1 files changed, 975 insertions, 0 deletions
diff --git a/gfx/layers/ipc/ImageBridgeChild.cpp b/gfx/layers/ipc/ImageBridgeChild.cpp
new file mode 100644
index 0000000000..32489afabd
--- /dev/null
+++ b/gfx/layers/ipc/ImageBridgeChild.cpp
@@ -0,0 +1,975 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 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 "ImageBridgeChild.h"
+
+#include <vector>  // for vector
+
+#include "ImageBridgeParent.h"  // for ImageBridgeParent
+#include "ImageContainer.h"     // for ImageContainer
+#include "SynchronousTask.h"
+#include "mozilla/Assertions.h"        // for MOZ_ASSERT, etc
+#include "mozilla/Monitor.h"           // for Monitor, MonitorAutoLock
+#include "mozilla/ReentrantMonitor.h"  // for ReentrantMonitor, etc
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPtr.h"  // for StaticRefPtr
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/gfx/Point.h"  // for IntSize
+#include "mozilla/gfx/gfxVars.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/ipc/MessageChannel.h"         // for MessageChannel, etc
+#include "mozilla/layers/CompositableClient.h"  // for CompositableChild, etc
+#include "mozilla/layers/CompositorThread.h"
+#include "mozilla/layers/ISurfaceAllocator.h"  // for ISurfaceAllocator
+#include "mozilla/layers/ImageClient.h"        // for ImageClient
+#include "mozilla/layers/LayersMessages.h"     // for CompositableOperation
+#include "mozilla/layers/TextureClient.h"      // for TextureClient
+#include "mozilla/layers/TextureClient.h"
+#include "mozilla/media/MediaSystemResourceManager.h"  // for MediaSystemResourceManager
+#include "mozilla/media/MediaSystemResourceManagerChild.h"  // for MediaSystemResourceManagerChild
+#include "mozilla/mozalloc.h"  // for operator new, etc
+#include "transport/runnable_utils.h"
+#include "nsContentUtils.h"
+#include "nsGlobalWindowInner.h"
+#include "nsISupportsImpl.h"         // for ImageContainer::AddRef, etc
+#include "nsTArray.h"                // for AutoTArray, nsTArray, etc
+#include "nsTArrayForwardDeclare.h"  // for AutoTArray
+#include "nsThreadUtils.h"           // for NS_IsMainThread
+#include "WindowRenderer.h"
+
+#if defined(XP_WIN)
+#  include "mozilla/gfx/DeviceManagerDx.h"
+#endif
+
+namespace mozilla {
+namespace ipc {
+class Shmem;
+}  // namespace ipc
+
+namespace layers {
+
+using namespace mozilla::ipc;
+using namespace mozilla::gfx;
+using namespace mozilla::media;
+
+typedef std::vector<CompositableOperation> OpVector;
+typedef nsTArray<OpDestroy> OpDestroyVector;
+
+struct CompositableTransaction {
+  CompositableTransaction() : mFinished(true) {}
+  ~CompositableTransaction() { End(); }
+  bool Finished() const { return mFinished; }
+  void Begin() {
+    MOZ_ASSERT(mFinished);
+    mFinished = false;
+  }
+  void End() {
+    mFinished = true;
+    mOperations.clear();
+    mDestroyedActors.Clear();
+  }
+  bool IsEmpty() const {
+    return mOperations.empty() && mDestroyedActors.IsEmpty();
+  }
+  void AddNoSwapEdit(const CompositableOperation& op) {
+    MOZ_ASSERT(!Finished(), "forgot BeginTransaction?");
+    mOperations.push_back(op);
+  }
+
+  OpVector mOperations;
+  OpDestroyVector mDestroyedActors;
+
+  bool mFinished;
+};
+
+struct AutoEndTransaction final {
+  explicit AutoEndTransaction(CompositableTransaction* aTxn) : mTxn(aTxn) {}
+  ~AutoEndTransaction() { mTxn->End(); }
+  CompositableTransaction* mTxn;
+};
+
+void ImageBridgeChild::UseTextures(
+    CompositableClient* aCompositable,
+    const nsTArray<TimedTextureClient>& aTextures) {
+  MOZ_ASSERT(aCompositable);
+  MOZ_ASSERT(aCompositable->GetIPCHandle());
