|  | #include "hardware_composer.h" | 
|  |  | 
|  | #include <cutils/properties.h> | 
|  | #include <cutils/sched_policy.h> | 
|  | #include <fcntl.h> | 
|  | #include <log/log.h> | 
|  | #include <poll.h> | 
|  | #include <sync/sync.h> | 
|  | #include <sys/eventfd.h> | 
|  | #include <sys/prctl.h> | 
|  | #include <sys/resource.h> | 
|  | #include <sys/system_properties.h> | 
|  | #include <sys/timerfd.h> | 
|  | #include <time.h> | 
|  | #include <unistd.h> | 
|  | #include <utils/Trace.h> | 
|  |  | 
|  | #include <algorithm> | 
|  | #include <chrono> | 
|  | #include <functional> | 
|  | #include <map> | 
|  | #include <sstream> | 
|  | #include <string> | 
|  | #include <tuple> | 
|  |  | 
|  | #include <dvr/dvr_display_types.h> | 
|  | #include <dvr/performance_client_api.h> | 
|  | #include <private/dvr/clock_ns.h> | 
|  | #include <private/dvr/ion_buffer.h> | 
|  |  | 
|  | using android::hardware::Return; | 
|  | using android::hardware::Void; | 
|  | using android::pdx::LocalHandle; | 
|  | using android::pdx::rpc::EmptyVariant; | 
|  | using android::pdx::rpc::IfAnyOf; | 
|  |  | 
|  | using namespace std::chrono_literals; | 
|  |  | 
|  | namespace android { | 
|  | namespace dvr { | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | const char kBacklightBrightnessSysFile[] = | 
|  | "/sys/class/leds/lcd-backlight/brightness"; | 
|  |  | 
|  | const char kPrimaryDisplayWaitPPEventFile[] = "/sys/class/graphics/fb0/wait_pp"; | 
|  |  | 
|  | const char kDvrPerformanceProperty[] = "sys.dvr.performance"; | 
|  |  | 
|  | const char kRightEyeOffsetProperty[] = "dvr.right_eye_offset_ns"; | 
|  |  | 
|  | // Get time offset from a vsync to when the pose for that vsync should be | 
|  | // predicted out to. For example, if scanout gets halfway through the frame | 
|  | // at the halfway point between vsyncs, then this could be half the period. | 
|  | // With global shutter displays, this should be changed to the offset to when | 
|  | // illumination begins. Low persistence adds a frame of latency, so we predict | 
|  | // to the center of the next frame. | 
|  | inline int64_t GetPosePredictionTimeOffset(int64_t vsync_period_ns) { | 
|  | return (vsync_period_ns * 150) / 100; | 
|  | } | 
|  |  | 
|  | // Attempts to set the scheduler class and partiton for the current thread. | 
|  | // Returns true on success or false on failure. | 
|  | bool SetThreadPolicy(const std::string& scheduler_class, | 
|  | const std::string& partition) { | 
|  | int error = dvrSetSchedulerClass(0, scheduler_class.c_str()); | 
|  | if (error < 0) { | 
|  | ALOGE( | 
|  | "SetThreadPolicy: Failed to set scheduler class \"%s\" for " | 
|  | "thread_id=%d: %s", | 
|  | scheduler_class.c_str(), gettid(), strerror(-error)); | 
|  | return false; | 
|  | } | 
|  | error = dvrSetCpuPartition(0, partition.c_str()); | 
|  | if (error < 0) { | 
|  | ALOGE( | 
|  | "SetThreadPolicy: Failed to set cpu partiton \"%s\" for thread_id=%d: " | 
|  | "%s", | 
|  | partition.c_str(), gettid(), strerror(-error)); | 
|  | return false; | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | }  // anonymous namespace | 
|  |  | 
|  | // HardwareComposer static data; | 
|  | constexpr size_t HardwareComposer::kMaxHardwareLayers; | 
|  |  | 
|  | HardwareComposer::HardwareComposer() | 
|  | : initialized_(false), request_display_callback_(nullptr) {} | 
|  |  | 
|  | HardwareComposer::~HardwareComposer(void) { | 
|  | UpdatePostThreadState(PostThreadState::Quit, true); | 
|  | if (post_thread_.joinable()) | 
|  | post_thread_.join(); | 
|  | } | 
|  |  | 
|  | bool HardwareComposer::Initialize( | 
|  | Hwc2::Composer* hidl, RequestDisplayCallback request_display_callback) { | 
|  | if (initialized_) { | 
|  | ALOGE("HardwareComposer::Initialize: already initialized."); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | request_display_callback_ = request_display_callback; | 
|  |  | 
|  | HWC::Error error = HWC::Error::None; | 
|  |  | 
|  | Hwc2::Config config; | 
|  | error = hidl->getActiveConfig(HWC_DISPLAY_PRIMARY, &config); | 
|  |  | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE("HardwareComposer: Failed to get current display config : %d", | 
|  | config); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | error = GetDisplayMetrics(hidl, HWC_DISPLAY_PRIMARY, config, | 
|  | &native_display_metrics_); | 
|  |  | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer: Failed to get display attributes for current " | 
|  | "configuration : %d", | 
|  | error.value); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | ALOGI( | 
|  | "HardwareComposer: primary display attributes: width=%d height=%d " | 
|  | "vsync_period_ns=%d DPI=%dx%d", | 
|  | native_display_metrics_.width, native_display_metrics_.height, | 
|  | native_display_metrics_.vsync_period_ns, native_display_metrics_.dpi.x, | 
|  | native_display_metrics_.dpi.y); | 
|  |  | 
|  | // Set the display metrics but never use rotation to avoid the long latency of | 
|  | // rotation processing in hwc. | 
|  | display_transform_ = HWC_TRANSFORM_NONE; | 
|  | display_metrics_ = native_display_metrics_; | 
|  |  | 
|  | post_thread_event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)); | 
