Return type of getId() on a thread object
<p>Why does, for example, <code>Thread.currentThread().getId()</code> return a long?</p>

<p>Does this really need to be 64 bits? Like I'm going to ever have a machine running that number of threads!</p>

<p>Seriously, it's a bit of a pain since I'm writing something that keeps a track of thread identifiers along with other bits and I'd really rather not have to use such a long number, else the unique key I have to generate is enormous.</p>

<p>Perhaps there is a convention on the long return; like the first 48 bits are always zero. I had a dig about on the internet but didn't find anything. I hope so; does anyone know for sure?</p>

<p>Thanks.</p>