+  MOZ_ASSERT(aCompositable->IsConnected());
+
+  AutoTArray<TimedTexture, 4> textures;
+
+  for (auto& t : aTextures) {
+    MOZ_ASSERT(t.mTextureClient);
+    MOZ_ASSERT(t.mTextureClient->GetIPDLActor());
+
+    if (!t.mTextureClient->IsSharedWithCompositor()) {
+      return;
+    }
+
+    bool readLocked = t.mTextureClient->OnForwardedToHost();
+
+    textures.AppendElement(TimedTexture(
+        WrapNotNull(t.mTextureClient->GetIPDLActor()), t.mTimeStamp,
+        t.mPictureRect, t.mFrameID, t.mProducerID, readLocked));
+
+    // Wait end of usage on host side if TextureFlags::RECYCLE is set
+    HoldUntilCompositableRefReleasedIfNecessary(t.mTextureClient);
+  }
+  mTxn->AddNoSwapEdit(CompositableOperation(aCompositable->GetIPCHandle(),
+                                            OpUseTexture(textures)));
+}
+
+void ImageBridgeChild::UseRemoteTexture(
+    CompositableClient* aCompositable, const RemoteTextureId aTextureId,
+    const RemoteTextureOwnerId aOwnerId, const gfx::IntSize aSize,
+    const TextureFlags aFlags, const RefPtr<FwdTransactionTracker>& aTracker) {
+  MOZ_ASSERT(aCompositable);
+  MOZ_ASSERT(aCompositable->GetIPCHandle());
+  MOZ_ASSERT(aCompositable->IsConnected());
+
+  mTxn->AddNoSwapEdit(CompositableOperation(
+      aCompositable->GetIPCHandle(),
+      OpUseRemoteTexture(aTextureId, aOwnerId, aSize, aFlags)));
+  TrackFwdTransaction(aTracker);
+}
+
+void ImageBridgeChild::HoldUntilCompositableRefReleasedIfNecessary(
+    TextureClient* aClient) {
+  if (!aClient) {
+    return;
+  }
+
+  // Wait ReleaseCompositableRef only when TextureFlags::RECYCLE or
+  // TextureFlags::WAIT_HOST_USAGE_END is set on ImageBridge.
+  bool waitNotifyNotUsed =
+      aClient->GetFlags() & TextureFlags::RECYCLE ||
+      aClient->GetFlags() & TextureFlags::WAIT_HOST_USAGE_END;
+  if (!waitNotifyNotUsed) {
+    return;
+  }
+
+  aClient->SetLastFwdTransactionId(GetFwdTransactionId());
+  mTexturesWaitingNotifyNotUsed.emplace(aClient->GetSerial(), aClient);
+}
+
+void ImageBridgeChild::NotifyNotUsed(uint64_t aTextureId,
+                                     uint64_t aFwdTransactionId) {
+  auto it = mTexturesWaitingNotifyNotUsed.find(aTextureId);
+  if (it != mTexturesWaitingNotifyNotUsed.end()) {
+    if (aFwdTransactionId < it->second->GetLastFwdTransactionId()) {
+      // Released on host side, but client already requested newer use texture.
+      return;
+    }
+    mTexturesWaitingNotifyNotUsed.erase(it);
+  }
+}
+
+void ImageBridgeChild::CancelWaitForNotifyNotUsed(uint64_t aTextureId) {
+  MOZ_ASSERT(InImageBridgeChildThread());
+  mTexturesWaitingNotifyNotUsed.erase(aTextureId);
+}
+
+// Singleton
+static StaticMutex sImageBridgeSingletonLock MOZ_UNANNOTATED;
+static StaticRefPtr<ImageBridgeChild> sImageBridgeChildSingleton;
+static StaticRefPtr<nsIThread> sImageBridgeChildThread;
+
+// dispatched function
+void ImageBridgeChild::ShutdownStep1(SynchronousTask* aTask) {
+  AutoCompleteTask complete(aTask);
+
+  MOZ_ASSERT(InImageBridgeChildThread(),
+             "Should be in ImageBridgeChild thread.");
+
+  MediaSystemResourceManager::Shutdown();
+
+  // Force all managed protocols to shut themselves down cleanly
+  nsTArray<PTextureChild*> textures;
+  ManagedPTextureChild(textures);
+  for (int i = textures.Length() - 1; i >= 0; --i) {
+    RefPtr<TextureClient> client = TextureClient::AsTextureClient(textures[i]);
+    if (client) {
+      client->Destroy();
+    }
+  }
+
+  if (mCanSend) {
+    SendWillClose();
+  }
+  MarkShutDown();
+
+  // From now on, no message can be sent through the image bridge from the
+  // client side except the final Stop message.
