gecko-dev/gfx/layers/wr/WebRenderBridgeParent.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=4 ts=8 et tw=80 : */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/layers/WebRenderBridgeParent.h"

#include "CompositableHost.h"
#include "GLContext.h"
#include "GLContextProvider.h"
#include "mozilla/Range.h"
#include "mozilla/layers/Compositor.h"
#include "mozilla/layers/CompositorBridgeParent.h"
#include "mozilla/layers/CompositorThread.h"
#include "mozilla/layers/CompositorVsyncScheduler.h"
#include "mozilla/layers/ImageBridgeParent.h"
#include "mozilla/layers/ImageDataSerializer.h"
#include "mozilla/layers/TextureHost.h"
#include "mozilla/layers/WebRenderCompositableHolder.h"
#include "mozilla/layers/WebRenderTextureHost.h"
#include "mozilla/webrender/RenderThread.h"
#include "mozilla/widget/CompositorWidget.h"

#if defined(MOZ_WIDGET_ANDROID)
# include "mozilla/widget/AndroidCompositorWidget.h"
#endif

bool is_in_main_thread()
{
  return NS_IsMainThread();
}

bool is_in_compositor_thread()
{
  return mozilla::layers::CompositorThreadHolder::IsInCompositorThread();
}

bool is_in_render_thread()
{
  return mozilla::wr::RenderThread::IsInRenderThread();
}

bool is_glcontext_egl(void* glcontext_ptr)
{
  MOZ_ASSERT(glcontext_ptr);

  mozilla::gl::GLContext* glcontext = reinterpret_cast<mozilla::gl::GLContext*>(glcontext_ptr);
  if (!glcontext) {
    return false;
  }
  return glcontext->GetContextType() == mozilla::gl::GLContextType::EGL;
}

void gfx_critical_note(const char* msg)
{
  gfxCriticalNote << msg;
}

void* get_proc_address_from_glcontext(void* glcontext_ptr, const char* procname)
{
  MOZ_ASSERT(glcontext_ptr);

  mozilla::gl::GLContext* glcontext = reinterpret_cast<mozilla::gl::GLContext*>(glcontext_ptr);
  if (!glcontext) {
    return nullptr;
  }
  PRFuncPtr p = glcontext->LookupSymbol(procname);
  return reinterpret_cast<void*>(p);
}

namespace mozilla {
namespace layers {

using namespace mozilla::gfx;

class MOZ_STACK_CLASS AutoWebRenderBridgeParentAsyncMessageSender
{
public:
  explicit AutoWebRenderBridgeParentAsyncMessageSender(WebRenderBridgeParent* aWebRenderBridgeParent,
                                                       InfallibleTArray<OpDestroy>* aDestroyActors = nullptr)
    : mWebRenderBridgeParent(aWebRenderBridgeParent)
    , mActorsToDestroy(aDestroyActors)
  {
    mWebRenderBridgeParent->SetAboutToSendAsyncMessages();
  }

  ~AutoWebRenderBridgeParentAsyncMessageSender()
  {
    mWebRenderBridgeParent->SendPendingAsyncMessages();
    if (mActorsToDestroy) {
      // Destroy the actors after sending the async messages because the latter may contain
      // references to some actors.
      for (const auto& op : *mActorsToDestroy) {
        mWebRenderBridgeParent->DestroyActor(op);
      }
    }
  }
private:
  WebRenderBridgeParent* mWebRenderBridgeParent;
  InfallibleTArray<OpDestroy>* mActorsToDestroy;
};

/* static */ uint32_t WebRenderBridgeParent::sIdNameSpace = 0;