|  | LOG_ALWAYS_FATAL_IF( | 
|  | !post_thread_event_fd_, | 
|  | "HardwareComposer: Failed to create interrupt event fd : %s", | 
|  | strerror(errno)); | 
|  |  | 
|  | post_thread_ = std::thread(&HardwareComposer::PostThread, this); | 
|  |  | 
|  | initialized_ = true; | 
|  |  | 
|  | return initialized_; | 
|  | } | 
|  |  | 
|  | void HardwareComposer::Enable() { | 
|  | UpdatePostThreadState(PostThreadState::Suspended, false); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::Disable() { | 
|  | UpdatePostThreadState(PostThreadState::Suspended, true); | 
|  | } | 
|  |  | 
|  | // Update the post thread quiescent state based on idle and suspended inputs. | 
|  | void HardwareComposer::UpdatePostThreadState(PostThreadStateType state, | 
|  | bool suspend) { | 
|  | std::unique_lock<std::mutex> lock(post_thread_mutex_); | 
|  |  | 
|  | // Update the votes in the state variable before evaluating the effective | 
|  | // quiescent state. Any bits set in post_thread_state_ indicate that the post | 
|  | // thread should be suspended. | 
|  | if (suspend) { | 
|  | post_thread_state_ |= state; | 
|  | } else { | 
|  | post_thread_state_ &= ~state; | 
|  | } | 
|  |  | 
|  | const bool quit = post_thread_state_ & PostThreadState::Quit; | 
|  | const bool effective_suspend = post_thread_state_ != PostThreadState::Active; | 
|  | if (quit) { | 
|  | post_thread_quiescent_ = true; | 
|  | eventfd_write(post_thread_event_fd_.Get(), 1); | 
|  | post_thread_wait_.notify_one(); | 
|  | } else if (effective_suspend && !post_thread_quiescent_) { | 
|  | post_thread_quiescent_ = true; | 
|  | eventfd_write(post_thread_event_fd_.Get(), 1); | 
|  | } else if (!effective_suspend && post_thread_quiescent_) { | 
|  | post_thread_quiescent_ = false; | 
|  | eventfd_t value; | 
|  | eventfd_read(post_thread_event_fd_.Get(), &value); | 
|  | post_thread_wait_.notify_one(); | 
|  | } | 
|  |  | 
|  | // Wait until the post thread is in the requested state. | 
|  | post_thread_ready_.wait(lock, [this, effective_suspend] { | 
|  | return effective_suspend != post_thread_resumed_; | 
|  | }); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::OnPostThreadResumed() { | 
|  | hidl_.reset(new Hwc2::Composer(false)); | 
|  | hidl_callback_ = new ComposerCallback; | 
|  | hidl_->registerCallback(hidl_callback_); | 
|  |  | 
|  | EnableVsync(true); | 
|  |  | 
|  | // TODO(skiazyk): We need to do something about accessing this directly, | 
|  | // supposedly there is a backlight service on the way. | 
|  | // TODO(steventhomas): When we change the backlight setting, will surface | 
|  | // flinger (or something else) set it back to its original value once we give | 
|  | // control of the display back to surface flinger? | 
|  | SetBacklightBrightness(255); | 
|  |  | 
|  | // Trigger target-specific performance mode change. | 
|  | property_set(kDvrPerformanceProperty, "performance"); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::OnPostThreadPaused() { | 
|  | retire_fence_fds_.clear(); | 
|  | display_surfaces_.clear(); | 
|  |  | 
|  | for (size_t i = 0; i < kMaxHardwareLayers; ++i) { | 
|  | layers_[i].Reset(); | 
|  | } | 
|  | active_layer_count_ = 0; | 
|  |  | 
|  | if (hidl_) { | 
|  | EnableVsync(false); | 
|  | } | 
|  |  | 
|  | hidl_callback_ = nullptr; | 
|  | hidl_.reset(nullptr); | 
|  |  | 
|  | // Trigger target-specific performance mode change. | 
|  | property_set(kDvrPerformanceProperty, "idle"); | 
|  | } | 
|  |  | 
|  | HWC::Error HardwareComposer::Validate(hwc2_display_t display) { | 
|  | uint32_t num_types; | 
|  | uint32_t num_requests; | 
|  | HWC::Error error = | 
|  | hidl_->validateDisplay(display, &num_types, &num_requests); | 
|  |  | 
|  | if (error == HWC2_ERROR_HAS_CHANGES) { | 
|  | // TODO(skiazyk): We might need to inspect the requested changes first, but | 
|  | // so far it seems like we shouldn't ever hit a bad state. | 
|  | // error = hwc2_funcs_.accept_display_changes_fn_(hardware_composer_device_, | 
|  | //                                               display); | 
|  | error = hidl_->acceptDisplayChanges(display); | 
|  | } | 
|  |  | 
|  | return error; | 
|  | } | 
|  |  | 
|  | HWC::Error HardwareComposer::EnableVsync(bool enabled) { | 
|  | return hidl_->setVsyncEnabled( | 
|  | HWC_DISPLAY_PRIMARY, | 
|  | (Hwc2::IComposerClient::Vsync)(enabled ? HWC2_VSYNC_ENABLE | 
|  | : HWC2_VSYNC_DISABLE)); | 
|  | } | 
|  |  | 
|  | HWC::Error HardwareComposer::Present(hwc2_display_t display) { | 
|  | int32_t present_fence; | 
|  | HWC::Error error = hidl_->presentDisplay(display, &present_fence); | 
|  |  | 
|  | // According to the documentation, this fence is signaled at the time of | 
|  | // vsync/DMA for physical displays. | 
|  | if (error == HWC::Error::None) { | 
|  | ATRACE_INT("HardwareComposer: VsyncFence", present_fence); | 
|  | retire_fence_fds_.emplace_back(present_fence); | 
|  | } else { | 
|  | ATRACE_INT("HardwareComposer: PresentResult", error); | 
|  | } | 
|  |  | 
|  | return error; | 
|  | } | 
|  |  | 
|  | HWC::Error HardwareComposer::GetDisplayAttribute(Hwc2::Composer* hidl, | 
|  | hwc2_display_t display, | 
|  | hwc2_config_t config, | 
|  | hwc2_attribute_t attribute, | 