+}
+
+// dispatched function
+void ImageBridgeChild::ShutdownStep2(SynchronousTask* aTask) {
+  AutoCompleteTask complete(aTask);
+
+  MOZ_ASSERT(InImageBridgeChildThread(),
+             "Should be in ImageBridgeChild thread.");
+
+  mSectionAllocator = nullptr;
+
+  if (!mDestroyed) {
+    Close();
+  }
+}
+
+void ImageBridgeChild::ActorDestroy(ActorDestroyReason aWhy) {
+  mCanSend = false;
+  mDestroyed = true;
+  {
+    MutexAutoLock lock(mContainerMapLock);
+    mImageContainerListeners.clear();
+  }
+}
+
+void ImageBridgeChild::CreateImageClientSync(SynchronousTask* aTask,
+                                             RefPtr<ImageClient>* result,
+                                             CompositableType aType,
+                                             ImageContainer* aImageContainer) {
+  AutoCompleteTask complete(aTask);
+  *result = CreateImageClientNow(aType, aImageContainer);
+}
+
+ImageBridgeChild::ImageBridgeChild(uint32_t aNamespace)
+    : mNamespace(aNamespace),
+      mCanSend(false),
+      mDestroyed(false),
+      mFwdTransactionCounter(this),
+      mContainerMapLock("ImageBridgeChild.mContainerMapLock") {
+  MOZ_ASSERT(mNamespace);
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mTxn = new CompositableTransaction();
+}
+
+ImageBridgeChild::~ImageBridgeChild() { delete mTxn; }
+
+void ImageBridgeChild::MarkShutDown() {
+  mTexturesWaitingNotifyNotUsed.clear();
+
+  mCanSend = false;
+}
+
+void ImageBridgeChild::Connect(CompositableClient* aCompositable,
+                               ImageContainer* aImageContainer) {
+  MOZ_ASSERT(aCompositable);
+  MOZ_ASSERT(InImageBridgeChildThread());
+  MOZ_ASSERT(CanSend());
+
+  CompositableHandle handle = CompositableHandle::GetNext();
+
+  // ImageClient of ImageContainer provides aImageContainer.
+  // But offscreen canvas does not provide it.
+  if (aImageContainer) {
+    MutexAutoLock lock(mContainerMapLock);
+    MOZ_ASSERT(mImageContainerListeners.find(uint64_t(handle)) ==
+               mImageContainerListeners.end());
+    mImageContainerListeners.emplace(
+        uint64_t(handle), aImageContainer->GetImageContainerListener());
+  }
+
+  aCompositable->InitIPDL(handle);
+  SendNewCompositable(handle, aCompositable->GetTextureInfo());
+}
+
+void ImageBridgeChild::ForgetImageContainer(const CompositableHandle& aHandle) {
+  MutexAutoLock lock(mContainerMapLock);
+  mImageContainerListeners.erase(aHandle.Value());
+}
+
+/* static */
+RefPtr<ImageBridgeChild> ImageBridgeChild::GetSingleton() {
+  StaticMutexAutoLock lock(sImageBridgeSingletonLock);
+  return sImageBridgeChildSingleton;
+}
+
+void ImageBridgeChild::UpdateImageClient(RefPtr<ImageContainer> aContainer) {
+  if (!aContainer) {
+    return;
+  }
+
+  if (!InImageBridgeChildThread()) {
+    RefPtr<Runnable> runnable =
+        WrapRunnable(RefPtr<ImageBridgeChild>(this),
+                     &ImageBridgeChild::UpdateImageClient, aContainer);
+    GetThread()->Dispatch(runnable.forget());
+    return;
+  }
+
+  if (!CanSend()) {
+    return;
+  }
+
+  RefPtr<ImageClient> client = aContainer->GetImageClient();
+  if (NS_WARN_IF(!client)) {
+    return;
+  }
+
+  // If the client has become disconnected before this event was dispatched,
+  // early return now.
+  if (!client->IsConnected()) {
+    return;
+  }
+
+  BeginTransaction();
+  client->UpdateImage(aContainer);
+  EndTransaction();
+}
+
+void ImageBridgeChild::UpdateCompositable(
+    const RefPtr<ImageContainer> aContainer, const RemoteTextureId aTextureId,
+    const RemoteTextureOwnerId aOwnerId, const gfx::IntSize aSize,
+    const TextureFlags aFlags, const RefPtr<FwdTransactionTracker> aTracker) {
+  if (!aContainer) {
+    return;
+  }
+
+  if (!InImageBridgeChildThread()) {
+    RefPtr<Runnable> runnable = WrapRunnable(
+        RefPtr<ImageBridgeChild>(this), &ImageBridgeChild::UpdateCompositable,
+        aContainer, aTextureId, aOwnerId, aSize, aFlags, aTracker);
+    GetThread()->Dispatch(runnable.forget());
+    return;
+  }
+
+  if (!CanSend()) {
+    return;
+  }
+
+  RefPtr<ImageClient> client = aContainer->GetImageClient();
+  if (NS_WARN_IF(!client)) {
+    return;
+  }
+
+  // If the client has become disconnected before this event was dispatched,
+  // early return now.
