Bug 866232 - Break assumption of a single global root layer tree. r=BenWa, mattwoodrow

gfx/layers/composite/APZCTreeManager.cpp

@@ -64,7 +64,9 @@ APZCTreeManager::UpdatePanZoomControllerTree(CompositorParent* aCompositor, Laye
 
   if (aRoot) {
     UpdatePanZoomControllerTree(aCompositor,
-                                aRoot, CompositorParent::ROOT_LAYER_TREE_ID,
+                                aRoot,
+                                // aCompositor is null in gtest scenarios
+                                aCompositor ? aCompositor->RootLayerTreeId() : 0,
                                 nullptr, nullptr,
                                 aIsFirstPaint, aFirstPaintLayersId,
                                 &apzcsToDestroy);

gfx/layers/ipc/CompositorParent.cpp

@@ -154,6 +154,9 @@ CompositorParent::CompositorParent(nsIWidget* aWidget,
   CompositorLoop()->PostTask(FROM_HERE, NewRunnableFunction(&AddCompositor,
                                                           this, &mCompositorID));
 
+  mRootLayerTreeID = AllocateLayerTreeId();
+  sIndirectLayerTrees[mRootLayerTreeID].mParent = this;
+
   mApzcTreeManager = new APZCTreeManager();
   ++sCompositorThreadRefCount;
 }
@@ -170,11 +173,16 @@ CompositorParent::IsInCompositorThread()
   return CompositorThreadID() == PlatformThread::CurrentId();
 }
 
+uint64_t
+CompositorParent::RootLayerTreeId()
+{
+  return mRootLayerTreeID;
+}
+
 CompositorParent::~CompositorParent()
 {
   MOZ_COUNT_DTOR(CompositorParent);
 
-  mApzcTreeManager->ClearTree();
   ReleaseCompositorThread();
 }
 
@@ -187,6 +195,9 @@ CompositorParent::Destroy()
   // Ensure that the layer manager is destructed on the compositor thread.
   mLayerManager = nullptr;
   mCompositionManager = nullptr;
+  mApzcTreeManager->ClearTree();
+  mApzcTreeManager = nullptr;
+  sIndirectLayerTrees.erase(mRootLayerTreeID);
 }
 
 void
@@ -568,7 +579,7 @@ CompositorParent::ShadowLayersUpdated(LayerTransactionParent* aLayerTree,
 
   if (mApzcTreeManager) {
     AutoResolveRefLayers resolve(mCompositionManager);
-    mApzcTreeManager->UpdatePanZoomControllerTree(this, root, isFirstPaint, ROOT_LAYER_TREE_ID);
+    mApzcTreeManager->UpdatePanZoomControllerTree(this, root, isFirstPaint, mRootLayerTreeID);
   }
 
   if (root) {
@@ -709,17 +720,12 @@ CompositorParent::NotifyChildCreated(uint64_t aChild)
   sIndirectLayerTrees[aChild].mParent = this;
 }
 
-// Ensure all layer tree IDs are greater than zero, so if we
-// ever see a zero-valued layer tree id we know it's actually
-// uninitialized and/or garbage.
-uint64_t CompositorParent::ROOT_LAYER_TREE_ID = 1;
-
 /*static*/ uint64_t
 CompositorParent::AllocateLayerTreeId()
 {
   MOZ_ASSERT(CompositorLoop());
   MOZ_ASSERT(NS_IsMainThread());
-  static uint64_t ids = ROOT_LAYER_TREE_ID;
+  static uint64_t ids = 0;
   return ++ids;
 }
 

gfx/layers/ipc/CompositorParent.h

@@ -103,6 +103,12 @@ public:
   virtual void ScheduleComposition();
   void NotifyShadowTreeTransaction(uint64_t aId, bool aIsFirstPaint);
 
+  /**
+   * Returns the unique layer tree identifier that corresponds to the root
+   * tree of this compositor.
+   */
+  uint64_t RootLayerTreeId();
+
   /**
    * Returns a pointer to the compositor corresponding to the given ID.
    */
@@ -125,11 +131,6 @@ public:
    */
   static void ShutDown();
 
-  /**
-   * The reserved layer tree ID for the root of the layer tree.
-   */
-  static uint64_t ROOT_LAYER_TREE_ID;
-
   /**
    * Allocate an ID that can be used to refer to a layer tree and
    * associated resources that live only on the compositor thread.
@@ -287,6 +288,7 @@ private:
   mozilla::Monitor mResumeCompositionMonitor;
 
   uint64_t mCompositorID;
+  uint64_t mRootLayerTreeID;
 
   bool mOverrideComposeReadiness;
   CancelableTask* mForceCompositionTask;

gfx/tests/gtest/TestAsyncPanZoomController.cpp

@@ -373,7 +373,7 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
   TimeStamp testStartTime = TimeStamp::Now();
   AsyncPanZoomController::SetFrameTime(testStartTime);
   nsRefPtr<MockContentController> mcc = new MockContentController();
-  ScopedLayerTreeRegistration controller(CompositorParent::ROOT_LAYER_TREE_ID, root, mcc);
+  ScopedLayerTreeRegistration controller(0, root, mcc);
 
   nsRefPtr<APZCTreeManager> manager = new TestAPZCTreeManager();
 
