Compositor performance warnings

--HG--
extra : rebase_source : e8b2a0f4c4cb69fb88a478750cecc9f21327e018

gfx/layers/ipc/CompositorParent.cpp

@@ -140,9 +140,16 @@ CompositorParent::ScheduleComposition()
   if (!initialComposition)
     delta = mozilla::TimeStamp::Now() - mLastCompose;
 
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+  mExpectedComposeTime = mozilla::TimeStamp::Now() + TimeDuration::FromMilliseconds(15);
+#endif
+
   printf_stderr("Schedule composition\n");
   mCurrentCompositeTask = NewRunnableMethod(this, &CompositorParent::Composite);
   if (!initialComposition && delta.ToMilliseconds() < 15) {
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+    mExpectedComposeTime = mozilla::TimeStamp::Now() + TimeDuration::FromMilliseconds(15 - delta.ToMilliseconds());
+#endif
     MessageLoop::current()->PostDelayedTask(FROM_HERE, mCurrentCompositeTask, 15 - delta.ToMilliseconds());
   } else {
     MessageLoop::current()->PostTask(FROM_HERE, mCurrentCompositeTask);
@@ -162,6 +169,8 @@ CompositorParent::Composite()
 {
   mCurrentCompositeTask = NULL;
 
+  mLastCompose = mozilla::TimeStamp::Now();
+
   if (mPaused || !mLayerManager) {
     return;
   }
@@ -188,7 +197,13 @@ CompositorParent::Composite()
 #endif
 
   mLayerManager->EndEmptyTransaction();
-  mLastCompose = mozilla::TimeStamp::Now();
+
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+  if (mExpectedComposeTime + TimeDuration::FromMilliseconds(15) < mozilla::TimeStamp::Now()) {
+    printf_stderr("Compositor: Compose frame took %i time then expected.\n",
+                  (int)(mozilla::TimeStamp::Now() - mExpectedComposeTime).ToMilliseconds());
+  }
+#endif
 }
 
 #ifdef MOZ_WIDGET_ANDROID

gfx/layers/ipc/CompositorParent.h

@@ -41,6 +41,14 @@
 #ifndef mozilla_layers_CompositorParent_h
 #define mozilla_layers_CompositorParent_h
 
+// Enable this pref to turn on compositor performance warning.
+// This will print warnings if the compositor isn't meeting
+// it's responsiveness objectives:
+//    1) Compose a frame within 15ms of receiving a ScheduleCompositeCall
+//    2) Unless a frame was composited within the throttle threshold in
+//       which the deadline will be 15ms + throttle threshold
+#define COMPOSITOR_PERFORMANCE_WARNING
+
 #include "mozilla/layers/PCompositorParent.h"
 #include "mozilla/layers/PLayersParent.h"
 #include "base/thread.h"
@@ -129,6 +137,9 @@ private:
   nsIWidget* mWidget;
   CancelableTask *mCurrentCompositeTask;
   TimeStamp mLastCompose;
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+  TimeStamp mExpectedComposeTime;
+#endif
 
   bool mPaused;
   float mXScale;

gfx/layers/ipc/ShadowLayersParent.cpp

@@ -149,6 +149,10 @@ bool
 ShadowLayersParent::RecvUpdate(const InfallibleTArray<Edit>& cset,
                                InfallibleTArray<EditReply>* reply)
 {
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+  TimeStamp updateStart = TimeStamp::Now();
+#endif
+
   MOZ_LAYERS_LOG(("[ParentSide] received txn with %d edits", cset.Length()));
 
   if (mDestroyed || layer_manager()->IsDestroyed()) {
@@ -385,6 +389,11 @@ ShadowLayersParent::RecvUpdate(const InfallibleTArray<Edit>& cset,
 
   mShadowLayersManager->ShadowLayersUpdated();
 
+#ifdef COMPOSITOR_PERFORMANCE_WARNING
+  printf_stderr("Compositor: Layers update took %i ms (blocking gecko).\n",
+                (int)(mozilla::TimeStamp::Now() - updateStart).ToMilliseconds());
+#endif
+
   return true;
 }