sp<GraphicBuffer> GraphicBufferAlloc::createGraphicBuffer(uint32_t w, uint32_t h,
        PixelFormat format, uint32_t usage, status_t* error) {
    sp<GraphicBuffer> graphicBuffer(new GraphicBuffer(w, h, format, usage));
    status_t err = graphicBuffer->initCheck();
    *error = err;
    if (err != 0 || graphicBuffer->handle == 0) {
        if (err == NO_MEMORY) {
            GraphicBuffer::dumpAllocationsToSystemLog();
        }
        ALOGE("GraphicBufferAlloc::createGraphicBuffer(w=%d, h=%d) "
             "failed (%s), handle=%p",
                w, h, strerror(-err), graphicBuffer->handle);
        return 0;
    }
    return graphicBuffer;
}
Exemplo n.º 2
0
status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h,
        uint32_t format, uint32_t usage) {
    ATRACE_CALL();
    ST_LOGV("dequeueBuffer: w=%d h=%d fmt=%#x usage=%#x", w, h, format, usage);

    if ((w && !h) || (!w && h)) {
        ST_LOGE("dequeueBuffer: invalid size: w=%u, h=%u", w, h);
        return BAD_VALUE;
    }

    status_t returnFlags(OK);
    EGLDisplay dpy = EGL_NO_DISPLAY;
    EGLSyncKHR fence = EGL_NO_SYNC_KHR;

    { // Scope for the lock
        Mutex::Autolock lock(mMutex);

        if (format == 0) {
            format = mDefaultBufferFormat;
        }
        // turn on usage bits the consumer requested
        usage |= mConsumerUsageBits;

        int found = -1;
        int foundSync = -1;
        int dequeuedCount = 0;
        bool tryAgain = true;
        while (tryAgain) {
            if (mAbandoned) {
                ST_LOGE("dequeueBuffer: SurfaceTexture has been abandoned!");
                return NO_INIT;
            }

            // We need to wait for the FIFO to drain if the number of buffer
            // needs to change.
            //
            // The condition "number of buffers needs to change" is true if
            // - the client doesn't care about how many buffers there are
            // - AND the actual number of buffer is different from what was
            //   set in the last setBufferCountServer()
            //                         - OR -
            //   setBufferCountServer() was set to a value incompatible with
            //   the synchronization mode (for instance because the sync mode
            //   changed since)
            //
            // As long as this condition is true AND the FIFO is not empty, we
            // wait on mDequeueCondition.

            const int minBufferCountNeeded = mSynchronousMode ?
                    mMinSyncBufferSlots : mMinAsyncBufferSlots;

            const bool numberOfBuffersNeedsToChange = !mClientBufferCount &&
                    ((mServerBufferCount != mBufferCount) ||
                            (mServerBufferCount < minBufferCountNeeded));

            if (!mQueue.isEmpty() && numberOfBuffersNeedsToChange) {
                // wait for the FIFO to drain
                mDequeueCondition.wait(mMutex);
                // NOTE: we continue here because we need to reevaluate our
                // whole state (eg: we could be abandoned or disconnected)
                continue;
            }

            if (numberOfBuffersNeedsToChange) {
                // here we're guaranteed that mQueue is empty
                freeAllBuffersLocked();
                mBufferCount = mServerBufferCount;
                if (mBufferCount < minBufferCountNeeded)
                    mBufferCount = minBufferCountNeeded;
                mBufferHasBeenQueued = false;
                returnFlags |= ISurfaceTexture::RELEASE_ALL_BUFFERS;
            }

            // look for a free buffer to give to the client
            found = INVALID_BUFFER_SLOT;
            foundSync = INVALID_BUFFER_SLOT;
            dequeuedCount = 0;
            for (int i = 0; i < mBufferCount; i++) {
                const int state = mSlots[i].mBufferState;
                if (state == BufferSlot::DEQUEUED) {
                    dequeuedCount++;
                }

                // this logic used to be if (FLAG_ALLOW_DEQUEUE_CURRENT_BUFFER)
                // but dequeuing the current buffer is disabled.
                if (false) {
                    // This functionality has been temporarily removed so
                    // BufferQueue and SurfaceTexture can be refactored into
                    // separate objects
                } else {
                    if (state == BufferSlot::FREE) {
                        /* We return the oldest of the free buffers to avoid
                         * stalling the producer if possible.  This is because
                         * the consumer may still have pending reads of the
                         * buffers in flight.
                         */
                        bool isOlder = mSlots[i].mFrameNumber <
                                mSlots[found].mFrameNumber;
                        if (found < 0 || isOlder) {
                            foundSync = i;
                            found = i;
                        }
                    }
                }
            }

