commit 6d1186c2fd8ed6d49f0adf1902792868a8d49af7
author Brad Ebinger <breadley@google.com> Thu Apr 26 14:23:45 2018 -0700
committer Brad Ebinger <breadley@google.com> Thu Apr 26 15:42:22 2018 -0700
tree 708d562abeaadaa96977d436bbc3856d2c1fdb88
parent 01720f232536a5f266918d9da1d1b8a500ee7113

Handle Dead Objects from Phone Crashes better

1) Check to make sure ImsService is available when calling
changeMmTelCapability.
2) Remove caching of ImsConfig in ImsManager. It is already
cached properly in MmTelFeatureConnection.
3) Create a DeathRecipient for MmTelFeature in
MmTelFeatureConnection that cleans up all caches and notifies
ImsManager that the connection is now unavailable.

Bug: 77941698
Test: Manual
Change-Id: I9c3721fe275a94f7f8841e8e84a2f9d8a3c4823b

src/java/com/android/ims/MmTelFeatureConnection.java

diff --git a/src/java/com/android/ims/MmTelFeatureConnection.java b/src/java/com/android/ims/MmTelFeatureConnection.java
index 0706921..d6954f3 100644
--- a/src/java/com/android/ims/MmTelFeatureConnection.java
+++ b/src/java/com/android/ims/MmTelFeatureConnection.java
@@ -75,6 +75,11 @@
     private IImsRegistration mRegistrationBinder;
     private IImsConfig mConfigBinder;
 
+    private IBinder.DeathRecipient mDeathRecipient = () -> {
+            Log.w(TAG, "DeathRecipient triggered, binder died.");
+            onRemovedOrDied();
+    };
+
     private abstract class CallbackAdapterManager<T> {
         private static final String TAG = "CallbackAdapterManager";
 
@@ -337,14 +342,8 @@
                 }
                 switch (feature) {
                     case ImsFeature.FEATURE_MMTEL: {
-                        if (mIsAvailable) {
-                            Log.i(TAG, "MmTel disabled on slotId: " + slotId);
-                            mIsAvailable = false;
-                            mmTelFeatureRemoved();
-                            if (mStatusCallback != null) {
-                                mStatusCallback.notifyUnavailable();
-                            }
-                        }
+                        Log.i(TAG, "MmTel removed on slotId: " + slotId);
+                        onRemovedOrDied();
                         break;
                     }
                     case ImsFeature.FEATURE_EMERGENCY_MMTEL : {
@@ -376,12 +375,23 @@
         mContext = context;
     }
 
-    // Called when the MmTelFeatureConnection has received an unavailable notification.
-    private void mmTelFeatureRemoved() {
+    /**
+     * Called when the MmTelFeature has either been removed by Telephony or crashed.
+     */
+    private void onRemovedOrDied() {
         synchronized (mLock) {
-            // invalidate caches.
-            mRegistrationBinder = null;
-            mConfigBinder = null;
+            if (mIsAvailable) {
+                mIsAvailable = false;
+                // invalidate caches.
+                mRegistrationBinder = null;
+                mConfigBinder = null;
+                if (mBinder != null) {
+                    mBinder.unlinkToDeath(mDeathRecipient, 0);
+                }
+                if (mStatusCallback != null) {
+                    mStatusCallback.notifyUnavailable();
+                }
+            }
         }
     }
 
@@ -434,7 +444,16 @@
     }
 
     public void setBinder(IBinder binder) {
-        mBinder = binder;
+        synchronized (mLock) {
+            mBinder = binder;
+            try {
+                if (mBinder != null) {
+                    mBinder.linkToDeath(mDeathRecipient, 0);
+                }
+            } catch (RemoteException e) {
+                // No need to do anything if the binder is already dead.
+            }
+        }
     }
 
     /**