src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/memory/MetaspaceObj.java
author iklam
Wed, 07 Nov 2018 19:40:27 -0800
changeset 52514 f4e3900c8d08
permissions -rw-r--r--
8213346: Re-implement shared dictionary using CompactHashtable Reviewed-by: jiangli

/*
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 * 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.
 *
 * 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.
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package sun.jvm.hotspot.memory;

import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.types.*;

public class MetaspaceObj {
  private static Address sharedMetaspaceBaseAddr;
  private static Address sharedMetaspaceTopAddr;

  static {
    VM.registerVMInitializedObserver(new Observer() {
        public void update(Observable o, Object data) {
          initialize(VM.getVM().getTypeDataBase());
        }
      });
  }

  private static synchronized void initialize(TypeDataBase db) {
    Type type = db.lookupType("MetaspaceObj");
    sharedMetaspaceBaseAddr = type.getAddressField("_shared_metaspace_base").getStaticFieldAddress();
    sharedMetaspaceTopAddr  = type.getAddressField("_shared_metaspace_top").getStaticFieldAddress();
  }

  public static boolean isShared(Address addr) {
    Address base = sharedMetaspaceBaseAddr.getAddressAt(0);
    Address top  = sharedMetaspaceTopAddr. getAddressAt(0);

    return base.lessThanOrEqual(addr) && addr.lessThan(top);
  }
}