services/tests/servicestests/src/com/android/server/SystemServiceManagerTest.java

/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.server;

import static org.junit.Assert.assertThrows;

import android.test.AndroidTestCase;

import org.junit.Test;

import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;


/**
 * Tests for {@link SystemServiceManager}.
 */
public class SystemServiceManagerTest extends AndroidTestCase {

    private static final String TAG = "SystemServiceManagerTest";

    private final SystemServiceManager mSystemServiceManager =
            new SystemServiceManager(getContext());

    @Test
    public void testSealStartedServices() throws Exception {
        // must be effectively final, since it's changed from inner class below
        AtomicBoolean serviceStarted = new AtomicBoolean(false);
        SystemService service1 = new SystemService(getContext()) {
            @Override
            public void onStart() {
                serviceStarted.set(true);
            }
        };
        SystemService service2 = new SystemService(getContext()) {
            @Override
            public void onStart() {
                throw new IllegalStateException("Second service must not be called");
            }
        };

        // started services have their #onStart methods called
        mSystemServiceManager.startService(service1);
        assertTrue(serviceStarted.get());

        // however, after locking started services, it is not possible to start a new service
        mSystemServiceManager.sealStartedServices();
        assertThrows(UnsupportedOperationException.class,
                () -> mSystemServiceManager.startService(service2));
    }

    @Test
    public void testDuplicateServices() throws Exception {
        AtomicInteger counter = new AtomicInteger(0);
        SystemService service = new SystemService(getContext()) {
            @Override
            public void onStart() {
                counter.incrementAndGet();
            }
        };

        mSystemServiceManager.startService(service);
        assertEquals(1, counter.get());

        // manager does not start the same service twice
        mSystemServiceManager.startService(service);
        assertEquals(1, counter.get());
    }

}