src/java.desktop/share/classes/com/sun/beans/introspect/ClassInfo.java - master - githubmirror/jdk22

src/java.desktop/share/classes/com/sun/beans/introspect/ClassInfo.java
117 строк4 KB
Andrey Turbanov
8293986: Incorrect double-checked locking in com.sun.beans.introspect.ClassInfo
11 окт 2022, 08:59
11 окт 2022, 08:59e775acf
/*
 * Copyright (c) 2014, 2022, 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 com.sun.beans.introspect;

import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;

import com.sun.beans.util.Cache;

import static sun.reflect.misc.ReflectUtil.checkPackageAccess;

public final class ClassInfo {
    private static final ClassInfo DEFAULT = new ClassInfo(null);
    private static final Cache<Class<?>,ClassInfo> CACHE
            = new Cache<Class<?>,ClassInfo>(Cache.Kind.SOFT, Cache.Kind.SOFT) {
        @Override
        public ClassInfo create(Class<?> type) {
            return new ClassInfo(type);
        }
    };

    public static ClassInfo get(Class<?> type) {
        if (type == null) {
            return DEFAULT;
        }
        try {
            checkPackageAccess(type);
            return CACHE.get(type);
        } catch (SecurityException exception) {
            return DEFAULT;
        }
    }

    public static void clear() {
        CACHE.clear();
    }

    public static void remove(Class<?> clz) {
        CACHE.remove(clz);
    }

    private final Object mutex = new Object();
    private final Class<?> type;
    private volatile List<Method> methods;
    private volatile Map<String,PropertyInfo> properties;
    private volatile Map<String,EventSetInfo> eventSets;

    private ClassInfo(Class<?> type) {
        this.type = type;
    }

    public List<Method> getMethods() {
        List<Method> methods = this.methods;
        if (methods == null) {
            synchronized (this.mutex) {
                methods = this.methods;
                if (methods == null) {
                    methods = MethodInfo.get(this.type);
                    this.methods = methods;
                }
            }
        }
        return methods;
    }

    public Map<String,PropertyInfo> getProperties() {
        Map<String, PropertyInfo> properties = this.properties;
        if (properties == null) {
            synchronized (this.mutex) {
                properties = this.properties;
                if (properties == null) {
                    properties = PropertyInfo.get(this.type);
                    this.properties = properties;
                }
            }
        }
        return properties;
    }

    public Map<String,EventSetInfo> getEventSets() {
        Map<String, EventSetInfo> eventSets = this.eventSets;
        if (eventSets == null) {
            synchronized (this.mutex) {
                eventSets = this.eventSets;
                if (eventSets == null) {
                    eventSets = EventSetInfo.get(this.type);
                    this.eventSets = eventSets;
                }
            }
        }
        return eventSets;
    }
}