            // clients are not allowed to dequeue more than one buffer
            // if they didn't set a buffer count.
            if (!mClientBufferCount && dequeuedCount) {
                ST_LOGE("dequeueBuffer: can't dequeue multiple buffers without "
                        "setting the buffer count");
                return -EINVAL;
            }

            // See whether a buffer has been queued since the last
            // setBufferCount so we know whether to perform the
            // mMinUndequeuedBuffers check below.
            if (mBufferHasBeenQueued) {
                // make sure the client is not trying to dequeue more buffers
                // than allowed.
                const int avail = mBufferCount - (dequeuedCount+1);
                if (avail < (mMinUndequeuedBuffers-int(mSynchronousMode))) {
                    ST_LOGE("dequeueBuffer: mMinUndequeuedBuffers=%d exceeded "
                            "(dequeued=%d)",
                            mMinUndequeuedBuffers-int(mSynchronousMode),
                            dequeuedCount);
                    return -EBUSY;
                }
            }

            // if no buffer is found, wait for a buffer to be released
            tryAgain = found == INVALID_BUFFER_SLOT;
            if (tryAgain) {
                mDequeueCondition.wait(mMutex);
            }
        }


        if (found == INVALID_BUFFER_SLOT) {
            // This should not happen.
            ST_LOGE("dequeueBuffer: no available buffer slots");
            return -EBUSY;
        }

        const int buf = found;
        *outBuf = found;

        ATRACE_BUFFER_INDEX(buf);

        const bool useDefaultSize = !w && !h;
        if (useDefaultSize) {
            // use the default size
            w = mDefaultWidth;
            h = mDefaultHeight;
        }

        const bool updateFormat = (format != 0);
        if (!updateFormat) {
            // keep the current (or default) format
            format = mPixelFormat;
        }

        // buffer is now in DEQUEUED (but can also be current at the same time,
        // if we're in synchronous mode)
        mSlots[buf].mBufferState = BufferSlot::DEQUEUED;

        const sp<GraphicBuffer>& buffer(mSlots[buf].mGraphicBuffer);
        if ((buffer == NULL) ||
            (uint32_t(buffer->width)  != w) ||
            (uint32_t(buffer->height) != h) ||
            (uint32_t(buffer->format) != format) ||
            ((uint32_t(buffer->usage) & usage) != usage))
        {
            status_t error;
            sp<GraphicBuffer> graphicBuffer(
                    mGraphicBufferAlloc->createGraphicBuffer(
                            w, h, format, usage, &error));
            if (graphicBuffer == 0) {
                ST_LOGE("dequeueBuffer: SurfaceComposer::createGraphicBuffer "
                        "failed");
                return error;
            }
            if (updateFormat) {
                mPixelFormat = format;
            }

            mSlots[buf].mAcquireCalled = false;
            mSlots[buf].mGraphicBuffer = graphicBuffer;
            mSlots[buf].mRequestBufferCalled = false;
            mSlots[buf].mFence = EGL_NO_SYNC_KHR;
            mSlots[buf].mEglDisplay = EGL_NO_DISPLAY;

            returnFlags |= ISurfaceTexture::BUFFER_NEEDS_REALLOCATION;
        }

        dpy = mSlots[buf].mEglDisplay;
        fence = mSlots[buf].mFence;
        mSlots[buf].mFence = EGL_NO_SYNC_KHR;
    }  // end lock scope

    if (fence != EGL_NO_SYNC_KHR) {
        EGLint result = eglClientWaitSyncKHR(dpy, fence, 0, 1000000000);
        // If something goes wrong, log the error, but return the buffer without
        // synchronizing access to it.  It's too late at this point to abort the
        // dequeue operation.
        if (result == EGL_FALSE) {
            ST_LOGE("dequeueBuffer: error waiting for fence: %#x", eglGetError());
        } else if (result == EGL_TIMEOUT_EXPIRED_KHR) {
            ST_LOGE("dequeueBuffer: timeout waiting for fence");
        }
        eglDestroySyncKHR(dpy, fence);
    }

