1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License 15 */ 16 17 package com.android.server 18 19 import java.util.concurrent.atomic.AtomicInteger 20 21 /** 22 * A [NetIdManager] that generates ID starting from [NetIdManager.MAX_NET_ID] and decreasing, rather 23 * than starting from [NetIdManager.MIN_NET_ID] and increasing. 24 * 25 * Useful for testing ConnectivityService, to minimize the risk of test ConnectivityService netIDs 26 * overlapping with netIDs used by the real ConnectivityService on the device. 27 * 28 * IDs may still overlap if many networks have been used on the device (so the "real" netIDs 29 * are close to MAX_NET_ID), but this is typically not the case when running unit tests. Also, there 30 * is no way to fully solve the overlap issue without altering ID allocation in non-test code, as 31 * the real ConnectivityService could start using netIds that have been used by the test in the 32 * past. 33 */ 34 class TestNetIdManager : NetIdManager() { 35 private val nextId = AtomicInteger(MAX_NET_ID) reserveNetIdnull36 override fun reserveNetId() = nextId.decrementAndGet() 37 override fun releaseNetId(id: Int) = Unit 38 fun peekNextNetId() = nextId.get() - 1 39 } 40