+  if (!client->IsConnected()) {
+    return;
+  }
+
+  BeginTransaction();
+  UseRemoteTexture(client, aTextureId, aOwnerId, aSize, aFlags, aTracker);
+  EndTransaction();
+}
+
+void ImageBridgeChild::FlushAllImagesSync(SynchronousTask* aTask,
+                                          ImageClient* aClient,
+                                          ImageContainer* aContainer) {
+  AutoCompleteTask complete(aTask);
+
+  if (!CanSend()) {
+    return;
+  }
+
+  MOZ_ASSERT(aClient);
+  BeginTransaction();
+  if (aContainer) {
+    aContainer->ClearImagesFromImageBridge();
+  }
+  aClient->FlushAllImages();
+  EndTransaction();
+}
+
+void ImageBridgeChild::FlushAllImages(ImageClient* aClient,
+                                      ImageContainer* aContainer) {
+  MOZ_ASSERT(aClient);
+  MOZ_ASSERT(!InImageBridgeChildThread());
+
+  if (InImageBridgeChildThread()) {
+    NS_ERROR(
+        "ImageBridgeChild::FlushAllImages() is called on ImageBridge thread.");
+    return;
+  }
+
+  SynchronousTask task("FlushAllImages Lock");
+
+  // RefPtrs on arguments are not needed since this dispatches synchronously.
+  RefPtr<Runnable> runnable = WrapRunnable(
+      RefPtr<ImageBridgeChild>(this), &ImageBridgeChild::FlushAllImagesSync,
+      &task, aClient, aContainer);
+  GetThread()->Dispatch(runnable.forget());
+
+  task.Wait();
+}
+
+void ImageBridgeChild::SyncWithCompositor(const Maybe<uint64_t>& aWindowID) {
+  if (NS_WARN_IF(InImageBridgeChildThread())) {
+    MOZ_ASSERT_UNREACHABLE("Cannot call on ImageBridge thread!");
+    return;
+  }
+
+  if (!aWindowID) {
+    return;
+  }
+
+  const auto fnSyncWithWindow = [&]() {
+    if (auto* window = nsGlobalWindowInner::GetInnerWindowWithId(*aWindowID)) {
+      if (auto* widget = window->GetNearestWidget()) {
+        if (auto* renderer = widget->GetWindowRenderer()) {
+          if (auto* kc = renderer->AsKnowsCompositor()) {
+            kc->SyncWithCompositor();
+          }
+        }
+      }
+    }
+  };
+
+  if (NS_IsMainThread()) {
+    fnSyncWithWindow();
+    return;
+  }
+
+  SynchronousTask task("SyncWithCompositor Lock");
+  RefPtr<Runnable> runnable =
+      NS_NewRunnableFunction("ImageBridgeChild::SyncWithCompositor", [&]() {
+        AutoCompleteTask complete(&task);
+        fnSyncWithWindow();
+      });
+  NS_DispatchToMainThread(runnable.forget());
+  task.Wait();
+}
+
+void ImageBridgeChild::BeginTransaction() {
+  MOZ_ASSERT(CanSend());
+  MOZ_ASSERT(mTxn->Finished(), "uncommitted txn?");
+  UpdateFwdTransactionId();
+  mTxn->Begin();
+}
+
+void ImageBridgeChild::EndTransaction() {
+  MOZ_ASSERT(CanSend());
+  MOZ_ASSERT(!mTxn->Finished(), "forgot BeginTransaction?");
+
+  AutoEndTransaction _(mTxn);
+
+  if (mTxn->IsEmpty()) {
+    return;
+  }
+
+  AutoTArray<CompositableOperation, 10> cset;
+  cset.SetCapacity(mTxn->mOperations.size());
+  if (!mTxn->mOperations.empty()) {
+    cset.AppendElements(&mTxn->mOperations.front(), mTxn->mOperations.size());
+  }
+
+  if (!SendUpdate(cset, mTxn->mDestroyedActors, GetFwdTransactionId())) {
+    NS_WARNING("could not send async texture transaction");
+    return;
+  }
+}
+
+bool ImageBridgeChild::InitForContent(Endpoint<PImageBridgeChild>&& aEndpoint,
+                                      uint32_t aNamespace) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  gfxPlatform::GetPlatform();
+
+  if (!sImageBridgeChildThread) {
+    nsCOMPtr<nsIThread> thread;
+    nsresult rv = NS_NewNamedThread("ImageBridgeChld", getter_AddRefs(thread));
+    MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv),
+                       "Failed to start ImageBridgeChild thread!");
+    sImageBridgeChildThread = thread.forget();
+  }
+
+  RefPtr<ImageBridgeChild> child = new ImageBridgeChild(aNamespace);
+
+  child->GetThread()->Dispatch(NS_NewRunnableFunction(
+      "layers::ImageBridgeChild::Bind",
+      [child, endpoint = std::move(aEndpoint)]() mutable {
+        child->Bind(std::move(endpoint));
+      }));
+
+  // Assign this after so other threads can't post messages before we connect to
+  // IPDL.
