Re: epoll design problems with common fork/exec patterns

Sam Varshavchik
2008-03-02T15:17:34Z

[-- Attachment #1: Type: text/plain, Size: 677 bytes --]

Hijacking this epoll thread, the following related question occurs to me:

#Q8
# Does an operation on a file descriptor affect the already collected but
#not yet reported events?
#
#A8
# You can do two operations on an existing file descriptor. Remove would
#be meaningless for this case. Modify will re-read available I/O.

Why is EPOLL_CTL_DEL considered meaningless? A process is wrapping up its
business and is preparing to remove the fd from the epoll set, and then
close the file descriptor itself. In the meantime, the fd became readable,
and a POLLIN event gets collected. So, what happens to the collected event,
when the EPOLL_CTL_DEL operation is made?

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]