// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/viz/service/display_embedder/skia_output_device_buffer_queue.h"

#include <iterator>
#include <memory>
#include <set>
#include <utility>
#include <vector>

#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/debug/alias.h"
#include "base/feature_list.h"
#include "base/notreached.h"
#include "build/build_config.h"
#include "components/viz/common/features.h"
#include "components/viz/common/switches.h"
#include "components/viz/service/display/overlay_candidate.h"
#include "components/viz/service/display_embedder/skia_output_surface_dependency.h"
#include "gpu/command_buffer/common/capabilities.h"
#include "gpu/command_buffer/common/shared_image_usage.h"
#include "gpu/command_buffer/service/feature_info.h"
#include "gpu/command_buffer/service/shared_context_state.h"
#include "gpu/command_buffer/service/shared_image/shared_image_factory.h"
#include "gpu/command_buffer/service/shared_image/shared_image_representation.h"
#include "gpu/command_buffer/service/skia_utils.h"
#include "gpu/config/gpu_finch_features.h"
#include "third_party/skia/include/core/SkColor.h"
#include "third_party/skia/include/core/SkSurface.h"
#include "third_party/skia/include/core/SkSurfaceProps.h"
#include "ui/gfx/gpu_fence_handle.h"
#include "ui/gfx/swap_result.h"
#include "ui/gl/gl_fence.h"
#include "ui/gl/gl_surface.h"

#if BUILDFLAG(IS_OZONE)
#include "ui/ozone/public/ozone_platform.h"
#endif  // BUILDFLAG(IS_OZONE)

namespace {
BASE_FEATURE(kRestartReadAccessForConcurrentReadWrite,
             base::FEATURE_ENABLED_BY_DEFAULT);

base::TimeTicks g_last_reshape_failure = base::TimeTicks();

NOINLINE void CheckForLoopFailuresBufferQueue() {
  const auto threshold = base::Seconds(1);
  auto now = base::TimeTicks::Now();
  if (!g_last_reshape_failure.is_null() &&
      now - g_last_reshape_failure < threshold) {
    NOTREACHED();
  }
  g_last_reshape_failure = now;
}
}  // namespace

namespace viz {

class SkiaOutputDeviceBufferQueue::OverlayData {
 public:
  OverlayData() = delete;
  OverlayData(OverlayData&& other) = delete;

  OverlayData(std::unique_ptr<gpu::OverlayImageRepresentation> representation,
              std::unique_ptr<gpu::OverlayImageRepresentation::ScopedReadAccess>
                  scoped_read_access,
              bool is_root_render_pass)
      : representation_(std::move(representation)),
        scoped_read_access_(std::move(scoped_read_access)),
        is_root_render_pass_(is_root_render_pass) {
    DCHECK(representation_);
    DCHECK(scoped_read_access_);
  }

  ~OverlayData() = default;

  OverlayData& operator=(OverlayData&& other) = delete;

  bool IsInUseByWindowServer() const {
#if BUILDFLAG(IS_APPLE)
    if (!scoped_read_access_) {
      return false;
    }
    // The root render pass buffers are managed by SkiaRenderer so we don't care
    // if they're in use by the window server.
    if (is_root_render_pass_) {
      return false;
    }
    return scoped_read_access_->IsInUseByWindowServer();
#else
    return false;
#endif
  }

  void Ref() const { ++ref_; }

  void Unref() const {
    // Unref should only be called when there is more than one reference.
    DCHECK_GT(ref_, 1);
    --ref_;
  }

  void OnReuse() const {
    // This is a proxy check for single-buffered overlay.
    if (representation_->usage().Has(
            gpu::SHARED_IMAGE_USAGE_CONCURRENT_READ_WRITE) &&
        base::FeatureList::IsEnabled(
            kRestartReadAccessForConcurrentReadWrite)) {
      // If this is a single-buffered overlay, want to restart read access to
      // pick up any new write fences for this frame.
      scoped_read_access_.reset();
      scoped_read_access_ = representation_->BeginScopedReadAccess();
    }
  }

