp;
+        item.mIsAutoTimestamp = isAutoTimestamp;
+        item.mFrameNumber = mCore->mFrameCounter;
+        item.mSlot = slot;
+        item.mFence = fence;
+        item.mIsDroppable = mCore->mDequeueBufferCannotBlock || async;
+
+        mStickyTransform = stickyTransform;
+
+        if (mCore->mQueue.empty()) {
+            // When the queue is empty, we can ignore mDequeueBufferCannotBlock
+            // and simply queue this buffer
+            mCore->mQueue.push_back(item);
+            listener = mCore->mConsumerListener;
+        } else {
+            // When the queue is not empty, we need to look at the front buffer
+            // state to see if we need to replace it
+            GonkBufferQueueCore::Fifo::iterator front(mCore->mQueue.begin());
+            if (front->mIsDroppable || !mSynchronousMode) {
+                // If the front queued buffer is still being tracked, we first
+                // mark it as freed
+                if (mCore->stillTracking(front)) {
+                    mSlots[front->mSlot].mBufferState = GonkBufferSlot::FREE;
+                    // Reset the frame number of the freed buffer so that it is
+                    // the first in line to be dequeued again
+                    mSlots[front->mSlot].mFrameNumber = 0;
+                }
+                // Overwrite the droppable buffer with the incoming one
+                *front = item;
+                listener = mCore->mConsumerListener;
+            } else {
+                mCore->mQueue.push_back(item);
+                listener = mCore->mConsumerListener;
+            }
+        }
+
+        mCore->mBufferHasBeenQueued = true;
+        mCore->mDequeueCondition.broadcast();
+
+        output->inflate(mCore->mDefaultWidth, mCore->mDefaultHeight,
+                mCore->mTransformHint, mCore->mQueue.size());
+
+        item.mGraphicBuffer.clear();
+        item.mSlot = GonkBufferItem::INVALID_BUFFER_SLOT;
+    } // Autolock scope
+
+    // Call back without lock held
+    if (listener != NULL) {
+#if ANDROID_VERSION == 21
+        listener->onFrameAvailable();
+#else
+        listener->onFrameAvailable(reinterpret_cast<::android::BufferItem&>(item));
+#endif
+    }
+
+    return NO_ERROR;
+}
+
+void GonkBufferQueueProducer::cancelBuffer(int slot, const sp<Fence>& fence) {
+    ATRACE_CALL();
+    ALOGV("cancelBuffer: slot %d", slot);
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("cancelBuffer: GonkBufferQueue has been abandoned");
+        return;
+    }
+
+    if (slot < 0 || slot >= GonkBufferQueueDefs::NUM_BUFFER_SLOTS) {
+        ALOGE("cancelBuffer: slot index %d out of range [0, %d)",
+                slot, GonkBufferQueueDefs::NUM_BUFFER_SLOTS);
+        return;
+    } else if (mSlots[slot].mBufferState != GonkBufferSlot::DEQUEUED) {
+        ALOGE("cancelBuffer: slot %d is not owned by the producer "
+                "(state = %d)", slot, mSlots[slot].mBufferState);
+        return;
+    } else if (fence == NULL) {
+        ALOGE("cancelBuffer: fence is NULL");
+        return;
+    }
+
+    mSlots[slot].mBufferState = GonkBufferSlot::FREE;
+    mSlots[slot].mFrameNumber = 0;
+    mSlots[slot].mFence = fence;
+    mCore->mDequeueCondition.broadcast();
+}
+
+int GonkBufferQueueProducer::query(int what, int *outValue) {
+    ATRACE_CALL();
+    Mutex::Autolock lock(mCore->mMutex);
+
+    if (outValue == NULL) {
+        ALOGE("query: outValue was NULL");
+        return BAD_VALUE;
+    }
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("query: GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    int value;
+    switch (what) {
+        case NATIVE_WINDOW_WIDTH:
+            value = mCore->mDefaultWidth;
