GuardedBy.kt

/*
 * Copyright (C) 2017 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 androidx.annotation

import kotlin.annotation.AnnotationRetention.BINARY

/**
 * Denotes that the annotated method or field can only be accessed when holding the referenced lock.
 *
 * Example:
 * ```
 * final Object objectLock = new Object();
 *
 * @GuardedBy("objectLock")
 * volatile Object object;
 *
 * Object getObject() {
 *     synchronized (objectLock) {
 *         if (object == null) {
 *             object = new Object();
 *         }
 *     }
 *     return object;
 * }
 * ```
 */
@Target(
    AnnotationTarget.FIELD,
    AnnotationTarget.FUNCTION,
    AnnotationTarget.PROPERTY_GETTER,
    AnnotationTarget.PROPERTY_SETTER
)
@Retention(BINARY)
public annotation class GuardedBy(val value: String)