    ST_LOGV("dequeueBuffer: returning slot=%d buf=%p flags=%#x", *outBuf,
            mSlots[*outBuf].mGraphicBuffer->handle, returnFlags);

    return returnFlags;
}
status_t BufferQueue::dequeueBuffer(int *outBuf, sp<Fence>* outFence,
        uint32_t w, uint32_t h, uint32_t format, uint32_t usage) {
    ATRACE_CALL();
    ST_LOGV("dequeueBuffer: w=%d h=%d fmt=%#x usage=%#x", w, h, format, usage);

    if ((w && !h) || (!w && h)) {
        ST_LOGE("dequeueBuffer: invalid size: w=%u, h=%u", w, h);
        return BAD_VALUE;
    }

    status_t returnFlags(OK);
    EGLDisplay dpy = EGL_NO_DISPLAY;
    EGLSyncKHR eglFence = EGL_NO_SYNC_KHR;

    { // Scope for the lock
        Mutex::Autolock lock(mMutex);

        if (format == 0) {
            format = mDefaultBufferFormat;
        }
        // turn on usage bits the consumer requested
        usage |= mConsumerUsageBits;

        int found = -1;
        int dequeuedCount = 0;
        bool tryAgain = true;
        while (tryAgain) {
            if (mAbandoned) {
                ST_LOGE("dequeueBuffer: BufferQueue has been abandoned!");
                return NO_INIT;
            }

            const int maxBufferCount = getMaxBufferCountLocked();

            // Free up any buffers that are in slots beyond the max buffer
            // count.
            for (int i = maxBufferCount; i < NUM_BUFFER_SLOTS; i++) {
                assert(mSlots[i].mBufferState == BufferSlot::FREE);
                if (mSlots[i].mGraphicBuffer != NULL) {
                    freeBufferLocked(i);
                    returnFlags |= IGraphicBufferProducer::RELEASE_ALL_BUFFERS;
                }
            }

            // look for a free buffer to give to the client
            found = INVALID_BUFFER_SLOT;
            dequeuedCount = 0;
            for (int i = 0; i < maxBufferCount; i++) {
                const int state = mSlots[i].mBufferState;
                if (state == BufferSlot::DEQUEUED) {
                    dequeuedCount++;
                }

                if (state == BufferSlot::FREE) {
                    /* We return the oldest of the free buffers to avoid
                     * stalling the producer if possible.  This is because
                     * the consumer may still have pending reads of the
                     * buffers in flight.
                     */
                    if ((found < 0) ||
                            mSlots[i].mFrameNumber < mSlots[found].mFrameNumber) {
                        found = i;
                    }
                }
            }

            // clients are not allowed to dequeue more than one buffer
            // if they didn't set a buffer count.
            if (!mOverrideMaxBufferCount && dequeuedCount) {
                ST_LOGE("dequeueBuffer: can't dequeue multiple buffers without "
                        "setting the buffer count");
                return -EINVAL;
            }

            // See whether a buffer has been queued since the last
            // setBufferCount so we know whether to perform the min undequeued
            // buffers check below.
            if (mBufferHasBeenQueued) {
                // make sure the client is not trying to dequeue more buffers
                // than allowed.
                const int newUndequeuedCount = maxBufferCount - (dequeuedCount+1);
                const int minUndequeuedCount = getMinUndequeuedBufferCountLocked();
                if (newUndequeuedCount < minUndequeuedCount) {
                    ST_LOGE("dequeueBuffer: min undequeued buffer count (%d) "
                            "exceeded (dequeued=%d undequeudCount=%d)",
                            minUndequeuedCount, dequeuedCount,
                            newUndequeuedCount);
                    return -EBUSY;
                }
            }

            // If no buffer is found, wait for a buffer to be released or for
            // the max buffer count to change.
            tryAgain = found == INVALID_BUFFER_SLOT;
            if (tryAgain) {
                mDequeueCondition.wait(mMutex);
            }
        }


        if (found == INVALID_BUFFER_SLOT) {
            // This should not happen.
            ST_LOGE("dequeueBuffer: no available buffer slots");
            return -EBUSY;
        }

        const int buf = found;
        *outBuf = found;

