services/surfaceflinger/BufferStateLayer.cpp

/*
 * Copyright (C) 2017 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.
 */

//#define LOG_NDEBUG 0
#undef LOG_TAG
#define LOG_TAG "BufferStateLayer"
#define ATRACE_TAG ATRACE_TAG_GRAPHICS

#include "BufferStateLayer.h"
#include "ColorLayer.h"

#include "TimeStats/TimeStats.h"

#include <private/gui/SyncFeatures.h>
#include <renderengine/Image.h>

#include <limits>

namespace android {

// clang-format off
const std::array<float, 16> BufferStateLayer::IDENTITY_MATRIX{
        1, 0, 0, 0,
        0, 1, 0, 0,
        0, 0, 1, 0,
        0, 0, 0, 1
};
// clang-format on

BufferStateLayer::BufferStateLayer(const LayerCreationArgs& args) : BufferLayer(args) {
    mOverrideScalingMode = NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW;
    mCurrentState.dataspace = ui::Dataspace::V0_SRGB;
}
BufferStateLayer::~BufferStateLayer() = default;

// -----------------------------------------------------------------------
// Interface implementation for Layer
// -----------------------------------------------------------------------
void BufferStateLayer::onLayerDisplayed(const sp<Fence>& releaseFence) {
    // The previous release fence notifies the client that SurfaceFlinger is done with the previous
    // buffer that was presented on this layer. The first transaction that came in this frame that
    // replaced the previous buffer on this layer needs this release fence, because the fence will
    // let the client know when that previous buffer is removed from the screen.
    //
    // Every other transaction on this layer does not need a release fence because no other
    // Transactions that were set on this layer this frame are going to have their preceeding buffer
    // removed from the display this frame.
    //
    // For example, if we have 3 transactions this frame. The first transaction doesn't contain a
    // buffer so it doesn't need a previous release fence because the layer still needs the previous
    // buffer. The second transaction contains a buffer so it needs a previous release fence because
    // the previous buffer will be released this frame. The third transaction also contains a
    // buffer. It replaces the buffer in the second transaction. The buffer in the second
    // transaction will now no longer be presented so it is released immediately and the third
    // transaction doesn't need a previous release fence.
    for (auto& handle : mDrawingState.callbackHandles) {
        if (handle->releasePreviousBuffer) {
            handle->previousReleaseFence = releaseFence;
            break;
        }
    }
}

void BufferStateLayer::setTransformHint(uint32_t /*orientation*/) const {
    // TODO(marissaw): send the transform hint to buffer owner
    return;
}

void BufferStateLayer::releasePendingBuffer(nsecs_t /*dequeueReadyTime*/) {
    mFlinger->getTransactionCompletedThread().addPresentedCallbackHandles(
            mDrawingState.callbackHandles);

    mDrawingState.callbackHandles = {};
}

bool BufferStateLayer::shouldPresentNow(nsecs_t /*expectedPresentTime*/) const {
    if (getSidebandStreamChanged() || getAutoRefresh()) {
        return true;
    }

    return hasFrameUpdate();
}

bool BufferStateLayer::willPresentCurrentTransaction() const {
    // Returns true if the most recent Transaction applied to CurrentState will be presented.
    return getSidebandStreamChanged() || getAutoRefresh() ||
            (mCurrentState.modified && mCurrentState.buffer != nullptr);
}

bool BufferStateLayer::getTransformToDisplayInverse() const {
    return mCurrentState.transformToDisplayInverse;
}

void BufferStateLayer::pushPendingState() {
    if (!mCurrentState.modified) {
        return;
    }
    mPendingStates.push_back(mCurrentState);
    ATRACE_INT(mTransactionName.string(), mPendingStates.size());
}

bool BufferStateLayer::applyPendingStates(Layer::State* stateToCommit) {
    const bool stateUpdateAvailable = !mPendingStates.empty();
    while (!mPendingStates.empty()) {
        popPendingState(stateToCommit);
    }
    mCurrentStateModified = stateUpdateAvailable && mCurrentState.modified;
    mCurrentState.modified = false;
    return stateUpdateAvailable;
}

