From b0424de7d3103998e1e633db4bfaf31c939a09d6 Mon Sep 17 00:00:00 2001
From: Zim <zezeozue@google.com>
Date: Thu, 25 Feb 2021 14:24:39 +0000
Subject: [PATCH] Retrieve max ANR dialog before dumping thread stacks

Dumping thread stacks can take >5s, after which the cause of the ANR
might have completed and there might not longer be a valid ANR
controller to cancel the dialog.

Test: Manual
Bug: 170486601

Fix comment from Idb9190a0e6014ce64bf1412c26f6ae03f97e922d

Test: m
Bug: 170486601
Change-Id: Ibb5699693fac054fd8a8237af7036e610d7af189
---
 .../server/am/ProcessErrorStateRecord.java    | 30 ++++++++++---------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/services/core/java/com/android/server/am/ProcessErrorStateRecord.java b/services/core/java/com/android/server/am/ProcessErrorStateRecord.java
index 3258f8af0da21..d03a47afed8ac 100644
--- a/services/core/java/com/android/server/am/ProcessErrorStateRecord.java
+++ b/services/core/java/com/android/server/am/ProcessErrorStateRecord.java
@@ -329,6 +329,22 @@ class ProcessErrorStateRecord {
             info.append("Package is ").append((int) (loadingProgress * 100)).append("% loaded.\n");
         }
 
+        // Retrieve controller with max ANR delay from AnrControllers
+        // Note that we retrieve the controller before dumping stacks because dumping stacks can
+        // take a few seconds, after which the cause of the ANR delay might have completed and
+        // there might no longer be a valid ANR controller to cancel the dialog in that case
+        AnrController anrController = mService.mActivityTaskManager.getAnrController(aInfo);
+        long anrDialogDelayMs = 0;
+        if (anrController != null) {
+            String packageName = aInfo.packageName;
+            int uid = aInfo.uid;
+            anrDialogDelayMs = anrController.getAnrDelayMillis(packageName, uid);
+            // Might execute an async binder call to a system app to show an interim
+            // ANR progress UI
+            anrController.onAnrDelayStarted(packageName, uid);
+            Slog.i(TAG, "ANR delay of " + anrDialogDelayMs + "ms started for " + packageName);
+        }
+
         StringBuilder report = new StringBuilder();
         report.append(MemoryPressureUtil.currentPsiState());
         ProcessCpuTracker processCpuTracker = new ProcessCpuTracker(true);
@@ -417,20 +433,6 @@ class ProcessErrorStateRecord {
             return;
         }
 
-        // Retrieve max ANR delay from AnrControllers without the mService lock since the
-        // controllers might in turn call into apps
-        AnrController anrController = mService.mActivityTaskManager.getAnrController(aInfo);
-        long anrDialogDelayMs = 0;
-        if (anrController != null) {
-            String packageName = aInfo.packageName;
-            int uid = aInfo.uid;
-            anrDialogDelayMs = anrController.getAnrDelayMillis(packageName, uid);
-            // Might execute an async binder call to a system app to show an interim
-            // ANR progress UI
-            anrController.onAnrDelayStarted(packageName, uid);
-            Slog.i(TAG, "ANR delay of " + anrDialogDelayMs + "ms started for " + packageName);
-        }
-
         synchronized (mService) {
             // mBatteryStatsService can be null if the AMS is constructed with injector only. This
             // will only happen in tests.