|  | int32_t* out_value) const { | 
|  | return hidl->getDisplayAttribute( | 
|  | display, config, (Hwc2::IComposerClient::Attribute)attribute, out_value); | 
|  | } | 
|  |  | 
|  | HWC::Error HardwareComposer::GetDisplayMetrics( | 
|  | Hwc2::Composer* hidl, hwc2_display_t display, hwc2_config_t config, | 
|  | HWCDisplayMetrics* out_metrics) const { | 
|  | HWC::Error error; | 
|  |  | 
|  | error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_WIDTH, | 
|  | &out_metrics->width); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer::GetDisplayMetrics: Failed to get display width: %s", | 
|  | error.to_string().c_str()); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_HEIGHT, | 
|  | &out_metrics->height); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer::GetDisplayMetrics: Failed to get display height: %s", | 
|  | error.to_string().c_str()); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = GetDisplayAttribute(hidl, display, config, | 
|  | HWC2_ATTRIBUTE_VSYNC_PERIOD, | 
|  | &out_metrics->vsync_period_ns); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer::GetDisplayMetrics: Failed to get display height: %s", | 
|  | error.to_string().c_str()); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_DPI_X, | 
|  | &out_metrics->dpi.x); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer::GetDisplayMetrics: Failed to get display DPI X: %s", | 
|  | error.to_string().c_str()); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_DPI_Y, | 
|  | &out_metrics->dpi.y); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE( | 
|  | "HardwareComposer::GetDisplayMetrics: Failed to get display DPI Y: %s", | 
|  | error.to_string().c_str()); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | return HWC::Error::None; | 
|  | } | 
|  |  | 
|  | std::string HardwareComposer::Dump() { | 
|  | std::unique_lock<std::mutex> lock(post_thread_mutex_); | 
|  | std::ostringstream stream; | 
|  |  | 
|  | stream << "Display metrics:     " << display_metrics_.width << "x" | 
|  | << display_metrics_.height << " " << (display_metrics_.dpi.x / 1000.0) | 
|  | << "x" << (display_metrics_.dpi.y / 1000.0) << " dpi @ " | 
|  | << (1000000000.0 / display_metrics_.vsync_period_ns) << " Hz" | 
|  | << std::endl; | 
|  |  | 
|  | stream << "Post thread resumed: " << post_thread_resumed_ << std::endl; | 
|  | stream << "Active layers:       " << active_layer_count_ << std::endl; | 
|  | stream << std::endl; | 
|  |  | 
|  | for (size_t i = 0; i < active_layer_count_; i++) { | 
|  | stream << "Layer " << i << ":"; | 
|  | stream << " type=" << layers_[i].GetCompositionType().to_string(); | 
|  | stream << " surface_id=" << layers_[i].GetSurfaceId(); | 
|  | stream << " buffer_id=" << layers_[i].GetBufferId(); | 
|  | stream << std::endl; | 
|  | } | 
|  | stream << std::endl; | 
|  |  | 
|  | if (post_thread_resumed_) { | 
|  | stream << "Hardware Composer Debug Info:" << std::endl; | 
|  | stream << hidl_->dumpDebugInfo(); | 
|  | } | 
|  |  | 
|  | return stream.str(); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::PostLayers() { | 
|  | ATRACE_NAME("HardwareComposer::PostLayers"); | 
|  |  | 
|  | // Setup the hardware composer layers with current buffers. | 
|  | for (size_t i = 0; i < active_layer_count_; i++) { | 
|  | layers_[i].Prepare(); | 
|  | } | 
|  |  | 
|  | HWC::Error error = Validate(HWC_DISPLAY_PRIMARY); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE("HardwareComposer::PostLayers: Validate failed: %s", | 
|  | error.to_string().c_str()); | 
|  | return; | 
|  | } | 
|  |  | 
|  | // Now that we have taken in a frame from the application, we have a chance | 
|  | // to drop the frame before passing the frame along to HWC. | 
|  | // If the display driver has become backed up, we detect it here and then | 
|  | // react by skipping this frame to catch up latency. | 
|  | while (!retire_fence_fds_.empty() && | 
|  | (!retire_fence_fds_.front() || | 
|  | sync_wait(retire_fence_fds_.front().Get(), 0) == 0)) { | 
|  | // There are only 2 fences in here, no performance problem to shift the | 
|  | // array of ints. | 
|  | retire_fence_fds_.erase(retire_fence_fds_.begin()); | 
|  | } | 
|  |  | 
|  | const bool is_frame_pending = IsFramePendingInDriver(); | 
|  | const bool is_fence_pending = static_cast<int32_t>(retire_fence_fds_.size()) > | 
|  | post_thread_config_.allowed_pending_fence_count; | 
|  |  | 
|  | if (is_fence_pending || is_frame_pending) { | 
|  | ATRACE_INT("frame_skip_count", ++frame_skip_count_); | 
|  |  | 
|  | ALOGW_IF(is_frame_pending, "Warning: frame already queued, dropping frame"); | 
|  | ALOGW_IF(is_fence_pending, | 
|  | "Warning: dropping a frame to catch up with HWC (pending = %zd)", | 
|  | retire_fence_fds_.size()); | 
|  |  | 
|  | for (size_t i = 0; i < active_layer_count_; i++) { | 
|  | layers_[i].Drop(); | 
|  | } | 
|  | return; | 
|  | } else { | 
|  | // Make the transition more obvious in systrace when the frame skip happens | 
|  | // above. | 
|  | ATRACE_INT("frame_skip_count", 0); | 
|  | } | 
|  |  | 
|  | #if TRACE > 1 | 
|  | for (size_t i = 0; i < active_layer_count_; i++) { | 
|  | ALOGI("HardwareComposer::PostLayers: layer=%zu buffer_id=%d composition=%s", | 