+  {
+    StaticMutexAutoLock lock(sImageBridgeSingletonLock);
+    sImageBridgeChildSingleton = child;
+  }
+
+  return true;
+}
+
+bool ImageBridgeChild::ReinitForContent(Endpoint<PImageBridgeChild>&& aEndpoint,
+                                        uint32_t aNamespace) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Note that at this point, ActorDestroy may not have been called yet,
+  // meaning mCanSend is still true. In this case we will try to send a
+  // synchronous WillClose message to the parent, and will certainly get a
+  // false result and a MsgDropped processing error. This is okay.
+  ShutdownSingleton();
+
+  return InitForContent(std::move(aEndpoint), aNamespace);
+}
+
+void ImageBridgeChild::Bind(Endpoint<PImageBridgeChild>&& aEndpoint) {
+  if (!aEndpoint.Bind(this)) {
+    return;
+  }
+
+  mSectionAllocator = MakeUnique<FixedSizeSmallShmemSectionAllocator>(this);
+  mCanSend = true;
+}
+
+void ImageBridgeChild::BindSameProcess(RefPtr<ImageBridgeParent> aParent) {
+  Open(aParent, aParent->GetThread(), mozilla::ipc::ChildSide);
+
+  mSectionAllocator = MakeUnique<FixedSizeSmallShmemSectionAllocator>(this);
+  mCanSend = true;
+}
+
+/* static */
+void ImageBridgeChild::ShutDown() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  ShutdownSingleton();
+
+  if (sImageBridgeChildThread) {
+    sImageBridgeChildThread->Shutdown();
+    sImageBridgeChildThread = nullptr;
+  }
+}
+
+/* static */
+void ImageBridgeChild::ShutdownSingleton() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (RefPtr<ImageBridgeChild> child = GetSingleton()) {
+    child->WillShutdown();
+
+    StaticMutexAutoLock lock(sImageBridgeSingletonLock);
+    sImageBridgeChildSingleton = nullptr;
+  }
+}
+
+void ImageBridgeChild::WillShutdown() {
+  {
+    SynchronousTask task("ImageBridge ShutdownStep1 lock");
+
+    RefPtr<Runnable> runnable =
+        WrapRunnable(RefPtr<ImageBridgeChild>(this),
+                     &ImageBridgeChild::ShutdownStep1, &task);
+    GetThread()->Dispatch(runnable.forget());
+
+    task.Wait();
+  }
+
+  {
+    SynchronousTask task("ImageBridge ShutdownStep2 lock");
+
+    RefPtr<Runnable> runnable =
+        WrapRunnable(RefPtr<ImageBridgeChild>(this),
+                     &ImageBridgeChild::ShutdownStep2, &task);
+    GetThread()->Dispatch(runnable.forget());
+
+    task.Wait();
+  }
+}
+
+void ImageBridgeChild::InitSameProcess(uint32_t aNamespace) {
+  NS_ASSERTION(NS_IsMainThread(), "Should be on the main Thread!");
+
+  MOZ_ASSERT(!sImageBridgeChildSingleton);
+  MOZ_ASSERT(!sImageBridgeChildThread);
+
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("ImageBridgeChld", getter_AddRefs(thread));
+  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv),
+                     "Failed to start ImageBridgeChild thread!");
+  sImageBridgeChildThread = thread.forget();
+
+  RefPtr<ImageBridgeChild> child = new ImageBridgeChild(aNamespace);
+  RefPtr<ImageBridgeParent> parent = ImageBridgeParent::CreateSameProcess();
+
+  RefPtr<Runnable> runnable =
+      WrapRunnable(child, &ImageBridgeChild::BindSameProcess, parent);
+  child->GetThread()->Dispatch(runnable.forget());
+
+  // Assign this after so other threads can't post messages before we connect to
+  // IPDL.
