/**
* Check if an address appears to point to an instance of RVMType
*
* @param typeAddress the address to check
* @return {@code true} if and only if the address appears to be an an instance of RVMType
*/
@Uninterruptible
public static boolean validType(ObjectReference typeAddress) {
if (!Space.isMappedObject(typeAddress)) {
return false; // type address is outside of heap
}
// check if types tib is one of three possible values
TIB typeTib = ObjectModel.getTIB(typeAddress);
return ((typeTib == tibForClassType)
|| (typeTib == tibForArrayType)
|| (typeTib == tibForPrimitiveType));
}
@Uninterruptible
public static boolean validRef(ObjectReference ref) {
if (ref.isNull()) return true;
if (!Space.isMappedObject(ref)) {
VM.sysWrite("validRef: REF outside heap, ref = ");
VM.sysWrite(ref);
VM.sysWrite("\n");
Space.printVMMap();
return false;
}
if (MOVES_OBJECTS) {
/*
TODO: Work out how to check if forwarded
if (Plan.isForwardedOrBeingForwarded(ref)) {
// TODO: actually follow forwarding pointer
// (need to bound recursion when things are broken!!)
return true;
}
*/
}
TIB tib = ObjectModel.getTIB(ref);
Address tibAddr = Magic.objectAsAddress(tib);
if (!Space.isMappedObject(ObjectReference.fromObject(tib))) {
VM.sysWrite("validRef: TIB outside heap, ref = ");
VM.sysWrite(ref);
VM.sysWrite(" tib = ");
VM.sysWrite(tibAddr);
VM.sysWrite("\n");
ObjectModel.dumpHeader(ref);
return false;
}
if (tibAddr.isZero()) {
VM.sysWrite("validRef: TIB is Zero! ");
VM.sysWrite(ref);
VM.sysWrite("\n");
ObjectModel.dumpHeader(ref);
return false;
}
if (tib.length() == 0) {
VM.sysWrite("validRef: TIB length zero, ref = ");
VM.sysWrite(ref);
VM.sysWrite(" tib = ");
VM.sysWrite(tibAddr);
VM.sysWrite("\n");
ObjectModel.dumpHeader(ref);
return false;
}
ObjectReference type = ObjectReference.fromObject(tib.getType());
if (!validType(type)) {
VM.sysWrite("validRef: invalid TYPE, ref = ");
VM.sysWrite(ref);
VM.sysWrite(" tib = ");
VM.sysWrite(Magic.objectAsAddress(tib));
VM.sysWrite(" type = ");
VM.sysWrite(type);
VM.sysWrite("\n");
ObjectModel.dumpHeader(ref);
return false;
}
return true;
} // validRef
@Uninterruptible
public static boolean mappedVMRef(ObjectReference ref) {
return Space.isMappedObject(ref) && Mmapper.objectIsMapped(ref);
}