+            break;
+        case NATIVE_WINDOW_HEIGHT:
+            value = mCore->mDefaultHeight;
+            break;
+        case NATIVE_WINDOW_FORMAT:
+            value = mCore->mDefaultBufferFormat;
+            break;
+        case NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS:
+            value = mCore->getMinUndequeuedBufferCountLocked(false);
+            break;
+        case NATIVE_WINDOW_STICKY_TRANSFORM:
+            value = static_cast<int>(mStickyTransform);
+            break;
+        case NATIVE_WINDOW_CONSUMER_RUNNING_BEHIND:
+            value = (mCore->mQueue.size() > 1);
+            break;
+        case NATIVE_WINDOW_CONSUMER_USAGE_BITS:
+            value = mCore->mConsumerUsageBits;
+            break;
+        default:
+            return BAD_VALUE;
+    }
+
+    ALOGV("query: %d? %d", what, value);
+    *outValue = value;
+    return NO_ERROR;
+}
+
+status_t GonkBufferQueueProducer::connect(const sp<IProducerListener>& listener,
+        int api, bool producerControlledByApp, QueueBufferOutput *output) {
+    ATRACE_CALL();
+    Mutex::Autolock lock(mCore->mMutex);
+    mConsumerName = mCore->mConsumerName;
+    ALOGV("connect(P): api=%d producerControlledByApp=%s", api,
+            producerControlledByApp ? "true" : "false");
+
+    if (mCore->mIsAbandoned) {
+        ALOGE("connect(P): GonkBufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    if (mCore->mConsumerListener == NULL) {
+        ALOGE("connect(P): GonkBufferQueue has no consumer");
+        return NO_INIT;
+    }
+
+    if (output == NULL) {
+        ALOGE("connect(P): output was NULL");
+        return BAD_VALUE;
+    }
+
+    if (mCore->mConnectedApi != GonkBufferQueueCore::NO_CONNECTED_API) {
+        ALOGE("connect(P): already connected (cur=%d req=%d)", mCore->mConnectedApi,
+              api);
+        return BAD_VALUE;
+    }
+
+    int status = NO_ERROR;
+    switch (api) {
+        case NATIVE_WINDOW_API_EGL:
+        case NATIVE_WINDOW_API_CPU:
+        case NATIVE_WINDOW_API_MEDIA:
+        case NATIVE_WINDOW_API_CAMERA:
+            mCore->mConnectedApi = api;
+            output->inflate(mCore->mDefaultWidth, mCore->mDefaultHeight,
+                    mCore->mTransformHint, mCore->mQueue.size());
+
+            // Set up a death notification so that we can disconnect
+            // automatically if the remote producer dies
+            if (listener != NULL &&
+                    listener->asBinder()->remoteBinder() != NULL) {
+                status = listener->asBinder()->linkToDeath(
+                        static_cast<IBinder::DeathRecipient*>(this));
+                if (status != NO_ERROR) {
+                    ALOGE("connect(P): linkToDeath failed: %s (%d)",
+                            strerror(-status), status);
+                }
+            }
+            mCore->mConnectedProducerListener = listener;
+            break;
+        default:
+            ALOGE("connect(P): unknown API %d", api);
+            status = BAD_VALUE;
+            break;
+    }
+
+    mCore->mBufferHasBeenQueued = false;
+    mCore->mDequeueBufferCannotBlock =
+            mCore->mConsumerControlledByApp && producerControlledByApp;
+
+    return status;
+}
+
+status_t GonkBufferQueueProducer::disconnect(int api) {
+    ATRACE_CALL();
+    ALOGV("disconnect(P): api %d", api);
+
+    int status = NO_ERROR;
+    sp<IConsumerListener> listener;
+    { // Autolock scope
+        Mutex::Autolock lock(mCore->mMutex);
+        mCore->waitWhileAllocatingLocked();
+
+        if (mCore->mIsAbandoned) {
+            // It's not really an error to disconnect after the surface has
+            // been abandoned; it should just be a no-op.
