blob: 539a7fb6d7db56307a50f91715cb1276618552f1 [file] [log] [blame]
#include <ui/GraphicBuffer.h>
#include "DisplayHardware/ComposerHal.h"
#include "hwc_types.h"
#include <dvr/dvr_shared_buffers.h>
#include <hardware/gralloc.h>
#include <log/log.h>
#include <array>
#include <condition_variable>
#include <memory>
#include <mutex>
#include <optional>
#include <thread>
#include <tuple>
#include <vector>
#include <dvr/dvr_config.h>
#include <dvr/dvr_vsync.h>
#include <pdx/file_handle.h>
#include <pdx/rpc/variant.h>
#include <private/dvr/buffer_hub_client.h>
#include <private/dvr/shared_buffer_helpers.h>
#include "acquired_buffer.h"
#include "display_surface.h"
// Hardware composer HAL doesn't define HWC_TRANSFORM_NONE as of this writing.
#define HWC_TRANSFORM_NONE static_cast<hwc_transform_t>(0)
namespace android {
namespace dvr {
// Basic display metrics for physical displays.
struct DisplayParams {
hwc2_display_t id;
bool is_primary;
int width;
int height;
struct {
int x;
int y;
} dpi;
int vsync_period_ns;
// Layer represents the connection between a hardware composer layer and the
// source supplying buffers for the layer's contents.
class Layer {
Layer() = default;
// Sets up the layer to use a display surface as its content source. The Layer
// automatically handles ACQUIRE/RELEASE phases for the surface's buffer train
// every frame.
// |composer| The composer instance.
// |display_params| Info about the display to use.
// |blending| receives HWC_BLENDING_* values.
// |composition_type| receives either HWC_FRAMEBUFFER for most layers or
// HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
// |index| is the index of this surface in the DirectDisplaySurface array.
Layer(Hwc2::Composer* composer, const DisplayParams& display_params,
const std::shared_ptr<DirectDisplaySurface>& surface,
HWC::BlendMode blending, HWC::Composition composition_type,
size_t z_order);
// Sets up the layer to use a direct buffer as its content source. No special
// handling of the buffer is performed; responsibility for updating or
// changing the buffer each frame is on the caller.
// |composer| The composer instance.
// |display_params| Info about the display to use.
// |blending| receives HWC_BLENDING_* values.
// |composition_type| receives either HWC_FRAMEBUFFER for most layers or
// HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
Layer(Hwc2::Composer* composer, const DisplayParams& display_params,
const std::shared_ptr<IonBuffer>& buffer, HWC::BlendMode blending,
HWC::Composition composition_type, size_t z_order);
Layer(Layer&&) noexcept;
Layer& operator=(Layer&&) noexcept;
// Releases any shared pointers and fence handles held by this instance.
void Reset();
// Layers that use a direct IonBuffer should call this each frame to update
// which buffer will be used for the next PostLayers.
void UpdateBuffer(const std::shared_ptr<IonBuffer>& buffer);
// Sets up the hardware composer layer for the next frame. When the layer is
// associated with a display surface, this method automatically ACQUIRES a new
// buffer if one is available.
void Prepare();
// After calling prepare, if this frame is to be dropped instead of passing
// along to the HWC, call Drop to close the contained fence(s).
void Drop();
// Performs fence bookkeeping after the frame has been posted to hardware
// composer.
void Finish(int release_fence_fd);
// Sets the blending for the layer. |blending| receives HWC_BLENDING_* values.
void SetBlending(HWC::BlendMode blending);
// Sets the z-order of this layer
void SetZOrder(size_t z_order);
// Gets the current IonBuffer associated with this layer. Ownership of the
// buffer DOES NOT pass to the caller and the pointer is not guaranteed to
// remain valid across calls to Layer::Setup(), Layer::Prepare(), or
// Layer::Reset(). YOU HAVE BEEN WARNED.
IonBuffer* GetBuffer();
HWC::Composition GetCompositionType() const { return composition_type_; }
HWC::Layer GetLayerHandle() const { return hardware_composer_layer_; }
bool IsLayerSetup() const { return !source_.empty(); }
int GetSurfaceId() const {
int surface_id = -1;
&source_, [&surface_id](const SourceSurface& surface_source) {
surface_id = surface_source.GetSurfaceId();
return surface_id;
int GetBufferId() const {
int buffer_id = -1;
&source_, [&buffer_id](const SourceSurface& surface_source) {
buffer_id = surface_source.GetBufferId();
return buffer_id;
// Compares Layers by surface id.
