From 19c4883c850c2d1628e844b48778856673d8bfe6 Mon Sep 17 00:00:00 2001
From: Wei Wang <weiwa@google.com>
Date: Mon, 28 Mar 2016 12:50:52 -0700
Subject: [PATCH] Add death monitor to AsyncChannel Server.

Bug:27878941
Change-Id: Ia6d12b49979b47434db7969372d6c02f799bc7d4
---
 .../android/internal/util/AsyncChannel.java   | 26 ++++++++++++-------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/core/java/com/android/internal/util/AsyncChannel.java b/core/java/com/android/internal/util/AsyncChannel.java
index bd0e6cef8ae9e..d8be9fdc33bda 100644
--- a/core/java/com/android/internal/util/AsyncChannel.java
+++ b/core/java/com/android/internal/util/AsyncChannel.java
@@ -402,7 +402,7 @@ public class AsyncChannel {
 
         // Initialize destination fields
         mDstMessenger = dstMessenger;
-
+        linkToDeathMonitor();
         if (DBG) log("connected srcHandler to the dstMessenger X");
     }
 
@@ -844,22 +844,30 @@ public class AsyncChannel {
         msg.arg1 = status;
         msg.obj = this;
         msg.replyTo = mDstMessenger;
+        if (!linkToDeathMonitor()) {
+            // Override status to indicate failure
+            msg.arg1 = STATUS_BINDING_UNSUCCESSFUL;
+        }
 
-        /*
-         * Link to death only when bindService isn't used.
-         */
-        if (mConnection == null) {
+        mSrcHandler.sendMessage(msg);
+    }
+
+    /**
+     * Link to death monitor for destination messenger. Returns true if successfully binded to
+     * destination messenger; false otherwise.
+     */
+    private boolean linkToDeathMonitor() {
+        // Link to death only when bindService isn't used and not already linked.
+        if (mConnection == null && mDeathMonitor == null) {
             mDeathMonitor = new DeathMonitor();
             try {
                 mDstMessenger.getBinder().linkToDeath(mDeathMonitor, 0);
             } catch (RemoteException e) {
                 mDeathMonitor = null;
-                // Override status to indicate failure
-                msg.arg1 = STATUS_BINDING_UNSUCCESSFUL;
+                return false;
             }
         }
-
-        mSrcHandler.sendMessage(msg);
+        return true;
     }
 
     /**