Messages in this thread |  | | From | Chris Fearnley <> | Subject | Re: Gack, this shouldn't happen under a stable OS I think | Date | Mon, 23 Sep 1996 10:04:37 -0400 (EDT) |
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'Keith Owens wrote:' > >On Sun, 22 Sep 1996, Chris Fearnley wrote: > >> root@syntropy # ps aux|grep 27231 >> root 27231 0.0 2.1 828 324 p7 S 23:28 0:00 /usr/sbin/radiusd >> root@syntropy # ps aux|grep 27231 >> root 27231 0.0 2.1 828 324 p7 S 23:28 0:00 /usr/sbin/radiusd >> root@syntropy # ps aux|grep 27231 >> root 27231 0.0 2.1 828 324 p7 S 23:28 0:00 /usr/sbin/radiusd >> root 27239 0.0 2.5 916 376 p7 S 23:28 0:00 grep 27231 >> >> Why doesn't the grep process show up each time??? >> >> Can others reproduce this? > >Happens all the time. The shell starts the ps task running then starts grep >running, i.e. ps is started and can be processing its input before grep >exists. In addition, ps uses readdir to access the entries in /proc and the >"directory entries" for tasks are in no defined order (try "ls -fl /proc") so >it also depends on whether the /proc entry for the grep task is inserted >before or after the point that ps has got to in its readdir loop. Nobody has >ever claimed that concurrent tasks are deterministic (except in DOS where >they are not really concurrent).
Sorry, I was "rushing" looking for clues that may be relevant to hanging TCP connections and overlooked the issue of time in pipes.
-- Christopher J. Fearnley | Linux/Internet Consulting cjf@netaxs.com, cjf@onit.net | UNIX SIG Leader at PACS http://www.netaxs.com/~cjf | (Philadelphia Area Computer Society) ftp://ftp.netaxs.com/people/cjf | Design Science Revolutionary "Dare to be Naive" -- Bucky Fuller | Explorer in Universe
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