// Crop that applies to the window
Rect BufferStateLayer::getCrop(const Layer::State& /*s*/) const {
    return Rect::INVALID_RECT;
}

bool BufferStateLayer::setTransform(uint32_t transform) {
    if (mCurrentState.transform == transform) return false;
    mCurrentState.sequence++;
    mCurrentState.transform = transform;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setTransformToDisplayInverse(bool transformToDisplayInverse) {
    if (mCurrentState.transformToDisplayInverse == transformToDisplayInverse) return false;
    mCurrentState.sequence++;
    mCurrentState.transformToDisplayInverse = transformToDisplayInverse;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setCrop(const Rect& crop) {
    if (mCurrentState.crop == crop) return false;
    mCurrentState.sequence++;
    mCurrentState.crop = crop;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setFrame(const Rect& frame) {
    int x = frame.left;
    int y = frame.top;
    int w = frame.getWidth();
    int h = frame.getHeight();

    if (x < 0) {
        x = 0;
        w = frame.right;
    }

    if (y < 0) {
        y = 0;
        h = frame.bottom;
    }

    if (mCurrentState.active.transform.tx() == x && mCurrentState.active.transform.ty() == y &&
        mCurrentState.active.w == w && mCurrentState.active.h == h) {
        return false;
    }

    if (!frame.isValid()) {
        x = y = w = h = 0;
    }
    mCurrentState.active.transform.set(x, y);
    mCurrentState.active.w = w;
    mCurrentState.active.h = h;

    mCurrentState.sequence++;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setBuffer(const sp<GraphicBuffer>& buffer) {
    if (mCurrentState.buffer) {
        mReleasePreviousBuffer = true;
    }

    mCurrentState.sequence++;
    mCurrentState.buffer = buffer;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setAcquireFence(const sp<Fence>& fence) {
    // The acquire fences of BufferStateLayers have already signaled before they are set
    mCallbackHandleAcquireTime = fence->getSignalTime();

    mCurrentState.acquireFence = fence;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setDataspace(ui::Dataspace dataspace) {
    if (mCurrentState.dataspace == dataspace) return false;
    mCurrentState.sequence++;
    mCurrentState.dataspace = dataspace;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setHdrMetadata(const HdrMetadata& hdrMetadata) {
    if (mCurrentState.hdrMetadata == hdrMetadata) return false;
    mCurrentState.sequence++;
    mCurrentState.hdrMetadata = hdrMetadata;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setSurfaceDamageRegion(const Region& surfaceDamage) {
    mCurrentState.sequence++;
    mCurrentState.surfaceDamageRegion = surfaceDamage;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setApi(int32_t api) {
    if (mCurrentState.api == api) return false;
    mCurrentState.sequence++;
    mCurrentState.api = api;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setSidebandStream(const sp<NativeHandle>& sidebandStream) {
    if (mCurrentState.sidebandStream == sidebandStream) return false;
    mCurrentState.sequence++;
    mCurrentState.sidebandStream = sidebandStream;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);

    if (!mSidebandStreamChanged.exchange(true)) {
        // mSidebandStreamChanged was false
        mFlinger->signalLayerUpdate();
    }
    return true;
}

bool BufferStateLayer::setTransactionCompletedListeners(
        const std::vector<sp<CallbackHandle>>& handles) {
    // If there is no handle, we will not send a callback so reset mReleasePreviousBuffer and return
    if (handles.empty()) {
        mReleasePreviousBuffer = false;
        return false;
    }

    const bool willPresent = willPresentCurrentTransaction();

    for (const auto& handle : handles) {
        // If this transaction set a buffer on this layer, release its previous buffer
        handle->releasePreviousBuffer = mReleasePreviousBuffer;

        // If this layer will be presented in this frame
        if (willPresent) {
            // If this transaction set an acquire fence on this layer, set its acquire time
            handle->acquireTime = mCallbackHandleAcquireTime;

            // Notify the transaction completed thread that there is a pending latched callback
            // handle
            mFlinger->getTransactionCompletedThread().registerPendingCallbackHandle(handle);

            // Store so latched time and release fence can be set
            mCurrentState.callbackHandles.push_back(handle);

        } else { // If this layer will NOT need to be relatched and presented this frame
            // Notify the transaction completed thread this handle is done
            mFlinger->getTransactionCompletedThread().addUnpresentedCallbackHandle(handle);
        }
    }

    mReleasePreviousBuffer = false;
    mCallbackHandleAcquireTime = -1;

    return willPresent;
}

bool BufferStateLayer::setTransparentRegionHint(const Region& transparent) {
    mCurrentState.transparentRegionHint = transparent;
    mCurrentState.modified = true;
    setTransactionFlags(eTransactionNeeded);
    return true;
}

bool BufferStateLayer::setColor(const half3& color) {
    // create color layer if one does not yet exist
    if (!mCurrentState.bgColorLayer) {
        uint32_t flags = ISurfaceComposerClient::eFXSurfaceColor;
        const String8& name = mName + "BackgroundColorLayer";
        mCurrentState.bgColorLayer =
                new ColorLayer(LayerCreationArgs(mFlinger.get(), nullptr, name, 0, 0, flags));