  void OnContextLost() const { representation_->OnContextLost(); }

  bool unique() const { return ref_ == 1; }
  const gpu::Mailbox& mailbox() const { return representation_->mailbox(); }
  gpu::OverlayImageRepresentation::ScopedReadAccess* scoped_read_access()
      const {
    return scoped_read_access_.get();
  }

  bool IsRootRenderPass() const { return is_root_render_pass_; }

 private:
  const std::unique_ptr<gpu::OverlayImageRepresentation> representation_;
  mutable std::unique_ptr<gpu::OverlayImageRepresentation::ScopedReadAccess>
      scoped_read_access_;
  mutable int ref_ = 1;
  const bool is_root_render_pass_ = false;
};

SkiaOutputDeviceBufferQueue::SkiaOutputDeviceBufferQueue(
    std::unique_ptr<OutputPresenter> presenter,
    SkiaOutputSurfaceDependency* deps,
    gpu::SharedImageRepresentationFactory* representation_factory,
    scoped_refptr<gpu::MemoryTracker> memory_tracker,
    const DidSwapBufferCompleteCallback& did_swap_buffer_complete_callback,
    const ReleaseOverlaysCallback& release_overlays_callback)
    : SkiaOutputDevice(deps->GetSharedContextState()->gr_context(),
                       deps->GetSharedContextState()->graphite_shared_context(),
                       std::move(memory_tracker),
                       did_swap_buffer_complete_callback,
                       release_overlays_callback),
      presenter_(std::move(presenter)),
      workarounds_(deps->GetGpuDriverBugWorkarounds()),
      context_state_(deps->GetSharedContextState()),
      representation_factory_(representation_factory) {
#if BUILDFLAG(IS_OZONE)
  capabilities_.needs_background_image = ui::OzonePlatform::GetInstance()
                                             ->GetPlatformRuntimeProperties()
                                             .needs_background_image;
  capabilities_.supports_single_pixel_buffer =
      ui::OzonePlatform::GetInstance()
          ->GetPlatformRuntimeProperties()
          .supports_single_pixel_buffer;

#elif BUILDFLAG(IS_APPLE)
  capabilities_.supports_non_backed_solid_color_overlays = true;
#endif  // BUILDFLAG(IS_OZONE)

  capabilities_.uses_default_gl_framebuffer = false;
  capabilities_.number_of_buffers = 3;
  capabilities_.renderer_allocates_images = true;

#if BUILDFLAG(IS_ANDROID)
  if (::features::IncreaseBufferCountForHighFrameRate()) {
    capabilities_.number_of_buffers = 5;
  }
#endif
  capabilities_.orientation_mode = OutputSurface::OrientationMode::kHardware;

  // Force the number of max pending frames to one when the switch
  // "double-buffer-compositing" is passed.
  // This will keep compositing in double buffered mode assuming |buffer_queue|
  // allocates at most one additional buffer.
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(switches::kDoubleBufferCompositing))
    capabilities_.number_of_buffers = 2;
  capabilities_.pending_swap_params.max_pending_swaps =
      capabilities_.number_of_buffers - 1;
#if BUILDFLAG(IS_ANDROID)
  if (::features::IncreaseBufferCountForHighFrameRate() &&
      capabilities_.number_of_buffers == 5) {
    capabilities_.pending_swap_params.max_pending_swaps = 2;
    capabilities_.pending_swap_params.max_pending_swaps_72hz = 3;
    capabilities_.pending_swap_params.max_pending_swaps_90hz = 3;
    capabilities_.pending_swap_params.max_pending_swaps_120hz = 4;
  }
#endif

  DCHECK_LT(capabilities_.pending_swap_params.max_pending_swaps,
            capabilities_.number_of_buffers);
  DCHECK_LT(
      capabilities_.pending_swap_params.max_pending_swaps_90hz.value_or(0),
      capabilities_.number_of_buffers);
  DCHECK_LT(
      capabilities_.pending_swap_params.max_pending_swaps_120hz.value_or(0),
      capabilities_.number_of_buffers);

  presenter_->InitializeCapabilities(&capabilities_);

  if (capabilities_.supports_post_sub_buffer)
    capabilities_.supports_target_damage = true;

