private int getMaximumCapacity(int requestedCapacity) {
        return Pow2.roundToPowerOfTwo(requestedCapacity + getLookaheadStep(requestedCapacity));
    }
This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

@param buffer
@param requestedCapacity
jctools-channels/src/main/java/org/jctools/channels/spsc/SpscChannel.java