        // add to child list
        addChild(mCurrentState.bgColorLayer);
        mFlinger->mLayersAdded = true;
        // set up SF to handle added color layer
        if (isRemovedFromCurrentState()) {
            mCurrentState.bgColorLayer->onRemovedFromCurrentState();
        }
        mFlinger->setTransactionFlags(eTransactionNeeded);
    }

    mCurrentState.bgColorLayer->setColor(color);
    mCurrentState.bgColorLayer->setLayer(std::numeric_limits<int32_t>::min());

    return true;
}

bool BufferStateLayer::setColorAlpha(float alpha) {
    if (!mCurrentState.bgColorLayer) {
        ALOGE("Attempting to set color alpha on a buffer state layer with no background color");
        return false;
    }
    mCurrentState.bgColorLayer->setAlpha(alpha);
    return true;
}

bool BufferStateLayer::setColorDataspace(ui::Dataspace dataspace) {
    if (!mCurrentState.bgColorLayer) {
        ALOGE("Attempting to set color dataspace on a buffer state layer with no background color");
        return false;
    }
    mCurrentState.bgColorLayer->setDataspace(dataspace);
    return true;
}

Rect BufferStateLayer::getBufferSize(const State& s) const {
    // for buffer state layers we use the display frame size as the buffer size.
    if (getActiveWidth(s) < UINT32_MAX && getActiveHeight(s) < UINT32_MAX) {
        return Rect(getActiveWidth(s), getActiveHeight(s));
    }

    // if the display frame is not defined, use the parent bounds as the buffer size.
    const auto& p = mDrawingParent.promote();
    if (p != nullptr) {
        Rect parentBounds = Rect(p->computeBounds(Region()));
        if (!parentBounds.isEmpty()) {
            return parentBounds;
        }
    }

    // if there is no parent layer, use the buffer's bounds as the buffer size
    if (s.buffer) {
        return s.buffer->getBounds();
    }
    return Rect::INVALID_RECT;
}
// -----------------------------------------------------------------------

// -----------------------------------------------------------------------
// Interface implementation for BufferLayer
// -----------------------------------------------------------------------
bool BufferStateLayer::fenceHasSignaled() const {
    if (latchUnsignaledBuffers()) {
        return true;
    }

    return getDrawingState().acquireFence->getStatus() == Fence::Status::Signaled;
}

nsecs_t BufferStateLayer::getDesiredPresentTime() {
    // TODO(marissaw): support an equivalent to desiredPresentTime for timestats metrics
    return 0;
}

std::shared_ptr<FenceTime> BufferStateLayer::getCurrentFenceTime() const {
    return std::make_shared<FenceTime>(getDrawingState().acquireFence);
}

void BufferStateLayer::getDrawingTransformMatrix(float *matrix) {
    std::copy(std::begin(mTransformMatrix), std::end(mTransformMatrix), matrix);
}

uint32_t BufferStateLayer::getDrawingTransform() const {
    return getDrawingState().transform;
}

ui::Dataspace BufferStateLayer::getDrawingDataSpace() const {
    return getDrawingState().dataspace;
}

// Crop that applies to the buffer
Rect BufferStateLayer::getDrawingCrop() const {
    const State& s(getDrawingState());

    if (s.crop.isEmpty() && s.buffer) {
        return s.buffer->getBounds();
    } else if (s.buffer) {
        Rect crop = s.crop;
        crop.left = std::max(crop.left, 0);
        crop.top = std::max(crop.top, 0);
        uint32_t bufferWidth = s.buffer->getWidth();
        uint32_t bufferHeight = s.buffer->getHeight();
        if (bufferHeight <= std::numeric_limits<int32_t>::max() &&
            bufferWidth <= std::numeric_limits<int32_t>::max()) {
            crop.right = std::min(crop.right, static_cast<int32_t>(bufferWidth));
            crop.bottom = std::min(crop.bottom, static_cast<int32_t>(bufferHeight));
        }
        if (!crop.isValid()) {
            // Crop rect is out of bounds, return whole buffer
            return s.buffer->getBounds();
        }
        return crop;
    }
    return s.crop;
}

uint32_t BufferStateLayer::getDrawingScalingMode() const {
    return NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW;
}

