deep-c-rsc/JCGO/goclsp/vm/java/lang/ref/VMReference.java
2021-07-16 17:12:20 -05:00

106 lines
3.3 KiB
Java

/*
* @(#) $(JCGO)/goclsp/vm/java/lang/ref/VMReference.java --
* VM specific methods for Java "Reference" class.
**
* Project: JCGO (http://www.ivmaisoft.com/jcgo/)
* Copyright (C) 2001-2008 Ivan Maidanski <ivmai@ivmaisoft.com>
* All rights reserved.
*/
/*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
**
* This software 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 (GPL) for more details.
**
* Linking this library statically or dynamically with other modules is
* making a combined work based on this library. Thus, the terms and
* conditions of the GNU General Public License cover the whole
* combination.
**
* As a special exception, the copyright holders of this library give you
* permission to link this library with independent modules to produce an
* executable, regardless of the license terms of these independent
* modules, and to copy and distribute the resulting executable under
* terms of your choice, provided that you also meet, for each linked
* independent module, the terms and conditions of the license of that
* module. An independent module is a module which is not derived from
* or based on this library. If you modify this library, you may extend
* this exception to your version of the library, but you are not
* obligated to do so. If you do not wish to do so, delete this
* exception statement from your version.
*/
package java.lang.ref;
final class VMReference
{ /* VM class */ /* used by VM classes only */
static
{
if (!"".equals("")) /* hack */
enqueueByGC0X(null, null); /* hack */
}
private VMReference() {}
static final void initReferent(Reference ref, Object referent)
{
if (referent != null)
setReferenceVmData(initReferent0(referent), ref);
}
static final void initEnqueuedReferent(Reference ref, Object referent)
{
if (referent != null)
setReferenceVmData(initEnqueuedReferent0(ref, referent,
ref instanceof PhantomReference ? 1 : 0), ref);
}
static final Object getReferent(Reference ref)
{
Object vmdata;
return (vmdata = ref.vmdata) != null ? (ref instanceof SoftReference ?
updateSoftRefAndGet0(vmdata) : getReferent0(vmdata)) : null;
}
static final void clearReferent(Reference ref)
{
ref.vmdata = null;
}
static final int enqueueByGC0X(Object refObj, Object vmdata)
{ /* called from native code */
Reference ref = (Reference) refObj;
ref.vmdata = vmdata;
ReferenceQueue queue;
if ((queue = ref.queue) != null)
queue.enqueue(ref);
return 0;
}
private static void setReferenceVmData(Object vmdata, Reference ref)
{
if (vmdata == null)
throw new OutOfMemoryError();
ref.vmdata = vmdata;
if (ref instanceof SoftReference)
updateSoftRefAndGet0(vmdata);
}
private static native Object initReferent0(Object referent); /* JVM-core */
private static native Object initEnqueuedReferent0(Object refObj,
Object referent, int noclear); /* JVM-core */
private static native Object getReferent0(Object vmdata); /* JVM-core */
private static native Object updateSoftRefAndGet0(
Object vmdata); /* JVM-core */
}