libs/gui/BLASTBufferQueue.cpp

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#undef LOG_TAG
#define LOG_TAG "BLASTBufferQueue"

#define ATRACE_TAG ATRACE_TAG_GRAPHICS

#include <gui/BLASTBufferQueue.h>
#include <gui/BufferItemConsumer.h>
#include <gui/GLConsumer.h>

#include <utils/Trace.h>

#include <chrono>

using namespace std::chrono_literals;

namespace android {

void BLASTBufferItemConsumer::onDisconnect() {
    Mutex::Autolock lock(mFrameEventHistoryMutex);
    mPreviouslyConnected = mCurrentlyConnected;
    mCurrentlyConnected = false;
    if (mPreviouslyConnected) {
        mDisconnectEvents.push(mCurrentFrameNumber);
    }
    mFrameEventHistory.onDisconnect();
}

void BLASTBufferItemConsumer::addAndGetFrameTimestamps(const NewFrameEventsEntry* newTimestamps,
                                                       FrameEventHistoryDelta* outDelta) {
    Mutex::Autolock lock(mFrameEventHistoryMutex);
    if (newTimestamps) {
        // BufferQueueProducer only adds a new timestamp on
        // queueBuffer
        mCurrentFrameNumber = newTimestamps->frameNumber;
        mFrameEventHistory.addQueue(*newTimestamps);
    }
    if (outDelta) {
        // frame event histories will be processed
        // only after the producer connects and requests
        // deltas for the first time.  Forward this intent
        // to SF-side to turn event processing back on
        mPreviouslyConnected = mCurrentlyConnected;
        mCurrentlyConnected = true;
        mFrameEventHistory.getAndResetDelta(outDelta);
    }
}

void BLASTBufferItemConsumer::updateFrameTimestamps(uint64_t frameNumber, nsecs_t refreshStartTime,
                                                    const sp<Fence>& glDoneFence,
                                                    const sp<Fence>& presentFence,
                                                    const sp<Fence>& prevReleaseFence,
                                                    CompositorTiming compositorTiming,
                                                    nsecs_t latchTime, nsecs_t dequeueReadyTime) {
    Mutex::Autolock lock(mFrameEventHistoryMutex);

    // if the producer is not connected, don't bother updating,
    // the next producer that connects won't access this frame event
    if (!mCurrentlyConnected) return;
    std::shared_ptr<FenceTime> glDoneFenceTime = std::make_shared<FenceTime>(glDoneFence);
    std::shared_ptr<FenceTime> presentFenceTime = std::make_shared<FenceTime>(presentFence);
    std::shared_ptr<FenceTime> releaseFenceTime = std::make_shared<FenceTime>(prevReleaseFence);

    mFrameEventHistory.addLatch(frameNumber, latchTime);
    mFrameEventHistory.addRelease(frameNumber, dequeueReadyTime, std::move(releaseFenceTime));
    mFrameEventHistory.addPreComposition(frameNumber, refreshStartTime);
    mFrameEventHistory.addPostComposition(frameNumber, glDoneFenceTime, presentFenceTime,
                                          compositorTiming);
}

void BLASTBufferItemConsumer::getConnectionEvents(uint64_t frameNumber, bool* needsDisconnect) {
    bool disconnect = false;
    Mutex::Autolock lock(mFrameEventHistoryMutex);
    while (!mDisconnectEvents.empty() && mDisconnectEvents.front() <= frameNumber) {
        disconnect = true;
        mDisconnectEvents.pop();
    }
    if (needsDisconnect != nullptr) *needsDisconnect = disconnect;
}

BLASTBufferQueue::BLASTBufferQueue(const sp<SurfaceControl>& surface, int width, int height,
                                   bool enableTripleBuffering)
      : mSurfaceControl(surface),
        mWidth(width),
        mHeight(height),
        mNextTransaction(nullptr) {
    BufferQueue::createBufferQueue(&mProducer, &mConsumer);
    // since the adapter is in the client process, set dequeue timeout
    // explicitly so that dequeueBuffer will block
    mProducer->setDequeueTimeout(std::numeric_limits<int64_t>::max());

    if (enableTripleBuffering) {
        mProducer->setMaxDequeuedBufferCount(2);
    }
    mBufferItemConsumer =
        new BLASTBufferItemConsumer(mConsumer, GraphicBuffer::USAGE_HW_COMPOSER, 1, true);
    static int32_t id = 0;
    auto name = std::string("BLAST Consumer") + std::to_string(id);
    id++;
    mBufferItemConsumer->setName(String8(name.c_str()));
    mBufferItemConsumer->setFrameAvailableListener(this);
    mBufferItemConsumer->setBufferFreedListener(this);
    mBufferItemConsumer->setDefaultBufferSize(mWidth, mHeight);
    mBufferItemConsumer->setDefaultBufferFormat(PIXEL_FORMAT_RGBA_8888);

    mTransformHint = mSurfaceControl->getTransformHint();
    mBufferItemConsumer->setTransformHint(mTransformHint);

    mNumAcquired = 0;
    mNumFrameAvailable = 0;
    mPendingReleaseItem.item = BufferItem();
    mPendingReleaseItem.releaseFence = nullptr;
}

void BLASTBufferQueue::update(const sp<SurfaceControl>& surface, int width, int height) {
    std::unique_lock _lock{mMutex};
    mSurfaceControl = surface;

    if (mWidth != width || mHeight != height) {
        mWidth = width;
        mHeight = height;
        mBufferItemConsumer->setDefaultBufferSize(mWidth, mHeight);
    }
}

