// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gpu/command_buffer/service/shared_context_state.h"

#include "base/threading/thread_task_runner_handle.h"
#include "base/trace_event/memory_dump_manager.h"
#include "gpu/command_buffer/common/activity_flags.h"
#include "gpu/command_buffer/service/context_state.h"
#include "gpu/command_buffer/service/gl_context_virtual.h"
#include "gpu/command_buffer/service/service_transfer_cache.h"
#include "gpu/command_buffer/service/service_utils.h"
#include "gpu/config/gpu_driver_bug_workarounds.h"
#include "gpu/vulkan/buildflags.h"
#include "skia/buildflags.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/gl_share_group.h"
#include "ui/gl/gl_surface.h"
#include "ui/gl/gl_version_info.h"
#include "ui/gl/init/create_gr_gl_interface.h"

#if BUILDFLAG(ENABLE_VULKAN)
#include "components/viz/common/gpu/vulkan_context_provider.h"
#endif

#if defined(OS_MACOSX)
#include "components/viz/common/gpu/metal_context_provider.h"
#endif

#if BUILDFLAG(SKIA_USE_DAWN)
#include "components/viz/common/gpu/dawn_context_provider.h"
#endif

namespace {
static constexpr size_t kInitialScratchDeserializationBufferSize = 1024;
}

namespace gpu {

void SharedContextState::compileError(const char* shader, const char* errors) {
  if (!context_lost_) {
    LOG(ERROR) << "Skia shader compilation error\n"
               << "------------------------\n"
               << shader << "\nErrors:\n"
               << errors;
  }
}

SharedContextState::SharedContextState(
    scoped_refptr<gl::GLShareGroup> share_group,
    scoped_refptr<gl::GLSurface> surface,
    scoped_refptr<gl::GLContext> context,
    bool use_virtualized_gl_contexts,
    base::OnceClosure context_lost_callback,
    GrContextType gr_context_type,
    viz::VulkanContextProvider* vulkan_context_provider,
    viz::MetalContextProvider* metal_context_provider,
    viz::DawnContextProvider* dawn_context_provider)
    : use_virtualized_gl_contexts_(use_virtualized_gl_contexts),
      context_lost_callback_(std::move(context_lost_callback)),
      gr_context_type_(gr_context_type),
      vk_context_provider_(vulkan_context_provider),
      metal_context_provider_(metal_context_provider),
      dawn_context_provider_(dawn_context_provider),
      share_group_(std::move(share_group)),
      context_(context),
      real_context_(std::move(context)),
      surface_(std::move(surface)) {
  raster::DetermineGrCacheLimitsFromAvailableMemory(
      &max_resource_cache_bytes_, &glyph_cache_max_texture_bytes_);
  if (GrContextIsVulkan()) {
#if BUILDFLAG(ENABLE_VULKAN)
    gr_context_ = vk_context_provider_->GetGrContext();
#endif
    use_virtualized_gl_contexts_ = false;
    DCHECK(gr_context_);
  }
  if (GrContextIsMetal()) {
#if defined(OS_MACOSX)
    gr_context_ = metal_context_provider_->GetGrContext();
#endif
    use_virtualized_gl_contexts_ = false;
    DCHECK(gr_context_);
  }
  if (GrContextIsDawn()) {
#if BUILDFLAG(SKIA_USE_DAWN)
    gr_context_ = dawn_context_provider_->GetGrContext();
#endif
    use_virtualized_gl_contexts_ = false;
    DCHECK(gr_context_);
  }

  if (base::ThreadTaskRunnerHandle::IsSet()) {
    base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
        this, "SharedContextState", base::ThreadTaskRunnerHandle::Get());
  }
  // Initialize the scratch buffer to some small initial size.
  scratch_deserialization_buffer_.resize(
      kInitialScratchDeserializationBufferSize);
}

SharedContextState::~SharedContextState() {
  // Delete the transfer cache first: that way, destruction callbacks for image
  // entries can use *|this| to make the context current and do GPU clean up.
  // The context should be current so that texture deletes that result from
  // destroying the cache happen in the right context (unless the context is
  // lost in which case we don't delete the textures).
  DCHECK(IsCurrent(nullptr) || context_lost_);
  transfer_cache_.reset();