WebRenderBridgeParent::WebRenderBridgeParent(CompositorBridgeParentBase* aCompositorBridge,
                                             const wr::PipelineId& aPipelineId,
                                             widget::CompositorWidget* aWidget,
                                             CompositorVsyncScheduler* aScheduler,
                                             RefPtr<wr::WebRenderAPI>&& aApi,
                                             RefPtr<WebRenderCompositableHolder>&& aHolder)
  : mCompositorBridge(aCompositorBridge)
  , mPipelineId(aPipelineId)
  , mWidget(aWidget)
  , mApi(aApi)
  , mCompositableHolder(aHolder)
  , mCompositorScheduler(aScheduler)
  , mChildLayerObserverEpoch(0)
  , mParentLayerObserverEpoch(0)
  , mWrEpoch(0)
  , mIdNameSpace(++sIdNameSpace)
  , mPaused(false)
  , mDestroyed(false)
{
  MOZ_ASSERT(mCompositableHolder);
  mCompositableHolder->AddPipeline(mPipelineId);
  if (mWidget) {
    MOZ_ASSERT(!mCompositorScheduler);
    mCompositorScheduler = new CompositorVsyncScheduler(this, mWidget);
  }
}


mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvCreate(const gfx::IntSize& aSize)
{
  if (mDestroyed) {
    return IPC_OK();
  }

  MOZ_ASSERT(mApi);

#ifdef MOZ_WIDGET_ANDROID
  // XXX temporary hack.
  // XXX Remove it when APZ is supported.
  widget::AndroidCompositorWidget* widget = mWidget->AsAndroid();
  if (widget) {
    widget->SetFirstPaintViewport(LayerIntPoint(0, 0), CSSToLayerScale(), CSSRect(0, 0, aSize.width, aSize.height));
  }
#endif

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvShutdown()
{
  if (mDestroyed) {
    return IPC_OK();
  }
  Destroy();
  if (!Send__delete__(this)) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

void
WebRenderBridgeParent::Destroy()
{
  if (mDestroyed) {
    return;
  }
  mDestroyed = true;
  ClearResources();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvAddImage(const wr::ImageKey& aImageKey,
                                    const gfx::IntSize& aSize,
                                    const uint32_t& aStride,
                                    const gfx::SurfaceFormat& aFormat,
                                    const ByteBuffer& aBuffer)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  wr::ImageDescriptor descriptor(aSize, aStride, aFormat);
  mApi->AddImage(aImageKey, descriptor,
                 aBuffer.AsSlice());

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvAddBlobImage(const wr::ImageKey& aImageKey,
                        				        const gfx::IntSize& aSize,
                                        const uint32_t& aStride,
                                        const gfx::SurfaceFormat& aFormat,
                                        const ByteBuffer& aBuffer)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  wr::ImageDescriptor descriptor(aSize, aStride, aFormat);
  mApi->AddBlobImage(aImageKey, descriptor,
                     aBuffer.AsSlice());

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvAddRawFont(const wr::FontKey& aFontKey,
                                      const ByteBuffer& aBuffer,
                                      const uint32_t& aFontIndex)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  auto slice = aBuffer.AsSlice();
  mApi->AddRawFont(aFontKey, slice);

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDeleteFont(const wr::FontKey& aFontKey)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  mApi->DeleteFont(aFontKey);
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvUpdateImage(const wr::ImageKey& aImageKey,
                                       const gfx::IntSize& aSize,
                                       const gfx::SurfaceFormat& aFormat,
                                       const ByteBuffer& aBuffer)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  wr::ImageDescriptor descriptor(aSize, aFormat);
  mApi->UpdateImageBuffer(aImageKey, descriptor, aBuffer.AsSlice());

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDeleteImage(const wr::ImageKey& aImageKey)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mApi);
  mKeysToDelete.push_back(aImageKey);
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDPBegin(const gfx::IntSize& aSize)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  return IPC_OK();
}

void
WebRenderBridgeParent::HandleDPEnd(const gfx::IntSize& aSize,
                                 InfallibleTArray<WebRenderParentCommand>&& aCommands,
                                 InfallibleTArray<OpDestroy>&& aToDestroy,
                                 const uint64_t& aFwdTransactionId,
                                 const uint64_t& aTransactionId,
                                 const ByteBuffer& dl,
                                 const WrBuiltDisplayListDescriptor& dlDesc,
                                 const ByteBuffer& aux,
                                 const WrAuxiliaryListsDescriptor& auxDesc)
{
  UpdateFwdTransactionId(aFwdTransactionId);
  AutoClearReadLocks clearLocks(mReadLocks);

  if (mDestroyed) {
    for (const auto& op : aToDestroy) {
      DestroyActor(op);
    }
    return;
  }
  // This ensures that destroy operations are always processed. It is not safe
  // to early-return from RecvDPEnd without doing so.
  AutoWebRenderBridgeParentAsyncMessageSender autoAsyncMessageSender(this, &aToDestroy);