+            return NO_ERROR;
+        }
+
+        switch (api) {
+            case NATIVE_WINDOW_API_EGL:
+            case NATIVE_WINDOW_API_CPU:
+            case NATIVE_WINDOW_API_MEDIA:
+            case NATIVE_WINDOW_API_CAMERA:
+                if (mCore->mConnectedApi == api) {
+                    mCore->freeAllBuffersLocked();
+                    mCore->mConnectedApi = GonkBufferQueueCore::NO_CONNECTED_API;
+                    mCore->mSidebandStream.clear();
+                    mCore->mDequeueCondition.broadcast();
+                    listener = mCore->mConsumerListener;
+                } else {
+                    ALOGE("disconnect(P): connected to another API "
+                            "(cur=%d req=%d)", mCore->mConnectedApi, api);
+                    status = BAD_VALUE;
+                }
+                break;
+            default:
+                ALOGE("disconnect(P): unknown API %d", api);
+                status = BAD_VALUE;
+                break;
+        }
+    } // Autolock scope
+
+    // Call back without lock held
+    if (listener != NULL) {
+        listener->onBuffersReleased();
+    }
+
+    return status;
+}
+
+status_t GonkBufferQueueProducer::setSidebandStream(const sp<NativeHandle>& stream) {
+    return INVALID_OPERATION;
+}
+
+void GonkBufferQueueProducer::allocateBuffers(bool async, uint32_t width,
+        uint32_t height, uint32_t format, uint32_t usage) {
+    ALOGE("allocateBuffers: no op");
+}
+
+void GonkBufferQueueProducer::binderDied(const wp<android::IBinder>& /* who */) {
+    // If we're here, it means that a producer we were connected to died.
+    // We're guaranteed that we are still connected to it because we remove
+    // this callback upon disconnect. It's therefore safe to read mConnectedApi
+    // without synchronization here.
+    int api = mCore->mConnectedApi;
+    disconnect(api);
+}
+
+} // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.h
new file mode 100644
index 000000000..a1a22416a
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferQueueProducer.h
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERQUEUEPRODUCER_LL_H
+#define NATIVEWINDOW_GONKBUFFERQUEUEPRODUCER_LL_H
+
+#include "GonkBufferQueueDefs.h"
+#include <gui/IGraphicBufferProducer.h>
+
+namespace android {
+
+class GonkBufferQueueProducer : public BnGraphicBufferProducer,
+                            private IBinder::DeathRecipient {
+public:
+    friend class GonkBufferQueue; // Needed to access binderDied
+
+    GonkBufferQueueProducer(const sp<GonkBufferQueueCore>& core);
+    virtual ~GonkBufferQueueProducer();
+
+    // requestBuffer returns the GraphicBuffer for slot N.
+    //
+    // In normal operation, this is called the first time slot N is returned
+    // by dequeueBuffer.  It must be called again if dequeueBuffer returns
+    // flags indicating that previously-returned buffers are no longer valid.
+    virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf);
+
+    // setBufferCount updates the number of available buffer slots.  If this
+    // method succeeds, buffer slots will be both unallocated and owned by
+    // the GonkBufferQueue object (i.e. they are not owned by the producer or
+    // consumer).
+    //
+    // This will fail if the producer has dequeued any buffers, or if
+    // bufferCount is invalid.  bufferCount must generally be a value
+    // between the minimum undequeued buffer count (exclusive) and NUM_BUFFER_SLOTS
+    // (inclusive).  It may also be set to zero (the default) to indicate
+    // that the producer does not wish to set a value.  The minimum value
+    // can be obtained by calling query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS,
+    // ...).
+    //
+    // This may only be called by the producer.  The consumer will be told
+    // to discard buffers through the onBuffersReleased callback.
+    virtual status_t setBufferCount(int bufferCount);
+
+    // dequeueBuffer gets the next buffer slot index for the producer to use.
+    // If a buffer slot is available then that slot index is written to the
+    // location pointed to by the buf argument and a status of OK is returned.
+    // If no slot is available then a status of -EBUSY is returned and buf is
+    // unmodified.
+    //
+    // The outFence parameter will be updated to hold the fence associated with
+    // the buffer. The contents of the buffer must not be overwritten until the
+    // fence signals. If the fence is Fence::NO_FENCE, the buffer may be
+    // written immediately.
