Bug 1167235 - Part 2 - Detach DrawTarget snapshots before unlocking TextureClient. r=Bas

gfx/2d/2D.h

@@ -1175,6 +1175,17 @@ public:
     return mPermitSubpixelAA;
   }
 
+  /**
+   * Ensures that no snapshot is still pointing to this DrawTarget's surface data.
+   *
+   * This can be useful if the DrawTarget is wrapped around data that it does not
+   * own, and for some reason the owner of the data has to make it temporarily
+   * unavailable without the DrawTarget knowing about it.
+   * This can cause costly surface copies, so it should not be used without a
+   * a good reason.
+   */
+  virtual void DetachAllSnapshots() = 0;
+
 #ifdef USE_SKIA_GPU
   virtual bool InitWithGrContext(GrContext* aGrContext,
                                  const IntSize &aSize,

gfx/2d/DrawTargetCG.h

@@ -128,6 +128,7 @@ public:
   virtual DrawTargetType GetType() const override;
   virtual BackendType GetBackendType() const override;
   virtual already_AddRefed<SourceSurface> Snapshot() override;
+  virtual void DetachAllSnapshots() override { MarkChanged(); }
 
   virtual void DrawSurface(SourceSurface *aSurface,
                            const Rect &aDest,

gfx/2d/DrawTargetCairo.h

@@ -177,6 +177,8 @@ public:
 
   virtual void SetTransform(const Matrix& aTransform) override;
 
+  virtual void DetachAllSnapshots() override { MarkSnapshotIndependent(); }
+
   // Call to set up aContext for drawing (with the current transform, etc).
   // Pass the path you're going to be using if you have one.
   // Implicitly calls WillChange(aPath).

gfx/2d/DrawTargetCapture.cpp

@@ -45,6 +45,10 @@ DrawTargetCaptureImpl::Snapshot()
   return dt->Snapshot();
 }
 
+void
+DrawTargetCaptureImpl::DetachAllSnapshots()
+{}
+
 #define AppendCommand(arg) new (AppendToCommandList<arg>()) arg
 
 void

gfx/2d/DrawTargetCapture.h

@@ -28,6 +28,9 @@ public:
   virtual DrawTargetType GetType() const { return mRefDT->GetType(); }
 
   virtual already_AddRefed<SourceSurface> Snapshot();
+
+  virtual void DetachAllSnapshots();
+
   virtual IntSize GetSize() { return mSize; }
 
   virtual void Flush() {}

gfx/2d/DrawTargetD2D1.h

@@ -127,6 +127,8 @@ public:
 
   virtual void *GetNativeSurface(NativeSurfaceType aType) override { return nullptr; }
 
+  virtual void DetachAllSnapshots() override { MarkChanged(); }
+
   bool Init(const IntSize &aSize, SurfaceFormat aFormat);
   bool Init(ID3D11Texture2D* aTexture, SurfaceFormat aFormat);
   uint32_t GetByteSize() const;

gfx/2d/DrawTargetDual.cpp

@@ -86,6 +86,13 @@ public:
   bool mPatternsInitialized;
 };
 
+void
+DrawTargetDual::DetachAllSnapshots()
+{
+  mA->DetachAllSnapshots();
+  mB->DetachAllSnapshots();
+}
+
 void
 DrawTargetDual::DrawSurface(SourceSurface *aSurface, const Rect &aDest, const Rect &aSource,
                             const DrawSurfaceOptions &aSurfOptions, const DrawOptions &aOptions)

gfx/2d/DrawTargetDual.h

@@ -49,7 +49,9 @@ public:
     return MakeAndAddRef<SourceSurfaceDual>(mA, mB);
   }
   virtual IntSize GetSize() override { return mA->GetSize(); }
-     
+
+  virtual void DetachAllSnapshots() override;
+
   FORWARD_FUNCTION(Flush)
   FORWARD_FUNCTION1(PushClip, const Path *, aPath)
   FORWARD_FUNCTION1(PushClipRect, const Rect &, aRect)

gfx/2d/DrawTargetRecording.cpp

@@ -477,6 +477,12 @@ DrawTargetRecording::Snapshot()
   return retSurf.forget();
 }
 
