Bug 1037704 - Add polling support to ShSurf. - r=mattwoodrow

gfx/gl/SharedSurface.h

@@ -80,6 +80,7 @@ protected:
 public:
     virtual void Fence() = 0;
     virtual bool WaitSync() = 0;
+    virtual bool PollSync() = 0;
 
     // This function waits until the buffer is no longer being used.
     // To optimize the performance, some implementaions recycle SharedSurfaces

gfx/gl/SharedSurfaceANGLE.cpp

@@ -51,20 +51,12 @@ SharedSurface_ANGLEShareHandle::UnlockProdImpl()
 {
 }
 
-
 void
 SharedSurface_ANGLEShareHandle::Fence()
 {
     mGL->fFinish();
 }
 
-bool
-SharedSurface_ANGLEShareHandle::WaitSync()
-{
-    // Since we glFinish in Fence(), we're always going to be resolved here.
-    return true;
-}
-
 static void
 FillPBufferAttribs_ByBits(nsTArray<EGLint>& aAttrs,
                           int redBits, int greenBits,

gfx/gl/SharedSurfaceANGLE.h

@@ -64,7 +64,8 @@ public:
     virtual void UnlockProdImpl() MOZ_OVERRIDE;
 
     virtual void Fence() MOZ_OVERRIDE;
-    virtual bool WaitSync() MOZ_OVERRIDE;
+    virtual bool WaitSync() MOZ_OVERRIDE { return true; } // Fence is glFinish.
+    virtual bool PollSync() MOZ_OVERRIDE { return true; }
 
     // Implementation-specific functions below:
     HANDLE GetShareHandle() {

gfx/gl/SharedSurfaceEGL.cpp

@@ -162,6 +162,30 @@ SharedSurface_EGLImage::WaitSync()
     return true;
 }
 
+bool
+SharedSurface_EGLImage::PollSync()
+{
+    MutexAutoLock lock(mMutex);
+    if (!mSync) {
+        // We must not be needed.
+        return true;
+    }
+    MOZ_ASSERT(mEGL->IsExtensionSupported(GLLibraryEGL::KHR_fence_sync));
+
+    EGLint status = 0;
+    MOZ_ALWAYS_TRUE( mEGL->fGetSyncAttrib(mEGL->Display(),
+                                         mSync,
+                                         LOCAL_EGL_SYNC_STATUS_KHR,
+                                         &status) );
+    if (status != LOCAL_EGL_SIGNALED_KHR) {
+        return false;
+    }
+
+    MOZ_ALWAYS_TRUE( mEGL->fDestroySync(mEGL->Display(), mSync) );
+    mSync = 0;
+
+    return true;
+}
 
 EGLDisplay
 SharedSurface_EGLImage::Display() const

gfx/gl/SharedSurfaceEGL.h

@@ -64,9 +64,9 @@ public:
     virtual void LockProdImpl() MOZ_OVERRIDE {}
     virtual void UnlockProdImpl() MOZ_OVERRIDE {}
 
-
     virtual void Fence() MOZ_OVERRIDE;
     virtual bool WaitSync() MOZ_OVERRIDE;
+    virtual bool PollSync() MOZ_OVERRIDE;
 
     virtual GLuint ProdTexture() MOZ_OVERRIDE {
       return mProdTex;

gfx/gl/SharedSurfaceGL.cpp

@@ -169,7 +169,8 @@ SharedSurface_GLTexture::WaitSync()
 {
     MutexAutoLock lock(mMutex);
     if (!mSync) {
-        // We must have used glFinish instead of glFenceSync.
+        // We either used glFinish, or we passed this fence already.
+        // (PollSync/WaitSync returned true previously)
         return true;
     }
 
@@ -185,6 +186,34 @@ SharedSurface_GLTexture::WaitSync()
     return true;
 }
 
+bool
+SharedSurface_GLTexture::PollSync()
+{
+    MutexAutoLock lock(mMutex);
+    if (!mSync) {
+        // We either used glFinish, or we passed this fence already.
+        // (PollSync/WaitSync returned true previously)
+        return true;
+    }
+
+    mConsGL->MakeCurrent();
+    MOZ_ASSERT(mConsGL->IsExtensionSupported(GLContext::ARB_sync));
+
+    GLint status = 0;
+    mConsGL->fGetSynciv(mSync,
+                        LOCAL_GL_SYNC_STATUS,
+                        1,
+                        nullptr,
+                        &status);
+    if (status != LOCAL_GL_SIGNALED)
+        return false;
+
+    mConsGL->fDeleteSync(mSync);
+    mSync = 0;
+
+    return true;
+}
+
 GLuint
 SharedSurface_GLTexture::ConsTexture(GLContext* consGL)
 {

gfx/gl/SharedSurfaceGL.h

@@ -70,6 +70,7 @@ public:
         // Since we already store the data in Fence, we're always done already.
         return true;
     }
+    virtual bool PollSync() MOZ_OVERRIDE { return true; }
 
     virtual GLuint ProdTexture() MOZ_OVERRIDE {
         return mTex;
@@ -146,10 +147,9 @@ public:
     virtual void LockProdImpl() MOZ_OVERRIDE {}
     virtual void UnlockProdImpl() MOZ_OVERRIDE {}
 
-
     virtual void Fence() MOZ_OVERRIDE;
     virtual bool WaitSync() MOZ_OVERRIDE;
-
+    virtual bool PollSync() MOZ_OVERRIDE;
 
     virtual GLuint ProdTexture() MOZ_OVERRIDE {
         return mTex;

gfx/gl/SharedSurfaceGralloc.cpp

@@ -251,6 +251,30 @@ SharedSurface_Gralloc::WaitSync()
     return true;
 }
 
+bool
+SharedSurface_Gralloc::PollSync()
+{
+    if (!mSync) {
+        // We must not be needed.
+        return true;
+    }
+    MOZ_ASSERT(mEGL->IsExtensionSupported(GLLibraryEGL::KHR_fence_sync));
+
+    EGLint status = 0;
+    MOZ_ALWAYS_TRUE( mEGL->fGetSyncAttrib(mEGL->Display(),
+                                         mSync,
+                                         LOCAL_EGL_SYNC_STATUS_KHR,
+                                         &status) );
+    if (status != LOCAL_EGL_SIGNALED_KHR) {
+        return false;
+    }
+
+    MOZ_ALWAYS_TRUE( mEGL->fDestroySync(mEGL->Display(), mSync) );
+    mSync = 0;
+
+    return true;
+}
+
 void
 SharedSurface_Gralloc::WaitForBufferOwnership()
 {

gfx/gl/SharedSurfaceGralloc.h

@@ -57,6 +57,7 @@ public:
 
     virtual void Fence() MOZ_OVERRIDE;
     virtual bool WaitSync() MOZ_OVERRIDE;
+    virtual bool PollSync() MOZ_OVERRIDE;
 
     virtual void WaitForBufferOwnership() MOZ_OVERRIDE;
 

gfx/gl/SharedSurfaceIO.h

@@ -26,6 +26,7 @@ public:
 
     virtual void Fence() MOZ_OVERRIDE;
     virtual bool WaitSync() MOZ_OVERRIDE { return true; }
+    virtual bool PollSync() MOZ_OVERRIDE { return true; }
 
     virtual bool ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height,
                             GLenum format, GLenum type, GLvoid *pixels) MOZ_OVERRIDE;