+    //
+    // The width and height parameters must be no greater than the minimum of
+    // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv).
+    // An error due to invalid dimensions might not be reported until
+    // updateTexImage() is called.  If width and height are both zero, the
+    // default values specified by setDefaultBufferSize() are used instead.
+    //
+    // The pixel formats are enumerated in graphics.h, e.g.
+    // HAL_PIXEL_FORMAT_RGBA_8888.  If the format is 0, the default format
+    // will be used.
+    //
+    // The usage argument specifies gralloc buffer usage flags.  The values
+    // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER.  These
+    // will be merged with the usage flags specified by setConsumerUsageBits.
+    //
+    // The return value may be a negative error value or a non-negative
+    // collection of flags.  If the flags are set, the return values are
+    // valid, but additional actions must be performed.
+    //
+    // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the
+    // producer must discard cached GraphicBuffer references for the slot
+    // returned in buf.
+    // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer
+    // must discard cached GraphicBuffer references for all slots.
+    //
+    // In both cases, the producer will need to call requestBuffer to get a
+    // GraphicBuffer handle for the returned slot.
+    virtual status_t dequeueBuffer(int *outSlot, sp<Fence>* outFence, bool async,
+            uint32_t width, uint32_t height, uint32_t format, uint32_t usage);
+
+    // See IGraphicBufferProducer::detachBuffer
+    virtual status_t detachBuffer(int slot);
+
+    // See IGraphicBufferProducer::detachNextBuffer
+    virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer,
+            sp<Fence>* outFence);
+
+    // See IGraphicBufferProducer::attachBuffer
+    virtual status_t attachBuffer(int* outSlot, const sp<GraphicBuffer>& buffer);
+
+    // queueBuffer returns a filled buffer to the GonkBufferQueue.
+    //
+    // Additional data is provided in the QueueBufferInput struct.  Notably,
+    // a timestamp must be provided for the buffer. The timestamp is in
+    // nanoseconds, and must be monotonically increasing. Its other semantics
+    // (zero point, etc) are producer-specific and should be documented by the
+    // producer.
+    //
+    // The caller may provide a fence that signals when all rendering
+    // operations have completed.  Alternatively, NO_FENCE may be used,
+    // indicating that the buffer is ready immediately.
+    //
+    // Some values are returned in the output struct: the current settings
+    // for default width and height, the current transform hint, and the
+    // number of queued buffers.
+    virtual status_t queueBuffer(int slot,
+            const QueueBufferInput& input, QueueBufferOutput* output);
+
+    // cancelBuffer returns a dequeued buffer to the GonkBufferQueue, but doesn't
+    // queue it for use by the consumer.
+    //
+    // The buffer will not be overwritten until the fence signals.  The fence
+    // will usually be the one obtained from dequeueBuffer.
+    virtual void cancelBuffer(int slot, const sp<Fence>& fence);
+
+    // Query native window attributes.  The "what" values are enumerated in
+    // window.h (e.g. NATIVE_WINDOW_FORMAT).
+    virtual int query(int what, int* outValue);
+
+    // connect attempts to connect a producer API to the GonkBufferQueue.  This
+    // must be called before any other IGraphicBufferProducer methods are
+    // called except for getAllocator.  A consumer must already be connected.
+    //
+    // This method will fail if connect was previously called on the
+    // GonkBufferQueue and no corresponding disconnect call was made (i.e. if
+    // it's still connected to a producer).
+    //
+    // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU).
+    virtual status_t connect(const sp<IProducerListener>& listener,
+            int api, bool producerControlledByApp, QueueBufferOutput* output);
+
+    // disconnect attempts to disconnect a producer API from the GonkBufferQueue.
+    // Calling this method will cause any subsequent calls to other
+    // IGraphicBufferProducer methods to fail except for getAllocator and connect.
+    // Successfully calling connect after this will allow the other methods to
+    // succeed again.
+    //
+    // This method will fail if the the GonkBufferQueue is not currently
+    // connected to the specified producer API.