|  | i, layers_[i].GetBufferId(), | 
|  | layers_[i].GetCompositionType().to_string().c_str()); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | error = Present(HWC_DISPLAY_PRIMARY); | 
|  | if (error != HWC::Error::None) { | 
|  | ALOGE("HardwareComposer::PostLayers: Present failed: %s", | 
|  | error.to_string().c_str()); | 
|  | return; | 
|  | } | 
|  |  | 
|  | std::vector<Hwc2::Layer> out_layers; | 
|  | std::vector<int> out_fences; | 
|  | error = hidl_->getReleaseFences(HWC_DISPLAY_PRIMARY, &out_layers, | 
|  | &out_fences); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "HardwareComposer::PostLayers: Failed to get release fences: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | // Perform post-frame bookkeeping. Unused layers are a no-op. | 
|  | uint32_t num_elements = out_layers.size(); | 
|  | for (size_t i = 0; i < num_elements; ++i) { | 
|  | for (size_t j = 0; j < active_layer_count_; ++j) { | 
|  | if (layers_[j].GetLayerHandle() == out_layers[i]) { | 
|  | layers_[j].Finish(out_fences[i]); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | void HardwareComposer::SetDisplaySurfaces( | 
|  | std::vector<std::shared_ptr<DirectDisplaySurface>> surfaces) { | 
|  | ALOGI("HardwareComposer::SetDisplaySurfaces: surface count=%zd", | 
|  | surfaces.size()); | 
|  | const bool display_idle = surfaces.size() == 0; | 
|  | { | 
|  | std::unique_lock<std::mutex> lock(post_thread_mutex_); | 
|  | pending_surfaces_ = std::move(surfaces); | 
|  | } | 
|  |  | 
|  | if (request_display_callback_) | 
|  | request_display_callback_(!display_idle); | 
|  |  | 
|  | // Set idle state based on whether there are any surfaces to handle. | 
|  | UpdatePostThreadState(PostThreadState::Idle, display_idle); | 
|  | } | 
|  |  | 
|  | int HardwareComposer::OnNewGlobalBuffer(DvrGlobalBufferKey key, | 
|  | IonBuffer& ion_buffer) { | 
|  | if (key == DvrGlobalBuffers::kVsyncBuffer) { | 
|  | vsync_ring_ = std::make_unique<CPUMappedBroadcastRing<DvrVsyncRing>>( | 
|  | &ion_buffer, CPUUsageMode::WRITE_OFTEN); | 
|  |  | 
|  | if (vsync_ring_->IsMapped() == false) { | 
|  | return -EPERM; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (key == DvrGlobalBuffers::kVrFlingerConfigBufferKey) { | 
|  | return MapConfigBuffer(ion_buffer); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | void HardwareComposer::OnDeletedGlobalBuffer(DvrGlobalBufferKey key) { | 
|  | if (key == DvrGlobalBuffers::kVrFlingerConfigBufferKey) { | 
|  | ConfigBufferDeleted(); | 
|  | } | 
|  | } | 
|  |  | 
|  | int HardwareComposer::MapConfigBuffer(IonBuffer& ion_buffer) { | 
|  | std::lock_guard<std::mutex> lock(shared_config_mutex_); | 
|  | shared_config_ring_ = DvrConfigRing(); | 
|  |  | 
|  | if (ion_buffer.width() < DvrConfigRing::MemorySize()) { | 
|  | ALOGE("HardwareComposer::MapConfigBuffer: invalid buffer size."); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | void* buffer_base = 0; | 
|  | int result = ion_buffer.Lock(ion_buffer.usage(), 0, 0, ion_buffer.width(), | 
|  | ion_buffer.height(), &buffer_base); | 
|  | if (result != 0) { | 
|  | ALOGE( | 
|  | "HardwareComposer::MapConfigBuffer: Failed to map vrflinger config " | 
|  | "buffer."); | 
|  | return -EPERM; | 
|  | } | 
|  |  | 
|  | shared_config_ring_ = DvrConfigRing::Create(buffer_base, ion_buffer.width()); | 
|  | ion_buffer.Unlock(); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | void HardwareComposer::ConfigBufferDeleted() { | 
|  | std::lock_guard<std::mutex> lock(shared_config_mutex_); | 
|  | shared_config_ring_ = DvrConfigRing(); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::UpdateConfigBuffer() { | 
|  | std::lock_guard<std::mutex> lock(shared_config_mutex_); | 
|  | if (!shared_config_ring_.is_valid()) | 
|  | return; | 
|  | // Copy from latest record in shared_config_ring_ to local copy. | 
|  | DvrConfig record; | 
|  | if (shared_config_ring_.GetNewest(&shared_config_ring_sequence_, &record)) { | 
|  | post_thread_config_ = record; | 
|  | } | 
|  | } | 
|  |  | 
|  | int HardwareComposer::PostThreadPollInterruptible( | 
|  | const pdx::LocalHandle& event_fd, int requested_events, int timeout_ms) { | 
|  | pollfd pfd[2] = { | 
|  | { | 
|  | .fd = event_fd.Get(), | 
|  | .events = static_cast<short>(requested_events), | 
|  | .revents = 0, | 
|  | }, | 
|  | { | 
|  | .fd = post_thread_event_fd_.Get(), | 
|  | .events = POLLPRI | POLLIN, | 
|  | .revents = 0, | 
|  | }, | 
|  | }; | 
|  | int ret, error; | 
|  | do { | 
|  | ret = poll(pfd, 2, timeout_ms); | 
|  | error = errno; | 
|  | ALOGW_IF(ret < 0, | 
|  | "HardwareComposer::PostThreadPollInterruptible: Error during " | 
|  | "poll(): %s (%d)", | 
|  | strerror(error), error); | 
|  | } while (ret < 0 && error == EINTR); | 
|  |  | 
|  | if (ret < 0) { | 
|  | return -error; | 
|  | } else if (ret == 0) { | 
|  | return -ETIMEDOUT; | 
|  | } else if (pfd[0].revents != 0) { | 
|  | return 0; | 
|  | } else if (pfd[1].revents != 0) { | 
|  | ALOGI("VrHwcPost thread interrupted"); | 
|  | return kPostThreadInterrupted; | 
|  | } else { | 
|  | return 0; | 
|  | } | 
|  | } | 
|  |  | 
|  | // Reads the value of the display driver wait_pingpong state. Returns 0 or 1 | 