bool operator<(const Layer& other) const {
return GetSurfaceId() < other.GetSurfaceId();
bool operator<(int surface_id) const { return GetSurfaceId() < surface_id; }
void IgnoreBadDisplayErrorsOnDestroy(bool ignore) {
ignore_bad_display_errors_on_destroy_ = ignore;
void CommonLayerSetup();
// Applies all of the settings to this layer using the hwc functions
void UpdateLayerSettings();
// Applies visibility settings that may have changed.
void UpdateVisibilitySettings();
// Checks whether the buffer, given by id, is associated with the given slot
// in the HWC buffer cache. If the slot is not associated with the given
// buffer the cache is updated to establish the association and the buffer
// should be sent to HWC using setLayerBuffer. Returns true if the association
// was already established, false if not. A buffer_id of -1 is never
// associated and always returns false.
bool CheckAndUpdateCachedBuffer(std::size_t slot, int buffer_id);
// Composer instance.
Hwc2::Composer* composer_ = nullptr;
// Parameters of the display to use for this layer.
DisplayParams display_params_;
// The hardware composer layer and metrics to use during the prepare cycle.
hwc2_layer_t hardware_composer_layer_ = 0;
// Layer properties used to setup the hardware composer layer during the
// Prepare phase.
size_t z_order_ = 0;
HWC::BlendMode blending_ = HWC::BlendMode::None;
HWC::Composition composition_type_ = HWC::Composition::Invalid;
HWC::Composition target_composition_type_ = HWC::Composition::Device;
// State when the layer is connected to a surface. Provides the same interface
// as SourceBuffer to simplify internal use by Layer.
struct SourceSurface {
std::shared_ptr<DirectDisplaySurface> surface;
AcquiredBuffer acquired_buffer;
pdx::LocalHandle release_fence;
SourceSurface(const std::shared_ptr<DirectDisplaySurface>& surface)
: surface(surface) {}
// Attempts to acquire a new buffer from the surface and return a tuple with
// width, height, buffer handle, and fence. If a new buffer is not available
// the previous buffer is returned or an empty value if no buffer has ever
// been posted. When a new buffer is acquired the previous buffer's release
// fence is passed out automatically.
std::tuple<int, int, int, sp<GraphicBuffer>, pdx::LocalHandle, std::size_t>
Acquire() {
if (surface->IsBufferAvailable()) {
acquired_buffer = surface->AcquireCurrentBuffer();
ATRACE_ASYNC_END("BufferPost", acquired_buffer.buffer()->id());
if (!acquired_buffer.IsEmpty()) {
return std::make_tuple(
acquired_buffer.buffer()->height(), acquired_buffer.buffer()->id(),
acquired_buffer.ClaimAcquireFence(), acquired_buffer.slot());
} else {
return std::make_tuple(0, 0, -1, nullptr, pdx::LocalHandle{}, 0);
void Finish(pdx::LocalHandle fence) { release_fence = std::move(fence); }
// Gets a pointer to the current acquired buffer or returns nullptr if there
// isn't one.
IonBuffer* GetBuffer() {
if (acquired_buffer.IsAvailable())
return acquired_buffer.buffer()->buffer();
return nullptr;
// Returns the surface id of the surface.
int GetSurfaceId() const { return surface->surface_id(); }
// Returns the buffer id for the current buffer.
int GetBufferId() const {
if (acquired_buffer.IsAvailable())
return acquired_buffer.buffer()->id();
return -1;
// State when the layer is connected to a buffer. Provides the same interface
// as SourceSurface to simplify internal use by Layer.
struct SourceBuffer {
std::shared_ptr<IonBuffer> buffer;
std::tuple<int, int, int, sp<GraphicBuffer>, pdx::LocalHandle, std::size_t>
Acquire() {
if (buffer)
return std::make_tuple(buffer->width(), buffer->height(), -1,
buffer->buffer(), pdx::LocalHandle{}, 0);
return std::make_tuple(0, 0, -1, nullptr, pdx::LocalHandle{}, 0);
void Finish(pdx::LocalHandle /*fence*/) {}
IonBuffer* GetBuffer() { return buffer.get(); }
int GetSurfaceId() const { return -1; }
int GetBufferId() const { return -1; }
// The underlying hardware composer layer is supplied buffers either from a
// surface buffer train or from a buffer directly.
pdx::rpc::Variant<SourceSurface, SourceBuffer> source_;
pdx::LocalHandle acquire_fence_;
bool surface_rect_functions_applied_ = false;
bool pending_visibility_settings_ = true;
// Map of buffer slot assignments that have already been established with HWC:
// slot -> buffer_id. When this map contains a matching slot and buffer_id the
// buffer argument to setLayerBuffer may be nullptr to avoid the cost of
// importing a buffer HWC already knows about.
std::map<std::size_t, int> cached_buffer_map_;
// When calling destroyLayer() on an external display that's been removed we
// typically get HWC2_ERROR_BAD_DISPLAY errors. If
// ignore_bad_display_errors_on_destroy_ is true, don't log the bad display
// errors, since they're expected.
bool ignore_bad_display_errors_on_destroy_ = false;
Layer(const Layer&) = delete;
void operator=(const Layer&) = delete;
// HardwareComposer encapsulates the hardware composer HAL, exposing a
// simplified API to post buffers to the display.