@@ -384,14 +384,14 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
 
   // Now we have a root APZC that will match the page
   SetScrollableFrameMetrics(root, FrameMetrics::ROOT_SCROLL_ID, mcc);
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   hit = manager->GetTargetAPZC(ScreenPoint(15, 15));
   EXPECT_EQ(root->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());
   // expect hit point at LayerIntPoint(15, 15)
 
   // Now we have a sub APZC with a better fit
   SetScrollableFrameMetrics(layers[3], FrameMetrics::START_SCROLL_ID, mcc);
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   EXPECT_NE(root->AsContainerLayer()->GetAsyncPanZoomController(), layers[3]->AsContainerLayer()->GetAsyncPanZoomController());
   hit = manager->GetTargetAPZC(ScreenPoint(15, 15));
   EXPECT_EQ(layers[3]->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());
@@ -401,7 +401,7 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
   hit = manager->GetTargetAPZC(ScreenPoint(15, 15));
   EXPECT_EQ(layers[3]->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());
   SetScrollableFrameMetrics(layers[4], FrameMetrics::START_SCROLL_ID + 1, mcc);
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   hit = manager->GetTargetAPZC(ScreenPoint(15, 15));
   EXPECT_EQ(layers[4]->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());
   // expect hit point at LayerIntPoint(15, 15)
@@ -422,7 +422,7 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
   transform.ScalePost(0.1, 0.1, 1);
   root->SetBaseTransform(transform);
   root->ComputeEffectiveTransforms(gfx3DMatrix());
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   hit = manager->GetTargetAPZC(ScreenPoint(50, 50)); // This point is now outside the root layer
   EXPECT_EQ(nullAPZC, hit.get());
 
@@ -435,7 +435,7 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
   // layer 4 effective visible screenrect: (0.05, 0.05, 0.2, 0.2)
   // Does not contain (2, 2)
   root->ComputeEffectiveTransforms(gfx3DMatrix());
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   hit = manager->GetTargetAPZC(ScreenPoint(2, 2));
   EXPECT_EQ(layers[3]->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());
   // expect hit point at LayerPoint(20, 20)
@@ -456,7 +456,7 @@ TEST(APZCTreeManager, GetAPZCAtPoint) {
   layers[7]->SetBaseTransform(translateTransform3);
 
   root->ComputeEffectiveTransforms(gfx3DMatrix());
-  manager->UpdatePanZoomControllerTree(nullptr, root, CompositorParent::ROOT_LAYER_TREE_ID, false);
+  manager->UpdatePanZoomControllerTree(nullptr, root, 0, false);
   // layer 7 effective visible screenrect (0,16,4,60) but clipped by parent layers
   hit = manager->GetTargetAPZC(ScreenPoint(1, 45));
   EXPECT_EQ(layers[7]->AsContainerLayer()->GetAsyncPanZoomController(), hit.get());

widget/android/AndroidJNI.cpp

@@ -847,9 +847,9 @@ Java_org_mozilla_gecko_GeckoJavaSampler_getProfilerTime(JNIEnv *jenv, jclass jc)
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_gfx_NativePanZoomController_abortAnimation(JNIEnv* env, jobject instance)
 {
-    APZCTreeManager *controller = CompositorParent::GetAPZCTreeManager(CompositorParent::ROOT_LAYER_TREE_ID);
+    APZCTreeManager *controller = nsWindow::GetAPZCTreeManager();
     if (controller) {
-        controller->CancelAnimation(ScrollableLayerGuid(CompositorParent::ROOT_LAYER_TREE_ID));
+        controller->CancelAnimation(ScrollableLayerGuid(nsWindow::RootLayerTreeId()));
     }
 }
 
@@ -865,13 +865,12 @@ Java_org_mozilla_gecko_gfx_NativePanZoomController_init(JNIEnv* env, jobject ins
         MOZ_ASSERT(false, "Registering a new NPZC when we already have one");
         env->DeleteGlobalRef(oldRef);
     }
-    CompositorParent::SetControllerForLayerTree(CompositorParent::ROOT_LAYER_TREE_ID, AndroidBridge::Bridge());
 }
 