  ++mWrEpoch; // Update webrender epoch
  ProcessWebRenderCommands(aSize, aCommands, wr::NewEpoch(mWrEpoch),
                           dl, dlDesc, aux, auxDesc);
  HoldPendingTransactionId(mWrEpoch, aTransactionId);
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDPEnd(const gfx::IntSize& aSize,
                                 InfallibleTArray<WebRenderParentCommand>&& aCommands,
                                 InfallibleTArray<OpDestroy>&& aToDestroy,
                                 const uint64_t& aFwdTransactionId,
                                 const uint64_t& aTransactionId,
                                 const ByteBuffer& dl,
                                 const WrBuiltDisplayListDescriptor& dlDesc,
                                 const ByteBuffer& aux,
                                 const WrAuxiliaryListsDescriptor& auxDesc)
{
  HandleDPEnd(aSize, Move(aCommands), Move(aToDestroy), aFwdTransactionId, aTransactionId,
              dl, dlDesc, aux, auxDesc);
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDPSyncEnd(const gfx::IntSize &aSize,
                                     InfallibleTArray<WebRenderParentCommand>&& aCommands,
                                     InfallibleTArray<OpDestroy>&& aToDestroy,
                                     const uint64_t& aFwdTransactionId,
                                     const uint64_t& aTransactionId,
                                     const ByteBuffer& dl,
                                     const WrBuiltDisplayListDescriptor& dlDesc,
                                     const ByteBuffer& aux,
                                     const WrAuxiliaryListsDescriptor& auxDesc)
{
  HandleDPEnd(aSize, Move(aCommands), Move(aToDestroy), aFwdTransactionId, aTransactionId,
              dl, dlDesc, aux, auxDesc);
  return IPC_OK();
}

void
WebRenderBridgeParent::ProcessWebRenderCommands(const gfx::IntSize &aSize,
                                                InfallibleTArray<WebRenderParentCommand>& aCommands, const wr::Epoch& aEpoch,
                                                const ByteBuffer& dl,
                                                const WrBuiltDisplayListDescriptor& dlDesc,
                                                const ByteBuffer& aux,
                                                const WrAuxiliaryListsDescriptor& auxDesc)
{
  // XXX remove it when external image key is used.
  std::vector<wr::ImageKey> keysToDelete;

  for (InfallibleTArray<WebRenderParentCommand>::index_type i = 0; i < aCommands.Length(); ++i) {
    const WebRenderParentCommand& cmd = aCommands[i];
    switch (cmd.type()) {
      case WebRenderParentCommand::TOpAddExternalImage: {
        const OpAddExternalImage& op = cmd.get_OpAddExternalImage();
        wr::ImageKey key = op.key();
        MOZ_ASSERT(mExternalImageIds.Get(op.externalImageId()).get());

        RefPtr<CompositableHost> host = mExternalImageIds.Get(op.externalImageId());
        if (!host) {
          NS_ERROR("CompositableHost does not exist");
          break;
        }
        // XXX select Texture for video in CompositeToTarget().
        TextureHost* texture = host->GetAsTextureHost();
        if (!texture) {
          NS_ERROR("TextureHost does not exist");
          break;
        }
        WebRenderTextureHost* wrTexture = texture->AsWebRenderTextureHost();
        if (wrTexture) {
          if (wrTexture->IsWrappingNativeHandle()) {
            // XXX only for MacIOSurface right now.
            // XXX remove the redundant codes for both native handle and yuv case.
            wr::ImageDescriptor descriptor(wrTexture->GetSize(), wrTexture->GetReadFormat());
            mApi->AddExternalImageHandle(key,
                                         descriptor,
                                         wrTexture->GetExternalImageKey());
            mCompositableHolder->HoldExternalImage(mPipelineId, aEpoch, texture->AsWebRenderTextureHost());
            keysToDelete.push_back(key);
          } else {
            // XXX handling YUV
            gfx::SurfaceFormat format =
              wrTexture->GetFormat() == SurfaceFormat::YUV ? SurfaceFormat::B8G8R8A8 : wrTexture->GetFormat();
            wr::ImageDescriptor descriptor(wrTexture->GetSize(), wrTexture->GetRGBStride(), format);
            mApi->AddExternalImageBuffer(key,
                                         descriptor,
                                         wrTexture->GetExternalImageKey());
            mCompositableHolder->HoldExternalImage(mPipelineId, aEpoch, texture->AsWebRenderTextureHost());
            keysToDelete.push_back(key);
          }

          break;
        }
        RefPtr<DataSourceSurface> dSurf = host->GetAsSurface();
        if (!dSurf) {
          break;
        }