#if BUILDFLAG(IS_MAC)
  presenter_->SetMaxPendingSwaps(
      capabilities_.pending_swap_params.max_pending_swaps);
#endif
}

SkiaOutputDeviceBufferQueue::~SkiaOutputDeviceBufferQueue() {
  // GL textures are cached in IOSurfaceImageBacking/OzoneImageBacking and when
  // overlay representations are destroyed, backing may get destroyed leading
  // to GL texture destruction. This destruction needs GL context current.
  // TODO(vasilyt): Eliminate this when neither IOSurfaceImageBacking nor
  // OzoneImageBacking cache GLTextures and require the GLContext to be current
  // when they are destroyed.
  if (context_state_->context_lost()) {
    for (auto& overlay : overlays_) {
      overlay.OnContextLost();
    }
  }
}

const SkiaOutputDeviceBufferQueue::OverlayData*
SkiaOutputDeviceBufferQueue::GetOrCreateOverlayData(const gpu::Mailbox& mailbox,
                                                    bool is_root_render_pass,
                                                    bool* is_existing) {
  if (is_existing)
    *is_existing = false;

  if (mailbox.IsZero()) {
    return nullptr;
  }

  auto it = overlays_.find(mailbox);
  if (it != overlays_.end()) {
    // If the overlay is in |overlays_|, we will reuse it, and a ref will be
    // added to keep it alive. This ref will be removed, when the overlay is
    // replaced by a new frame.
    it->Ref();
    it->OnReuse();
    if (is_existing)
      *is_existing = true;
    return &*it;
  }

  auto shared_image = representation_factory_->ProduceOverlay(mailbox);
  // When display is re-opened, the first few frames might not have video
  // resource ready. Possible investigation crbug.com/1023971.
  if (!shared_image) {
    LOG(ERROR) << "Invalid mailbox.";
    return nullptr;
  }

  auto shared_image_access = shared_image->BeginScopedReadAccess();
  if (!shared_image_access) {
    LOG(ERROR) << "Could not access SharedImage for read.";
    return nullptr;
  }

  bool result;
  std::tie(it, result) =
      overlays_.emplace(std::move(shared_image), std::move(shared_image_access),
                        is_root_render_pass);
  DCHECK(result);
  DCHECK(it->unique());

  // Add an extra ref to keep it alive. This extra ref will be removed when
  // the backing is not used by system compositor anymore.
  it->Ref();
  return &*it;
}

void SkiaOutputDeviceBufferQueue::ScheduleOverlays(
    SkiaOutputSurface::OverlayList overlays) {
  DCHECK(pending_overlay_mailboxes_.empty());
  has_overlays_scheduled_but_swap_not_finished_ = true;

  for (const auto& overlay : overlays) {
    auto mailbox = overlay.mailbox;
#if BUILDFLAG(IS_OZONE)
    if (overlay.is_solid_color) {
      DCHECK(overlay.color.has_value());
      DCHECK(capabilities_.supports_non_backed_solid_color_overlays ||
        capabilities_.supports_single_pixel_buffer);
      presenter_->ScheduleOverlayPlane(overlay, nullptr);
      continue;
    }
#endif

    OutputPresenter::ScopedOverlayAccess* access = nullptr;
    bool overlay_has_been_submitted;
    auto* overlay_data = GetOrCreateOverlayData(
        mailbox, overlay.is_root_render_pass, &overlay_has_been_submitted);
    if (overlay_data) {
      access = overlay_data->scoped_read_access();
      pending_overlay_mailboxes_.emplace_back(mailbox);
    }
    presenter_->ScheduleOverlayPlane(overlay, access);
  }
}

void SkiaOutputDeviceBufferQueue::Present(
    const std::optional<gfx::Rect>& update_rect,
    BufferPresentedCallback feedback,
    OutputSurfaceFrame frame) {
  StartSwapBuffers({});