// HardwareComposer is accessed by both the vr flinger dispatcher thread and the
// surface flinger main thread, in addition to internally running a separate
// thread for compositing/EDS and posting layers to the HAL. When changing how
// variables are used or adding new state think carefully about which threads
// will access the state and whether it needs to be synchronized.
class HardwareComposer {
// Type for vsync callback.
using VSyncCallback = std::function<void(int64_t, int64_t, uint32_t)>;
using RequestDisplayCallback = std::function<void(bool)>;
bool Initialize(Hwc2::Composer* composer,
hwc2_display_t primary_display_id,
RequestDisplayCallback request_display_callback);
bool IsInitialized() const { return initialized_; }
// Start the post thread if there's work to do (i.e. visible layers). This
// should only be called from surface flinger's main thread.
void Enable();
// Pause the post thread, blocking until the post thread has signaled that
// it's paused. This should only be called from surface flinger's main thread.
void Disable();
// Called on a binder thread.
void OnBootFinished();
std::string Dump();
void SetVSyncCallback(VSyncCallback callback);
const DisplayParams& GetPrimaryDisplayParams() const {
return primary_display_;
// Sets the display surfaces to compose the hardware layer stack.
void SetDisplaySurfaces(
std::vector<std::shared_ptr<DirectDisplaySurface>> surfaces);
int OnNewGlobalBuffer(DvrGlobalBufferKey key, IonBuffer& ion_buffer);
void OnDeletedGlobalBuffer(DvrGlobalBufferKey key);
DisplayParams GetDisplayParams(Hwc2::Composer* composer,
hwc2_display_t display, bool is_primary);
// Turn display vsync on/off. Returns true on success, false on failure.
bool EnableVsync(const DisplayParams& display, bool enabled);
// Turn display power on/off. Returns true on success, false on failure.
bool SetPowerMode(const DisplayParams& display, bool active);
// Convenience function to turn a display on/off. Turns both power and vsync
// on/off. Returns true on success, false on failure.
bool EnableDisplay(const DisplayParams& display, bool enabled);
class ComposerCallback : public Hwc2::IComposerCallback {
ComposerCallback() = default;
hardware::Return<void> onHotplug(Hwc2::Display display,
Connection conn) override;
hardware::Return<void> onRefresh(Hwc2::Display display) override;
hardware::Return<void> onVsync(Hwc2::Display display,
int64_t timestamp) override;
bool GotFirstHotplug() { return got_first_hotplug_; }
struct Displays {
hwc2_display_t primary_display = 0;
std::optional<hwc2_display_t> external_display;
bool external_display_was_hotplugged = false;
Displays GetDisplays();
pdx::Status<int64_t> GetVsyncTime(hwc2_display_t display);
struct DisplayInfo {
hwc2_display_t id = 0;
pdx::LocalHandle driver_vsync_event_fd;
int64_t callback_vsync_timestamp{0};
DisplayInfo* GetDisplayInfo(hwc2_display_t display);
std::mutex mutex_;
bool got_first_hotplug_ = false;
DisplayInfo primary_display_;
std::optional<DisplayInfo> external_display_;
bool external_display_was_hotplugged_ = false;
HWC::Error Validate(hwc2_display_t display);
HWC::Error Present(hwc2_display_t display);
void PostLayers(hwc2_display_t display);
void PostThread();
// The post thread has two controlling states:
// 1. Idle: no work to do (no visible surfaces).
// 2. Suspended: explicitly halted (system is not in VR mode).