        ATRACE_BUFFER_INDEX(buf);

        const bool useDefaultSize = !w && !h;
        if (useDefaultSize) {
            // use the default size
            w = mDefaultWidth;
            h = mDefaultHeight;
        }

        mSlots[buf].mBufferState = BufferSlot::DEQUEUED;

        const sp<GraphicBuffer>& buffer(mSlots[buf].mGraphicBuffer);
        if ((buffer == NULL) ||
            (uint32_t(buffer->width)  != w) ||
            (uint32_t(buffer->height) != h) ||
            (uint32_t(buffer->format) != format) ||
            ((uint32_t(buffer->usage) & usage) != usage))
        {
            mSlots[buf].mAcquireCalled = false;
            mSlots[buf].mGraphicBuffer = NULL;
            mSlots[buf].mRequestBufferCalled = false;
            mSlots[buf].mEglFence = EGL_NO_SYNC_KHR;
            mSlots[buf].mFence = Fence::NO_FENCE;
            mSlots[buf].mEglDisplay = EGL_NO_DISPLAY;

            returnFlags |= IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION;
        }

        dpy = mSlots[buf].mEglDisplay;
        eglFence = mSlots[buf].mEglFence;
        *outFence = mSlots[buf].mFence;
        mSlots[buf].mEglFence = EGL_NO_SYNC_KHR;
        mSlots[buf].mFence = Fence::NO_FENCE;
    }  // end lock scope

    if (returnFlags & IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION) {
        status_t error;
        sp<GraphicBuffer> graphicBuffer(
                mGraphicBufferAlloc->createGraphicBuffer(
                        w, h, format, usage, &error));
        if (graphicBuffer == 0) {
            ST_LOGE("dequeueBuffer: SurfaceComposer::createGraphicBuffer "
                    "failed");
            return error;
        }

        { // Scope for the lock
            Mutex::Autolock lock(mMutex);

            if (mAbandoned) {
                ST_LOGE("dequeueBuffer: BufferQueue has been abandoned!");
                return NO_INIT;
            }

            mSlots[*outBuf].mGraphicBuffer = graphicBuffer;
        }
    }

    if (eglFence != EGL_NO_SYNC_KHR) {
        EGLint result = eglClientWaitSyncKHR(dpy, eglFence, 0, 1000000000);
        // If something goes wrong, log the error, but return the buffer without
        // synchronizing access to it.  It's too late at this point to abort the
        // dequeue operation.
        if (result == EGL_FALSE) {
            ST_LOGE("dequeueBuffer: error waiting for fence: %#x", eglGetError());
        } else if (result == EGL_TIMEOUT_EXPIRED_KHR) {
            ST_LOGE("dequeueBuffer: timeout waiting for fence");
        }
        eglDestroySyncKHR(dpy, eglFence);
    }

    ST_LOGV("dequeueBuffer: returning slot=%d buf=%p flags=%#x", *outBuf,
            mSlots[*outBuf].mGraphicBuffer->handle, returnFlags);

    return returnFlags;
}
Exemplo n.º 4
0
status_t SurfaceTexture::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h,
        uint32_t format, uint32_t usage) {
    ST_LOGV("dequeueBuffer: w=%d h=%d fmt=%#x usage=%#x", w, h, format, usage);

    if ((w && !h) || (!w && h)) {
        ST_LOGE("dequeueBuffer: invalid size: w=%u, h=%u", w, h);
        return BAD_VALUE;
    }

    status_t returnFlags(OK);
    EGLDisplay dpy = EGL_NO_DISPLAY;
    EGLSyncKHR fence = EGL_NO_SYNC_KHR;

    { // Scope for the lock
        Mutex::Autolock lock(mMutex);

        int found = -1;
        int foundSync = -1;
        int dequeuedCount = 0;
        bool tryAgain = true;
#ifdef MISSING_GRALLOC_BUFFERS
        int dequeueRetries = 5;
#endif
        while (tryAgain) {
            if (mAbandoned) {
                ST_LOGE("dequeueBuffer: SurfaceTexture has been abandoned!");
                return NO_INIT;
            }

            // We need to wait for the FIFO to drain if the number of buffer
            // needs to change.
            //
            // The condition "number of buffers needs to change" is true if
            // - the client doesn't care about how many buffers there are
            // - AND the actual number of buffer is different from what was
            //   set in the last setBufferCountServer()
            //                         - OR -
            //   setBufferCountServer() was set to a value incompatible with
            //   the synchronization mode (for instance because the sync mode
            //   changed since)
            //
            // As long as this condition is true AND the FIFO is not empty, we
            // wait on mDequeueCondition.

