Use FgThread for callbacks in RemoteRoleControllerService.

Previously RemoteRoleControllerService was calling callbacks on
BackgroundThread, which was causing disk writes delaying queued binder
calls significantly. FgThread is the right thread for this and should
solve this issue.

Bug: 110557011
Test: manual
Change-Id: I6b7a55c2197b1f86572705e6df46cd3f18ff91f7

services/core/java/com/android/server/role/RemoteRoleControllerService.java

@@ -34,8 +34,8 @@ import android.rolecontrollerservice.IRoleControllerService;
 import android.rolecontrollerservice.RoleControllerService;
 import android.util.Slog;
 
-import com.android.internal.os.BackgroundThread;
 import com.android.internal.util.function.pooled.PooledLambda;
+import com.android.server.FgThread;
 
 import java.util.ArrayDeque;
 import java.util.Queue;
@@ -48,10 +48,6 @@ public class RemoteRoleControllerService {
     static final boolean DEBUG = false;
     private static final String LOG_TAG = RemoteRoleControllerService.class.getSimpleName();
 
-    // TODO: STOPSHIP: This isn't the right thread, as we are also using it to write to disk.
-    @NonNull
-    private static final Handler sCallbackHandler = BackgroundThread.getHandler();
-
     @NonNull
     private final Connection mConnection;
 
@@ -99,8 +95,8 @@ public class RemoteRoleControllerService {
      * @see RoleControllerService#onGrantDefaultRoles(RoleManagerCallback)
      */
     public void onGrantDefaultRoles(@NonNull IRoleManagerCallback callback) {
-        mConnection.enqueueCall(
-                new Connection.Call(IRoleControllerService::onGrantDefaultRoles, callback));
+        mConnection.enqueueCall(new Connection.Call(IRoleControllerService::onGrantDefaultRoles,
+                callback));
     }
 
     private static final class Connection implements ServiceConnection {
@@ -113,6 +109,9 @@ public class RemoteRoleControllerService {
         @NonNull
         private final Context mContext;
 
+        @NonNull
+        private final Handler mHandler = FgThread.getHandler();
+
         private boolean mBound;
 
         @Nullable
@@ -161,8 +160,8 @@ public class RemoteRoleControllerService {
             if (DEBUG) {
                 Slog.i(LOG_TAG, "Enqueue " + call);
             }
-            sCallbackHandler.executeOrSendMessage(PooledLambda.obtainMessage(
-                    Connection::executeCall, this, call));
+            mHandler.executeOrSendMessage(PooledLambda.obtainMessage(Connection::executeCall, this,
+                    call));
         }
 
         @WorkerThread
@@ -181,7 +180,7 @@ public class RemoteRoleControllerService {
 
         @WorkerThread
         private void ensureBound() {
-            sCallbackHandler.removeCallbacks(mUnbindRunnable);
+            mHandler.removeCallbacks(mUnbindRunnable);
             if (!mBound) {
                 Intent intent = new Intent(RoleControllerService.SERVICE_INTERFACE);
                 intent.setPackage(mContext.getPackageManager()
@@ -191,13 +190,13 @@ public class RemoteRoleControllerService {
                 //
                 // Note that as a result, onServiceConnected may happen not on main thread!
                 mBound = mContext.bindServiceAsUser(intent, this, Context.BIND_AUTO_CREATE,
-                        sCallbackHandler, UserHandle.of(mUserId));
+                        mHandler, UserHandle.of(mUserId));
             }
         }
 
         private void scheduleUnbind() {
-            sCallbackHandler.removeCallbacks(mUnbindRunnable);
-            sCallbackHandler.postDelayed(mUnbindRunnable, UNBIND_DELAY_MILLIS);
+            mHandler.removeCallbacks(mUnbindRunnable);
+            mHandler.postDelayed(mUnbindRunnable, UNBIND_DELAY_MILLIS);
         }
 
         @WorkerThread
@@ -219,6 +218,9 @@ public class RemoteRoleControllerService {
             @NonNull
             private final IRoleManagerCallback mCallback;
 
+            @NonNull
+            private final Handler mHandler = FgThread.getHandler();
+
             @NonNull
             private final Runnable mTimeoutRunnable = this::notifyTimeout;
 
@@ -236,7 +238,7 @@ public class RemoteRoleControllerService {
                     Slog.i(LOG_TAG, "Executing " + this);
                 }
                 try {
-                    sCallbackHandler.postDelayed(mTimeoutRunnable, TIMEOUT_MILLIS);
+                    mHandler.postDelayed(mTimeoutRunnable, TIMEOUT_MILLIS);
                     mCallExecutor.execute(service, new CallbackDelegate());
                 } catch (RemoteException e) {
                     Slog.e(LOG_TAG, "Error calling RoleControllerService", e);
@@ -256,7 +258,7 @@ public class RemoteRoleControllerService {
                     return;
                 }
                 mCallbackNotified = true;
-                sCallbackHandler.removeCallbacks(mTimeoutRunnable);
+                mHandler.removeCallbacks(mTimeoutRunnable);
                 try {
                     if (success) {
                         mCallback.onSuccess();
@@ -286,14 +288,14 @@ public class RemoteRoleControllerService {
 
                 @Override
                 public void onSuccess() throws RemoteException {
-                    sCallbackHandler.sendMessage(PooledLambda.obtainMessage(
-                            Call::notifyCallback, Call.this, true));
+                    mHandler.sendMessage(PooledLambda.obtainMessage(Call::notifyCallback, Call.this,
+                            true));
                 }
 
                 @Override
                 public void onFailure() throws RemoteException {
-                    sCallbackHandler.sendMessage(PooledLambda.obtainMessage(
-                            Call::notifyCallback, Call.this, false));
+                    mHandler.sendMessage(PooledLambda.obtainMessage(Call::notifyCallback, Call.this,
+                            false));
                 }
             }
         }