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_gfx_NativePanZoomController_handleTouchEvent(JNIEnv* env, jobject instance, jobject event)
 {
-    APZCTreeManager *controller = CompositorParent::GetAPZCTreeManager(CompositorParent::ROOT_LAYER_TREE_ID);
+    APZCTreeManager *controller = nsWindow::GetAPZCTreeManager();
     if (controller) {
         AndroidGeckoEvent* wrapper = AndroidGeckoEvent::MakeFromJavaObject(env, event);
         const MultiTouchInput& input = wrapper->MakeMultiTouchInput(nsWindow::TopWindow());
@@ -916,9 +915,9 @@ Java_org_mozilla_gecko_gfx_NativePanZoomController_destroy(JNIEnv* env, jobject
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_gfx_NativePanZoomController_notifyDefaultActionPrevented(JNIEnv* env, jobject instance, jboolean prevented)
 {
-    APZCTreeManager *controller = CompositorParent::GetAPZCTreeManager(CompositorParent::ROOT_LAYER_TREE_ID);
+    APZCTreeManager *controller = nsWindow::GetAPZCTreeManager();
     if (controller) {
-        controller->ContentReceivedTouch(ScrollableLayerGuid(CompositorParent::ROOT_LAYER_TREE_ID), prevented);
+        controller->ContentReceivedTouch(ScrollableLayerGuid(nsWindow::RootLayerTreeId()), prevented);
     }
 }
 
@@ -945,9 +944,9 @@ Java_org_mozilla_gecko_gfx_NativePanZoomController_getOverScrollMode(JNIEnv* env
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_gfx_NativePanZoomController_updateScrollOffset(JNIEnv* env, jobject instance, jfloat cssX, jfloat cssY)
 {
-    APZCTreeManager *controller = CompositorParent::GetAPZCTreeManager(CompositorParent::ROOT_LAYER_TREE_ID);
+    APZCTreeManager *controller = nsWindow::GetAPZCTreeManager();
     if (controller) {
-        controller->UpdateScrollOffset(ScrollableLayerGuid(CompositorParent::ROOT_LAYER_TREE_ID), CSSPoint(cssX, cssY));
+        controller->UpdateScrollOffset(ScrollableLayerGuid(nsWindow::RootLayerTreeId()), CSSPoint(cssX, cssY));
     }
 }
 

widget/android/nsWindow.cpp

@@ -2417,6 +2417,7 @@ nsWindow::DrawWindowOverlay(LayerManager* aManager, nsIntRect aRect)
 
 // off-main-thread compositor fields and functions
 
+nsRefPtr<mozilla::layers::APZCTreeManager> nsWindow::sApzcTreeManager = 0;
 nsRefPtr<mozilla::layers::LayerManager> nsWindow::sLayerManager = 0;
 nsRefPtr<mozilla::layers::CompositorParent> nsWindow::sCompositorParent = 0;
 nsRefPtr<mozilla::layers::CompositorChild> nsWindow::sCompositorChild = 0;
@@ -2500,3 +2501,25 @@ nsWindow::NewCompositorParent(int aSurfaceWidth, int aSurfaceHeight)
 {
     return new CompositorParent(this, true, aSurfaceWidth, aSurfaceHeight);
 }
+
+mozilla::layers::APZCTreeManager*
+nsWindow::GetAPZCTreeManager()
+{
+    if (!sApzcTreeManager) {
+        CompositorParent* compositor = sCompositorParent;
+        if (!compositor) {
+            return nullptr;
+        }
+        uint64_t rootLayerTreeId = compositor->RootLayerTreeId();
+        CompositorParent::SetControllerForLayerTree(rootLayerTreeId, AndroidBridge::Bridge());
+        sApzcTreeManager = CompositorParent::GetAPZCTreeManager(rootLayerTreeId);
+    }
+    return sApzcTreeManager;
+}
+
+uint64_t
+nsWindow::RootLayerTreeId()
+{
+    MOZ_ASSERT(sCompositorParent);
+    return sCompositorParent->RootLayerTreeId();
+}

widget/android/nsWindow.h

@@ -155,6 +155,9 @@ public:
     static void ScheduleResumeComposition(int width, int height);
     static void ForceIsFirstPaint();
     static float ComputeRenderIntegrity();
+    static mozilla::layers::APZCTreeManager* GetAPZCTreeManager();
+    /* RootLayerTreeId() can only be called when GetAPZCTreeManager() returns non-null */
+    static uint64_t RootLayerTreeId();
 
     virtual bool WidgetPaintsBackground();
 
@@ -229,6 +232,7 @@ private:
 
     mozilla::AndroidLayerRendererFrame mLayerRendererFrame;
 
+    static nsRefPtr<mozilla::layers::APZCTreeManager> sApzcTreeManager;
     static nsRefPtr<mozilla::layers::LayerManager> sLayerManager;
     static nsRefPtr<mozilla::layers::CompositorParent> sCompositorParent;
     static nsRefPtr<mozilla::layers::CompositorChild> sCompositorChild;