            const int minBufferCountNeeded = mSynchronousMode ?
                    MIN_SYNC_BUFFER_SLOTS : MIN_ASYNC_BUFFER_SLOTS;

            const bool numberOfBuffersNeedsToChange = !mClientBufferCount &&
                    ((mServerBufferCount != mBufferCount) ||
                            (mServerBufferCount < minBufferCountNeeded));

            if (!mQueue.isEmpty() && numberOfBuffersNeedsToChange) {
                // wait for the FIFO to drain
                mDequeueCondition.wait(mMutex);
                // NOTE: we continue here because we need to reevaluate our
                // whole state (eg: we could be abandoned or disconnected)
                continue;
            }

            if (numberOfBuffersNeedsToChange) {
                // here we're guaranteed that mQueue is empty
                freeAllBuffersLocked();
                mBufferCount = mServerBufferCount;
                if (mBufferCount < minBufferCountNeeded)
                    mBufferCount = minBufferCountNeeded;
                mCurrentTexture = INVALID_BUFFER_SLOT;
                returnFlags |= ISurfaceTexture::RELEASE_ALL_BUFFERS;
            }

            // look for a free buffer to give to the client
            found = INVALID_BUFFER_SLOT;
            foundSync = INVALID_BUFFER_SLOT;
            dequeuedCount = 0;
            for (int i = 0; i < mBufferCount; i++) {
                const int state = mSlots[i].mBufferState;
                if (state == BufferSlot::DEQUEUED) {
                    dequeuedCount++;
                }

                // if buffer is FREE it CANNOT be current
                LOGW_IF((state == BufferSlot::FREE) && (mCurrentTexture==i),
                        "dequeueBuffer: buffer %d is both FREE and current!",
                        i);

                if (FLAG_ALLOW_DEQUEUE_CURRENT_BUFFER) {
                    if (state == BufferSlot::FREE || i == mCurrentTexture) {
                        foundSync = i;
                        if (i != mCurrentTexture) {
                            found = i;
                            break;
                        }
                    }
                } else {
                    if (state == BufferSlot::FREE) {
                        /* We return the oldest of the free buffers to avoid
                         * stalling the producer if possible.  This is because
                         * the consumer may still have pending reads of the
                         * buffers in flight.
                         */
                        bool isOlder = mSlots[i].mFrameNumber <
                                mSlots[found].mFrameNumber;
                        if (found < 0 || isOlder) {
                            foundSync = i;
                            found = i;
                        }
                    }
                }
            }

            // clients are not allowed to dequeue more than one buffer
            // if they didn't set a buffer count.
            if (!mClientBufferCount && dequeuedCount) {
#ifdef MISSING_GRALLOC_BUFFERS
                if (--dequeueRetries) {
                    LOGD("SurfaceTexture::dequeue: Not allowed to dequeue more "
                            "than a buffer SLEEPING\n");
                    usleep(10000);
                } else {
                    mClientBufferCount = mServerBufferCount;
                    LOGD("SurfaceTexture::dequeue: Not allowed to dequeue more "
                            "than a buffer RETRY mBufferCount:%d mServerBufferCount:%d\n",
                            mBufferCount, mServerBufferCount);
                }
                continue;
#else
                ST_LOGE("dequeueBuffer: can't dequeue multiple buffers without "
                        "setting the buffer count");
#endif
                return -EINVAL;
            }

            // See whether a buffer has been queued since the last
            // setBufferCount so we know whether to perform the
            // MIN_UNDEQUEUED_BUFFERS check below.
            bool bufferHasBeenQueued = mCurrentTexture != INVALID_BUFFER_SLOT;
            if (bufferHasBeenQueued) {
                // make sure the client is not trying to dequeue more buffers
                // than allowed.
                const int avail = mBufferCount - (dequeuedCount+1);
                if (avail < (MIN_UNDEQUEUED_BUFFERS-int(mSynchronousMode))) {
#ifdef MISSING_GRALLOC_BUFFERS
                    if (mClientBufferCount != 0) {
                        mBufferCount++;
                        mClientBufferCount = mServerBufferCount = mBufferCount;
                        LOGD("SurfaceTexture::dequeuebuffer: MIN EXCEEDED "
                                "mBuffer:%d bumped\n", mBufferCount);
                        continue;
                    }
#endif
                    ST_LOGE("dequeueBuffer: MIN_UNDEQUEUED_BUFFERS=%d exceeded "
                            "(dequeued=%d)",
                            MIN_UNDEQUEUED_BUFFERS-int(mSynchronousMode),
                            dequeuedCount);
                    return -EBUSY;
                }
            }

