Bug 999694 - Use fence objects in SharedSurfaceGralloc, r=jgilbert

gfx/gl/GLLibraryEGL.cpp

@@ -31,6 +31,7 @@ static const char *sEGLExtensionNames[] = {
     "EGL_EXT_create_context_robustness",
     "EGL_KHR_image",
     "EGL_KHR_fence_sync",
+    "EGL_ANDROID_native_fence_sync",
     nullptr
 };
 
@@ -208,6 +209,21 @@ GLLibraryEGL::EnsureInitialized()
         return false;
     }
 
+    GLLibraryLoader::SymLoadStruct optionalSymbols[] = {
+        // On Android 4.2 and up, certain features like ANDROID_native_fence_sync
+        // can only be queried by using a special eglQueryString.
+        { (PRFuncPtr*) &mSymbols.fQueryStringImplementationANDROID,
+          { "_Z35eglQueryStringImplementationANDROIDPvi", nullptr } },
+        { nullptr, { nullptr } }
+    };
+
+    GLLibraryLoader::LoadSymbols(mEGLLibrary, &optionalSymbols[0]);
+
+#if defined(MOZ_WIDGET_GONK) && ANDROID_VERSION >= 17
+    MOZ_RELEASE_ASSERT(mSymbols.fQueryStringImplementationANDROID,
+                       "Couldn't find eglQueryStringImplementationANDROID");
+#endif
+
     mEGLDisplay = fGetDisplay(EGL_DEFAULT_DISPLAY);
     if (!fInitialize(mEGLDisplay, nullptr, nullptr))
         return false;

gfx/gl/GLLibraryEGL.h

@@ -117,6 +117,7 @@ public:
         EXT_create_context_robustness,
         KHR_image,
         KHR_fence_sync,
+        ANDROID_native_fence_sync,
         Extensions_Max
     };
 
@@ -296,7 +297,12 @@ public:
     const GLubyte* fQueryString(EGLDisplay dpy, EGLint name)
     {
         BEFORE_GL_CALL;
-        const GLubyte* b = mSymbols.fQueryString(dpy, name);
+        const GLubyte* b;
+        if (mSymbols.fQueryStringImplementationANDROID) {
+          b = mSymbols.fQueryStringImplementationANDROID(dpy, name);
+        } else {
+          b = mSymbols.fQueryString(dpy, name);
+        }
         AFTER_GL_CALL;
         return b;
     }
@@ -484,6 +490,7 @@ public:
         pfnCopyBuffers fCopyBuffers;
         typedef const GLubyte* (GLAPIENTRY * pfnQueryString)(EGLDisplay, EGLint name);
         pfnQueryString fQueryString;
+        pfnQueryString fQueryStringImplementationANDROID;
         typedef EGLBoolean (GLAPIENTRY * pfnQueryContext)(EGLDisplay dpy, EGLContext ctx,
                                                           EGLint attribute, EGLint *value);
         pfnQueryContext fQueryContext;

gfx/gl/SharedSurfaceGralloc.cpp

@@ -132,11 +132,46 @@ SharedSurface_Gralloc::~SharedSurface_Gralloc()
 
     mGL->MakeCurrent();
     mGL->fDeleteTextures(1, &mProdTex);
+
+    if (mSync) {
+        MOZ_ALWAYS_TRUE( mEGL->fDestroySync(mEGL->Display(), mSync) );
+        mSync = 0;
+    }
 }
 
 void
 SharedSurface_Gralloc::Fence()
 {
+    if (mSync) {
+        MOZ_ALWAYS_TRUE( mEGL->fDestroySync(mEGL->Display(), mSync) );
+        mSync = 0;
+    }
+
+    // When Android native fences are available, try
+    // them first since they're more likely to work.
+    // Android native fences are also likely to perform better.
+    if (mEGL->IsExtensionSupported(GLLibraryEGL::ANDROID_native_fence_sync)) {
+        mGL->MakeCurrent();
+        mSync = mEGL->fCreateSync(mEGL->Display(),
+                                  LOCAL_EGL_SYNC_NATIVE_FENCE_ANDROID,
+                                  nullptr);
+        if (mSync) {
+            mGL->fFlush();
+            return;
+        }
+    }
+
+    if (mEGL->IsExtensionSupported(GLLibraryEGL::KHR_fence_sync)) {
+        mGL->MakeCurrent();
+        mSync = mEGL->fCreateSync(mEGL->Display(),
+                                  LOCAL_EGL_SYNC_FENCE,
+                                  nullptr);
+        if (mSync) {
+            mGL->fFlush();
+            return;
+        }
+    }
+
     // We should be able to rely on genlock write locks/read locks.
     // But they're broken on some configs, and even a glFinish doesn't
     // work.  glReadPixels seems to, though.
@@ -150,6 +185,24 @@ SharedSurface_Gralloc::Fence()
 bool
 SharedSurface_Gralloc::WaitSync()
 {
+    if (!mSync) {
+        // We must not be needed.
+        return true;
+    }
+    MOZ_ASSERT(mEGL->IsExtensionSupported(GLLibraryEGL::KHR_fence_sync));
+
+    EGLint status = mEGL->fClientWaitSync(mEGL->Display(),
+                                          mSync,
+                                          0,
+                                          LOCAL_EGL_FOREVER);
+
+    if (status != LOCAL_EGL_CONDITION_SATISFIED) {
+        return false;
+    }
+
+    MOZ_ALWAYS_TRUE( mEGL->fDestroySync(mEGL->Display(), mSync) );
+    mSync = 0;
+
     return true;
 }
 

gfx/gl/SharedSurfaceGralloc.h

@@ -38,6 +38,7 @@ public:
 
 protected:
     GLLibraryEGL* const mEGL;
+    EGLSync mSync;
     RefPtr<layers::ISurfaceAllocator> mAllocator;
     RefPtr<layers::TextureClient> mTextureClient;
     const GLuint mProdTex;
@@ -55,6 +56,7 @@ protected:
                            size,
                            hasAlpha)
         , mEGL(egl)
+        , mSync(0)
         , mAllocator(allocator)
         , mTextureClient(textureClient)
         , mProdTex(prodTex)