  // We should have the last ref on this GrContext to ensure we're not holding
  // onto any skia objects using this context. Note that some tests don't run
  // InitializeGrContext(), so |owned_gr_context_| is not expected to be
  // initialized.
  DCHECK(!owned_gr_context_ || owned_gr_context_->unique());

  // Delete the GrContext. This will either do cleanup if the context is
  // current, or the GrContext was already abandoned if the GLContext was lost.
  owned_gr_context_.reset();

  if (context_->IsCurrent(nullptr))
    context_->ReleaseCurrent(nullptr);
  base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
      this);
}

void SharedContextState::InitializeGrContext(
    const GpuDriverBugWorkarounds& workarounds,
    GrContextOptions::PersistentCache* cache,
    GpuProcessActivityFlags* activity_flags,
    gl::ProgressReporter* progress_reporter) {
  progress_reporter_ = progress_reporter;

#if defined(OS_MACOSX)
  if (metal_context_provider_)
    metal_context_provider_->SetProgressReporter(progress_reporter);
#endif

  if (GrContextIsGL()) {
    DCHECK(context_->IsCurrent(nullptr));
    sk_sp<GrGLInterface> interface(gl::init::CreateGrGLInterface(
        *context_->GetVersionInfo(), workarounds.use_es2_for_oopr,
        progress_reporter));
    if (!interface) {
      LOG(ERROR) << "OOP raster support disabled: GrGLInterface creation "
                    "failed.";
      return;
    }

    if (activity_flags && cache) {
      // |activity_flags| is safe to capture here since it must outlive the
      // this context state.
      interface->fFunctions.fProgramBinary =
          [activity_flags](GrGLuint program, GrGLenum binaryFormat,
                           void* binary, GrGLsizei length) {
            GpuProcessActivityFlags::ScopedSetFlag scoped_set_flag(
                activity_flags, ActivityFlagsBase::FLAG_LOADING_PROGRAM_BINARY);
            glProgramBinary(program, binaryFormat, binary, length);
          };
    }
    // If you make any changes to the GrContext::Options here that could
    // affect text rendering, make sure to match the capabilities initialized
    // in GetCapabilities and ensuring these are also used by the
    // PaintOpBufferSerializer.
    GrContextOptions options;
    if (GrContextIsMetal()) {
      options.fRuntimeProgramCacheSize = 1024;
    }
    options.fDriverBugWorkarounds =
        GrDriverBugWorkarounds(workarounds.ToIntSet());
    options.fDisableCoverageCountingPaths = true;
    options.fGlyphCacheTextureMaximumBytes = glyph_cache_max_texture_bytes_;
    options.fPersistentCache = cache;
    options.fAvoidStencilBuffers = workarounds.avoid_stencil_buffers;
    if (workarounds.disable_program_disk_cache) {
      options.fShaderCacheStrategy =
          GrContextOptions::ShaderCacheStrategy::kBackendSource;
    }
    options.fShaderErrorHandler = this;
    // TODO(csmartdalton): enable internal multisampling after the related Skia
    // rolls are in.
    options.fInternalMultisampleCount = 0;
    owned_gr_context_ = GrContext::MakeGL(std::move(interface), options);
    gr_context_ = owned_gr_context_.get();
  }

  if (!gr_context_) {
    LOG(ERROR) << "OOP raster support disabled: GrContext creation "
                  "failed.";
  } else {
    gr_context_->setResourceCacheLimit(max_resource_cache_bytes_);
  }
  transfer_cache_ = std::make_unique<ServiceTransferCache>();
}

bool SharedContextState::InitializeGL(
    const GpuPreferences& gpu_preferences,
    scoped_refptr<gles2::FeatureInfo> feature_info) {
  // We still need initialize GL when Vulkan is used, because RasterDecoder
  // depends on GL.
  // TODO(penghuang): don't initialize GL when RasterDecoder can work without
  // GL.
  if (IsGLInitialized()) {
    DCHECK(feature_info == feature_info_);
    DCHECK(context_state_);
    return true;
  }

