>jit.os</tt></a>.
</p>

<h3 id="ffi_arch"><tt>ffi.arch</tt></h3>
<p>
Contains the target architecture name. Same contents as
<a href="ext_jit.html#jit_arch"><tt>jit.arch</tt></a>.
</p>

<h2 id="callback">Methods for Callbacks</h2>
<p>
The C&nbsp;types for <a href="ext_ffi_semantics.html#callback">callbacks</a>
have some extra methods:
</p>

<h3 id="callback_free"><tt>cb:free()</tt></h3>
<p>
Free the resources associated with a callback. The associated Lua
function is unanchored and may be garbage collected.