Bug 844275 - Make the GLController a singleton instance. r=Cwiiis

mobile/android/base/gfx/GLController.java

@@ -14,10 +14,22 @@ import javax.microedition.khronos.egl.EGLContext;
 import javax.microedition.khronos.egl.EGLDisplay;
 import javax.microedition.khronos.egl.EGLSurface;
 
+/**
+ * This class is a singleton that tracks EGL and compositor things over
+ * the lifetime of Fennec running.
+ * We only ever create one C++ compositor over Fennec's lifetime, but
+ * most of the Java-side objects (e.g. LayerView, GeckoLayerClient,
+ * LayerRenderer) can all get destroyed and re-created if the GeckoApp
+ * activity is destroyed. This GLController is never destroyed, so that
+ * the mCompositorCreated field and other state variables are always
+ * accurate.
+ */
 public class GLController {
     private static final int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
     private static final String LOGTAG = "GeckoGLController";
 
+    private static GLController sInstance;
+
     private LayerView mView;
     private boolean mSurfaceValid;
     private int mWidth, mHeight;
@@ -41,19 +53,15 @@ public class GLController {
         EGL10.EGL_NONE
     };
 
-    GLController(LayerView view) {
-        mView = view;
-        mSurfaceValid = false;
+    private GLController() {
     }
 
-    /* This function is invoked by JNI */
-    void resumeCompositorIfValid() {
-        synchronized (this) {
-            if (!mSurfaceValid) {
-                return;
-            }
+    static GLController getInstance(LayerView view) {
+        if (sInstance == null) {
+            sInstance = new GLController();
         }
-        resumeCompositor(mWidth, mHeight);
+        sInstance.mView = view;
+        return sInstance;
     }
 
     /* Wait until we are allowed to use EGL functions on the Surface backing

mobile/android/base/gfx/LayerView.java

@@ -91,7 +91,7 @@ public class LayerView extends FrameLayout {
     public LayerView(Context context, AttributeSet attrs) {
         super(context, attrs);
 
-        mGLController = new GLController(this);
+        mGLController = GLController.getInstance(this);
         mPaintState = PAINT_START;
         mBackgroundColor = Color.WHITE;
     }

widget/android/AndroidBridge.cpp

@@ -1099,7 +1099,6 @@ AndroidBridge::SetLayerClient(JNIEnv* env, jobject jobj)
     mLayerClient = client;
 
     if (resetting) {
-        RegisterCompositor(env, true);
         // since we are re-linking the new java objects to Gecko, we need to get
         // the viewport from the compositor (since the Java copy was thrown away)
         // and we do that by setting the first-paint flag.
@@ -1123,7 +1122,7 @@ AndroidBridge::ShowInputMethodPicker()
 static AndroidGLController sController;
 
 void
-AndroidBridge::RegisterCompositor(JNIEnv *env, bool resetting)
+AndroidBridge::RegisterCompositor(JNIEnv *env)
 {
     ALOG_BRIDGE("AndroidBridge::RegisterCompositor");
     if (!env)
@@ -1139,11 +1138,7 @@ AndroidBridge::RegisterCompositor(JNIEnv *env, bool resetting)
     if (jniFrame.CheckForException())
         return;
 
-    if (resetting) {
-        sController.Reacquire(env, glController);
-    } else {
-        sController.Acquire(env, glController);
-    }
+    sController.Acquire(env, glController);
 }
 
 EGLSurface

widget/android/AndroidBridge.h

@@ -255,7 +255,7 @@ public:
     bool GetShowPasswordSetting();
 
     // Switch Java to composite with the Gecko Compositor thread
-    void RegisterCompositor(JNIEnv* env = NULL, bool resetting = false);
+    void RegisterCompositor(JNIEnv* env = NULL);
     EGLSurface ProvideEGLSurface(bool waitUntilValid);
 
     bool GetStaticStringField(const char *classID, const char *field, nsAString &result, JNIEnv* env = nullptr);

widget/android/AndroidLayerViewWrapper.cpp

@@ -28,7 +28,6 @@ void AndroidEGLObject::Init(JNIEnv* aJEnv) {
 
 jmethodID AndroidGLController::jWaitForValidSurfaceMethod = 0;
 jmethodID AndroidGLController::jProvideEGLSurfaceMethod = 0;
-jmethodID AndroidGLController::jResumeCompositorIfValidMethod = 0;
 
 void
 AndroidGLController::Init(JNIEnv* aJEnv)
@@ -37,7 +36,6 @@ AndroidGLController::Init(JNIEnv* aJEnv)
 
     jProvideEGLSurfaceMethod = aJEnv->GetMethodID(jClass, "provideEGLSurface",
                                                   "()Ljavax/microedition/khronos/egl/EGLSurface;");
-    jResumeCompositorIfValidMethod = aJEnv->GetMethodID(jClass, "resumeCompositorIfValid", "()V");
     jWaitForValidSurfaceMethod = aJEnv->GetMethodID(jClass, "waitForValidSurface", "()V");
 }
 
@@ -49,16 +47,6 @@ AndroidGLController::Acquire(JNIEnv* aJEnv, jobject aJObj)
     mJObj = aJEnv->NewGlobalRef(aJObj);
 }
 
-void
-AndroidGLController::Reacquire(JNIEnv *aJEnv, jobject aJObj)
-{
-    aJEnv->DeleteGlobalRef(mJObj);
-    mJObj = aJEnv->NewGlobalRef(aJObj);
-
-    AutoLocalJNIFrame jniFrame(aJEnv, 0);
-    aJEnv->CallVoidMethod(mJObj, jResumeCompositorIfValidMethod);
-}
-
 EGLSurface
 AndroidGLController::ProvideEGLSurface()
 {

widget/android/AndroidLayerViewWrapper.h

@@ -21,14 +21,12 @@ public:
     static void Init(JNIEnv* aJEnv);
 
     void Acquire(JNIEnv* aJEnv, jobject aJObj);
-    void Reacquire(JNIEnv* aJEnv, jobject aJObj);
     EGLSurface ProvideEGLSurface();
     void WaitForValidSurface();
 
 private:
     static jmethodID jWaitForValidSurfaceMethod;
     static jmethodID jProvideEGLSurfaceMethod;
-    static jmethodID jResumeCompositorIfValidMethod;
 
     // the JNIEnv for the compositor thread
     JNIEnv* mJEnv;