Bug 1478754 - WebGL crash when webgl.enable-surface-texture is enabled on Android; r=jgilbert,rbarker

MozReview-Commit-ID: GBTvZiLspvP

gfx/gl/SharedSurface.h

@@ -132,6 +132,10 @@ public:
     // even when its buffer is still being used.
     virtual void WaitForBufferOwnership() {}
 
+    // Returns true if the buffer is available.
+    // You can call WaitForBufferOwnership to wait for availability.
+    virtual bool IsBufferAvailable() const { return true; }
+
     // For use when AttachType is correct.
     virtual GLenum ProdTextureTarget() const {
         MOZ_ASSERT(mAttachType == AttachmentType::GLTexture);

gfx/gl/SharedSurfaceEGL.cpp

@@ -272,6 +272,11 @@ SharedSurface_SurfaceTexture::WaitForBufferOwnership()
     mSurface->SetAvailable(true);
 }
 
+bool
+SharedSurface_SurfaceTexture::IsBufferAvailable() const {
+    return mSurface->GetAvailable();
+}
+
 bool
 SharedSurface_SurfaceTexture::ToSurfaceDescriptor(layers::SurfaceDescriptor* const out_descriptor)
 {

gfx/gl/SharedSurfaceEGL.h

@@ -174,6 +174,8 @@ public:
     virtual void Commit() override;
 
     virtual void WaitForBufferOwnership() override;
+
+    virtual bool IsBufferAvailable() const override;
 };
 
 

gfx/layers/client/CanvasClient.cpp

@@ -429,6 +429,11 @@ CanvasClientSharedSurface::UpdateRenderer(gfx::IntSize aSize, Renderer& aRendere
 
   SharedSurface* surf = mShSurfClient->Surf();
 
+  if (!surf->IsBufferAvailable()) {
+    NS_WARNING("SharedSurface buffer not available, skip update");
+    return;
+  }
+  
   // Readback if needed.
   mReadbackClient = nullptr;