/*
* Copyright (c) 2007, 2011, 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 com.sun.max.vm.monitor;
import com.sun.max.annotate.*;
import com.sun.max.vm.*;
import com.sun.max.vm.reference.*;
/**
*/
public abstract class AbstractMonitorScheme extends AbstractVMScheme implements MonitorScheme {
@HOSTED_ONLY
protected AbstractMonitorScheme() {
}
private int counter;
@INLINE
public final int createHashCode(Object object) {
if (MaxineVM.isHosted()) {
return System.identityHashCode(object);
}
int hashCode = Reference.fromJava(object).toOrigin().unsignedShiftedRight(3).toInt() ^ counter++;
// Ensure the hash code is positive. Even though the specification does not require this, at
// least one application (NetBeans) assumes this is the case (see https://netbeans.org/bugzilla/show_bug.cgi?id=178688).
return hashCode & ~0x80000000;
}
}