UNIX v7 calling sched()
Scott Lurndal
scottl at convergent.com
Tue Apr 16 05:32:08 AEST 1991
In article <7101 at segue.segue.com>, jim at segue.segue.com (Jim Balter) writes:
|> In article <1991Apr12.172939.6348 at ncsu.edu> miler at osl.csc.ncsu.edu (George Miler) writes:
|> > main ()
|> > {
|> > ......
|> > if (newproc()) <==== true, create /etc/init process
|> > {
|> > copy (/etc/init)
|> > return; <==== exit main, starts copied process
|> > }
|> > sched (); <==== never reached if did /etc/init
|> > }
|>
|> Do you understand how
|>
|> main ()
|> {
|> if (fork() == 0)
|> {
|> childstuff();
|> return;
|> }
|> parentstuff();
|> }
|>
|> works? newproc() is just the kernel level equivalent of fork.
|> It returns twice, into two different processes, with a 0 return to the parent
|> and a non-zero return to the child (fork is the other way around).
|>
[examples deleted]
I seem to recall a caveat in Lyons commentary to the effect of
"you're not expected to understand this."
:-)
scott.
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