Region BufferStateLayer::getDrawingSurfaceDamage() const {
    return getDrawingState().surfaceDamageRegion;
}

const HdrMetadata& BufferStateLayer::getDrawingHdrMetadata() const {
    return getDrawingState().hdrMetadata;
}

int BufferStateLayer::getDrawingApi() const {
    return getDrawingState().api;
}

PixelFormat BufferStateLayer::getPixelFormat() const {
    if (!mActiveBuffer) {
        return PIXEL_FORMAT_NONE;
    }
    return mActiveBuffer->format;
}

uint64_t BufferStateLayer::getFrameNumber() const {
    return mFrameNumber;
}

bool BufferStateLayer::getAutoRefresh() const {
    // TODO(marissaw): support shared buffer mode
    return false;
}

bool BufferStateLayer::getSidebandStreamChanged() const {
    return mSidebandStreamChanged.load();
}

std::optional<Region> BufferStateLayer::latchSidebandStream(bool& recomputeVisibleRegions) {
    if (mSidebandStreamChanged.exchange(false)) {
        const State& s(getDrawingState());
        // mSidebandStreamChanged was true
        // replicated in LayerBE until FE/BE is ready to be synchronized
        getBE().compositionInfo.hwc.sidebandStream = s.sidebandStream;
        if (getBE().compositionInfo.hwc.sidebandStream != nullptr) {
            setTransactionFlags(eTransactionNeeded);
            mFlinger->setTransactionFlags(eTraversalNeeded);
        }
        recomputeVisibleRegions = true;

        return getTransform().transform(Region(Rect(s.active.w, s.active.h)));
    }
    return {};
}

bool BufferStateLayer::hasFrameUpdate() const {
    return mCurrentStateModified && getCurrentState().buffer != nullptr;
}

void BufferStateLayer::setFilteringEnabled(bool enabled) {
    GLConsumer::computeTransformMatrix(mTransformMatrix.data(), mActiveBuffer, mCurrentCrop,
                                       mCurrentTransform, enabled);
}

status_t BufferStateLayer::bindTextureImage() {
    const State& s(getDrawingState());
    auto& engine(mFlinger->getRenderEngine());

    return engine.bindExternalTextureBuffer(mTextureName, s.buffer, s.acquireFence, false);
}

status_t BufferStateLayer::updateTexImage(bool& /*recomputeVisibleRegions*/, nsecs_t latchTime,
                                          const sp<Fence>& releaseFence) {
    const State& s(getDrawingState());

    if (!s.buffer) {
        return NO_ERROR;
    }

    const int32_t layerID = getSequence();

    // Reject if the layer is invalid
    uint32_t bufferWidth = s.buffer->width;
    uint32_t bufferHeight = s.buffer->height;

    if (s.transform & ui::Transform::ROT_90) {
        std::swap(bufferWidth, bufferHeight);
    }

    if (s.transformToDisplayInverse) {
        uint32_t invTransform = DisplayDevice::getPrimaryDisplayOrientationTransform();
        if (invTransform & ui::Transform::ROT_90) {
            std::swap(bufferWidth, bufferHeight);
        }
    }

    if (getEffectiveScalingMode() == NATIVE_WINDOW_SCALING_MODE_FREEZE &&
        (s.active.w != bufferWidth || s.active.h != bufferHeight)) {
        ALOGE("[%s] rejecting buffer: "
              "bufferWidth=%d, bufferHeight=%d, front.active.{w=%d, h=%d}",
              mName.string(), bufferWidth, bufferHeight, s.active.w, s.active.h);
        mFlinger->mTimeStats->removeTimeRecord(layerID, getFrameNumber());
        return BAD_VALUE;
    }

    for (auto& handle : mDrawingState.callbackHandles) {
        handle->latchTime = latchTime;
    }

    // Handle sync fences
    if (SyncFeatures::getInstance().useNativeFenceSync() && releaseFence != Fence::NO_FENCE) {
        // TODO(alecmouri): Fail somewhere upstream if the fence is invalid.
        if (!releaseFence->isValid()) {
            mFlinger->mTimeStats->onDestroy(layerID);
            return UNKNOWN_ERROR;
        }

