/* ... Thread safety and multiplicity ...................................... */
/* Always safe when the workaround isn't needed */
/* ... Thread safety and multiplicity ...................................... */
/* Always safe when the workaround isn't needed */
if (ptable_fetch(seen, o))
return;
ptable_seen_store(seen, o, o);
if (ptable_fetch(seen, o))
return;
ptable_seen_store(seen, o, o);