From b4da4f362dce1aeb6c7463540859f7c9d720cc97 Mon Sep 17 00:00:00 2001
From: Suprabh Shukla <suprabh@google.com>
Date: Tue, 25 May 2021 16:33:35 -0700
Subject: [PATCH] Unlink listener death recipient on alarms

Stopped using BinderDeathDispatcher as deduping is no longer required.
If an app sets the same listener, it is first removed internally which
will result in a call to unlink before the subsequent call to set.

Test: Manually using a test app that cancels and sets an alarm with a
new listener instance in a loop.
atest CtsAlarmManagerTestCases:BasicApiTests

Bug: 189091551
Change-Id: I390d9bba37a4040b7e789e0ae04f9980fbed5c12
---
 .../server/alarm/AlarmManagerService.java     | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/apex/jobscheduler/service/java/com/android/server/alarm/AlarmManagerService.java b/apex/jobscheduler/service/java/com/android/server/alarm/AlarmManagerService.java
index 5365218203d99..752dd2536487c 100644
--- a/apex/jobscheduler/service/java/com/android/server/alarm/AlarmManagerService.java
+++ b/apex/jobscheduler/service/java/com/android/server/alarm/AlarmManagerService.java
@@ -121,7 +121,6 @@ import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.app.IAppOpsCallback;
 import com.android.internal.app.IAppOpsService;
-import com.android.internal.os.BinderDeathDispatcher;
 import com.android.internal.util.DumpUtils;
 import com.android.internal.util.FrameworkStatsLog;
 import com.android.internal.util.LocalLog;
@@ -206,8 +205,6 @@ public class AlarmManagerService extends SystemService {
                     .addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING
                             | Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND);
 
-    private static final BinderDeathDispatcher<IAlarmListener> sListenerDeathDispatcher =
-            new BinderDeathDispatcher<>();
     final LocalLog mLog = new LocalLog(TAG);
 
     AppOpsManager mAppOps;
@@ -1837,8 +1834,9 @@ public class AlarmManagerService extends SystemService {
         }
 
         if (directReceiver != null) {
-            if (sListenerDeathDispatcher.linkToDeath(directReceiver, mListenerDeathRecipient)
-                    <= 0) {
+            try {
+                directReceiver.asBinder().linkToDeath(mListenerDeathRecipient, 0);
+            } catch (RemoteException e) {
                 Slog.w(TAG, "Dropping unreachable alarm listener " + listenerTag);
                 return;
             }
@@ -2851,12 +2849,6 @@ public class AlarmManagerService extends SystemService {
                 pw.println();
             }
 
-            pw.println("Listener death dispatcher state:");
-            pw.increaseIndent();
-            sListenerDeathDispatcher.dump(pw);
-            pw.println();
-            pw.decreaseIndent();
-
             if (mLog.dump(pw, "Recent problems:")) {
                 pw.println();
             }
@@ -3448,6 +3440,9 @@ public class AlarmManagerService extends SystemService {
 
         for (final Alarm removed : removedAlarms) {
             decrementAlarmCount(removed.uid, 1);
+            if (removed.listener != null) {
+                removed.listener.asBinder().unlinkToDeath(mListenerDeathRecipient, 0);
+            }
             if (!RemovedAlarm.isLoggable(reason)) {
                 continue;
             }
@@ -4701,6 +4696,8 @@ public class AlarmManagerService extends SystemService {
                     // Direct listener callback alarm
                     mListenerCount++;
 
+                    alarm.listener.asBinder().unlinkToDeath(mListenerDeathRecipient, 0);
+
                     if (RECORD_ALARMS_IN_HISTORY) {
                         if (alarm.listener == mTimeTickTrigger) {
                             mTickHistory[mNextTickHistory++] = nowELAPSED;