From 1440ee7834b32114e8404d87c67f01a6bfa8a5fe Mon Sep 17 00:00:00 2001
From: qinyige1 <qinyige1@xiaomi.com>
Date: Wed, 22 Feb 2023 11:02:53 +0800
Subject: [PATCH] [WMS][Bugfix] Catch exception when dump local window.

The local window may update its view on its ui thread.
Add synchronization in case the window is removing when dumping.
Also catch exception for the race condition inside the view.

Bug: 270280397
Test: Manual
Change-Id: Ic0268ffff9a6a087b9e18340783da0676bf9caee
---
 .../server/wm/WindowManagerShellCommand.java  | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/services/core/java/com/android/server/wm/WindowManagerShellCommand.java b/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
index 2c0e909a5cc04..ea07fe77e588c 100644
--- a/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
+++ b/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
@@ -42,6 +42,7 @@ import android.provider.Settings;
 import android.util.DisplayMetrics;
 import android.util.Pair;
 import android.view.Display;
+import android.view.IWindow;
 import android.view.IWindowManager;
 import android.view.ViewDebug;
 
@@ -553,6 +554,22 @@ public class WindowManagerShellCommand extends ShellCommand {
         return 0;
     }
 
+    private void dumpLocalWindowAsync(IWindow client, ParcelFileDescriptor pfd) {
+        // Make it asynchronous to avoid writer from being blocked
+        // by waiting for the buffer to be consumed in the same process.
+        IoThread.getExecutor().execute(() -> {
+            synchronized (mInternal.mGlobalLock) {
+                try {
+                    client.executeCommand(ViewDebug.REMOTE_COMMAND_DUMP_ENCODED, null, pfd);
+                } catch (Exception e) {
+                    // Ignore RemoteException for local call. Just print trace for other
+                    // exceptions caused by RC with tolerable low possibility.
+                    e.printStackTrace();
+                }
+            }
+        });
+    }
+
     private int runDumpVisibleWindowViews(PrintWriter pw) {
         if (!mInternal.checkCallingPermission(android.Manifest.permission.DUMP,
                 "runDumpVisibleWindowViews()")) {
@@ -575,16 +592,7 @@ public class WindowManagerShellCommand extends ShellCommand {
                             pipe = new ByteTransferPipe();
                             final ParcelFileDescriptor pfd = pipe.getWriteFd();
                             if (w.isClientLocal()) {
-                                // Make it asynchronous to avoid writer from being blocked
-                                // by waiting for the buffer to be consumed in the same process.
-                                IoThread.getExecutor().execute(() -> {
-                                    try {
-                                        w.mClient.executeCommand(
-                                                ViewDebug.REMOTE_COMMAND_DUMP_ENCODED, null, pfd);
-                                    } catch (RemoteException e) {
-                                        // Ignore for local call.
-                                    }
-                                });
+                                dumpLocalWindowAsync(w.mClient, pfd);
                             } else {
                                 w.mClient.executeCommand(
                                         ViewDebug.REMOTE_COMMAND_DUMP_ENCODED, null, pfd);