+    virtual status_t disconnect(int api);
+
+    // Attaches a sideband buffer stream to the IGraphicBufferProducer.
+    //
+    // A sideband stream is a device-specific mechanism for passing buffers
+    // from the producer to the consumer without using dequeueBuffer/
+    // queueBuffer. If a sideband stream is present, the consumer can choose
+    // whether to acquire buffers from the sideband stream or from the queued
+    // buffers.
+    //
+    // Passing NULL or a different stream handle will detach the previous
+    // handle if any.
+    virtual status_t setSidebandStream(const sp<NativeHandle>& stream);
+
+    // See IGraphicBufferProducer::allocateBuffers
+    virtual void allocateBuffers(bool async, uint32_t width, uint32_t height,
+            uint32_t format, uint32_t usage);
+
+    // setSynchronousMode sets whether dequeueBuffer is synchronous or
+    // asynchronous. In synchronous mode, dequeueBuffer blocks until
+    // a buffer is available, the currently bound buffer can be dequeued and
+    // queued buffers will be acquired in order.  In asynchronous mode,
+    // a queued buffer may be replaced by a subsequently queued buffer.
+    //
+    // The default mode is synchronous.
+    // This should be called only during initialization.
+    virtual status_t setSynchronousMode(bool enabled);
+
+private:
+    // This is required by the IBinder::DeathRecipient interface
+    virtual void binderDied(const wp<IBinder>& who);
+
+    // waitForFreeSlotThenRelock finds the oldest slot in the FREE state. It may
+    // block if there are no available slots and we are not in non-blocking
+    // mode (producer and consumer controlled by the application). If it blocks,
+    // it will release mCore->mMutex while blocked so that other operations on
+    // the GonkBufferQueue may succeed.
+    status_t waitForFreeSlotThenRelock(const char* caller, bool async,
+            int* found, status_t* returnFlags) const;
+
+    sp<GonkBufferQueueCore> mCore;
+
+    // This references mCore->mSlots. Lock mCore->mMutex while accessing.
+    GonkBufferQueueDefs::SlotsType& mSlots;
+
+    // This is a cached copy of the name stored in the GonkBufferQueueCore.
+    // It's updated during connect and dequeueBuffer (which should catch
+    // most updates).
+    String8 mConsumerName;
+
+    // mSynchronousMode whether we're in synchronous mode or not
+    bool mSynchronousMode;
+
+    uint32_t mStickyTransform;
+
+}; // class GonkBufferQueueProducer
+
+} // namespace android
+
+#endif
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.cpp b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.cpp
new file mode 100644
index 000000000..9e4a424a9
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.cpp
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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.
+ */
+
+#include "GonkBufferSlot.h"
+
+namespace android {
+
+const char* GonkBufferSlot::bufferStateName(BufferState state) {
+    switch (state) {
+        case GonkBufferSlot::DEQUEUED: return "DEQUEUED";
+        case GonkBufferSlot::QUEUED: return "QUEUED";
+        case GonkBufferSlot::FREE: return "FREE";
+        case GonkBufferSlot::ACQUIRED: return "ACQUIRED";
+        default: return "Unknown";
+    }
+}
+
+} // namespace android
diff --git a/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.h b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.h
new file mode 100644
index 000000000..759bb7b23
--- /dev/null
+++ b/widget/gonk/nativewindow/GonkBufferQueueLL/GonkBufferSlot.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ * Copyright (C) 2014 Mozilla Foundation
+ *
+ * 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 NATIVEWINDOW_GONKBUFFERSLOT_LL_H
+#define NATIVEWINDOW_GONKBUFFERSLOT_LL_H
+
+#include <ui/Fence.h>
+#include <ui/GraphicBuffer.h>
+
+#include <utils/StrongPointer.h>
+
+#include "mozilla/layers/TextureClient.h"
+
+namespace android {
+
+struct GonkBufferSlot {
+    typedef mozilla::layers::TextureClient TextureClient;
+
+    GonkBufferSlot()
+    : mBufferState(GonkBufferSlot::FREE),
+      mRequestBufferCalled(false),
+      mFrameNumber(0),
+      mAcquireCalled(false),
+      mNeedsCleanupOnRelease(false),
+      mAttachedByConsumer(false) {
+    }
+
+    // mGraphicBuffer points to the buffer allocated for this slot or is NULL
+    // if no buffer has been allocated.
