Bug 874823 - Support unknown consumer for ShSurf_GLTex. - r=mattwoodrow

gfx/gl/SharedSurfaceGL.cpp

@@ -339,9 +339,10 @@ SharedSurface_GLTexture::~SharedSurface_GLTexture()
 void
 SharedSurface_GLTexture::Fence()
 {
+    MutexAutoLock lock(mMutex);
     mGL->MakeCurrent();
 
-    if (mGL->IsExtensionSupported(GLContext::ARB_sync)) {
+    if (mConsGL && mGL->IsExtensionSupported(GLContext::ARB_sync)) {
         if (mSync) {
             mGL->fDeleteSync(mSync);
             mSync = 0;
@@ -361,10 +362,13 @@ SharedSurface_GLTexture::Fence()
 bool
 SharedSurface_GLTexture::WaitSync()
 {
+    MutexAutoLock lock(mMutex);
     if (!mSync) {
         // We must have used glFinish instead of glFenceSync.
         return true;
     }
+
+    MOZ_ASSERT(mConsGL, "Did you forget to call a deferred `SetConsumerGL()`?");
     mConsGL->MakeCurrent();
     MOZ_ASSERT(mConsGL->IsExtensionSupported(GLContext::ARB_sync));
 
@@ -377,5 +381,13 @@ SharedSurface_GLTexture::WaitSync()
     return true;
 }
 
+void
+SharedSurface_GLTexture::SetConsumerGL(GLContext* consGL)
+{
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(consGL);
+    mConsGL = consGL;
+}
+
 } /* namespace gfx */
 } /* namespace mozilla */

gfx/gl/SharedSurfaceGL.h

@@ -12,6 +12,7 @@
 #include "GLContextTypes.h"
 #include "nsAutoPtr.h"
 #include "gfxASurface.h"
+#include "mozilla/Mutex.h"
 
 #include <queue>
 
@@ -192,9 +193,10 @@ public:
     }
 
 protected:
-    GLContext* const mConsGL;
+    GLContext* mConsGL;
     const GLuint mTex;
     GLsync mSync;
+    mutable Mutex mMutex;
 
     SharedSurface_GLTexture(GLContext* prodGL,
                             GLContext* consGL,
@@ -209,6 +211,7 @@ protected:
         , mConsGL(consGL)
         , mTex(tex)
         , mSync(0)
+        , mMutex("SharedSurface_GLTexture mutex")
     {
     }
 
@@ -226,6 +229,9 @@ public:
     virtual GLuint Texture() const {
         return mTex;
     }
+
+    // Custom:
+    void SetConsumerGL(GLContext* consGL);
 };
 
 class SurfaceFactory_GLTexture
@@ -235,12 +241,17 @@ protected:
     GLContext* const mConsGL;
 
 public:
+    // If we don't know `consGL` at construction time, use `nullptr`, and call
+    // `SetConsumerGL()` on each `SharedSurface_GLTexture` before calling its
+    // `WaitSync()`.
     SurfaceFactory_GLTexture(GLContext* prodGL,
                              GLContext* consGL,
                              const SurfaceCaps& caps)
         : SurfaceFactory_GL(prodGL, SharedSurfaceType::GLTextureShare, caps)
         , mConsGL(consGL)
-    {}
+    {
+        MOZ_ASSERT(consGL != prodGL);
+    }
 
     virtual SharedSurface* CreateShared(const gfxIntSize& size) {
         bool hasAlpha = mReadCaps.alpha;

gfx/layers/client/ClientCanvasLayer.cpp

@@ -42,7 +42,7 @@ ClientCanvasLayer::Initialize(const Data& aData)
         } else {
           // [Basic Layers, OMTC] WebGL layer init.
           // Well, this *should* work...
-          factory = new SurfaceFactory_GLTexture(mGLContext, mGLContext, screen->Caps());
+          factory = new SurfaceFactory_GLTexture(mGLContext, nullptr, screen->Caps());
         }
       }
     }

gfx/layers/opengl/TextureHostOGL.cpp

@@ -407,7 +407,9 @@ SurfaceStreamHostOGL::Lock()
   gfxImageSurface* toUpload = nullptr;
   switch (sharedSurf->Type()) {
     case SharedSurfaceType::GLTextureShare: {
-      mTextureHandle = SharedSurface_GLTexture::Cast(sharedSurf)->Texture();
+      SharedSurface_GLTexture* glTexSurf = SharedSurface_GLTexture::Cast(sharedSurf);
+      glTexSurf->SetConsumerGL(mGL);
+      mTextureHandle = glTexSurf->Texture();
       MOZ_ASSERT(mTextureHandle);
       mShaderProgram = sharedSurf->HasAlpha() ? RGBALayerProgramType
                                               : RGBXLayerProgramType;