        DataSourceSurface::MappedSurface map;
        if (!dSurf->Map(gfx::DataSourceSurface::MapType::READ, &map)) {
          break;
        }

        IntSize size = dSurf->GetSize();
        wr::ImageDescriptor descriptor(size, map.mStride, dSurf->GetFormat());
        auto slice = Range<uint8_t>(map.mData, size.height * map.mStride);
        mApi->AddImage(key, descriptor, slice);

        keysToDelete.push_back(key);
        dSurf->Unmap();
        break;
      }
      case WebRenderParentCommand::TCompositableOperation: {
        if (!ReceiveCompositableUpdate(cmd.get_CompositableOperation())) {
          NS_ERROR("ReceiveCompositableUpdate failed");
        }
        break;
      }
      default: {
        // other commands are handle on the child
        break;
      }
    }
  }
  if (mWidget) {
    LayoutDeviceIntSize size = mWidget->GetClientSize();
    mApi->SetWindowParameters(size);
  }
  mApi->SetRootDisplayList(gfx::Color(0.3f, 0.f, 0.f, 1.f), aEpoch, LayerSize(aSize.width, aSize.height),
                           mPipelineId,
                           dlDesc, dl.mData, dl.mLength,
                           auxDesc, aux.mData, aux.mLength);

  ScheduleComposition();
  DeleteOldImages();

  // XXX remove it when external image key is used.
  if (!keysToDelete.empty()) {
    mKeysToDelete.swap(keysToDelete);
  }

  if (ShouldParentObserveEpoch()) {
    mCompositorBridge->ObserveLayerUpdate(wr::AsUint64(mPipelineId), GetChildLayerObserverEpoch(), true);
  }
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvDPGetSnapshot(PTextureParent* aTexture)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(!mPaused);

  RefPtr<TextureHost> texture = TextureHost::AsTextureHost(aTexture);
  if (!texture) {
    // We kill the content process rather than have it continue with an invalid
    // snapshot, that may be too harsh and we could decide to return some sort
    // of error to the child process and let it deal with it...
    return IPC_FAIL_NO_REASON(this);
  }

  // XXX Add other TextureHost supports.
  // Only BufferTextureHost is supported now.
  BufferTextureHost* bufferTexture = texture->AsBufferTextureHost();
  if (!bufferTexture) {
    // We kill the content process rather than have it continue with an invalid
    // snapshot, that may be too harsh and we could decide to return some sort
    // of error to the child process and let it deal with it...
    return IPC_FAIL_NO_REASON(this);
  }

  MOZ_ASSERT(bufferTexture->GetBufferDescriptor().type() == BufferDescriptor::TRGBDescriptor);
  DebugOnly<uint32_t> stride = ImageDataSerializer::GetRGBStride(bufferTexture->GetBufferDescriptor().get_RGBDescriptor());
  uint8_t* buffer = bufferTexture->GetBuffer();
  IntSize size = bufferTexture->GetSize();

  // We only support B8G8R8A8 for now.
  MOZ_ASSERT(buffer);
  MOZ_ASSERT(bufferTexture->GetFormat() == SurfaceFormat::B8G8R8A8);
  uint32_t buffer_size = size.width * size.height * 4;

  // Assert the stride of the buffer is what webrender expects
  MOZ_ASSERT((uint32_t)(size.width * 4) == stride);

  if (mCompositorScheduler->NeedsComposite()) {
    mCompositorScheduler->CancelCurrentCompositeTask();
    mCompositorScheduler->ForceComposeToTarget(nullptr, nullptr);
  }

  mApi->Readback(size, buffer, buffer_size);

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvAddExternalImageId(const uint64_t& aImageId,
                                              const CompositableHandle& aHandle)
{
  if (mDestroyed) {
    return IPC_OK();
  }

