2023-09-27 08:16:34 +00:00

113 lines
3.5 KiB
Java

/*
* Copyright (c) 2001, 2023, 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.runtime;
import java.util.*;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.utilities.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.utilities.Observable;
import sun.jvm.hotspot.utilities.Observer;
public class ObjectSynchronizer {
static {
VM.registerVMInitializedObserver(new Observer() {
public void update(Observable o, Object data) {
initialize(VM.getVM().getTypeDataBase());
}
});
}
private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
Type objectSynchronizerType = db.lookupType("ObjectSynchronizer");
Type monitorListType = db.lookupType("MonitorList");
Address monitorListAddr = objectSynchronizerType.getField("_in_use_list").getStaticFieldAddress();
inUseListHead = monitorListType.getAddressField("_head").getAddress(monitorListAddr);
}
public long identityHashValueFor(Oop obj) {
Mark mark = obj.getMark();
if (mark.isUnlocked()) {
// FIXME: can not generate marks in debugging system
return mark.hash();
} else if (mark.hasMonitor()) {
ObjectMonitor monitor = mark.monitor();
Mark temp = monitor.header();
return temp.hash();
} else {
if (Assert.ASSERTS_ENABLED) {
Assert.that(VM.getVM().isDebugging(), "Can not access displaced header otherwise");
}
if (mark.hasDisplacedMarkHelper()) {
Mark temp = mark.displacedMarkHelper();
return temp.hash();
}
// FIXME: can not do anything else here in debugging system
return 0;
}
}
public static Iterator objectMonitorIterator() {
return new ObjectMonitorIterator();
}
private static class ObjectMonitorIterator implements Iterator {
// JVMTI raw monitors are not included in _in_use_list and
// are not returned by this Iterator.
ObjectMonitorIterator() {
mon = inUseListHead == null ? null : new ObjectMonitor(inUseListHead);
}
public boolean hasNext() {
return (mon != null);
}
public Object next() {
ObjectMonitor ret = mon;
if (ret == null) {
throw new NoSuchElementException();
}
// advance to next entry
Address nextMon = mon.nextOM();
mon = nextMon == null ? null : new ObjectMonitor(nextMon);
return ret;
}
public void remove() {
throw new UnsupportedOperationException();
}
private ObjectMonitor mon;
}
private static Address inUseListHead;
}