            // we're in synchronous mode and didn't find a buffer, we need to
            // wait for some buffers to be consumed
            tryAgain = mSynchronousMode && (foundSync == INVALID_BUFFER_SLOT);
            if (tryAgain) {
                mDequeueCondition.wait(mMutex);
            }
        }

        if (mSynchronousMode && found == INVALID_BUFFER_SLOT) {
            // foundSync guaranteed to be != INVALID_BUFFER_SLOT
            found = foundSync;
        }

        if (found == INVALID_BUFFER_SLOT) {
            // This should not happen.
            ST_LOGE("dequeueBuffer: no available buffer slots");
            return -EBUSY;
        }

        const int buf = found;
        *outBuf = found;

        const bool useDefaultSize = !w && !h;
        if (useDefaultSize) {
            // use the default size
            w = mDefaultWidth;
            h = mDefaultHeight;
        }

        const bool updateFormat = (format != 0);
        if (!updateFormat) {
            // keep the current (or default) format
            format = mPixelFormat;
        }

        // buffer is now in DEQUEUED (but can also be current at the same time,
        // if we're in synchronous mode)
        mSlots[buf].mBufferState = BufferSlot::DEQUEUED;

        const sp<GraphicBuffer>& buffer(mSlots[buf].mGraphicBuffer);
#ifdef QCOM_HARDWARE
	qBufGeometry currentGeometry;
	if (buffer != NULL)
	   currentGeometry.set(buffer->width, buffer->height, buffer->format);
 	else
	   currentGeometry.set(0, 0, 0);
 
	qBufGeometry requiredGeometry;
	requiredGeometry.set(w, h, format);
 
	qBufGeometry updatedGeometry;
	updatedGeometry.set(mNextBufferInfo.width, mNextBufferInfo.height,
				mNextBufferInfo.format);
#endif
	if ((buffer == NULL) ||
#ifdef QCOM_HARDWARE
	   needNewBuffer(currentGeometry, requiredGeometry, updatedGeometry) ||
#else
	   (uint32_t(buffer->width)  != w) ||
	   (uint32_t(buffer->height) != h) ||
	   (uint32_t(buffer->format) != format) ||
#endif
	   ((uint32_t(buffer->usage) & usage) != usage))
	{
#ifdef QCOM_HARDWARE
            if (buffer != NULL) {
                mGraphicBufferAlloc->freeGraphicBufferAtIndex(buf);
            }
#endif
            usage |= GraphicBuffer::USAGE_HW_TEXTURE;
            status_t error;
            sp<GraphicBuffer> graphicBuffer(
                    mGraphicBufferAlloc->createGraphicBuffer(
                            w, h, format, usage, &error));
            if (graphicBuffer == 0) {
                ST_LOGE("dequeueBuffer: SurfaceComposer::createGraphicBuffer "
                        "failed");
                return error;
            }
            if (updateFormat) {
                mPixelFormat = format;
            }
#ifdef QCOM_HARDWARE
	    checkBuffer((native_handle_t *)graphicBuffer->handle, mReqSize, usage);
#endif
            mSlots[buf].mGraphicBuffer = graphicBuffer;
            mSlots[buf].mRequestBufferCalled = false;
            mSlots[buf].mFence = EGL_NO_SYNC_KHR;
            if (mSlots[buf].mEglImage != EGL_NO_IMAGE_KHR) {
                eglDestroyImageKHR(mSlots[buf].mEglDisplay,
                        mSlots[buf].mEglImage);
                mSlots[buf].mEglImage = EGL_NO_IMAGE_KHR;
                mSlots[buf].mEglDisplay = EGL_NO_DISPLAY;
            }
            if (mCurrentTexture == buf) {
                // The current texture no longer references the buffer in this slot
                // since we just allocated a new buffer.
                mCurrentTexture = INVALID_BUFFER_SLOT;
            }
            returnFlags |= ISurfaceTexture::BUFFER_NEEDS_REALLOCATION;
        }