static void transactionCallbackThunk(void* context, nsecs_t latchTime,
                                     const sp<Fence>& presentFence,
                                     const std::vector<SurfaceControlStats>& stats) {
    if (context == nullptr) {
        return;
    }
    BLASTBufferQueue* bq = static_cast<BLASTBufferQueue*>(context);
    bq->transactionCallback(latchTime, presentFence, stats);
}

void BLASTBufferQueue::transactionCallback(nsecs_t /*latchTime*/, const sp<Fence>& /*presentFence*/,
                                           const std::vector<SurfaceControlStats>& stats) {
    std::unique_lock _lock{mMutex};
    ATRACE_CALL();

    if (!stats.empty()) {
        mTransformHint = stats[0].transformHint;
        mBufferItemConsumer->setTransformHint(mTransformHint);
        mBufferItemConsumer->updateFrameTimestamps(stats[0].frameEventStats.frameNumber,
                                                   stats[0].frameEventStats.refreshStartTime,
                                                   stats[0].frameEventStats.gpuCompositionDoneFence,
                                                   stats[0].presentFence,
                                                   stats[0].previousReleaseFence,
                                                   stats[0].frameEventStats.compositorTiming,
                                                   stats[0].latchTime,
                                                   stats[0].frameEventStats.dequeueReadyTime);
    }
    if (mPendingReleaseItem.item.mGraphicBuffer != nullptr) {
        if (!stats.empty()) {
            mPendingReleaseItem.releaseFence = stats[0].previousReleaseFence;
        } else {
            ALOGE("Warning: no SurfaceControlStats returned in BLASTBufferQueue callback");
            mPendingReleaseItem.releaseFence = nullptr;
        }
        mBufferItemConsumer->releaseBuffer(mPendingReleaseItem.item,
                                           mPendingReleaseItem.releaseFence
                                                   ? mPendingReleaseItem.releaseFence
                                                   : Fence::NO_FENCE);
        mNumAcquired--;
        mPendingReleaseItem.item = BufferItem();
        mPendingReleaseItem.releaseFence = nullptr;
    }

    if (mSubmitted.empty()) {
        ALOGE("ERROR: callback with no corresponding submitted buffer item");
    }
    mPendingReleaseItem.item = std::move(mSubmitted.front());
    mSubmitted.pop();

    processNextBufferLocked(false);

    mCallbackCV.notify_all();
    decStrong((void*)transactionCallbackThunk);
}

void BLASTBufferQueue::processNextBufferLocked(bool useNextTransaction) {
    ATRACE_CALL();
    if (mNumFrameAvailable == 0 || mNumAcquired == MAX_ACQUIRED_BUFFERS + 1) {
        return;
    }

    if (mSurfaceControl == nullptr) {
        ALOGE("ERROR : surface control is null");
        return;
    }

    SurfaceComposerClient::Transaction localTransaction;
    bool applyTransaction = true;
    SurfaceComposerClient::Transaction* t = &localTransaction;
    if (mNextTransaction != nullptr && useNextTransaction) {
        t = mNextTransaction;
        mNextTransaction = nullptr;
        applyTransaction = false;
    }

    BufferItem bufferItem;

    status_t status = mBufferItemConsumer->acquireBuffer(&bufferItem, -1, false);
    if (status != OK) {
        return;
    }
    auto buffer = bufferItem.mGraphicBuffer;
    mNumFrameAvailable--;

    if (buffer == nullptr) {
        mBufferItemConsumer->releaseBuffer(bufferItem, Fence::NO_FENCE);
        return;
    }

    mNumAcquired++;
    mSubmitted.push(bufferItem);

    bool needsDisconnect = false;
    mBufferItemConsumer->getConnectionEvents(bufferItem.mFrameNumber, &needsDisconnect);

    // if producer disconnected before, notify SurfaceFlinger
    if (needsDisconnect) {
        t->notifyProducerDisconnect(mSurfaceControl);
    }

    // Ensure BLASTBufferQueue stays alive until we receive the transaction complete callback.
    incStrong((void*)transactionCallbackThunk);

    t->setBuffer(mSurfaceControl, buffer);
    t->setAcquireFence(mSurfaceControl,
                       bufferItem.mFence ? new Fence(bufferItem.mFence->dup()) : Fence::NO_FENCE);
    t->addTransactionCompletedCallback(transactionCallbackThunk, static_cast<void*>(this));

    t->setFrame(mSurfaceControl, {0, 0, mWidth, mHeight});
    t->setCrop(mSurfaceControl, computeCrop(bufferItem));
    t->setTransform(mSurfaceControl, bufferItem.mTransform);
    t->setTransformToDisplayInverse(mSurfaceControl, bufferItem.mTransformToDisplayInverse);
    t->setDesiredPresentTime(bufferItem.mTimestamp);

    if (applyTransaction) {
        t->apply();
    }
}

Rect BLASTBufferQueue::computeCrop(const BufferItem& item) {
    if (item.mScalingMode == NATIVE_WINDOW_SCALING_MODE_SCALE_CROP) {
        return GLConsumer::scaleDownCrop(item.mCrop, mWidth, mHeight);
    }
    return item.mCrop;
}

void BLASTBufferQueue::onFrameAvailable(const BufferItem& /*item*/) {
    ATRACE_CALL();
    std::unique_lock _lock{mMutex};

    if (mNextTransaction != nullptr) {
        while (mNumFrameAvailable > 0 || mNumAcquired == MAX_ACQUIRED_BUFFERS + 1) {
            mCallbackCV.wait(_lock);
        }
    }
    // add to shadow queue
    mNumFrameAvailable++;
    processNextBufferLocked(true);
}

void BLASTBufferQueue::setNextTransaction(SurfaceComposerClient::Transaction* t) {
    std::lock_guard _lock{mMutex};
    mNextTransaction = t;
}

} // namespace android