+    sp<GraphicBuffer> mGraphicBuffer;
+
+    // BufferState represents the different states in which a buffer slot
+    // can be.  All slots are initially FREE.
+    enum BufferState {
+        // FREE indicates that the buffer is available to be dequeued
+        // by the producer.  The buffer may be in use by the consumer for
+        // a finite time, so the buffer must not be modified until the
+        // associated fence is signaled.
+        //
+        // The slot is "owned" by BufferQueue.  It transitions to DEQUEUED
+        // when dequeueBuffer is called.
+        FREE = 0,
+
+        // DEQUEUED indicates that the buffer has been dequeued by the
+        // producer, but has not yet been queued or canceled.  The
+        // producer may modify the buffer's contents as soon as the
+        // associated ready fence is signaled.
+        //
+        // The slot is "owned" by the producer.  It can transition to
+        // QUEUED (via queueBuffer) or back to FREE (via cancelBuffer).
+        DEQUEUED = 1,
+
+        // QUEUED indicates that the buffer has been filled by the
+        // producer and queued for use by the consumer.  The buffer
+        // contents may continue to be modified for a finite time, so
+        // the contents must not be accessed until the associated fence
+        // is signaled.
+        //
+        // The slot is "owned" by BufferQueue.  It can transition to
+        // ACQUIRED (via acquireBuffer) or to FREE (if another buffer is
+        // queued in asynchronous mode).
+        QUEUED = 2,
+
+        // ACQUIRED indicates that the buffer has been acquired by the
+        // consumer.  As with QUEUED, the contents must not be accessed
+        // by the consumer until the fence is signaled.
+        //
+        // The slot is "owned" by the consumer.  It transitions to FREE
+        // when releaseBuffer is called.
+        ACQUIRED = 3
+    };
+
+    static const char* bufferStateName(BufferState state);
+
+    // mBufferState is the current state of this buffer slot.
+    BufferState mBufferState;
+
+    // mRequestBufferCalled is used for validating that the producer did
+    // call requestBuffer() when told to do so. Technically this is not
+    // needed but useful for debugging and catching producer bugs.
+    bool mRequestBufferCalled;
+
+    // mFrameNumber is the number of the queued frame for this slot.  This
+    // is used to dequeue buffers in LRU order (useful because buffers
+    // may be released before their release fence is signaled).
+    uint64_t mFrameNumber;
+
+    // mFence is a fence which will signal when work initiated by the
+    // previous owner of the buffer is finished. When the buffer is FREE,
+    // the fence indicates when the consumer has finished reading
+    // from the buffer, or when the producer has finished writing if it
+    // called cancelBuffer after queueing some writes. When the buffer is
+    // QUEUED, it indicates when the producer has finished filling the
+    // buffer. When the buffer is DEQUEUED or ACQUIRED, the fence has been
+    // passed to the consumer or producer along with ownership of the
+    // buffer, and mFence is set to NO_FENCE.
+    sp<Fence> mFence;
+
+    // Indicates whether this buffer has been seen by a consumer yet
+    bool mAcquireCalled;
+
+    // Indicates whether this buffer needs to be cleaned up by the
+    // consumer.  This is set when a buffer in ACQUIRED state is freed.
+    // It causes releaseBuffer to return STALE_BUFFER_SLOT.
+    bool mNeedsCleanupOnRelease;
+
+    // Indicates whether the buffer was attached on the consumer side.
+    // If so, it needs to set the BUFFER_NEEDS_REALLOCATION flag when dequeued
+    // to prevent the producer from using a stale cached buffer.
+    bool mAttachedByConsumer;
+
+    // mTextureClient is a thin abstraction over remotely allocated GraphicBuffer.
+    RefPtr<TextureClient> mTextureClient;
+};
+
+} // namespace android
+
+#endif