Is it the right way to pass an argument to callback?

Hello. I wonder if I pass a callback argument here the right way: http://susepaste.org/99481533 It generally works as follows. <?php function mycb($d, $r) { echo "mycb\n"; } eio_nop(0, "mycb", "some data"); while (eio_nreqs()) eio_poll(); ?> eio_nop calls an external library function with the same name. The latter allocates data for a new thread, and eventually calls pthread_create(). http://susepaste.org/14228605 (etp_submit() creates a thread). eio_nreqs() checks if there is something queued. eio_poll() makes some of the queued tasks to execute, and calls callbacks for each task (in our case the only, eio_nop with callback php_eio_res_cb). When the program flow goes into php_eio_res_cb(eio_req *req), the argument (req) looses it's value! Why and where? eio_poll() internally calls it like /* here req is correct */ int res = EIO_FINISH (req); /* php_eio_res_cb(req) { !!! req is incorrect here !!! } */ /* here req is correct again! */ I tried to disassemble the code. Didn't found what makes it to behave such a weird way. The extension is my first experience in PECL. So I'm asking for help of you, guru, who will notice my dumb fault. Thank you.