+  {
+    StaticMutexAutoLock lock(sImageBridgeSingletonLock);
+    sImageBridgeChildSingleton = child;
+  }
+}
+
+/* static */
+void ImageBridgeChild::InitWithGPUProcess(
+    Endpoint<PImageBridgeChild>&& aEndpoint, uint32_t aNamespace) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sImageBridgeChildSingleton);
+  MOZ_ASSERT(!sImageBridgeChildThread);
+
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("ImageBridgeChld", getter_AddRefs(thread));
+  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv),
+                     "Failed to start ImageBridgeChild thread!");
+  sImageBridgeChildThread = thread.forget();
+
+  RefPtr<ImageBridgeChild> child = new ImageBridgeChild(aNamespace);
+
+  child->GetThread()->Dispatch(NS_NewRunnableFunction(
+      "layers::ImageBridgeChild::Bind",
+      [child, endpoint = std::move(aEndpoint)]() mutable {
+        child->Bind(std::move(endpoint));
+      }));
+
+  // Assign this after so other threads can't post messages before we connect to
+  // IPDL.
+  {
+    StaticMutexAutoLock lock(sImageBridgeSingletonLock);
+    sImageBridgeChildSingleton = child;
+  }
+}
+
+bool InImageBridgeChildThread() {
+  return sImageBridgeChildThread &&
+         sImageBridgeChildThread->IsOnCurrentThread();
+}
+
+FixedSizeSmallShmemSectionAllocator* ImageBridgeChild::GetTileLockAllocator() {
+  return mSectionAllocator.get();
+}
+
+nsISerialEventTarget* ImageBridgeChild::GetThread() const {
+  return sImageBridgeChildThread;
+}
+
+/* static */
+void ImageBridgeChild::IdentifyCompositorTextureHost(
+    const TextureFactoryIdentifier& aIdentifier) {
+  if (RefPtr<ImageBridgeChild> child = GetSingleton()) {
+    child->UpdateTextureFactoryIdentifier(aIdentifier);
+  }
+}
+
+void ImageBridgeChild::UpdateTextureFactoryIdentifier(
+    const TextureFactoryIdentifier& aIdentifier) {
+  IdentifyTextureHost(aIdentifier);
+}
+
+RefPtr<ImageClient> ImageBridgeChild::CreateImageClient(
+    CompositableType aType, ImageContainer* aImageContainer) {
+  if (InImageBridgeChildThread()) {
+    return CreateImageClientNow(aType, aImageContainer);
+  }
+
+  SynchronousTask task("CreateImageClient Lock");
+
+  RefPtr<ImageClient> result = nullptr;
+
+  RefPtr<Runnable> runnable = WrapRunnable(
+      RefPtr<ImageBridgeChild>(this), &ImageBridgeChild::CreateImageClientSync,
+      &task, &result, aType, aImageContainer);
+  GetThread()->Dispatch(runnable.forget());
+
+  task.Wait();
+
+  return result;
+}
+
+RefPtr<ImageClient> ImageBridgeChild::CreateImageClientNow(
+    CompositableType aType, ImageContainer* aImageContainer) {
+  MOZ_ASSERT(InImageBridgeChildThread());
+  if (!CanSend()) {
+    return nullptr;
+  }
+
+  RefPtr<ImageClient> client =
+      ImageClient::CreateImageClient(aType, this, TextureFlags::NO_FLAGS);
+  MOZ_ASSERT(client, "failed to create ImageClient");
+  if (client) {
+    client->Connect(aImageContainer);
+  }
+  return client;
+}
+
+bool ImageBridgeChild::AllocUnsafeShmem(size_t aSize, ipc::Shmem* aShmem) {
+  if (!InImageBridgeChildThread()) {
+    return DispatchAllocShmemInternal(aSize, aShmem,
+                                      true);  // true: unsafe
+  }
+
+  if (!CanSend()) {
+    return false;
+  }
+  return PImageBridgeChild::AllocUnsafeShmem(aSize, aShmem);
+}
+
+bool ImageBridgeChild::AllocShmem(size_t aSize, ipc::Shmem* aShmem) {
+  if (!InImageBridgeChildThread()) {
+    return DispatchAllocShmemInternal(aSize, aShmem,
+                                      false);  // false: unsafe
+  }
+
+  if (!CanSend()) {
+    return false;
+  }
+  return PImageBridgeChild::AllocShmem(aSize, aShmem);
+}
+
+void ImageBridgeChild::ProxyAllocShmemNow(SynchronousTask* aTask, size_t aSize,
+                                          ipc::Shmem* aShmem, bool aUnsafe,
+                                          bool* aSuccess) {
+  AutoCompleteTask complete(aTask);
+
+  if (!CanSend()) {
+    return;
+  }
+
+  bool ok = false;
+  if (aUnsafe) {
+    ok = AllocUnsafeShmem(aSize, aShmem);
+  } else {
+    ok = AllocShmem(aSize, aShmem);
+  }
+  *aSuccess = ok;
+}
+
+bool ImageBridgeChild::DispatchAllocShmemInternal(size_t aSize,
+                                                  ipc::Shmem* aShmem,
+                                                  bool aUnsafe) {
+  SynchronousTask task("AllocatorProxy alloc");
+
+  bool success = false;
+  RefPtr<Runnable> runnable = WrapRunnable(
+      RefPtr<ImageBridgeChild>(this), &ImageBridgeChild::ProxyAllocShmemNow,
+      &task, aSize, aShmem, aUnsafe, &success);
+  GetThread()->Dispatch(runnable.forget());
+
+  task.Wait();
+
+  return success;
+}
+
+void ImageBridgeChild::ProxyDeallocShmemNow(SynchronousTask* aTask,
+                                            ipc::Shmem* aShmem, bool* aResult) {
+  AutoCompleteTask complete(aTask);
+
+  if (!CanSend()) {
+    return;
+  }
+  *aResult = DeallocShmem(*aShmem);
+}
+
+bool ImageBridgeChild::DeallocShmem(ipc::Shmem& aShmem) {
+  if (InImageBridgeChildThread()) {
+    if (!CanSend()) {
+      return false;
+    }
+    return PImageBridgeChild::DeallocShmem(aShmem);
+  }
+
+  // If we can't post a task, then we definitely cannot send, so there's
+  // no reason to queue up this send.
