/**
* Given a slot (ie the address of an ObjectReference), ensure that the referent will not move for
* the rest of the GC. This is achieved by calling the precopyObject method.
*
* @param slot The slot to check
*/
@Inline
public final void processPrecopyEdge(Address slot) {
ObjectReference child = slot.loadObjectReference();
if (!child.isNull()) {
child = precopyObject(child);
slot.store(child);
}
}
/**
* Load and return the value of a reference field of an object.
*
* @param object The object to load the field of.
* @param index The field index.
*/
public ObjectReference loadReferenceField(ObjectReference object, int index) {
int limit = ObjectModel.getRefs(object);
check(!object.isNull(), "Object can not be null");
check(index >= 0, "Index must be non-negative");
check(index < limit, "Index " + index + " out of bounds " + limit);
Address referenceSlot = ObjectModel.getRefSlot(object, index);
ObjectReference result;
if (ActivePlan.constraints.needsReadBarrier()) {
result = context.readBarrier(object, referenceSlot, null, null, Plan.AASTORE_WRITE_BARRIER);
} else {
result = referenceSlot.loadObjectReference();
}
Trace.trace(
Item.LOAD,
"[%s].object[%d] returned [%s]",
ObjectModel.getString(object),
index,
result.toString());
return result;
}
/**
* Load an object reference
*
* @param slot The location of the reference
* @return the object reference loaded from slot
*/
@Inline
public ObjectReference loadObjectReference(Address slot) {
return slot.loadObjectReference();
}
/**
* Trace a reference during GC. This involves determining which collection policy applies and
* calling the appropriate <code>trace</code> method.
*
* @param source The source of the reference.
* @param slot The location containing the object reference to be traced. The object reference is
* <i>NOT</i> an interior pointer.
* @param root True if <code>objLoc</code> is within a root.
*/
@Inline
public final void processEdge(ObjectReference source, Address slot) {
ObjectReference object = slot.loadObjectReference();
ObjectReference newObject = traceObject(object, false);
slot.store(newObject);
}
/**
* Trace a reference during GC. This involves determining which collection policy applies and
* calling the appropriate <code>trace</code> method.
*
* @param slot The location containing the object reference to be traced. The object reference is
* <i>NOT</i> an interior pointer.
* @param root True if <code>objLoc</code> is within a root.
*/
@Inline
public final void processRootEdge(Address slot) {
ObjectReference object = slot.loadObjectReference();
ObjectReference newObject = traceObject(object, true);
slot.store(newObject);
}