        dpy = mSlots[buf].mEglDisplay;
        fence = mSlots[buf].mFence;
        mSlots[buf].mFence = EGL_NO_SYNC_KHR;
    }

    if (fence != EGL_NO_SYNC_KHR) {
        EGLint result = eglClientWaitSyncKHR(dpy, fence, 0, 1000000000);
        // If something goes wrong, log the error, but return the buffer without
        // synchronizing access to it.  It's too late at this point to abort the
        // dequeue operation.
        if (result == EGL_FALSE) {
            LOGE("dequeueBuffer: error waiting for fence: %#x", eglGetError());
        } else if (result == EGL_TIMEOUT_EXPIRED_KHR) {
            LOGE("dequeueBuffer: timeout waiting for fence");
        }
        eglDestroySyncKHR(dpy, fence);
    }

    ST_LOGV("dequeueBuffer: returning slot=%d buf=%p flags=%#x", *outBuf,
            mSlots[*outBuf].mGraphicBuffer->handle, returnFlags);

    return returnFlags;
}
status_t SurfaceMediaSource::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h,
                                            uint32_t format, uint32_t usage) {
    LOGV("dequeueBuffer");
    Mutex::Autolock lock(mMutex);

    // Check for the buffer size- the client should just use the
    // default width and height, and not try to set those.
    // This is needed since
    // the getFormat() returns mDefaultWidth/ Height for the OMX. It is
    // queried by OMX in the beginning and not every time a frame comes.
    // Not sure if there is  a way to update the
    // frame size while recording. So as of now, the client side
    // sets the default values via the constructor, and the encoder is
    // setup to encode frames of that size
    // The design might need to change in the future.
    // TODO: Currently just uses mDefaultWidth/Height. In the future
    // we might declare mHeight and mWidth and check against those here.
    if ((w != 0) || (h != 0)) {
        if ((w != mDefaultWidth) || (h != mDefaultHeight)) {
            LOGE("dequeuebuffer: invalid buffer size! Req: %dx%d, Found: %dx%d",
                    mDefaultWidth, mDefaultHeight, w, h);
            return BAD_VALUE;
        }
    }

    status_t returnFlags(OK);
    int found, foundSync;
    int dequeuedCount = 0;
    bool tryAgain = true;
    while (tryAgain) {
        // We need to wait for the FIFO to drain if the number of buffer
        // needs to change.
        //
        // The condition "number of buffer needs to change" is true if
        // - the client doesn't care about how many buffers there are
        // - AND the actual number of buffer is different from what was
        //   set in the last setBufferCountServer()
        //                         - OR -
        //   setBufferCountServer() was set to a value incompatible with
        //   the synchronization mode (for instance because the sync mode
        //   changed since)
        //
        // As long as this condition is true AND the FIFO is not empty, we
        // wait on mDequeueCondition.

        int minBufferCountNeeded = mSynchronousMode ?
                MIN_SYNC_BUFFER_SLOTS : MIN_ASYNC_BUFFER_SLOTS;

        if (!mClientBufferCount &&
                ((mServerBufferCount != mBufferCount) ||
                        (mServerBufferCount < minBufferCountNeeded))) {
            // wait for the FIFO to drain
            while (!mQueue.isEmpty()) {
                LOGV("Waiting for the FIFO to drain");
                mDequeueCondition.wait(mMutex);
            }
            if (mStopped) {
                return NO_INIT;
            }
            // need to check again since the mode could have changed
            // while we were waiting
            minBufferCountNeeded = mSynchronousMode ?
                    MIN_SYNC_BUFFER_SLOTS : MIN_ASYNC_BUFFER_SLOTS;
        }

        if (!mClientBufferCount &&
                ((mServerBufferCount != mBufferCount) ||
                        (mServerBufferCount < minBufferCountNeeded))) {
            // here we're guaranteed that mQueue is empty
            freeAllBuffersLocked();
            mBufferCount = mServerBufferCount;
            if (mBufferCount < minBufferCountNeeded)
                mBufferCount = minBufferCountNeeded;
            mCurrentSlot = INVALID_BUFFER_SLOT;
            returnFlags |= ISurfaceTexture::RELEASE_ALL_BUFFERS;
        }