// When either #1 or #2 is true then the post thread is quiescent, otherwise
// it is active.
using PostThreadStateType = uint32_t;
struct PostThreadState {
enum : PostThreadStateType {
Active = 0,
Idle = (1 << 0),
Suspended = (1 << 1),
Quit = (1 << 2),
void UpdatePostThreadState(uint32_t state, bool suspend);
// Blocks until either event_fd becomes readable, or we're interrupted by a
// control thread, or timeout_ms is reached before any events occur. Any
// errors are returned as negative errno values, with -ETIMEDOUT returned in
// the case of a timeout. If we're interrupted, kPostThreadInterrupted will be
// returned.
int PostThreadPollInterruptible(const pdx::LocalHandle& event_fd,
int requested_events, int timeout_ms);
// WaitForPredictedVSync and SleepUntil are blocking calls made on the post
// thread that can be interrupted by a control thread. If interrupted, these
// calls return kPostThreadInterrupted.
int ReadWaitPPState();
pdx::Status<int64_t> WaitForPredictedVSync();
int SleepUntil(int64_t wakeup_timestamp);
// Initialize any newly connected displays, and set target_display_ to the
// display we should render to. Returns true if target_display_
// changed. Called only from the post thread.
bool UpdateTargetDisplay();
// Reconfigures the layer stack if the display surfaces changed since the last
// frame. Called only from the post thread.
void UpdateLayerConfig();
// Called on the post thread to create the Composer instance.
void CreateComposer();
// Called on the post thread when the post thread is resumed.
void OnPostThreadResumed();
// Called on the post thread when the post thread is paused or quits.
void OnPostThreadPaused();
// Use post_thread_wait_ to wait for a specific condition, specified by pred.
// timeout_sec < 0 means wait indefinitely, otherwise it specifies the timeout
// in seconds.
// The lock must be held when this function is called.
// Returns true if the wait was interrupted because the post thread was asked
// to quit.
bool PostThreadCondWait(std::unique_lock<std::mutex>& lock,
int timeout_sec,
const std::function<bool()>& pred);
// Map the given shared memory buffer to our broadcast ring to track updates
// to the config parameters.
int MapConfigBuffer(IonBuffer& ion_buffer);
void ConfigBufferDeleted();
// Poll for config udpates.
void UpdateConfigBuffer();
bool initialized_;
bool is_standalone_device_;
std::unique_ptr<Hwc2::Composer> composer_;
sp<ComposerCallback> composer_callback_;
RequestDisplayCallback request_display_callback_;
DisplayParams primary_display_;
std::optional<DisplayParams> external_display_;
DisplayParams* target_display_ = &primary_display_;
// The list of surfaces we should draw. Set by the display service when
// DirectSurfaces are added, removed, or change visibility. Written by the
// message dispatch thread and read by the post thread.
std::vector<std::shared_ptr<DirectDisplaySurface>> surfaces_;
// Set to true by the dispatch thread whenever surfaces_ changes. Set to false
// by the post thread when the new list of surfaces is processed.
bool surfaces_changed_ = false;
std::vector<std::shared_ptr<DirectDisplaySurface>> current_surfaces_;
// Layer set for handling buffer flow into hardware composer layers. This
// vector must be sorted by surface_id in ascending order.
std::vector<Layer> layers_;
// Handler to hook vsync events outside of this class.
VSyncCallback vsync_callback_;
// The layer posting thread. This thread wakes up a short time before vsync to
// hand buffers to hardware composer.
std::thread post_thread_;
// Post thread state machine and synchronization primitives.
PostThreadStateType post_thread_state_{PostThreadState::Idle |
std::atomic<bool> post_thread_quiescent_{true};
bool post_thread_resumed_{false};
pdx::LocalHandle post_thread_event_fd_;
std::mutex post_thread_mutex_;
std::condition_variable post_thread_wait_;
std::condition_variable post_thread_ready_;
// When boot is finished this will be set to true and the post thread will be
// notified via post_thread_wait_.
bool boot_finished_ = false;
// VSync sleep timerfd.
pdx::LocalHandle vsync_sleep_timer_fd_;
// The timestamp of the last vsync.
int64_t last_vsync_timestamp_ = 0;
// The number of vsync intervals to predict since the last vsync.
int vsync_prediction_interval_ = 1;
// Vsync count since display on.
uint32_t vsync_count_ = 0;
// Counter tracking the number of skipped frames.
int frame_skip_count_ = 0;
// Fd array for tracking retire fences that are returned by hwc. This allows
// us to detect when the display driver begins queuing frames.
std::vector<pdx::LocalHandle> retire_fence_fds_;
// If we are publishing vsync data, we will put it here.
std::unique_ptr<CPUMappedBroadcastRing<DvrVsyncRing>> vsync_ring_;
// Broadcast ring for receiving config data from the DisplayManager.
DvrConfigRing shared_config_ring_;
uint32_t shared_config_ring_sequence_{0};
// Config buffer for reading from the post thread.
DvrConfig post_thread_config_;
std::mutex shared_config_mutex_;
static constexpr int kPostThreadInterrupted = 1;
HardwareComposer(const HardwareComposer&) = delete;
void operator=(const HardwareComposer&) = delete;
} // namespace dvr
} // namespace android