From 5c26b0762633394cdb7617782d5a9b53401a9bf6 Mon Sep 17 00:00:00 2001
From: Randall Barker <rbarker@mozilla.com>
Date: Mon, 8 May 2017 12:06:10 -0700
Subject: [PATCH] Bug 1363123 - Queue compositor messages that are sent before
 UiCompositorControllerParent has been initialized r=botond

MozReview-Commit-ID: LNmCv9D6bS6
---
 .../apz/src/AndroidDynamicToolbarAnimator.cpp | 34 +++++++++++++++++++
 .../apz/src/AndroidDynamicToolbarAnimator.h   | 14 ++++++++
 2 files changed, 48 insertions(+)

diff --git a/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp b/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp
index 0d9ca3a56e35..e3aee9e3bbea 100644
--- a/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp
+++ b/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp
@@ -73,10 +73,17 @@ AndroidDynamicToolbarAnimator::AndroidDynamicToolbarAnimator()
 void
 AndroidDynamicToolbarAnimator::Initialize(uint64_t aRootLayerTreeId)
 {
+  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
   mRootLayerTreeId = aRootLayerTreeId;
   RefPtr<UiCompositorControllerParent> uiController = UiCompositorControllerParent::GetFromRootLayerTreeId(mRootLayerTreeId);
   MOZ_ASSERT(uiController);
   uiController->RegisterAndroidDynamicToolbarAnimator(this);
+
+  // Send queued messages that were posted before Initialize() was called.
+  for (QueuedMessage* message = mCompositorQueuedMessages.getFirst(); message != nullptr; message = message->getNext()) {
+    uiController->ToolbarAnimatorMessageFromCompositor(message->mMessage);
+  }
+  mCompositorQueuedMessages.clear();
 }
 
 static bool
@@ -461,6 +468,7 @@ AndroidDynamicToolbarAnimator::Shutdown()
   mCompositorShutdown = true;
   mCompositorToolbarEffect = nullptr;
   mCompositorToolbarTexture = nullptr;
+  mCompositorQueuedMessages.clear();
   if (mCompositorToolbarPixels) {
     RefPtr<UiCompositorControllerParent> uiController = UiCompositorControllerParent::GetFromRootLayerTreeId(mRootLayerTreeId);
     uiController->DeallocShmem(mCompositorToolbarPixels.ref());
@@ -620,11 +628,19 @@ AndroidDynamicToolbarAnimator::HandleTouchEnd(StaticToolbarState aCurrentToolbar
 
 void
 AndroidDynamicToolbarAnimator::PostMessage(int32_t aMessage) {
+  // if the root layer tree id is zero then Initialize() has not been called yet
+  // so queue the message until Initialize() is called.
+  if (mRootLayerTreeId == 0) {
+    QueueMessage(aMessage);
+    return;
+  }
+
   RefPtr<UiCompositorControllerParent> uiController = UiCompositorControllerParent::GetFromRootLayerTreeId(mRootLayerTreeId);
   if (!uiController) {
     // Looks like IPC may be shutdown.
     return;
   }
+
   // ToolbarAnimatorMessageFromCompositor may be called from any thread.
   uiController->ToolbarAnimatorMessageFromCompositor(aMessage);
 }
@@ -958,5 +974,23 @@ AndroidDynamicToolbarAnimator::CheckForResetOnNextMove(ScreenIntCoord aCurrentTo
   }
 }
 
+void
+AndroidDynamicToolbarAnimator::QueueMessage(int32_t aMessage)
+{
+  if (!CompositorThreadHolder::IsInCompositorThread()) {
+    CompositorThreadHolder::Loop()->PostTask(NewRunnableMethod<int32_t>(this, &AndroidDynamicToolbarAnimator::QueueMessage, aMessage));
+    return;
+  }
+
+  // If the root layer tree id is no longer zero, Initialize() was called before QueueMessage was processed
+  // so just post the message now.
+  if (mRootLayerTreeId != 0) {
+    PostMessage(aMessage);
+    return;
+  }
+
+  mCompositorQueuedMessages.insertBack(new QueuedMessage(aMessage));
+}
+
 } // namespace layers
 } // namespace mozilla
diff --git a/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.h b/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.h
index 0896d9194897..dac2b6a6d57b 100644
--- a/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.h
+++ b/gfx/layers/apz/src/AndroidDynamicToolbarAnimator.h
@@ -13,6 +13,7 @@
 #include "mozilla/ipc/Shmem.h"
 #include "mozilla/layers/Effects.h"
 #include "mozilla/layers/TextureHost.h"
+#include "mozilla/LinkedList.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/TimeStamp.h"
 #include "nsISupports.h"
@@ -151,6 +152,7 @@ protected:
   ScreenIntCoord GetFixedLayerMarginsBottom();
   void NotifyControllerSnapshotFailed();
   void CheckForResetOnNextMove(ScreenIntCoord aCurrentTouch);
+  void QueueMessage(int32_t aMessage);
 
   // Read only Compositor and Controller threads after Initialize()
   uint64_t mRootLayerTreeId;
@@ -195,6 +197,17 @@ protected:
   // Controller thread only
   FrameMetricsState mControllerFrameMetrics;
 
+  class QueuedMessage : public LinkedListElement<QueuedMessage> {
+  public:
+    explicit QueuedMessage(int32_t aMessage) :
+      mMessage(aMessage) {}
+    int32_t mMessage;
+  private:
+    QueuedMessage() = delete;
+    QueuedMessage(const QueuedMessage&) = delete;
+    QueuedMessage& operator=(const QueuedMessage&) = delete;
+  };
+
   // Compositor thread only
   bool    mCompositorShutdown;
   bool    mCompositorAnimationDeferred;           // An animation has been deferred until the toolbar is unlocked
@@ -211,6 +224,7 @@ protected:
   RefPtr<DataTextureSource> mCompositorToolbarTexture; // The OGL texture used to render the snapshot in the compositor
   RefPtr<EffectRGB> mCompositorToolbarEffect;          // Effect used to render the snapshot in the compositor
   TimeStamp mCompositorAnimationStartTimeStamp;        // Time stamp when the current animation started
+  AutoCleanLinkedList<QueuedMessage> mCompositorQueuedMessages; // Queue to contain messages sent before Initialize() called
 };
 
 } // namespace layers