long@castor.csg.uiuc.edu (Junsheng Long) (03/28/90)
Is that possible to clear all zombie children while the parent is still in execution under SunOS? I had the parent process to call signal(SIGCHLD, SIG_IGN). This should let init to clear the terminated child automaitically, when the parent got a SIGCHLD. But SunOS still kept all the zombies until the parent exited. Is SunOS different from other Unix systems in this regard? Is it possible to clear zombies in a SunOS environment? And how? Thank you. Junsheng
ables@lot.ACA.MCC.COM (King Ables) (03/28/90)
From article <1990Mar27.164632.18462@ux1.cso.uiuc.edu>, by long@castor.csg.uiuc.edu (Junsheng Long): > Is that possible to clear all zombie children while the parent > is still in execution under SunOS? Check the wait3() system call. The child process stays in the process table as a zombie until the parent waits on it and gets some indication that it's died. Yes, in your case you probably don't care. Neither did I, so I just called wait3(0,WNOHANG,0) to clear the condition on all child zombie processes. ----------------------------------------------------------------------------- King Ables Micro Electronics and Computer Technology Corp. ables@mcc.com 3500 W. Balcones Center Drive +1 512 338 3749 Austin, TX 78759 -----------------------------------------------------------------------------
mike@turing.cs.unm.edu (Michael I. Bushnell) (03/28/90)
You clear zombie children *only* by exiting (clearly out) or by doing
a wait(). Ignoring SIGCHLD doesn't change that, nor arrange to have
init clean them up. What you want to do is have a signal handler for
SIGCHLD that loops on wait3() (nonblocking) until there are no more
exited children to collect.
-mib
--
Michael I. Bushnell \ This above all; to thine own self be true
LIBERTE, EGALITE, FRATERNITE \ And it must follow, as the night the day,
mike@unmvax.cs.unm.edu /\ Thou canst not be false to any man.
CARPE DIEM / \ Farewell: my blessing season this in thee!eli@panda.uucp (Eli Taub/100000) (03/28/90)
> Is that possible to clear all zombie children while the parent > is still in execution under SunOS? I had the parent process to call > signal(SIGCHLD, SIG_IGN). This should let init to clear the > terminated child automaitically, when the parent got a SIGCHLD. Under System V signal(SIGCLD, SIG_IGN) tells the kernel not to create Zombies. This is special because the default for SIGCLD (or SIGCHLD) is to ignore the signal. > But SunOS still kept all the zombies until the parent exited. > Is SunOS different from other Unix systems in this regard? > Is it possible to clear zombies in a SunOS environment? And how? In SUN and other BSDs you Must catch the signal and issue a wait so that the Zombie is cleared up. Eli Taub Contractor at IBM (till Sep. `90) (512) 838-4810
gwyn@smoke.BRL.MIL (Doug Gwyn) (03/28/90)
if (fork() > 0) _exit(0);