  MOZ_ASSERT(!mExternalImageIds.Get(aImageId).get());

  ImageBridgeParent* imageBridge = ImageBridgeParent::GetInstance(OtherPid());
  if (!imageBridge) {
     return IPC_FAIL_NO_REASON(this);
  }
  RefPtr<CompositableHost> host = imageBridge->FindCompositable(aHandle);
  if (!host) {
    NS_ERROR("CompositableHost not found in the map!");
    return IPC_FAIL_NO_REASON(this);
  }
  if (host->GetType() != CompositableType::IMAGE &&
      host->GetType() != CompositableType::CONTENT_SINGLE &&
      host->GetType() != CompositableType::CONTENT_DOUBLE) {
    NS_ERROR("Incompatible CompositableHost");
    return IPC_OK();
  }

  mExternalImageIds.Put(aImageId, host);

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvAddExternalImageIdForCompositable(const uint64_t& aImageId,
                                                             const CompositableHandle& aHandle)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(!mExternalImageIds.Get(aImageId).get());

  RefPtr<CompositableHost> host = FindCompositable(aHandle);
  if (host->GetType() != CompositableType::IMAGE &&
      host->GetType() != CompositableType::CONTENT_SINGLE &&
      host->GetType() != CompositableType::CONTENT_DOUBLE) {
    NS_ERROR("Incompatible CompositableHost");
    return IPC_OK();
  }

  mExternalImageIds.Put(aImageId, host);

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvRemoveExternalImageId(const uint64_t& aImageId)
{
  if (mDestroyed) {
    return IPC_OK();
  }
  MOZ_ASSERT(mExternalImageIds.Get(aImageId).get());
  mExternalImageIds.Remove(aImageId);

  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvSetLayerObserverEpoch(const uint64_t& aLayerObserverEpoch)
{
  mChildLayerObserverEpoch = aLayerObserverEpoch;
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvClearCachedResources()
{
  mCompositorBridge->ObserveLayerUpdate(wr::AsUint64(mPipelineId), GetChildLayerObserverEpoch(), false);
  return IPC_OK();
}

void
WebRenderBridgeParent::ActorDestroy(ActorDestroyReason aWhy)
{
  Destroy();
}

void
WebRenderBridgeParent::CompositeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect)
{
  if (mPaused) {
    return;
  }
  mApi->GenerateFrame();
}

void
WebRenderBridgeParent::HoldPendingTransactionId(uint32_t aWrEpoch, uint64_t aTransactionId)
{
  // The transaction ID might get reset to 1 if the page gets reloaded, see
  // https://bugzilla.mozilla.org/show_bug.cgi?id=1145295#c41
  // Otherwise, it should be continually increasing.
  MOZ_ASSERT(aTransactionId == 1 || aTransactionId > LastPendingTransactionId());
  // Handle TransactionIdAllocator(RefreshDriver) change.
  if (aTransactionId == 1) {
    FlushPendingTransactionIds();
  }
  mPendingTransactionIds.push(PendingTransactionId(wr::NewEpoch(aWrEpoch), aTransactionId));
}

uint64_t
WebRenderBridgeParent::LastPendingTransactionId()
{
  uint64_t id = 0;
  if (!mPendingTransactionIds.empty()) {
    id = mPendingTransactionIds.back().mId;
  }
  return id;
}

uint64_t
WebRenderBridgeParent::FlushPendingTransactionIds()
{
  uint64_t id = 0;
  while (!mPendingTransactionIds.empty()) {
    id = mPendingTransactionIds.front().mId;
    mPendingTransactionIds.pop();
  }
  return id;
}

uint64_t
WebRenderBridgeParent::FlushTransactionIdsForEpoch(const wr::Epoch& aEpoch)
{
  uint64_t id = 0;
  while (!mPendingTransactionIds.empty()) {
    id = mPendingTransactionIds.front().mId;
    if (mPendingTransactionIds.front().mEpoch == aEpoch) {
      mPendingTransactionIds.pop();
      break;
    }
    mPendingTransactionIds.pop();
  }
  return id;
}