+  if (!CanPostTask()) {
+    return false;
+  }
+
+  SynchronousTask task("AllocatorProxy Dealloc");
+  bool result = false;
+
+  RefPtr<Runnable> runnable = WrapRunnable(
+      RefPtr<ImageBridgeChild>(this), &ImageBridgeChild::ProxyDeallocShmemNow,
+      &task, &aShmem, &result);
+  GetThread()->Dispatch(runnable.forget());
+
+  task.Wait();
+  return result;
+}
+
+PTextureChild* ImageBridgeChild::AllocPTextureChild(
+    const SurfaceDescriptor&, ReadLockDescriptor&, const LayersBackend&,
+    const TextureFlags&, const uint64_t& aSerial,
+    const wr::MaybeExternalImageId& aExternalImageId) {
+  MOZ_ASSERT(CanSend());
+  return TextureClient::CreateIPDLActor();
+}
+
+bool ImageBridgeChild::DeallocPTextureChild(PTextureChild* actor) {
+  return TextureClient::DestroyIPDLActor(actor);
+}
+
+PMediaSystemResourceManagerChild*
+ImageBridgeChild::AllocPMediaSystemResourceManagerChild() {
+  MOZ_ASSERT(CanSend());
+  return new mozilla::media::MediaSystemResourceManagerChild();
+}
+
+bool ImageBridgeChild::DeallocPMediaSystemResourceManagerChild(
+    PMediaSystemResourceManagerChild* aActor) {
+  MOZ_ASSERT(aActor);
+  delete static_cast<mozilla::media::MediaSystemResourceManagerChild*>(aActor);
+  return true;
+}
+
+mozilla::ipc::IPCResult ImageBridgeChild::RecvParentAsyncMessages(
+    nsTArray<AsyncParentMessageData>&& aMessages) {
+  for (AsyncParentMessageArray::index_type i = 0; i < aMessages.Length(); ++i) {
+    const AsyncParentMessageData& message = aMessages[i];
+
+    switch (message.type()) {
+      case AsyncParentMessageData::TOpNotifyNotUsed: {
+        const OpNotifyNotUsed& op = message.get_OpNotifyNotUsed();
+        NotifyNotUsed(op.TextureId(), op.fwdTransactionId());
+        break;
+      }
+      default:
+        NS_ERROR("unknown AsyncParentMessageData type");
+        return IPC_FAIL_NO_REASON(this);
+    }
+  }
+  return IPC_OK();
+}
+
+RefPtr<ImageContainerListener> ImageBridgeChild::FindListener(
+    const CompositableHandle& aHandle) {
+  RefPtr<ImageContainerListener> listener;
+  MutexAutoLock lock(mContainerMapLock);
+  auto it = mImageContainerListeners.find(aHandle.Value());
+  if (it != mImageContainerListeners.end()) {
+    listener = it->second;
+  }
+  return listener;
+}
+
+mozilla::ipc::IPCResult ImageBridgeChild::RecvDidComposite(
+    nsTArray<ImageCompositeNotification>&& aNotifications) {
+  for (auto& n : aNotifications) {
+    RefPtr<ImageContainerListener> listener = FindListener(n.compositable());
+    if (listener) {
+      listener->NotifyComposite(n);
+    }
+  }
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ImageBridgeChild::RecvReportFramesDropped(
+    const CompositableHandle& aHandle, const uint32_t& aFrames) {
+  RefPtr<ImageContainerListener> listener = FindListener(aHandle);
+  if (listener) {
+    listener->NotifyDropped(aFrames);
+  }
+
+  return IPC_OK();
+}
+
+PTextureChild* ImageBridgeChild::CreateTexture(
+    const SurfaceDescriptor& aSharedData, ReadLockDescriptor&& aReadLock,
+    LayersBackend aLayersBackend, TextureFlags aFlags,
+    const dom::ContentParentId& aContentId, uint64_t aSerial,
+    wr::MaybeExternalImageId& aExternalImageId) {
+  MOZ_ASSERT(CanSend());
+  return SendPTextureConstructor(aSharedData, std::move(aReadLock),
