hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/ContiguousSpace.java

/*
 * Copyright (c) 2000, 2004, 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.
 *
 * 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 sun.jvm.hotspot.memory;

import java.io.*;
import java.util.*;

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

public class ContiguousSpace extends CompactibleSpace {
  private static AddressField topField;

  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("ContiguousSpace");

    topField = type.getAddressField("_top");
  }

  public ContiguousSpace(Address addr) {
    super(addr);
  }

  public Address top() {
    return topField.getValue(addr);
  }

  /** In bytes */
  public long capacity() {
    return end().minus(bottom());
  }

  /** In bytes */
  public long used() {
    return top().minus(bottom());
  }

  /** In bytes */
  public long free() {
    return end().minus(top());
  }

  /** In a contiguous space we have a more obvious bound on what parts
      contain objects. */
  public MemRegion usedRegion() {
    return new MemRegion(bottom(), top());
  }

  /** Returns regions of Space where live objects live */
  public List/*<MemRegion>*/ getLiveRegions() {
    List res = new ArrayList();
    res.add(new MemRegion(bottom(), top()));
    return res;
  }

  /** Testers */
  public boolean contains(Address p) {
    return (bottom().lessThanOrEqual(p) && top().greaterThan(p));
  }

  public void printOn(PrintStream tty) {
    tty.print(" [" + bottom() + "," +
                top() + "," + end() + ")");
    super.printOn(tty);
  }
}