/** Sift element added at top down to its heap-ordered spot. Call only when holding lock. */
private void siftDown(int k, RunnableScheduledFuture<?> key) {
int half = size >>> 1;
while (k < half) {
int child = (k << 1) + 1;
RunnableScheduledFuture<?> c = queue[child];
int right = child + 1;
if (right < size && c.compareTo(queue[right]) > 0) c = queue[child = right];
if (key.compareTo(c) <= 0) break;
queue[k] = c;
setIndex(c, k);
k = child;
}
queue[k] = key;
setIndex(key, k);
}
/** Sift element added at bottom up to its heap-ordered spot. Call only when holding lock. */
private void siftUp(int k, RunnableScheduledFuture<?> key) {
while (k > 0) {
int parent = (k - 1) >>> 1;
RunnableScheduledFuture<?> e = queue[parent];
if (key.compareTo(e) >= 0) break;
queue[k] = e;
setIndex(e, k);
k = parent;
}
queue[k] = key;
setIndex(key, k);
}