+                                 aLayersBackend, aFlags, aSerial,
+                                 aExternalImageId);
+}
+
+static bool IBCAddOpDestroy(CompositableTransaction* aTxn,
+                            const OpDestroy& op) {
+  if (aTxn->Finished()) {
+    return false;
+  }
+
+  aTxn->mDestroyedActors.AppendElement(op);
+  return true;
+}
+
+bool ImageBridgeChild::DestroyInTransaction(PTextureChild* aTexture) {
+  return IBCAddOpDestroy(mTxn, OpDestroy(WrapNotNull(aTexture)));
+}
+
+bool ImageBridgeChild::DestroyInTransaction(const CompositableHandle& aHandle) {
+  return IBCAddOpDestroy(mTxn, OpDestroy(aHandle));
+}
+
+void ImageBridgeChild::RemoveTextureFromCompositable(
+    CompositableClient* aCompositable, TextureClient* aTexture) {
+  MOZ_ASSERT(CanSend());
+  MOZ_ASSERT(aTexture);
+  MOZ_ASSERT(aTexture->IsSharedWithCompositor());
+  MOZ_ASSERT(aCompositable->IsConnected());
+  if (!aTexture || !aTexture->IsSharedWithCompositor() ||
+      !aCompositable->IsConnected()) {
+    return;
+  }
+
+  mTxn->AddNoSwapEdit(CompositableOperation(
+      aCompositable->GetIPCHandle(),
+      OpRemoveTexture(WrapNotNull(aTexture->GetIPDLActor()))));
+}
+
+bool ImageBridgeChild::IsSameProcess() const {
+  return OtherPid() == base::GetCurrentProcId();
+}
+
+bool ImageBridgeChild::CanPostTask() const {
+  // During shutdown, the cycle collector may free objects that are holding a
+  // reference to ImageBridgeChild. Since this happens on the main thread,
+  // ImageBridgeChild will attempt to post a task to the ImageBridge thread.
+  // However the thread manager has already been shut down, so the task cannot
+  // post.
+  //
+  // It's okay if this races. We only care about the shutdown case where
+  // everything's happening on the main thread. Even if it races outside of
+  // shutdown, it's still harmless to post the task, since the task must
+  // check CanSend().
+  return !mDestroyed;
+}
+
+void ImageBridgeChild::ReleaseCompositable(const CompositableHandle& aHandle) {
+  if (!InImageBridgeChildThread()) {
+    // If we can't post a task, then we definitely cannot send, so there's
+    // no reason to queue up this send.
+    if (!CanPostTask()) {
+      return;
+    }
+
+    RefPtr<Runnable> runnable =
+        WrapRunnable(RefPtr<ImageBridgeChild>(this),
+                     &ImageBridgeChild::ReleaseCompositable, aHandle);
+    GetThread()->Dispatch(runnable.forget());
+    return;
+  }
+
+  if (!CanSend()) {
+    return;
+  }
+
+  if (!DestroyInTransaction(aHandle)) {
+    SendReleaseCompositable(aHandle);
+  }
+
+  {
+    MutexAutoLock lock(mContainerMapLock);
+    mImageContainerListeners.erase(aHandle.Value());
+  }
+}
+
+bool ImageBridgeChild::CanSend() const {
+  MOZ_ASSERT(InImageBridgeChildThread());
+  return mCanSend;
+}
+
+void ImageBridgeChild::HandleFatalError(const char* aMsg) {
+  dom::ContentChild::FatalErrorIfNotUsingGPUProcess(aMsg, OtherPid());
+}
+
+wr::MaybeExternalImageId ImageBridgeChild::GetNextExternalImageId() {
+  static uint32_t sNextID = 1;
+  ++sNextID;
+  MOZ_RELEASE_ASSERT(sNextID != UINT32_MAX);
+
+  uint64_t imageId = mNamespace;
+  imageId = imageId << 32 | sNextID;
+  return Some(wr::ToExternalImageId(imageId));
+}
+
+}  // namespace layers
+}  // namespace mozilla