|  | // (the value of the state) on success or a negative error otherwise. | 
|  | // TODO(eieio): This is pretty driver specific, this should be moved to a | 
|  | // separate class eventually. | 
|  | int HardwareComposer::ReadWaitPPState() { | 
|  | // Gracefully handle when the kernel does not support this feature. | 
|  | if (!primary_display_wait_pp_fd_) | 
|  | return 0; | 
|  |  | 
|  | const int wait_pp_fd = primary_display_wait_pp_fd_.Get(); | 
|  | int ret, error; | 
|  |  | 
|  | ret = lseek(wait_pp_fd, 0, SEEK_SET); | 
|  | if (ret < 0) { | 
|  | error = errno; | 
|  | ALOGE("HardwareComposer::ReadWaitPPState: Failed to seek wait_pp fd: %s", | 
|  | strerror(error)); | 
|  | return -error; | 
|  | } | 
|  |  | 
|  | char data = -1; | 
|  | ret = read(wait_pp_fd, &data, sizeof(data)); | 
|  | if (ret < 0) { | 
|  | error = errno; | 
|  | ALOGE("HardwareComposer::ReadWaitPPState: Failed to read wait_pp state: %s", | 
|  | strerror(error)); | 
|  | return -error; | 
|  | } | 
|  |  | 
|  | switch (data) { | 
|  | case '0': | 
|  | return 0; | 
|  | case '1': | 
|  | return 1; | 
|  | default: | 
|  | ALOGE( | 
|  | "HardwareComposer::ReadWaitPPState: Unexpected value for wait_pp: %d", | 
|  | data); | 
|  | return -EINVAL; | 
|  | } | 
|  | } | 
|  |  | 
|  | // Waits for the next vsync and returns the timestamp of the vsync event. If | 
|  | // vsync already passed since the last call, returns the latest vsync timestamp | 
|  | // instead of blocking. | 
|  | int HardwareComposer::WaitForVSync(int64_t* timestamp) { | 
|  | int error = PostThreadPollInterruptible( | 
|  | hidl_callback_->GetVsyncEventFd(), POLLIN, /*timeout_ms*/ 1000); | 
|  | if (error == kPostThreadInterrupted || error < 0) { | 
|  | return error; | 
|  | } else { | 
|  | *timestamp = hidl_callback_->GetVsyncTime(); | 
|  | return 0; | 
|  | } | 
|  | } | 
|  |  | 
|  | int HardwareComposer::SleepUntil(int64_t wakeup_timestamp) { | 
|  | const int timer_fd = vsync_sleep_timer_fd_.Get(); | 
|  | const itimerspec wakeup_itimerspec = { | 
|  | .it_interval = {.tv_sec = 0, .tv_nsec = 0}, | 
|  | .it_value = NsToTimespec(wakeup_timestamp), | 
|  | }; | 
|  | int ret = | 
|  | timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &wakeup_itimerspec, nullptr); | 
|  | int error = errno; | 
|  | if (ret < 0) { | 
|  | ALOGE("HardwareComposer::SleepUntil: Failed to set timerfd: %s", | 
|  | strerror(error)); | 
|  | return -error; | 
|  | } | 
|  |  | 
|  | return PostThreadPollInterruptible( | 
|  | vsync_sleep_timer_fd_, POLLIN, /*timeout_ms*/ -1); | 
|  | } | 
|  |  | 
|  | void HardwareComposer::PostThread() { | 
|  | // NOLINTNEXTLINE(runtime/int) | 
|  | prctl(PR_SET_NAME, reinterpret_cast<unsigned long>("VrHwcPost"), 0, 0, 0); | 
|  |  | 
|  | // Set the scheduler to SCHED_FIFO with high priority. If this fails here | 
|  | // there may have been a startup timing issue between this thread and | 
|  | // performanced. Try again later when this thread becomes active. | 
|  | bool thread_policy_setup = | 
|  | SetThreadPolicy("graphics:high", "/system/performance"); | 
|  |  | 
|  | #if ENABLE_BACKLIGHT_BRIGHTNESS | 
|  | // TODO(hendrikw): This isn't required at the moment. It's possible that there | 
|  | //                 is another method to access this when needed. | 
|  | // Open the backlight brightness control sysfs node. | 
|  | backlight_brightness_fd_ = LocalHandle(kBacklightBrightnessSysFile, O_RDWR); | 
|  | ALOGW_IF(!backlight_brightness_fd_, | 
|  | "HardwareComposer: Failed to open backlight brightness control: %s", | 
|  | strerror(errno)); | 
|  | #endif  // ENABLE_BACKLIGHT_BRIGHTNESS | 
|  |  | 
|  | // Open the wait pingpong status node for the primary display. | 
|  | // TODO(eieio): Move this into a platform-specific class. | 
|  | primary_display_wait_pp_fd_ = | 
|  | LocalHandle(kPrimaryDisplayWaitPPEventFile, O_RDONLY); | 
|  | ALOGW_IF( | 
|  | !primary_display_wait_pp_fd_, | 
|  | "HardwareComposer: Failed to open wait_pp node for primary display: %s", | 
|  | strerror(errno)); | 
|  |  | 
|  | // Create a timerfd based on CLOCK_MONOTINIC. | 
|  | vsync_sleep_timer_fd_.Reset(timerfd_create(CLOCK_MONOTONIC, 0)); | 
|  | LOG_ALWAYS_FATAL_IF( | 
|  | !vsync_sleep_timer_fd_, | 
|  | "HardwareComposer: Failed to create vsync sleep timerfd: %s", | 
|  | strerror(errno)); | 
|  |  | 
|  | const int64_t ns_per_frame = display_metrics_.vsync_period_ns; | 
|  | const int64_t photon_offset_ns = GetPosePredictionTimeOffset(ns_per_frame); | 
|  |  | 
|  | // TODO(jbates) Query vblank time from device, when such an API is available. | 
|  | // This value (6.3%) was measured on A00 in low persistence mode. | 
|  | int64_t vblank_ns = ns_per_frame * 63 / 1000; | 
|  | int64_t right_eye_photon_offset_ns = (ns_per_frame - vblank_ns) / 2; | 
|  |  | 
|  | // Check property for overriding right eye offset value. | 
|  | right_eye_photon_offset_ns = | 
|  | property_get_int64(kRightEyeOffsetProperty, right_eye_photon_offset_ns); | 
|  |  | 
|  | bool was_running = false; | 
|  |  | 
|  | while (1) { | 
|  | ATRACE_NAME("HardwareComposer::PostThread"); | 
|  |  | 
|  | // Check for updated config once per vsync. | 
|  | UpdateConfigBuffer(); | 
|  |  | 
|  | while (post_thread_quiescent_) { | 
