Revert "Fix update of services for multiple backend mode"

This reverts commit 468d4e8dc2.

Reason for revert: Change causing NPE b/20797663

Change-Id: Ia71efac2d8583cc5ac79879f10209784c700fbb0

services/core/java/com/android/server/infra/AbstractMasterSystemService.java

@@ -684,15 +684,6 @@ public abstract class AbstractMasterSystemService<M extends AbstractMasterSystem
      */
     @GuardedBy("mLock")
     protected List<S> updateCachedServiceListLocked(@UserIdInt int userId, boolean disabled) {
-        if (mServiceNameResolver.isConfiguredInMultipleMode()) {
-            // In multiple mode, we have multiple instances of AbstractPerUserSystemService, per
-            // user where each instance holds information needed to connect to a backend. An
-            // update operation in this mode needs to account for addition, deletion, change
-            // of backends and cannot be executed in the scope of a given
-            // AbstractPerUserSystemService.
-            return updateCachedServiceListMultiModeLocked(userId, disabled);
-        }
-        // isConfiguredInMultipleMode is false
         final List<S> services = getServiceListForUserLocked(userId);
         if (services == null) {
             return null;
@@ -713,19 +704,6 @@ public abstract class AbstractMasterSystemService<M extends AbstractMasterSystem
         return services;
     }
 
-    @GuardedBy("mLock")
-    private List<S> updateCachedServiceListMultiModeLocked(int userId, boolean disabled) {
-        final int resolvedUserId = ActivityManager.handleIncomingUser(Binder.getCallingPid(),
-                Binder.getCallingUid(), userId, false, false, null,
-                null);
-        List<S> services = new ArrayList<>();
-	synchronized (mLock) {
-            removeCachedServiceListLocked(resolvedUserId);
-            services = getServiceListForUserLocked(userId);
-        }
-        return services;
-    }
-
     /**
      * Gets the Settings property that defines the name of the component name used to bind this
      * service to an external service, or {@code null} when the service is not defined by such

services/core/java/com/android/server/infra/AbstractPerUserSystemService.java

@@ -154,14 +154,7 @@ public abstract class AbstractPerUserSystemService<S extends AbstractPerUserSyst
 
         if (mMaster.mServiceNameResolver != null
                 && mMaster.mServiceNameResolver.isConfiguredInMultipleMode()) {
-            // Update of multi configured mode should always happen in AbstractMasterSystemService
-            // as this class is not aware of the complete list of multiple backends. Since we
-            // should never end up in this state, it is safe to not do anything if we end up here
-            // through a different code path.
-            if (mMaster.debug) {
-                Slog.d(mTag, "Should not end up in updateLocked when "
-                        + "isConfiguredInMultipleMode is true");
-            }
+            updateServiceInfoListLocked();
         } else {
             updateServiceInfoLocked();
         }
@@ -173,14 +166,29 @@ public abstract class AbstractPerUserSystemService<S extends AbstractPerUserSyst
      */
     @GuardedBy("mLock")
     protected final ComponentName updateServiceInfoLocked() {
+        ComponentName[] componentNames = updateServiceInfoListLocked();
+        return componentNames == null || componentNames.length == 0 ? null : componentNames[0];
+    }
+
+    /**
+     * Updates the internal reference to the service info, and returns the service's component.
+     */
+    @GuardedBy("mLock")
+    protected final ComponentName[] updateServiceInfoListLocked() {
         if (mMaster.mServiceNameResolver == null) {
             return null;
         }
         if (!mMaster.mServiceNameResolver.isConfiguredInMultipleMode()) {
             final String componentName = getComponentNameLocked();
-            return getServiceComponent(componentName);
+            return new ComponentName[] { getServiceComponent(componentName) };
         }
-        return null;
+        final String[] componentNames = mMaster.mServiceNameResolver.getServiceNameList(
+                mUserId);
+        ComponentName[] serviceComponents = new ComponentName[componentNames.length];
+        for (int i = 0; i < componentNames.length; i++) {
+            serviceComponents[i] = getServiceComponent(componentNames[i]);
+        }
+        return serviceComponents;
     }
 
     private ComponentName getServiceComponent(String componentName) {