static int newGlobalRef(Object referent) {
if (VM.VerifyAssertions)
VM._assert(MemoryManager.validRef(ObjectReference.fromObject(referent)));
if (free >= JNIGlobalRefs.length()) {
AddressArray newGlobalRefs = AddressArray.create(JNIGlobalRefs.length() * 2);
copyAndReplaceGlobalRefs(newGlobalRefs);
}
JNIGlobalRefs.set(free, Magic.objectAsAddress(referent));
return -free++;
}
/**
* Weak Global References are global references (negative numbers), with the 2^30 bit UNset. Mask in
* the 2^30 bit to get the real index into the table.
*/
public class JNIGlobalRefTable {
@Entrypoint public static AddressArray JNIGlobalRefs = AddressArray.create(100);
private static int free = 1;
static int newGlobalRef(Object referent) {
if (VM.VerifyAssertions)
VM._assert(MemoryManager.validRef(ObjectReference.fromObject(referent)));
if (free >= JNIGlobalRefs.length()) {
AddressArray newGlobalRefs = AddressArray.create(JNIGlobalRefs.length() * 2);
copyAndReplaceGlobalRefs(newGlobalRefs);
}
JNIGlobalRefs.set(free, Magic.objectAsAddress(referent));
return -free++;
}
@Uninterruptible
private static void copyAndReplaceGlobalRefs(AddressArray newGlobalRefs) {
for (int i = 0; i < JNIGlobalRefs.length(); i++) {
newGlobalRefs.set(i, JNIGlobalRefs.get(i));
}
JNIGlobalRefs = newGlobalRefs;
}
/* Weak references are returned with the STRONG_REF_BIT bit UNset. */
public static final int STRONG_REF_BIT = 1 << 30;
static int newWeakRef(Object referent) {
int gref = newGlobalRef(new WeakReference<Object>(referent));
return gref & ~STRONG_REF_BIT;
}
static void deleteGlobalRef(int index) {
if (VM.VerifyAssertions) VM._assert(!isWeakRef(index));
JNIGlobalRefs.set(-index, Address.zero());
}
static void deleteWeakRef(int index) {
if (VM.VerifyAssertions) VM._assert(isWeakRef(index));
int gref = index | STRONG_REF_BIT;
deleteGlobalRef(gref);
}
@Uninterruptible
static Object globalRef(int index) {
if (VM.VerifyAssertions) VM._assert(!isWeakRef(index));
return Magic.addressAsObject(JNIGlobalRefs.get(-index));
}
@Uninterruptible
static Object weakRef(int index) {
if (VM.VerifyAssertions) VM._assert(isWeakRef(index));
@SuppressWarnings("unchecked") // yes, we're being bad.
WeakReference<Object> ref = (WeakReference<Object>) globalRef(index | STRONG_REF_BIT);
return java.lang.ref.JikesRVMSupport.uninterruptibleReferenceGet(ref);
}
@Uninterruptible
static Object ref(int index) {
if (isWeakRef(index)) {
return weakRef(index);
} else {
return globalRef(index);
}
}
@Uninterruptible
static boolean isWeakRef(int index) {
return (index & STRONG_REF_BIT) == 0;
}
}