  DCHECK(context_->IsCurrent(nullptr));

  bool use_passthrough_cmd_decoder =
      gpu_preferences.use_passthrough_cmd_decoder &&
      gles2::PassthroughCommandDecoderSupported();
  // Virtualized contexts don't work with passthrough command decoder.
  // See https://crbug.com/914976
  DCHECK(!use_passthrough_cmd_decoder || !use_virtualized_gl_contexts_);

  feature_info_ = std::move(feature_info);
  feature_info_->Initialize(gpu::CONTEXT_TYPE_OPENGLES2,
                            use_passthrough_cmd_decoder,
                            gles2::DisallowedFeatures());

  auto* api = gl::g_current_gl_context;
  const GLint kGLES2RequiredMinimumVertexAttribs = 8u;
  GLint max_vertex_attribs = 0;
  api->glGetIntegervFn(GL_MAX_VERTEX_ATTRIBS, &max_vertex_attribs);
  if (max_vertex_attribs < kGLES2RequiredMinimumVertexAttribs) {
    feature_info_ = nullptr;
    return false;
  }

  context_state_ = std::make_unique<gles2::ContextState>(
      feature_info_.get(), false /* track_texture_and_sampler_units */);

  context_state_->set_api(api);
  context_state_->InitGenericAttribs(max_vertex_attribs);

  // Set all the default state because some GL drivers get it wrong.
  // TODO(backer): Not all of this state needs to be initialized. Reduce the set
  // if perf becomes a problem.
  context_state_->InitCapabilities(nullptr);
  context_state_->InitState(nullptr);

  GLenum driver_status = real_context_->CheckStickyGraphicsResetStatus();
  if (driver_status != GL_NO_ERROR) {
    // If the context was lost at any point before or during initialization,
    // the values queried from the driver could be bogus, and potentially
    // inconsistent between various ContextStates on the same underlying real
    // GL context. Make sure to report the failure early, to not allow
    // virtualized context switches in that case.
    feature_info_ = nullptr;
    context_state_ = nullptr;
    return false;
  }

  if (use_virtualized_gl_contexts_) {
    auto virtual_context = base::MakeRefCounted<GLContextVirtual>(
        share_group_.get(), real_context_.get(),
        weak_ptr_factory_.GetWeakPtr());
    if (!virtual_context->Initialize(surface_.get(), gl::GLContextAttribs())) {
      feature_info_ = nullptr;
      context_state_ = nullptr;
      return false;
    }
    context_ = std::move(virtual_context);
    MakeCurrent(nullptr);
  }

  bool is_native_vulkan =
      gpu_preferences.use_vulkan == gpu::VulkanImplementationName::kNative ||
      gpu_preferences.use_vulkan ==
          gpu::VulkanImplementationName::kForcedNative;

  // Swiftshader GL and Vulkan report supporting external objects extensions,
  // but they don't.
  support_vulkan_external_object_ =
      !gl::g_current_gl_version->is_swiftshader && is_native_vulkan &&
      gl::g_current_gl_driver->ext.b_GL_EXT_memory_object_fd &&
      gl::g_current_gl_driver->ext.b_GL_EXT_semaphore_fd;

  return true;
}

bool SharedContextState::MakeCurrent(gl::GLSurface* surface, bool needs_gl) {
  if (!GrContextIsGL() && !needs_gl)
    return true;

  if (context_lost_)
    return false;

  if (!context_->MakeCurrent(surface ? surface : surface_.get())) {
    MarkContextLost();
    return false;
  }
  return true;
}

void SharedContextState::MarkContextLost() {
  DCHECK(GrContextIsGL());
  if (!context_lost_) {
    scoped_refptr<SharedContextState> prevent_last_ref_drop = this;
    context_lost_ = true;
    // context_state_ could be nullptr for some unittests.
    if (context_state_)
      context_state_->MarkContextLost();
    if (gr_context_)
      gr_context_->abandonContext();
    std::move(context_lost_callback_).Run();
    for (auto& observer : context_lost_observers_)
      observer.OnContextLost();
  }
}

bool SharedContextState::IsCurrent(gl::GLSurface* surface) {
  if (!GrContextIsGL())
    return true;
  if (context_lost_)
    return false;
  return context_->IsCurrent(surface);
}

bool SharedContextState::OnMemoryDump(
    const base::trace_event::MemoryDumpArgs& args,
    base::trace_event::ProcessMemoryDump* pmd) {
  if (!gr_context_)
    return true;

  if (args.level_of_detail ==
      base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND) {
    raster::DumpBackgroundGrMemoryStatistics(gr_context_, pmd);
  } else {
    raster::DumpGrMemoryStatistics(gr_context_, pmd, base::nullopt);
  }

  return true;
}

void SharedContextState::AddContextLostObserver(ContextLostObserver* obs) {
  context_lost_observers_.AddObserver(obs);
}

void SharedContextState::RemoveContextLostObserver(ContextLostObserver* obs) {
  context_lost_observers_.RemoveObserver(obs);
}

void SharedContextState::PurgeMemory(
    base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
  if (!gr_context_) {
    DCHECK(!transfer_cache_);
    return;
  }

