From 9b0767564eeb1ea691daa6c900bbb41556a50dbe Mon Sep 17 00:00:00 2001
From: Jorim Jaggi <jjaggi@google.com>
Date: Mon, 3 May 2021 15:51:22 +0200
Subject: [PATCH] Correctly start tracing only where we are counting frames

Test: Take  trace, do CUJ
Bug: 185902609
Change-Id: I17db03d290d0c1ab82b7969888f1d7c06575b5d0
---
 .../android/internal/jank/FrameTracker.java   | 25 ++++++++++++-------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/core/java/com/android/internal/jank/FrameTracker.java b/core/java/com/android/internal/jank/FrameTracker.java
index 4d3f7745decff..4d5b90a9ccbfd 100644
--- a/core/java/com/android/internal/jank/FrameTracker.java
+++ b/core/java/com/android/internal/jank/FrameTracker.java
@@ -167,6 +167,7 @@ public class FrameTracker extends SurfaceControl.OnJankDataListener
                         if (mBeginVsyncId != INVALID_ID) {
                             mSurfaceControlWrapper.addJankStatsListener(
                                     FrameTracker.this, mSurfaceControl);
+                            postTraceStartMarker();
                         }
                     }
                 }
@@ -208,15 +209,9 @@ public class FrameTracker extends SurfaceControl.OnJankDataListener
     public synchronized void begin() {
         mBeginVsyncId = mChoreographer.getVsyncId() + 1;
         mSession.setTimeStamp(System.nanoTime());
-        mChoreographer.mChoreographer.postCallback(Choreographer.CALLBACK_INPUT, () -> {
-            synchronized (FrameTracker.this) {
-                if (mCancelled || mEndVsyncId != INVALID_ID) {
-                    return;
-                }
-                mTracingStarted = true;
-                Trace.beginAsyncSection(mSession.getName(), (int) mBeginVsyncId);
-            }
-        }, null);
+        if (mSurfaceControl != null) {
+            postTraceStartMarker();
+        }
         mRendererWrapper.addObserver(mObserver);
         if (DEBUG) {
             Log.d(TAG, "begin: " + mSession.getName() + ", begin=" + mBeginVsyncId);
@@ -229,6 +224,18 @@ public class FrameTracker extends SurfaceControl.OnJankDataListener
         }
     }
 
+    private void postTraceStartMarker() {
+        mChoreographer.mChoreographer.postCallback(Choreographer.CALLBACK_INPUT, () -> {
+            synchronized (FrameTracker.this) {
+                if (mCancelled || mEndVsyncId != INVALID_ID) {
+                    return;
+                }
+                mTracingStarted = true;
+                Trace.beginAsyncSection(mSession.getName(), (int) mBeginVsyncId);
+            }
+        }, null);
+    }
+
     /**
      * End the trace session of the CUJ.
      */