  presenter_->Present(
      base::BindOnce(&SkiaOutputDeviceBufferQueue::DoFinishSwapBuffers,
                     weak_ptr_.GetWeakPtr(), GetSwapBuffersSize(),
                     std::move(frame), std::move(committed_overlay_mailboxes_)),
      std::move(feedback), frame.data);
  committed_overlay_mailboxes_.clear();
  std::swap(committed_overlay_mailboxes_, pending_overlay_mailboxes_);
}

void SkiaOutputDeviceBufferQueue::DoFinishSwapBuffers(
    const gfx::Size& size,
    OutputSurfaceFrame frame,
    std::vector<gpu::Mailbox> overlay_mailboxes,
    gfx::SwapCompletionResult result) {
  last_swap_time_ = swap_time_clock_->NowTicks();
  has_overlays_scheduled_but_swap_not_finished_ = false;

  // |overlay_mailboxes| are for overlays used by previous frame, they should
  // have been replaced.
  for (const auto& mailbox : overlay_mailboxes) {
    auto it = overlays_.find(mailbox);
    CHECK(it != overlays_.end());
    it->Unref();
  }

  bool need_gl_context = false;
#if BUILDFLAG(IS_APPLE)
  // GL textures are cached in IOSurfaceImageBacking and when
  // overlay representations are destroyed, backing may get destroyed leading to
  // GL texture destruction. This destruction needs GL context current.
  need_gl_context = true;
#endif

  // Code below can destroy last representation of the overlay shared image. On
  // MacOS and Ozone platforms it needs context to be current.
  if (need_gl_context) {
    if (!context_state_->MakeCurrent(nullptr)) {
      for (auto& overlay : overlays_) {
        overlay.OnContextLost();
      }
    }
  }

  bool has_in_use_overlays = false;
  [[maybe_unused]] std::vector<gpu::Mailbox> released_overlays;
  // Go through backings of all overlays, and release overlay backings which are
  // not used.
  std::erase_if(overlays_, [&result, &has_in_use_overlays,
                            &released_overlays](auto& overlay) {
    if (!overlay.unique()) {
      return false;
    }

    if (overlay.IsInUseByWindowServer()) {
      has_in_use_overlays = true;
      return false;
    }

    // macOS needs to signal to SkiaRenderer that render pass overlay resources
    // can be unlocked and returned.
#if BUILDFLAG(IS_APPLE)
    // The root render pass buffers are managed by SkiaRenderer so we don't need
    // to explicitly return them via callback.
    if (!overlay.IsRootRenderPass()) {
      released_overlays.push_back(overlay.mailbox());
    }
#else
    (void)released_overlays;
#endif
    // Setting fences on overlays every frame can be very costly for delegated
    // compositing where we have an overlay for each visible quad. So we only
    // set the release fence here iff this is the last 'Unref' call.
    if (!result.release_fence.is_null()) {
      overlay.scoped_read_access()->SetReleaseFence(
          result.release_fence.Clone());
    }
    return true;
  });

  FinishSwapBuffers(std::move(result), size, std::move(frame),
                    /*damage_area=*/std::nullopt, std::move(released_overlays));

  if (has_in_use_overlays) {
    // Try again later, even if no further swaps happen.
    PostReleaseOverlays();
  }
}

void SkiaOutputDeviceBufferQueue::PostReleaseOverlays() {
  if (!base::FeatureList::IsEnabled(::features::kDeferredOverlaysRelease) ||
      reclaim_overlays_timer_.IsRunning() ||
      !base::SingleThreadTaskRunner::HasCurrentDefault()) {
    return;
  }

  // Unretained: `reclaim_overlays_timer_` is a member of `this`, so the task
  // won't run if it has been destructed.
  reclaim_overlays_timer_.Start(
      FROM_HERE, kDelayForOverlaysReclaim,
      base::BindOnce(&SkiaOutputDeviceBufferQueue::ReleaseOverlays,
                     base::Unretained(this)));
}

void SkiaOutputDeviceBufferQueue::ReleaseOverlays() {
  // Reschedule if:
  // - The output device is not idle
  // - There is a slight chance that this could run too early, for instance if
  //   the last frame was just produced, and the window server is not done yet.
  // - We are currently between ScheduleOverlayPlanes() and
  //   DoFinishSwapBuffers(), so we should not touch the overlays.

