commit 6607196afb44cf3e000ba0e98e403d72df231062
author wilsonshih <wilsonshih@google.com> Fri Jul 10 10:45:23 2020 +0800
committer Wei Sheng Shih <wilsonshih@google.com> Fri Jul 31 10:01:05 2020 +0000
tree 1c1e3499fadc083d354a7b0fefc9a604cdfb8121
parent b8c40cdebefed3e8f5d2b578d4e2d0595b47bb4e

Prevent sleep tokens from being created recursively.

Sometimes a keyguard sleep token can be created with recursively call
because we use the local object existing as a condition to create it.
The code flow looks like:

KeyguardController#updateSleepToken
if (mSleepToken == null) then a = acquireSleepToken();
acquireSleepToken
  updateSleepIfNeededLocked
    ensureActivitiesVisible
      keyguardController#visibilitiesUpdated
        updateSleepToken
Then since the local mSleepToken haven't been assigned,
acquireSleepToken would be called again. Which would create another
sleep token and leave the previous one in RootWindowContainer.

To prevent this from happening again, separate updateSleepIfNeeded
from acquireSleepToken, and store sleep token as a map, so no more
sleep token can be created with same key.

Bug: 162441580
Test: atest MultiDisplayKeyguardTests MultiDisplayLockedKeyguardTests/
KeyguardTests KeyguardInputTests KeyguardLockedTests

Change-Id: I168dfe0fa101cb65eb676ca256c03439c8e4193d
Merged-In: I168dfe0fa101cb65eb676ca256c03439c8e4193d
(cherry picked from commit 3f51a96792d3770d82efcad645714ea8445a445f)

services/core/java/com/android/server/wm/ActivityTaskManagerService.java

diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 205523b..a1d0e56 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -5087,7 +5087,10 @@
         final long sleepToken = proto.start(ActivityManagerServiceDumpProcessesProto.SLEEP_STATUS);
         proto.write(ActivityManagerServiceDumpProcessesProto.SleepStatus.WAKEFULNESS,
                 PowerManagerInternal.wakefulnessToProtoEnum(wakeFullness));
-        for (ActivityTaskManagerInternal.SleepToken st : mRootWindowContainer.mSleepTokens) {
+        final int tokenSize = mRootWindowContainer.mSleepTokens.size();
+        for (int i = 0; i < tokenSize; i++) {
+            final RootWindowContainer.SleepToken st =
+                    mRootWindowContainer.mSleepTokens.valueAt(i);
             proto.write(ActivityManagerServiceDumpProcessesProto.SleepStatus.SLEEP_TOKENS,
                     st.toString());
         }
@@ -5521,12 +5524,35 @@
                 reason);
     }
 
-    ActivityTaskManagerInternal.SleepToken acquireSleepToken(String tag, int displayId) {
-        synchronized (mGlobalLock) {
-            final ActivityTaskManagerInternal.SleepToken token =
-                    mRootWindowContainer.createSleepToken(tag, displayId);
-            updateSleepIfNeededLocked();
-            return token;
+    final class SleepTokenAcquirerImpl implements ActivityTaskManagerInternal.SleepTokenAcquirer {
+        private final String mTag;
+        private final SparseArray<RootWindowContainer.SleepToken> mSleepTokens =
+                new SparseArray<>();
+
+        SleepTokenAcquirerImpl(@NonNull String tag) {
+            mTag = tag;
+        }
+
+        @Override
+        public void acquire(int displayId) {
+            synchronized (mGlobalLock) {
+                if (!mSleepTokens.contains(displayId)) {
+                    mSleepTokens.append(displayId,
+                            mRootWindowContainer.createSleepToken(mTag, displayId));
+                    updateSleepIfNeededLocked();
+                }
+            }
+        }
+
+        @Override
+        public void release(int displayId) {
+            synchronized (mGlobalLock) {
+                final RootWindowContainer.SleepToken token = mSleepTokens.get(displayId);
+                if (token != null) {
+                    mRootWindowContainer.removeSleepToken(token);
+                    mSleepTokens.remove(displayId);
+                }
+            }
         }
     }
 
@@ -6085,9 +6111,9 @@
 
     final class LocalService extends ActivityTaskManagerInternal {
         @Override
-        public SleepToken acquireSleepToken(String tag, int displayId) {
+        public SleepTokenAcquirer createSleepTokenAcquirer(@NonNull String tag) {
             Objects.requireNonNull(tag);
-            return ActivityTaskManagerService.this.acquireSleepToken(tag, displayId);
+            return new SleepTokenAcquirerImpl(tag);
         }
 
         @Override