From 21d46e388dd46a7411e2511ebedaf2e6c9e5f2f2 Mon Sep 17 00:00:00 2001
From: Vishnu Nair <vishnun@google.com>
Date: Fri, 30 Sep 2022 20:26:19 +0000
Subject: [PATCH] WMS AnrController: Don't hold WMS lock when calling into AMS

Change-Id: I20e543b0c89809cf16566744b1ad5ce83d0f2a2c
Test: atest AnrTests
Bug: 239907039
---
 .../com/android/server/wm/AnrController.java  | 40 ++++++++++---------
 1 file changed, 22 insertions(+), 18 deletions(-)

diff --git a/services/core/java/com/android/server/wm/AnrController.java b/services/core/java/com/android/server/wm/AnrController.java
index df72260121818..d42a74f60de9c 100644
--- a/services/core/java/com/android/server/wm/AnrController.java
+++ b/services/core/java/com/android/server/wm/AnrController.java
@@ -70,6 +70,9 @@ class AnrController {
             preDumpIfLockTooSlow();
             final ActivityRecord activity;
             timeoutRecord.mLatencyTracker.waitingOnGlobalLockStarted();
+            boolean blamePendingFocusRequest = false;
+            IBinder focusToken = null;
+            WindowState targetWindowState = null;
             synchronized (mService.mGlobalLock) {
                 timeoutRecord.mLatencyTracker.waitingOnGlobalLockEnded();
                 activity = ActivityRecord.forTokenLocked(applicationHandle.token);
@@ -82,35 +85,36 @@ class AnrController {
                 // App is unresponsive, but we are actively trying to give focus to a window.
                 // Blame the window if possible since the window may not belong to the app.
                 DisplayContent display = mService.mRoot.getDisplayContent(activity.getDisplayId());
-                IBinder focusToken =
-                        display == null ? null : display.getInputMonitor().mInputFocus;
+                if (display != null) {
+                    focusToken = display.getInputMonitor().mInputFocus;
+                }
                 InputTarget focusTarget = mService.getInputTargetFromToken(focusToken);
 
                 if (focusTarget != null) {
                     // Check if we have a recent focus request, newer than the dispatch timeout,
                     // then ignore the focus request.
-                    WindowState targetWindowState = focusTarget.getWindowState();
-                    boolean requestIsValid = SystemClock.uptimeMillis()
+                    targetWindowState = focusTarget.getWindowState();
+                    blamePendingFocusRequest = SystemClock.uptimeMillis()
                             - display.getInputMonitor().mInputFocusRequestTimeMillis
                             >= getInputDispatchingTimeoutMillisLocked(
                                     targetWindowState.getActivityRecord());
-
-                    if (requestIsValid) {
-                        if (notifyWindowUnresponsive(focusToken, timeoutRecord)) {
-                            Slog.i(TAG_WM, "Blamed " + focusTarget.getWindowState().getName()
-                                    + " using pending focus request. Focused activity: "
-                                    + activity.getName());
-                            return;
-                        }
-                    }
                 }
 
-                Slog.i(TAG_WM, "ANR in " + activity.getName() + ".  Reason: "
-                        + timeoutRecord.mReason);
-                dumpAnrStateLocked(activity, null /* windowState */, timeoutRecord.mReason);
-                mUnresponsiveAppByDisplay.put(activity.getDisplayId(), activity);
+                if (!blamePendingFocusRequest) {
+                    Slog.i(TAG_WM, "ANR in " + activity.getName() + ".  Reason: "
+                            + timeoutRecord.mReason);
+                    dumpAnrStateLocked(activity, null /* windowState */, timeoutRecord.mReason);
+                    mUnresponsiveAppByDisplay.put(activity.getDisplayId(), activity);
+                }
+            }
+
+            if (blamePendingFocusRequest && notifyWindowUnresponsive(focusToken, timeoutRecord)) {
+                Slog.i(TAG_WM, "Blamed " + targetWindowState.getName()
+                        + " using pending focus request. Focused activity: "
+                        + activity.getName());
+            } else {
+                activity.inputDispatchingTimedOut(timeoutRecord, INVALID_PID);
             }
-            activity.inputDispatchingTimedOut(timeoutRecord, INVALID_PID);
         } finally {
             Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
         }