| /* |
| * Copyright (C) 2019 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.connectivity; |
| |
| import android.annotation.NonNull; |
| |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| /** |
| * A ref that autodestructs at the first usage of it. |
| * @param <T> The type of the held object |
| * @hide |
| */ |
| public class AutodestructReference<T> { |
| private final AtomicReference<T> mHeld; |
| public AutodestructReference(@NonNull T obj) { |
| if (null == obj) throw new NullPointerException("Autodestruct reference to null"); |
| mHeld = new AtomicReference<>(obj); |
| } |
| |
| /** Get the ref and destruct it. NPE if already destructed. */ |
| @NonNull |
| public T getAndDestroy() { |
| final T obj = mHeld.getAndSet(null); |
| if (null == obj) throw new NullPointerException("Already autodestructed"); |
| return obj; |
| } |
| } |