poll_stop_timer(3) on FreeBSD
The text 33e7c240ece1, as FreeBSD 6.4-RELEASE, FreeBSD 6.3-RELEASE, FreeBSD 6.2-RELEASE, FreeBSD 6.1-RELEASE, FreeBSD 6.0-RELEASE, FreeBSD 5.5-RELEASE, FreeBSD 5.4-RELEASE, FreeBSD 5.3-RELEASE shipped it.
callback functions for file descriptors and timers