        // look for a free buffer to give to the client
        found = INVALID_BUFFER_SLOT;
        foundSync = INVALID_BUFFER_SLOT;
        dequeuedCount = 0;
        for (int i = 0; i < mBufferCount; i++) {
            const int state = mSlots[i].mBufferState;
            if (state == BufferSlot::DEQUEUED) {
                dequeuedCount++;
                continue; // won't be continuing if could
                // dequeue a non 'FREE' current slot like
                // that in SurfaceTexture
            }
            // In case of Encoding, we do not deque the mCurrentSlot buffer
            //  since we follow synchronous mode (unlike possibly in
            //  SurfaceTexture that could be using the asynch mode
            //  or has some mechanism in GL to be able to wait till the
            //  currentslot is done using the data)
            // Here, we have to wait for the MPEG4Writer(or equiv)
            // to tell us when it's done using the current buffer
            if (state == BufferSlot::FREE) {
                foundSync = i;
                // Unlike that in SurfaceTexture,
                // We don't need to worry if it is the
                // currentslot or not as it is in state FREE
                found = i;
                break;
            }
        }

        // clients are not allowed to dequeue more than one buffer
        // if they didn't set a buffer count.
        if (!mClientBufferCount && dequeuedCount) {
            return -EINVAL;
        }

        // See whether a buffer has been queued since the last setBufferCount so
        // we know whether to perform the MIN_UNDEQUEUED_BUFFERS check below.
        bool bufferHasBeenQueued = mCurrentSlot != INVALID_BUFFER_SLOT;
        if (bufferHasBeenQueued) {
            // make sure the client is not trying to dequeue more buffers
            // than allowed.
            const int avail = mBufferCount - (dequeuedCount+1);
            if (avail < (MIN_UNDEQUEUED_BUFFERS-int(mSynchronousMode))) {
                LOGE("dequeueBuffer: MIN_UNDEQUEUED_BUFFERS=%d exceeded (dequeued=%d)",
                        MIN_UNDEQUEUED_BUFFERS-int(mSynchronousMode),
                        dequeuedCount);
                return -EBUSY;
            }
        }

        // we're in synchronous mode and didn't find a buffer, we need to wait
        // for for some buffers to be consumed
        tryAgain = mSynchronousMode && (foundSync == INVALID_BUFFER_SLOT);
        if (tryAgain) {
            LOGV("Waiting..In synchronous mode and no buffer to dequeue");
            mDequeueCondition.wait(mMutex);
        }
        if (mStopped) {
            return NO_INIT;
        }
    }

    if (mSynchronousMode && found == INVALID_BUFFER_SLOT) {
        // foundSync guaranteed to be != INVALID_BUFFER_SLOT
        found = foundSync;
    }

    if (found == INVALID_BUFFER_SLOT) {
        return -EBUSY;
    }

    const int bufIndex = found;
    *outBuf = found;

    const bool useDefaultSize = !w && !h;
    if (useDefaultSize) {
        // use the default size
        w = mDefaultWidth;
        h = mDefaultHeight;
    }

    const bool updateFormat = (format != 0);
    if (!updateFormat) {
        // keep the current (or default) format
        format = mPixelFormat;
    }

    // buffer is now in DEQUEUED (but can also be current at the same time,
    // if we're in synchronous mode)
    mSlots[bufIndex].mBufferState = BufferSlot::DEQUEUED;

    const sp<GraphicBuffer>& buffer(mSlots[bufIndex].mGraphicBuffer);
    if ((buffer == NULL) ||
        (uint32_t(buffer->width)  != w) ||
        (uint32_t(buffer->height) != h) ||
        (uint32_t(buffer->format) != format) ||
        ((uint32_t(buffer->usage) & usage) != usage)) {
            // XXX: This will be changed to USAGE_HW_VIDEO_ENCODER once driver
            // issues with that flag get fixed.
            usage |= GraphicBuffer::USAGE_HW_TEXTURE;
            status_t error;
            sp<GraphicBuffer> graphicBuffer(
                    mGraphicBufferAlloc->createGraphicBuffer(
                                    w, h, format, usage, &error));
            if (graphicBuffer == 0) {
                LOGE("dequeueBuffer: SurfaceComposer::createGraphicBuffer failed");
                return error;
            }
            if (updateFormat) {
                mPixelFormat = format;
            }
            mSlots[bufIndex].mGraphicBuffer = graphicBuffer;
            mSlots[bufIndex].mRequestBufferCalled = false;
            returnFlags |= ISurfaceTexture::BUFFER_NEEDS_REALLOCATION;
    }
    return returnFlags;
}