|  | std::unique_lock<std::mutex> lock(post_thread_mutex_); | 
|  | ALOGI("HardwareComposer::PostThread: Entering quiescent state."); | 
|  |  | 
|  | // Tear down resources if necessary. | 
|  | if (was_running) | 
|  | OnPostThreadPaused(); | 
|  |  | 
|  | was_running = false; | 
|  | post_thread_resumed_ = false; | 
|  | post_thread_ready_.notify_all(); | 
|  |  | 
|  | if (post_thread_state_ & PostThreadState::Quit) { | 
|  | ALOGI("HardwareComposer::PostThread: Quitting."); | 
|  | return; | 
|  | } | 
|  |  | 
|  | post_thread_wait_.wait(lock, [this] { return !post_thread_quiescent_; }); | 
|  |  | 
|  | post_thread_resumed_ = true; | 
|  | post_thread_ready_.notify_all(); | 
|  |  | 
|  | ALOGI("HardwareComposer::PostThread: Exiting quiescent state."); | 
|  | } | 
|  |  | 
|  | if (!was_running) { | 
|  | // Setup resources. | 
|  | OnPostThreadResumed(); | 
|  | was_running = true; | 
|  |  | 
|  | // Try to setup the scheduler policy if it failed during startup. Only | 
|  | // attempt to do this on transitions from inactive to active to avoid | 
|  | // spamming the system with RPCs and log messages. | 
|  | if (!thread_policy_setup) { | 
|  | thread_policy_setup = | 
|  | SetThreadPolicy("graphics:high", "/system/performance"); | 
|  | } | 
|  | } | 
|  |  | 
|  | int64_t vsync_timestamp = 0; | 
|  | { | 
|  | std::array<char, 128> buf; | 
|  | snprintf(buf.data(), buf.size(), "wait_vsync|vsync=%d|", | 
|  | vsync_count_ + 1); | 
|  | ATRACE_NAME(buf.data()); | 
|  |  | 
|  | const int error = WaitForVSync(&vsync_timestamp); | 
|  | ALOGE_IF( | 
|  | error < 0, | 
|  | "HardwareComposer::PostThread: Failed to wait for vsync event: %s", | 
|  | strerror(-error)); | 
|  | // Don't bother processing this frame if a pause was requested | 
|  | if (error == kPostThreadInterrupted) | 
|  | continue; | 
|  | } | 
|  |  | 
|  | ++vsync_count_; | 
|  |  | 
|  | const bool layer_config_changed = UpdateLayerConfig(); | 
|  |  | 
|  | // Publish the vsync event. | 
|  | if (vsync_ring_) { | 
|  | DvrVsync vsync; | 
|  | vsync.vsync_count = vsync_count_; | 
|  | vsync.vsync_timestamp_ns = vsync_timestamp; | 
|  | vsync.vsync_left_eye_offset_ns = photon_offset_ns; | 
|  | vsync.vsync_right_eye_offset_ns = right_eye_photon_offset_ns; | 
|  | vsync.vsync_period_ns = ns_per_frame; | 
|  |  | 
|  | vsync_ring_->Publish(vsync); | 
|  | } | 
|  |  | 
|  | // Signal all of the vsync clients. Because absolute time is used for the | 
|  | // wakeup time below, this can take a little time if necessary. | 
|  | if (vsync_callback_) | 
|  | vsync_callback_(HWC_DISPLAY_PRIMARY, vsync_timestamp, | 
|  | /*frame_time_estimate*/ 0, vsync_count_); | 
|  |  | 
|  | { | 
|  | // Sleep until shortly before vsync. | 
|  | ATRACE_NAME("sleep"); | 
|  |  | 
|  | const int64_t display_time_est_ns = vsync_timestamp + ns_per_frame; | 
|  | const int64_t now_ns = GetSystemClockNs(); | 
|  | const int64_t sleep_time_ns = display_time_est_ns - now_ns - | 
|  | post_thread_config_.frame_post_offset_ns; | 
|  | const int64_t wakeup_time_ns = | 
|  | display_time_est_ns - post_thread_config_.frame_post_offset_ns; | 
|  |  | 
|  | ATRACE_INT64("sleep_time_ns", sleep_time_ns); | 
|  | if (sleep_time_ns > 0) { | 
|  | int error = SleepUntil(wakeup_time_ns); | 
|  | ALOGE_IF(error < 0, "HardwareComposer::PostThread: Failed to sleep: %s", | 
|  | strerror(-error)); | 
|  | if (error == kPostThreadInterrupted) { | 
|  | if (layer_config_changed) { | 
|  | // If the layer config changed we need to validateDisplay() even if | 
|  | // we're going to drop the frame, to flush the Composer object's | 
|  | // internal command buffer and apply our layer changes. | 
|  | Validate(HWC_DISPLAY_PRIMARY); | 
|  | } | 
|  | continue; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | PostLayers(); | 
|  | } | 
|  | } | 
|  |  | 
|  | // Checks for changes in the surface stack and updates the layer config to | 
|  | // accomodate the new stack. | 
|  | bool HardwareComposer::UpdateLayerConfig() { | 
|  | std::vector<std::shared_ptr<DirectDisplaySurface>> surfaces; | 
|  | { | 
|  | std::unique_lock<std::mutex> lock(post_thread_mutex_); | 
|  | if (pending_surfaces_.empty()) | 
|  | return false; | 
|  |  | 
|  | surfaces = std::move(pending_surfaces_); | 
|  | } | 
|  |  | 
|  | ATRACE_NAME("UpdateLayerConfig_HwLayers"); | 
|  |  | 
|  | display_surfaces_.clear(); | 
|  |  | 
|  | Layer* target_layer; | 
|  | size_t layer_index; | 
|  | for (layer_index = 0; | 
|  | layer_index < std::min(surfaces.size(), kMaxHardwareLayers); | 
|  | layer_index++) { | 
|  | // The bottom layer is opaque, other layers blend. | 
|  | HWC::BlendMode blending = | 
|  | layer_index == 0 ? HWC::BlendMode::None : HWC::BlendMode::Coverage; | 
|  | layers_[layer_index].Setup(surfaces[layer_index], native_display_metrics_, | 
|  | hidl_.get(), blending, | 
|  | display_transform_, HWC::Composition::Device, | 
|  | layer_index); | 
|  | display_surfaces_.push_back(surfaces[layer_index]); | 
|  | } | 
|  |  | 
|  | // Clear unused layers. | 
|  | for (size_t i = layer_index; i < kMaxHardwareLayers; i++) | 
|  | layers_[i].Reset(); | 
|  |  | 
|  | active_layer_count_ = layer_index; | 