  // Ensure the context is current before doing any GPU cleanup.
  MakeCurrent(nullptr);

  switch (memory_pressure_level) {
    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
      // This function is only called with moderate or critical pressure.
      NOTREACHED();
      return;
    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:
      // With moderate pressure, clear any unlocked resources.
      gr_context_->purgeUnlockedResources(true /* scratchResourcesOnly */);
      scratch_deserialization_buffer_.resize(
          kInitialScratchDeserializationBufferSize);
      scratch_deserialization_buffer_.shrink_to_fit();
      break;
    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
      // With critical pressure, purge as much as possible.
      gr_context_->freeGpuResources();
      scratch_deserialization_buffer_.resize(0u);
      scratch_deserialization_buffer_.shrink_to_fit();
      break;
  }

  transfer_cache_->PurgeMemory(memory_pressure_level);
}

void SharedContextState::PessimisticallyResetGrContext() const {
  // Calling GrContext::resetContext() is very cheap, so we do it
  // pessimistically. We could dirty less state if skia state setting
  // performance becomes an issue.
  if (gr_context_ && GrContextIsGL())
    gr_context_->resetContext();
}

bool SharedContextState::initialized() const {
  return true;
}

const gles2::ContextState* SharedContextState::GetContextState() {
  if (need_context_state_reset_) {
    // Returning nullptr to force full state restoration by the caller.  We do
    // this because GrContext changes to GL state are untracked in our
    // context_state_.
    return nullptr;
  }
  return context_state_.get();
}

void SharedContextState::RestoreState(const gles2::ContextState* prev_state) {
  PessimisticallyResetGrContext();
  context_state_->RestoreState(prev_state);
  need_context_state_reset_ = false;
}

void SharedContextState::RestoreGlobalState() const {
  PessimisticallyResetGrContext();
  context_state_->RestoreGlobalState(nullptr);
}
void SharedContextState::ClearAllAttributes() const {}

void SharedContextState::RestoreActiveTexture() const {
  PessimisticallyResetGrContext();
}

void SharedContextState::RestoreAllTextureUnitAndSamplerBindings(
    const gles2::ContextState* prev_state) const {
  PessimisticallyResetGrContext();
}

void SharedContextState::RestoreActiveTextureUnitBinding(
    unsigned int target) const {
  PessimisticallyResetGrContext();
}

void SharedContextState::RestoreBufferBinding(unsigned int target) {
  PessimisticallyResetGrContext();
  if (target == GL_PIXEL_PACK_BUFFER) {
    context_state_->UpdatePackParameters();
  } else if (target == GL_PIXEL_UNPACK_BUFFER) {
    context_state_->UpdateUnpackParameters();
  }
  context_state_->api()->glBindBufferFn(target, 0);
}

void SharedContextState::RestoreBufferBindings() const {
  PessimisticallyResetGrContext();
  context_state_->RestoreBufferBindings();
}

void SharedContextState::RestoreFramebufferBindings() const {
  PessimisticallyResetGrContext();
  context_state_->fbo_binding_for_scissor_workaround_dirty = true;
  context_state_->stencil_state_changed_since_validation = true;
}

void SharedContextState::RestoreRenderbufferBindings() {
  PessimisticallyResetGrContext();
  context_state_->RestoreRenderbufferBindings();
}

void SharedContextState::RestoreProgramBindings() const {
  PessimisticallyResetGrContext();
  context_state_->RestoreProgramSettings(nullptr, false);
}

void SharedContextState::RestoreTextureUnitBindings(unsigned unit) const {
  PessimisticallyResetGrContext();
}

void SharedContextState::RestoreVertexAttribArray(unsigned index) {
  NOTIMPLEMENTED();
}

void SharedContextState::RestoreAllExternalTextureBindingsIfNeeded() {
  PessimisticallyResetGrContext();
}

QueryManager* SharedContextState::GetQueryManager() {
  return nullptr;
}

}  // namespace gpu