Bug 1855742 - Part 3. Implement ImageBridgeChild::GetTileLockAllocato…

…r. r=gfx-reviewers,lsalzman

This patch adds support for allocationg shmem sections for
ImageBridgeChild. The recording infrastructure depends on it.

Differential Revision: https://phabricator.services.mozilla.com/D189528

gfx/layers/ipc/ISurfaceAllocator.cpp

@@ -74,6 +74,7 @@ bool FixedSizeSmallShmemSectionAllocator::AllocShmemSection(
     uint32_t aSize, ShmemSection* aShmemSection) {
   // For now we only support sizes of 4. If we want to support different sizes
   // some more complicated bookkeeping should be added.
+  NS_ASSERT_OWNINGTHREAD(FixedSizeSmallShmemSectionAllocator);
   MOZ_ASSERT(aSize == sSupportedBlockSize);
   MOZ_ASSERT(aShmemSection);
 
@@ -178,6 +179,8 @@ void FixedSizeSmallShmemSectionAllocator::FreeShmemSection(
 
 void FixedSizeSmallShmemSectionAllocator::DeallocShmemSection(
     mozilla::layers::ShmemSection& aShmemSection) {
+  NS_ASSERT_OWNINGTHREAD(FixedSizeSmallShmemSectionAllocator);
+
   if (!IPCOpen()) {
     gfxCriticalNote << "Attempt to dealloc a ShmemSections after shutdown.";
     return;
@@ -188,6 +191,8 @@ void FixedSizeSmallShmemSectionAllocator::DeallocShmemSection(
 }
 
 void FixedSizeSmallShmemSectionAllocator::ShrinkShmemSectionHeap() {
+  NS_ASSERT_OWNINGTHREAD(FixedSizeSmallShmemSectionAllocator);
+
   if (!IPCOpen()) {
     mUsedShmems.clear();
     return;

gfx/layers/ipc/ISurfaceAllocator.h

@@ -245,6 +245,8 @@ class GfxMemoryImageReporter final : public nsIMemoryReporter {
 /// copy-on-write locks for now).
 class FixedSizeSmallShmemSectionAllocator final : public ShmemSectionAllocator {
  public:
+  NS_DECL_OWNINGTHREAD
+
   enum AllocationStatus { STATUS_ALLOCATED, STATUS_FREED };
 
   struct ShmemSectionHeapHeader {

gfx/layers/ipc/ImageBridgeChild.cpp

@@ -220,6 +220,9 @@ void ImageBridgeChild::ShutdownStep2(SynchronousTask* aTask) {
 
   MOZ_ASSERT(InImageBridgeChildThread(),
              "Should be in ImageBridgeChild thread.");
+
+  mSectionAllocator = nullptr;
+
   if (!mDestroyed) {
     Close();
   }
@@ -483,12 +486,14 @@ void ImageBridgeChild::Bind(Endpoint<PImageBridgeChild>&& aEndpoint) {
     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;
 }
 
@@ -601,6 +606,10 @@ bool InImageBridgeChildThread() {
          sImageBridgeChildThread->IsOnCurrentThread();
 }
 
+FixedSizeSmallShmemSectionAllocator* ImageBridgeChild::GetTileLockAllocator() {
+  return mSectionAllocator.get();
+}
+
 nsISerialEventTarget* ImageBridgeChild::GetThread() const {
   return sImageBridgeChildThread;
 }

gfx/layers/ipc/ImageBridgeChild.h

@@ -20,6 +20,7 @@
 #include "mozilla/layers/PImageBridgeChild.h"
 #include "mozilla/layers/TextureForwarder.h"
 #include "mozilla/Mutex.h"
+#include "mozilla/UniquePtr.h"
 #include "mozilla/webrender/WebRenderTypes.h"
 #include "nsRegion.h"  // for nsIntRegion
 #include "mozilla/gfx/Rect.h"
@@ -154,6 +155,8 @@ class ImageBridgeChild final : public PImageBridgeChild,
   void BeginTransaction();
   void EndTransaction();
 
+  FixedSizeSmallShmemSectionAllocator* GetTileLockAllocator() override;
+
   /**
    * Returns the ImageBridgeChild's thread.
    *
@@ -342,8 +345,9 @@ class ImageBridgeChild final : public PImageBridgeChild,
   uint32_t mNamespace;
 
   CompositableTransaction* mTxn;
+  UniquePtr<FixedSizeSmallShmemSectionAllocator> mSectionAllocator;
 
-  bool mCanSend;
+  mozilla::Atomic<bool> mCanSend;
   mozilla::Atomic<bool> mDestroyed;
 
   /**