|  | ALOGD_IF(TRACE, "HardwareComposer::UpdateLayerConfig: %zd active layers", | 
|  | active_layer_count_); | 
|  |  | 
|  | // Any surfaces left over could not be assigned a hardware layer and will | 
|  | // not be displayed. | 
|  | ALOGW_IF(surfaces.size() != display_surfaces_.size(), | 
|  | "HardwareComposer::UpdateLayerConfig: More surfaces than layers: " | 
|  | "pending_surfaces=%zu display_surfaces=%zu", | 
|  | surfaces.size(), display_surfaces_.size()); | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | void HardwareComposer::SetVSyncCallback(VSyncCallback callback) { | 
|  | vsync_callback_ = callback; | 
|  | } | 
|  |  | 
|  | void HardwareComposer::SetBacklightBrightness(int brightness) { | 
|  | if (backlight_brightness_fd_) { | 
|  | std::array<char, 32> text; | 
|  | const int length = snprintf(text.data(), text.size(), "%d", brightness); | 
|  | write(backlight_brightness_fd_.Get(), text.data(), length); | 
|  | } | 
|  | } | 
|  |  | 
|  | HardwareComposer::ComposerCallback::ComposerCallback() { | 
|  | vsync_event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)); | 
|  | LOG_ALWAYS_FATAL_IF( | 
|  | !vsync_event_fd_, | 
|  | "Failed to create vsync event fd : %s", | 
|  | strerror(errno)); | 
|  | } | 
|  |  | 
|  | Return<void> HardwareComposer::ComposerCallback::onHotplug( | 
|  | Hwc2::Display /*display*/, | 
|  | IComposerCallback::Connection /*conn*/) { | 
|  | return Void(); | 
|  | } | 
|  |  | 
|  | Return<void> HardwareComposer::ComposerCallback::onRefresh( | 
|  | Hwc2::Display /*display*/) { | 
|  | return hardware::Void(); | 
|  | } | 
|  |  | 
|  | Return<void> HardwareComposer::ComposerCallback::onVsync( | 
|  | Hwc2::Display display, int64_t timestamp) { | 
|  | if (display == HWC_DISPLAY_PRIMARY) { | 
|  | std::lock_guard<std::mutex> lock(vsync_mutex_); | 
|  | vsync_time_ = timestamp; | 
|  | int error = eventfd_write(vsync_event_fd_.Get(), 1); | 
|  | LOG_ALWAYS_FATAL_IF(error != 0, "Failed writing to vsync event fd"); | 
|  | } | 
|  | return Void(); | 
|  | } | 
|  |  | 
|  | const pdx::LocalHandle& | 
|  | HardwareComposer::ComposerCallback::GetVsyncEventFd() const { | 
|  | return vsync_event_fd_; | 
|  | } | 
|  |  | 
|  | int64_t HardwareComposer::ComposerCallback::GetVsyncTime() { | 
|  | std::lock_guard<std::mutex> lock(vsync_mutex_); | 
|  | eventfd_t event; | 
|  | eventfd_read(vsync_event_fd_.Get(), &event); | 
|  | LOG_ALWAYS_FATAL_IF(vsync_time_ < 0, | 
|  | "Attempt to read vsync time before vsync event"); | 
|  | int64_t return_val = vsync_time_; | 
|  | vsync_time_ = -1; | 
|  | return return_val; | 
|  | } | 
|  |  | 
|  | void Layer::Reset() { | 
|  | if (hidl_ != nullptr && hardware_composer_layer_) { | 
|  | hidl_->destroyLayer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_); | 
|  | hardware_composer_layer_ = 0; | 
|  | } | 
|  |  | 
|  | hidl_ = nullptr; | 
|  | z_order_ = 0; | 
|  | blending_ = HWC::BlendMode::None; | 
|  | transform_ = HWC::Transform::None; | 
|  | composition_type_ = HWC::Composition::Invalid; | 
|  | target_composition_type_ = composition_type_; | 
|  | source_ = EmptyVariant{}; | 
|  | acquire_fence_.Close(); | 
|  | surface_rect_functions_applied_ = false; | 
|  | } | 
|  |  | 
|  | void Layer::Setup(const std::shared_ptr<DirectDisplaySurface>& surface, | 
|  | const HWCDisplayMetrics& display_metrics, | 
|  | Hwc2::Composer* hidl, HWC::BlendMode blending, | 
|  | HWC::Transform transform, HWC::Composition composition_type, | 
|  | size_t z_order) { | 
|  | Reset(); | 
|  | hidl_ = hidl; | 
|  | z_order_ = z_order; | 
|  | blending_ = blending; | 
|  | transform_ = transform; | 
|  | composition_type_ = HWC::Composition::Invalid; | 
|  | target_composition_type_ = composition_type; | 
|  | source_ = SourceSurface{surface}; | 
|  | CommonLayerSetup(display_metrics); | 
|  | } | 
|  |  | 
|  | void Layer::Setup(const std::shared_ptr<IonBuffer>& buffer, | 
|  | const HWCDisplayMetrics& display_metrics, | 
|  | Hwc2::Composer* hidl, HWC::BlendMode blending, | 
|  | HWC::Transform transform, HWC::Composition composition_type, | 
|  | size_t z_order) { | 
|  | Reset(); | 
|  | hidl_ = hidl; | 
|  | z_order_ = z_order; | 
|  | blending_ = blending; | 
|  | transform_ = transform; | 
|  | composition_type_ = HWC::Composition::Invalid; | 
|  | target_composition_type_ = composition_type; | 
|  | source_ = SourceBuffer{buffer}; | 
|  | CommonLayerSetup(display_metrics); | 
|  | } | 
|  |  | 
|  | void Layer::UpdateBuffer(const std::shared_ptr<IonBuffer>& buffer) { | 
|  | if (source_.is<SourceBuffer>()) | 
|  | std::get<SourceBuffer>(source_) = {buffer}; | 
|  | } | 
|  |  | 
|  | void Layer::SetBlending(HWC::BlendMode blending) { blending_ = blending; } | 
|  | void Layer::SetZOrder(size_t z_order) { z_order_ = z_order; } | 
|  |  | 
|  | IonBuffer* Layer::GetBuffer() { | 
|  | struct Visitor { | 
|  | IonBuffer* operator()(SourceSurface& source) { return source.GetBuffer(); } | 
|  | IonBuffer* operator()(SourceBuffer& source) { return source.GetBuffer(); } | 
|  | IonBuffer* operator()(EmptyVariant) { return nullptr; } | 
|  | }; | 
|  | return source_.Visit(Visitor{}); | 
|  | } | 
|  |  | 
|  | void Layer::UpdateLayerSettings(const HWCDisplayMetrics& display_metrics) { | 
