src/java.base/share/classes/jdk/internal/util/ReferenceKey.java - master - githubmirror/jdk22

src/java.base/share/classes/jdk/internal/util/ReferenceKey.java

51 строка2 KB

Jim Laskey

8310913: Move ReferencedKeyMap to jdk.internal so it may be shared

31 июл 2023, 22:11

31 июл 2023, 22:116af0af5

/*
 * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.internal.util;

import java.lang.ref.Reference;

/**
 * View/wrapper of keys used by the backing {@link ReferencedKeyMap}.
 * There are two style of keys; one for entries in the backing map and
 * one for queries to the backing map. This second style avoids the
 * overhead of a {@link Reference} object.
 *
 * @param <T> key type
 *
 * @since 21
 */
public sealed interface ReferenceKey<T> permits StrongReferenceKey, WeakReferenceKey, SoftReferenceKey {
    /**
     * {@return the value of the unwrapped key}
     */
    T get();

    /**
     * Cleanup unused key.
     */
    void unused();

}