Date: Mon, 7 Apr 1997 15:26:04 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: peter@spinner.DIALix.COM (Peter Wemm) Cc: terry@lambert.org, freebsd-current@freebsd.org Subject: Re: POLL & the Single FreeBSD'r Message-ID: <199704072226.PAA02421@phaeton.artisoft.com> In-Reply-To: <199704072215.GAA03730@spinner.DIALix.COM> from "Peter Wemm" at Apr 8, 97 06:15:09 am
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> > scheduler can't keep up, then it can't keep up (the part of the man > > page I was referrung to was the tv_usec reference). > > peter@spinner[6:07am]~src/sys/kern-132> man select | col -b | grep tv_ > peter@spinner[6:11am]~src/sys/kern-133> > What tv_usec reference? Are you on the wrong system? :-) > > Our 4.4BSD derived man page only says the word "timeout" and mentions nothing > about tv_* at all | If timeout is a non-nil pointer, it specifies a maximum interval | to wait for the selection to complete. And timeout specified a struct timeval. It draws a distinction between a "minimally non-zero valued" and a "zero valued" timeval as well: | To affect a poll, the timeout argument should be non-nil, | pointing to a zero-valued timeval structure. (This last is implicit, but no less real for it). Yeah, I'm picking nits, but you have to admit that those nits result in useful behaviours under most circumstances. For instance, a 200uS timeout for a select on an X fd is sufficient for ~30FPS cell animation, while still returning unused process time to the system instead of buzz-looping (I know, I know: now I have self-identified as "one of those graphics geeks"... 8-)). Mostly, I've found the SunOS 4.x behaviour useful in the past, and would like to see that code runable on FreeBSD without a round up by a factor of 50 in the inter-event delay. 8-). Regards, Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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