|  | if (!IsLayerSetup()) { | 
|  | ALOGE( | 
|  | "HardwareComposer::Layer::UpdateLayerSettings: Attempt to update " | 
|  | "unused Layer!"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | HWC::Error error; | 
|  | hwc2_display_t display = HWC_DISPLAY_PRIMARY; | 
|  |  | 
|  | error = hidl_->setLayerCompositionType( | 
|  | display, hardware_composer_layer_, | 
|  | composition_type_.cast<Hwc2::IComposerClient::Composition>()); | 
|  | ALOGE_IF( | 
|  | error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting layer composition type: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | error = hidl_->setLayerBlendMode( | 
|  | display, hardware_composer_layer_, | 
|  | blending_.cast<Hwc2::IComposerClient::BlendMode>()); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting layer blend mode: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | // TODO(eieio): Use surface attributes or some other mechanism to control | 
|  | // the layer display frame. | 
|  | error = hidl_->setLayerDisplayFrame( | 
|  | display, hardware_composer_layer_, | 
|  | {0, 0, display_metrics.width, display_metrics.height}); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting layer display frame: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | error = hidl_->setLayerVisibleRegion( | 
|  | display, hardware_composer_layer_, | 
|  | {{0, 0, display_metrics.width, display_metrics.height}}); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting layer visible region: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | error = hidl_->setLayerPlaneAlpha(display, hardware_composer_layer_, 1.0f); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting layer plane alpha: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | error = hidl_->setLayerZOrder(display, hardware_composer_layer_, z_order_); | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::UpdateLayerSettings: Error setting z_ order: %s", | 
|  | error.to_string().c_str()); | 
|  | } | 
|  |  | 
|  | void Layer::CommonLayerSetup(const HWCDisplayMetrics& display_metrics) { | 
|  | HWC::Error error = | 
|  | hidl_->createLayer(HWC_DISPLAY_PRIMARY, &hardware_composer_layer_); | 
|  | ALOGE_IF( | 
|  | error != HWC::Error::None, | 
|  | "Layer::CommonLayerSetup: Failed to create layer on primary display: %s", | 
|  | error.to_string().c_str()); | 
|  | UpdateLayerSettings(display_metrics); | 
|  | } | 
|  |  | 
|  | void Layer::Prepare() { | 
|  | int right, bottom; | 
|  | sp<GraphicBuffer> handle; | 
|  |  | 
|  | // Acquire the next buffer according to the type of source. | 
|  | IfAnyOf<SourceSurface, SourceBuffer>::Call(&source_, [&](auto& source) { | 
|  | std::tie(right, bottom, handle, acquire_fence_) = source.Acquire(); | 
|  | }); | 
|  |  | 
|  | // When a layer is first setup there may be some time before the first buffer | 
|  | // arrives. Setup the HWC layer as a solid color to stall for time until the | 
|  | // first buffer arrives. Once the first buffer arrives there will always be a | 
|  | // buffer for the frame even if it is old. | 
|  | if (!handle.get()) { | 
|  | if (composition_type_ == HWC::Composition::Invalid) { | 
|  | composition_type_ = HWC::Composition::SolidColor; | 
|  | hidl_->setLayerCompositionType( | 
|  | HWC_DISPLAY_PRIMARY, hardware_composer_layer_, | 
|  | composition_type_.cast<Hwc2::IComposerClient::Composition>()); | 
|  | Hwc2::IComposerClient::Color layer_color = {0, 0, 0, 0}; | 
|  | hidl_->setLayerColor(HWC_DISPLAY_PRIMARY, hardware_composer_layer_, | 
|  | layer_color); | 
|  | } else { | 
|  | // The composition type is already set. Nothing else to do until a | 
|  | // buffer arrives. | 
|  | } | 
|  | } else { | 
|  | if (composition_type_ != target_composition_type_) { | 
|  | composition_type_ = target_composition_type_; | 
|  | hidl_->setLayerCompositionType( | 
|  | HWC_DISPLAY_PRIMARY, hardware_composer_layer_, | 
|  | composition_type_.cast<Hwc2::IComposerClient::Composition>()); | 
|  | } | 
|  |  | 
|  | HWC::Error error{HWC::Error::None}; | 
|  | error = hidl_->setLayerBuffer(HWC_DISPLAY_PRIMARY, | 
|  | hardware_composer_layer_, 0, handle, | 
|  | acquire_fence_.Get()); | 
|  |  | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::Prepare: Error setting layer buffer: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | if (!surface_rect_functions_applied_) { | 
|  | const float float_right = right; | 
|  | const float float_bottom = bottom; | 
|  | error = hidl_->setLayerSourceCrop(HWC_DISPLAY_PRIMARY, | 
|  | hardware_composer_layer_, | 
|  | {0, 0, float_right, float_bottom}); | 
|  |  | 
|  | ALOGE_IF(error != HWC::Error::None, | 
|  | "Layer::Prepare: Error setting layer source crop: %s", | 
|  | error.to_string().c_str()); | 
|  |  | 
|  | surface_rect_functions_applied_ = true; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | void Layer::Finish(int release_fence_fd) { | 
|  | IfAnyOf<SourceSurface, SourceBuffer>::Call( | 
|  | &source_, [release_fence_fd](auto& source) { | 
|  | source.Finish(LocalHandle(release_fence_fd)); | 
|  | }); | 
|  | } | 
|  |  | 
|  | void Layer::Drop() { acquire_fence_.Close(); } | 
|  |  | 
|  | }  // namespace dvr | 
|  | }  // namespace android |