8204210: Implementation: JEP 333: ZGC: A Scalable Low-Latency Garbage Collector (Experimental)
Reviewed-by: pliden, stefank, eosterlund, ehelin, sjohanss, rbackman, coleenp, ihse, jgeorge, lmesnik, rkennke
Contributed-by: per.liden@oracle.com, stefan.karlsson@oracle.com, erik.osterlund@oracle.com, mikael.gerdin@oracle.com, kim.barrett@oracle.com, nils.eliasson@oracle.com, rickard.backman@oracle.com, rwestrel@redhat.com, coleen.phillimore@oracle.com, robbin.ehn@oracle.com, gerard.ziemski@oracle.com, hugh.wilkinson@intel.com, sandhya.viswanathan@intel.com, bill.npo.wheeler@intel.com, vinay.k.awasthi@intel.com, yasuenag@gmail.com
/*
* Copyright (c) 2000, 2015, 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.gc.shared;
import java.io.*;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.memory.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.types.*;
public abstract class CollectedHeap extends VMObject {
private static long reservedFieldOffset;
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("CollectedHeap");
reservedFieldOffset = type.getField("_reserved").getOffset();
}
public CollectedHeap(Address addr) {
super(addr);
}
/** Returns the lowest address of the heap. */
public Address start() {
return reservedRegion().start();
}
public long capacity() { return 0; }
public long used() { return 0; }
public MemRegion reservedRegion() {
return new MemRegion(addr.addOffsetTo(reservedFieldOffset));
}
public boolean isIn(Address a) {
return isInReserved(a);
}
public boolean isInReserved(Address a) {
return reservedRegion().contains(a);
}
public abstract CollectedHeapName kind();
public String oopAddressDescription(OopHandle handle) {
return handle.toString();
}
public OopHandle oop_load_at(OopHandle handle, long offset) {
return handle.getOopHandleAt(offset);
}
public void print() { printOn(System.out); }
public void printOn(PrintStream tty) {
MemRegion mr = reservedRegion();
tty.println("unknown subtype of CollectedHeap @ " + getAddress() + " (" +
mr.start() + "," + mr.end() + ")");
}
}