        // Check status of fences first because merging is expensive.
        // Merging an invalid fence with any other fence results in an
        // invalid fence.
        auto currentStatus = s.acquireFence->getStatus();
        if (currentStatus == Fence::Status::Invalid) {
            ALOGE("Existing fence has invalid state");
            mFlinger->mTimeStats->onDestroy(layerID);
            return BAD_VALUE;
        }

        auto incomingStatus = releaseFence->getStatus();
        if (incomingStatus == Fence::Status::Invalid) {
            ALOGE("New fence has invalid state");
            mDrawingState.acquireFence = releaseFence;
            mFlinger->mTimeStats->onDestroy(layerID);
            return BAD_VALUE;
        }

        // If both fences are signaled or both are unsignaled, we need to merge
        // them to get an accurate timestamp.
        if (currentStatus == incomingStatus) {
            char fenceName[32] = {};
            snprintf(fenceName, 32, "%.28s:%d", mName.string(), mFrameNumber);
            sp<Fence> mergedFence =
                    Fence::merge(fenceName, mDrawingState.acquireFence, releaseFence);
            if (!mergedFence.get()) {
                ALOGE("failed to merge release fences");
                // synchronization is broken, the best we can do is hope fences
                // signal in order so the new fence will act like a union
                mDrawingState.acquireFence = releaseFence;
                mFlinger->mTimeStats->onDestroy(layerID);
                return BAD_VALUE;
            }
            mDrawingState.acquireFence = mergedFence;
        } else if (incomingStatus == Fence::Status::Unsignaled) {
            // If one fence has signaled and the other hasn't, the unsignaled
            // fence will approximately correspond with the correct timestamp.
            // There's a small race if both fences signal at about the same time
            // and their statuses are retrieved with unfortunate timing. However,
            // by this point, they will have both signaled and only the timestamp
            // will be slightly off; any dependencies after this point will
            // already have been met.
            mDrawingState.acquireFence = releaseFence;
        }
    } else {
        // Bind the new buffer to the GL texture.
        //
        // Older devices require the "implicit" synchronization provided
        // by glEGLImageTargetTexture2DOES, which this method calls.  Newer
        // devices will either call this in Layer::onDraw, or (if it's not
        // a GL-composited layer) not at all.
        status_t err = bindTextureImage();
        if (err != NO_ERROR) {
            mFlinger->mTimeStats->onDestroy(layerID);
            return BAD_VALUE;
        }
    }

    // TODO(marissaw): properly support mTimeStats
    mFlinger->mTimeStats->setPostTime(layerID, getFrameNumber(), getName().c_str(), latchTime);
    mFlinger->mTimeStats->setAcquireFence(layerID, getFrameNumber(), getCurrentFenceTime());
    mFlinger->mTimeStats->setLatchTime(layerID, getFrameNumber(), latchTime);

    return NO_ERROR;
}

status_t BufferStateLayer::updateActiveBuffer() {
    const State& s(getDrawingState());

    if (s.buffer == nullptr) {
        return BAD_VALUE;
    }

    mActiveBuffer = s.buffer;
    mActiveBufferFence = s.acquireFence;
    getBE().compositionInfo.mBuffer = mActiveBuffer;
    getBE().compositionInfo.mBufferSlot = 0;

    return NO_ERROR;
}

bool BufferStateLayer::useCachedBufferForClientComposition() const {
    // TODO: Store a proper staleness bit to support EGLImage caching.
    return false;
}

status_t BufferStateLayer::updateFrameNumber(nsecs_t /*latchTime*/) {
    // TODO(marissaw): support frame history events
    mCurrentFrameNumber = mFrameNumber;
    return NO_ERROR;
}

void BufferStateLayer::setHwcLayerBuffer(DisplayId displayId) {
    auto& hwcInfo = getBE().mHwcLayers[displayId];
    auto& hwcLayer = hwcInfo.layer;

    const State& s(getDrawingState());

    // TODO(marissaw): support more than one slot
    uint32_t hwcSlot = 0;

    auto error = hwcLayer->setBuffer(hwcSlot, s.buffer, s.acquireFence);
    if (error != HWC2::Error::None) {
        ALOGE("[%s] Failed to set buffer %p: %s (%d)", mName.string(),
              s.buffer->handle, to_string(error).c_str(), static_cast<int32_t>(error));
    }

    mCurrentStateModified = false;
    mFrameNumber++;
}

void BufferStateLayer::onFirstRef() {
    BufferLayer::onFirstRef();

    if (const auto display = mFlinger->getDefaultDisplayDevice()) {
        updateTransformHint(display);
    }
}

} // namespace android