static Node safeNext(Node b) {
while (true) {
Node n = b.next;
if (n == null) return null;
n.incRefCnt();
if (n == b.next) return n;
else release(n);
}
}
public void found(Node n) {
n.incRefCnt();
}
// only used by putAtomic and PutAtomicIfAbsent. Inside synchronized(b) and synchronized(this).
private void putAtomicReally(
Node b, int pos, double key, Object value, ConcurrentDoubleOrderedListMap orderedMap) {
int len = len();
if (len + 1 <= keys.length) {
if (pos == len) { // in-place append in the current node
keys[pos] = key;
vals[pos] = value;
length = len + 1;
if (pos == 0) {
orderedMap.skipListMap.put(keys[0], this);
}
} else { // copied to a new node, replacing the current node
mark();
Node n = Node.alloc();
n.next = this.next;
if (next != null) next.incRefCnt();
double[] nkeys = n.keys;
Object[] nvals = n.vals;
n.length = len + 1;
nodeCopy(keys, vals, 0, nkeys, nvals, 0, pos);
nkeys[pos] = key;
nvals[pos] = value;
nodeCopy(keys, vals, pos, nkeys, nvals, pos + 1, len - pos);
orderedMap.skipListMap.put(nkeys[0], n);
b.casNext(this, n); // should always succeed.
if (pos == 0) {
orderedMap.skipListMap.remove(keys[0], this);
}
release(this);
free(this);
}
} else { // requires 2 new nodes, to replace the current node
mark();
Node n1 = Node.alloc();
double[] n1keys = n1.keys;
Object[] n1vals = n1.vals;
Node n2 = Node.alloc();
double[] n2keys = n2.keys;
Object[] n2vals = n2.vals;
int l1 = len / 2, l2 = len - l1;
if (pos < l1) { // key, value stored in n1
n1.length = l1 + 1;
n2.length = l2;
nodeCopy(keys, vals, 0, n1keys, n1vals, 0, pos);
n1keys[pos] = key;
n1vals[pos] = value;
nodeCopy(keys, vals, pos, n1keys, n1vals, pos + 1, l1 - pos);
nodeCopy(keys, vals, l1, n2keys, n2vals, 0, l2);
n1.next = n2;
n2.next = this.next;
if (next != null) next.incRefCnt();
orderedMap.skipListMap.put(n1keys[0], n1);
orderedMap.skipListMap.put(n2keys[0], n2);
b.casNext(this, n1); // should always succeed.
if (pos == 0) {
orderedMap.skipListMap.remove(keys[0], this);
}
release(this);
free(this);
} else { // key,value is stored in n2
n1.length = l1;
n2.length = l2 + 1;
int newpos = pos - l1;
nodeCopy(keys, vals, 0, n1keys, n1vals, 0, l1);
nodeCopy(keys, vals, l1, n2keys, n2vals, 0, newpos);
n2keys[newpos] = key;
n2vals[newpos] = value;
nodeCopy(keys, vals, pos, n2keys, n2vals, newpos + 1, l2 - newpos);
n1.next = n2;
n2.next = this.next;
if (next != null) next.incRefCnt();
orderedMap.skipListMap.put(n1keys[0], n1);
orderedMap.skipListMap.put(n2keys[0], n2);
b.casNext(this, n1); // should always succeed.
release(this);
free(this);
}
}
}