Fix ImsManager NPE encountered during GTS testing

ImsManager was throwing a NPE because multiple requests to get
ImsService look to be getting scheduled in a race condition where
we are internally scheduling a retry and the binder thread is
scheduling a retry.

Fix synchronization in retry block and check for null ImsManager
just in case.

Test: atest GtsTelephonyTestCases
Change-Id: I5e4b5bf656642c1d26a88fe77726c44f2cfe8607

1 files changed, 11 insertions, 8 deletions

diff --git a/src/java/com/android/ims/ImsManager.java b/src/java/com/android/ims/ImsManager.java
index 0b540e82..5996c9a6 100644
--- a/src/java/com/android/ims/ImsManager.java
+++ b/src/java/com/android/ims/ImsManager.java
@@ -332,15 +332,18 @@ public class ImsManager {
 
         private void retryGetImsService() {
             synchronized (mLock) {
-                // remove callback so we do not receive updates from old ImsServiceProxy when
-                // switching between ImsServices.
-                mImsManager.removeNotifyStatusChangedCallback(mNotifyStatusChangedCallback);
-                //Leave mImsManager as null, then CallStateException will be thrown when dialing
-                mImsManager = null;
+                if (mImsManager != null) {
+                    // remove callback so we do not receive updates from old ImsServiceProxy when
+                    // switching between ImsServices.
+                    mImsManager.removeNotifyStatusChangedCallback(mNotifyStatusChangedCallback);
+                    //Leave mImsManager as null, then CallStateException will be thrown when dialing
+                    mImsManager = null;
+                }
+
+                // Exponential backoff during retry, limited to 32 seconds.
+                removeCallbacks(mGetServiceRunnable);
+                postDelayed(mGetServiceRunnable, mRetryTimeout.get());
             }
-            // Exponential backoff during retry, limited to 32 seconds.
-            removeCallbacks(mGetServiceRunnable);
-            postDelayed(mGetServiceRunnable, mRetryTimeout.get());
         }
 
         private void getImsService() throws ImsException {