private static int tableSizeFor(int c) {
    int n = c - 1;
    n |= n >>> 1;
    n |= n >>> 2;
    n |= n >>> 4;
    n |= n >>> 8;
    n |= n >>> 16;
    return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
  }
Returns a power of two table size for the given desired capacity. See Hackers Delight, sec 3.2
geode-core/src/main/java/org/apache/geode/internal/concurrent/CompactConcurrentHashSet2.java