Bug 826300 - Don't block on waiting for a valid surface when trying to resume the compositor; allow resuming to fail gracefully. r=snorp,BenWa

gfx/gl/GLContextProviderEGL.cpp

@@ -520,7 +520,10 @@ public:
                                  EGL_NO_CONTEXT);
         if (!mSurface) {
 #ifdef MOZ_ANDROID_OMTC
-            mSurface = mozilla::AndroidBridge::Bridge()->ProvideEGLSurface();
+            mSurface = mozilla::AndroidBridge::Bridge()->ProvideEGLSurface(false);
+            if (!mSurface) {
+                return false;
+            }
 #else
             EGLConfig config;
             CreateConfig(&config);
@@ -2191,7 +2194,7 @@ GLContextProviderEGL::CreateForWindow(nsIWidget *aWidget)
 
 #ifdef MOZ_ANDROID_OMTC
     mozilla::AndroidBridge::Bridge()->RegisterCompositor();
-    EGLSurface surface = mozilla::AndroidBridge::Bridge()->ProvideEGLSurface();
+    EGLSurface surface = mozilla::AndroidBridge::Bridge()->ProvideEGLSurface(true);
 #else
     EGLSurface surface = CreateSurfaceForWindow(aWidget, config);
 #endif

gfx/layers/ipc/CompositorParent.cpp

@@ -346,12 +346,17 @@ CompositorParent::ResumeComposition()
 
   MonitorAutoLock lock(mResumeCompositionMonitor);
 
-  mPaused = false;
-
 #ifdef MOZ_WIDGET_ANDROID
-  static_cast<LayerManagerOGL*>(mLayerManager.get())->gl()->RenewSurface();
+  if (!static_cast<LayerManagerOGL*>(mLayerManager.get())->gl()->RenewSurface()) {
+    // We can't get a surface. This could be because the activity changed between
+    // the time resume was scheduled and now.
+    __android_log_print(ANDROID_LOG_INFO, "CompositorParent", "Unable to renew compositor surface; remaining in paused state");
+    lock.NotifyAll();
+    return;
+  }
 #endif
 
+  mPaused = false;
   Composite();
 
   // if anyone's waiting to make sure that composition really got resumed, tell them
@@ -402,7 +407,7 @@ CompositorParent::SchedulePauseOnCompositorThread()
   lock.Wait();
 }
 
-void
+bool
 CompositorParent::ScheduleResumeOnCompositorThread(int width, int height)
 {
   MonitorAutoLock lock(mResumeCompositionMonitor);
@@ -413,6 +418,8 @@ CompositorParent::ScheduleResumeOnCompositorThread(int width, int height)
 
   // Wait until the resume has actually been processed by the compositor thread
   lock.Wait();
+
+  return !mPaused;
 }
 
 void

gfx/layers/ipc/CompositorParent.h

@@ -85,7 +85,11 @@ public:
   // Can be called from any thread
   void ScheduleRenderOnCompositorThread();
   void SchedulePauseOnCompositorThread();
-  void ScheduleResumeOnCompositorThread(int width, int height);
+  /**
+   * Returns true if a surface was obtained and the resume succeeded; false
+   * otherwise.
+   */
+  bool ScheduleResumeOnCompositorThread(int width, int height);
 
   virtual void ScheduleComposition();
   void NotifyShadowTreeTransaction();

mobile/android/base/gfx/GLController.java

@@ -127,6 +127,12 @@ public class GLController {
      * caller assumes ownership of the surface once it is returned.
      * This function is invoked by JNI */
     private EGLSurface provideEGLSurface() {
+        synchronized (this) {
+            if (!mSurfaceValid) {
+                return null;
+            }
+        }
+
         if (mEGL == null) {
             initEGL();
         }

widget/android/AndroidBridge.cpp

@@ -1205,9 +1205,11 @@ AndroidBridge::RegisterCompositor(JNIEnv *env, bool resetting)
 }
 
 EGLSurface
-AndroidBridge::ProvideEGLSurface()
+AndroidBridge::ProvideEGLSurface(bool waitUntilValid)
 {
-    sController.WaitForValidSurface();
+    if (waitUntilValid) {
+        sController.WaitForValidSurface();
+    }
     return sController.ProvideEGLSurface();
 }
 

widget/android/AndroidBridge.h

@@ -261,7 +261,7 @@ public:
 
     // Switch Java to composite with the Gecko Compositor thread
     void RegisterCompositor(JNIEnv* env = NULL, bool resetting = false);
-    EGLSurface ProvideEGLSurface();
+    EGLSurface ProvideEGLSurface(bool waitUntilValid);
 
     bool GetStaticStringField(const char *classID, const char *field, nsAString &result, JNIEnv* env = nullptr);
 

widget/android/AndroidLayerViewWrapper.cpp

@@ -60,7 +60,7 @@ AndroidGLController::ProvideEGLSurface()
     ASSERT_THREAD();
     AutoLocalJNIFrame jniFrame(mJEnv);
     jobject jObj = mJEnv->CallObjectMethod(mJObj, jProvideEGLSurfaceMethod);
-    if (jniFrame.CheckForException())
+    if (jniFrame.CheckForException() || !jObj)
         return NULL;
 
     return reinterpret_cast<EGLSurface>(mJEnv->GetIntField(jObj, jEGLSurfacePointerField));

widget/android/nsWindow.cpp

@@ -940,8 +940,9 @@ nsWindow::OnGlobalAndroidEvent(AndroidGeckoEvent *ae)
             // Since we might have prevented one or more draw events from
             // occurring while the compositor was paused, we need to schedule
             // a draw event now.
-            sCompositorPaused = false;
-            win->RedrawAll();
+            if (!sCompositorPaused) {
+                win->RedrawAll();
+            }
             break;
 
         case AndroidGeckoEvent::GECKO_EVENT_SYNC:
@@ -2312,8 +2313,8 @@ nsWindow::SchedulePauseComposition()
 void
 nsWindow::ScheduleResumeComposition(int width, int height)
 {
-    if (sCompositorParent) {
-        sCompositorParent->ScheduleResumeOnCompositorThread(width, height);
+    if (sCompositorParent && sCompositorParent->ScheduleResumeOnCompositorThread(width, height)) {
+        sCompositorPaused = false;
     }
 }