 using <a class="el" href="group__threading.html#gaa24a0c9896f1ad241e45590065c3f643" title="Defer execution of a function to the main thread if (and only if) your function is executing in the s...">defer()</a> and a qelem is that <a class="el" href="group__threading.html#gaa24a0c9896f1ad241e45590065c3f643" title="Defer execution of a function to the main thread if (and only if) your function is executing in the s...">defer()</a> is a one-shot deal &ndash; it creates a qelem, sets it, and then gets rid of it