MetaspaceWrapperObject.java revision 12657:6ef01bd40ce2 
1/*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package jdk.vm.ci.hotspot;
24
25/**
26 * A tag interface indicating that this type is a wrapper around a HotSpot metaspace object that
27 * requires GC interaction to keep alive.
28 *
29 * It would preferable if this were the base class containing the pointer but that would require
30 * mixins since most of the wrapper types have complex supertype hierarchies.
31 */
32interface MetaspaceWrapperObject {
33
34    long getMetaspacePointer();
35
36    /**
37     * Check if this object is properly registered for metadata tracking. All classes which
38     * implement this interface must be registered with the
39     * {@link HotSpotJVMCIMetaAccessContext#add} unless they are kept alive through other means.
40     * Currently the only type which doesn't require explicit registration is
41     * {@link HotSpotResolvedObjectTypeImpl} since it's kept alive by references to the
42     * {@link Class}.
43     *
44     * @return true if this object is properly registered for meta data tracking.
45     */
46    default boolean isRegistered() {
47        return HotSpotJVMCIRuntime.runtime().metaAccessContext.isRegistered(this);
48    }
49}
50