  if (swap_time_clock_->NowTicks() - last_swap_time_ <
          kDelayForOverlaysReclaim ||
      has_overlays_scheduled_but_swap_not_finished_) {
    PostReleaseOverlays();
    return;
  }

  std::vector<gpu::Mailbox> released_overlays;

  std::erase_if(overlays_, [&released_overlays](auto& overlay) {
    if (!overlay.unique() || overlay.IsInUseByWindowServer() ||
        overlay.IsRootRenderPass()) {
      return false;
    }

    // SkiaRenderer wants to unlock resources for these released overlays as
    // well, so store their mailboxes here.
#if BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_OZONE)
    // The root render pass buffers are managed by SkiaRenderer so we don't need
    // to explicitly return them via callback.
    released_overlays.push_back(overlay.mailbox());
#else
    (void)released_overlays;
#endif
    return true;
  });

  if (!released_overlays.empty()) {
    release_overlays_callback_.Run(released_overlays);
  }
}

gfx::Size SkiaOutputDeviceBufferQueue::GetSwapBuffersSize() {
  switch (overlay_transform_) {
    case gfx::OVERLAY_TRANSFORM_ROTATE_CLOCKWISE_90:
    case gfx::OVERLAY_TRANSFORM_ROTATE_CLOCKWISE_270:
    case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL_CLOCKWISE_90:
    case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL_CLOCKWISE_270:
      return gfx::Size(image_size_.height(), image_size_.width());
    case gfx::OVERLAY_TRANSFORM_INVALID:
    case gfx::OVERLAY_TRANSFORM_NONE:
    case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
    case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
    case gfx::OVERLAY_TRANSFORM_ROTATE_CLOCKWISE_180:
      return image_size_;
  }
}

bool SkiaOutputDeviceBufferQueue::Reshape(const ReshapeParams& params) {
  DCHECK(pending_overlay_mailboxes_.empty());
  if (!presenter_->Reshape(params)) {
    LOG(ERROR) << "Failed to resize.";
    CheckForLoopFailuresBufferQueue();
    // To prevent tail call, so we can see the stack.
    base::debug::Alias(nullptr);
    return false;
  }

  overlay_transform_ = params.transform;
  color_space_ = params.color_space;
  image_size_ = params.GfxSize();

  return true;
}

SkSurface* SkiaOutputDeviceBufferQueue::BeginPaint(
    std::vector<GrBackendSemaphore>* end_semaphores) {
  NOTREACHED();
}

void SkiaOutputDeviceBufferQueue::EndPaint() {
  NOTREACHED();
}

size_t SkiaOutputDeviceBufferQueue::OverlayDataHash::operator()(
    const OverlayData& o) const {
  return std::hash<gpu::Mailbox>{}(o.mailbox());
}

size_t SkiaOutputDeviceBufferQueue::OverlayDataHash::operator()(
    const gpu::Mailbox& m) const {
  return std::hash<gpu::Mailbox>{}(m);
}

bool SkiaOutputDeviceBufferQueue::OverlayDataKeyEqual::operator()(
    const OverlayData& lhs,
    const OverlayData& rhs) const {
  return lhs.mailbox() == rhs.mailbox();
}

bool SkiaOutputDeviceBufferQueue::OverlayDataKeyEqual::operator()(
    const OverlayData& lhs,
    const gpu::Mailbox& rhs) const {
  return lhs.mailbox() == rhs;
}

bool SkiaOutputDeviceBufferQueue::OverlayDataKeyEqual::operator()(
    const gpu::Mailbox& lhs,
    const OverlayData& rhs) const {
  return lhs == rhs.mailbox();
}

void SkiaOutputDeviceBufferQueue::SetVSyncDisplayID(int64_t display_id,
                                                    bool force_update) {
  presenter_->SetVSyncDisplayID(display_id, force_update);
}

}  // namespace viz