Re: wait() spec (SIGCHLD ignored)

[Michael Kerrisk <mtk.lists@xxxxxxxxx>]

Roland McGrath wrote:
> I think you are reading it wrong.  In the scenario you described, your
> previously-terminated child was not transformed into a zombie process.  
Thanks Roland.  That makes sense.

> In _exit() and the "Signal Concepts" section, the standard specifies when a
> process "shall be transformed into a zombie process."  It's when its parent
> didn't use SIG_IGN or SA_NOCLDWAIT for SIGCHLD.
Yes.  Of course :-}.

> The wait() wording means that e.g. if you had SIGCHLD set to SIG_DFL, then
> had some children die, then subsequently changed SIGCHLD to SIG_IGN and
> then called wait(), you would get those previously-dead children.  However,
> if SIGCHLD was set to SIG_IGN before any children died, then the clause
> applies normally--wait() blocks until all are dead, then returns ECHILD.
Again, that all makes sense.

Thanks,

Michael