+void
+DrawTargetRecording::DetachAllSnapshots()
+{
+  mFinalDT->DetachAllSnapshots();
+}
+
 void
 DrawTargetRecording::DrawSurface(SourceSurface *aSurface,
                                  const Rect &aDest,

gfx/2d/DrawTargetRecording.h

@@ -37,6 +37,8 @@ public:
 
   virtual already_AddRefed<SourceSurface> Snapshot() override;
 
+  virtual void DetachAllSnapshots() override;
+
   virtual IntSize GetSize() override { return mFinalDT->GetSize(); }
 
   /* Ensure that the DrawTarget backend has flushed all drawing operations to

gfx/2d/DrawTargetSkia.h

@@ -125,6 +125,7 @@ public:
   virtual already_AddRefed<FilterNode> CreateFilter(FilterType aType) override;
   virtual void SetTransform(const Matrix &aTransform) override;
   virtual void *GetNativeSurface(NativeSurfaceType aType) override;
+  virtual void DetachAllSnapshots() override { MarkChanged(); }
 
   bool Init(const IntSize &aSize, SurfaceFormat aFormat);
   void Init(unsigned char* aData, const IntSize &aSize, int32_t aStride, SurfaceFormat aFormat, bool aUninitialized = false);

gfx/2d/DrawTargetTiled.cpp

@@ -54,6 +54,10 @@ DrawTargetTiled::Snapshot()
   return MakeAndAddRef<SnapshotTiled>(mTiles, mRect);
 }
 
+void
+DrawTargetTiled::DetachAllSnapshots()
+{}
+
 // Skip the mClippedOut check since this is only used for Flush() which
 // should happen even if we're clipped.
 #define TILED_COMMAND(command) \

gfx/2d/DrawTargetTiled.h

@@ -41,6 +41,7 @@ public:
   virtual DrawTargetType GetType() const override { return mTiles[0].mDrawTarget->GetType(); }
   virtual BackendType GetBackendType() const override { return mTiles[0].mDrawTarget->GetBackendType(); }
   virtual already_AddRefed<SourceSurface> Snapshot() override;
+  virtual void DetachAllSnapshots() override;
   virtual IntSize GetSize() override {
     MOZ_ASSERT(mRect.width > 0 && mRect.height > 0);
     return IntSize(mRect.XMost(), mRect.YMost());

gfx/layers/client/TextureClient.cpp

@@ -494,7 +494,6 @@ TextureClient::Unlock()
   }
 
   if (mBorrowedDrawTarget) {
-    MOZ_ASSERT(mBorrowedDrawTarget->refCount() <= mExpectedDtRefs);
     if (mOpenMode & OpenMode::OPEN_WRITE) {
       mBorrowedDrawTarget->Flush();
       if (mReadbackSink && !mData->ReadBack(mReadbackSink)) {
@@ -505,6 +504,12 @@ TextureClient::Unlock()
         mReadbackSink->ProcessReadback(dataSurf);
       }
     }
+
+    mBorrowedDrawTarget->DetachAllSnapshots();
+    // If this assertion is hit, it means something is holding a strong reference
+    // to our DrawTarget externally, which is not allowed.
+    MOZ_ASSERT(mBorrowedDrawTarget->refCount() <= mExpectedDtRefs);
+
     mBorrowedDrawTarget = nullptr;
   }
 

gfx/layers/d3d11/TextureD3D11.cpp

@@ -397,6 +397,7 @@ D3D11TextureData::Create(IntSize aSize, SurfaceFormat aFormat, TextureAllocation
 void
 D3D11TextureData::Deallocate(ClientIPCAllocator* aAllocator)
 {
+  mDrawTarget = nullptr;
   mTexture = nullptr;
 }