WebRenderBridgeParent::~WebRenderBridgeParent()
{
}

void
WebRenderBridgeParent::DeleteOldImages()
{
  for (wr::ImageKey key : mKeysToDelete) {
    mApi->DeleteImage(key);
  }
  mKeysToDelete.clear();
}

void
WebRenderBridgeParent::ScheduleComposition()
{
  if (mCompositorScheduler) {
    mCompositorScheduler->ScheduleComposition();
  }
}

void
WebRenderBridgeParent::Pause()
{
  MOZ_ASSERT(mWidget);
#ifdef MOZ_WIDGET_ANDROID
  if (!mWidget || mDestroyed) {
    return;
  }
  mApi->Pause();
#endif
  mPaused = true;
}

bool
WebRenderBridgeParent::Resume()
{
  MOZ_ASSERT(mWidget);
#ifdef MOZ_WIDGET_ANDROID
  if (!mWidget || mDestroyed) {
    return false;
  }

  if (!mApi->Resume()) {
    return false;
  }
#endif
  mPaused = false;
  return true;
}

void
WebRenderBridgeParent::ClearResources()
{
  if (mApi) {
    ++mWrEpoch; // Update webrender epoch
    mApi->ClearRootDisplayList(wr::NewEpoch(mWrEpoch), mPipelineId);
    if (!mKeysToDelete.empty()) {
      // XXX Sync wait.
      mApi->WaitFlushed();
      DeleteOldImages();
    }
  }
  mCompositableHolder->RemovePipeline(mPipelineId);
  mExternalImageIds.Clear();

  if (mWidget && mCompositorScheduler) {
    mCompositorScheduler->Destroy();
  }
  mCompositorScheduler = nullptr;
  mApi = nullptr;
  mCompositorBridge = nullptr;
}

bool
WebRenderBridgeParent::ShouldParentObserveEpoch()
{
  if (mParentLayerObserverEpoch == mChildLayerObserverEpoch) {
    return false;
  }

  mParentLayerObserverEpoch = mChildLayerObserverEpoch;
  return true;
}

void
WebRenderBridgeParent::SendAsyncMessage(const InfallibleTArray<AsyncParentMessageData>& aMessage)
{
  MOZ_ASSERT_UNREACHABLE("unexpected to be called");
}

void
WebRenderBridgeParent::SendPendingAsyncMessages()
{
  MOZ_ASSERT(mCompositorBridge);
  mCompositorBridge->SendPendingAsyncMessages();
}

void
WebRenderBridgeParent::SetAboutToSendAsyncMessages()
{
  MOZ_ASSERT(mCompositorBridge);
  mCompositorBridge->SetAboutToSendAsyncMessages();
}

void
WebRenderBridgeParent::NotifyNotUsed(PTextureParent* aTexture, uint64_t aTransactionId)
{
  MOZ_ASSERT_UNREACHABLE("unexpected to be called");
}

base::ProcessId
WebRenderBridgeParent::GetChildProcessId()
{
  return OtherPid();
}

bool
WebRenderBridgeParent::IsSameProcess() const
{
  return OtherPid() == base::GetCurrentProcId();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvNewCompositable(const CompositableHandle& aHandle,
                                           const TextureInfo& aInfo)
{
  if (!AddCompositable(aHandle, aInfo)) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvReleaseCompositable(const CompositableHandle& aHandle)
{
  ReleaseCompositable(aHandle);
  return IPC_OK();
}

mozilla::ipc::IPCResult
WebRenderBridgeParent::RecvInitReadLocks(ReadLockArray&& aReadLocks)
{
  if (!AddReadLocks(Move(aReadLocks))) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

void
WebRenderBridgeParent::SetWebRenderProfilerEnabled(bool aEnabled)
{
  if (mWidget) {
    // Only set the flag to "root" WebRenderBridgeParent.
    mApi->SetProfilerEnabled(aEnabled);
  }
}

TextureFactoryIdentifier
WebRenderBridgeParent::GetTextureFactoryIdentifier()
{
  MOZ_ASSERT(mApi);

  return TextureFactoryIdentifier(LayersBackend::LAYERS_WR,
                                  XRE_GetProcessType(),
                                  mApi->GetMaxTextureSize(),
                                  mApi->GetUseANGLE());
}

} // namespace layers
} // namespace mozilla