Messages in this thread | | | Date | Sat, 10 Jan 2009 16:14:49 -0500 | From | Casey Dahlin <> | Subject | Re: [RESEND][RFC PATCH v2] waitfd |
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Scott James Remnant wrote: > On Wed, 2009-01-07 at 18:19 +0100, Oleg Nesterov wrote: > > >> Please note that unlike other sys_...fd() syscalls, sys_waitfd() >> doesn't allow to pass O_CLOEXEC. Looks like we need a separate >> "flags" argument... >> >> Also, ioctl(FIONBIO) or fcntl(O_NONBLOCK) have no effect on >> waitfd, not very good. >> >> I'd suggest to remove WNOHANG from waitfd_ctx->ops and treat >> (->f_flags & O_NONBLOCK) as WNOHANG. >> >> (can't resist, ->ops is not the best name ;) >> >> > Definitely agree here, waitfd() doesn't need WNOHANG - we already have > ONONBLOCK. > > That also solves one of the strangest behaves of waitid when you use > WNOHANG (it returns zero and you have to check whether it changed the > struct), now you just read() - if no child you get EAGAIN, if a child > you read a struct. > > Scott > From the perspective of waitfd, the only difference between WNOHANG and O_NONBLOCK is which argument you put the flags in. The API should only support one or the other, but internally they would imply the same thing.
--CJD
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