Messages in this thread |  | | Date | Wed, 5 Jun 1996 18:38:18 -0500 (CDT) | From | Todd Larason <> | Subject | Re: On SIGCHLD signal semantics |
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On Tue, 4 Jun 1996, Theodore Y. Ts'o wrote:
> So the bottom line is what we're doing is allowed by POSIX, and > compatible with System V. Given that it's compatible with System V, it > may very well be required by SVID and/or Spec 1170. If someone who has > access to either SVID or Spec 1170, do please comment on this issue....
Single Unix Spec's version of System Headers & Interfaces, sigaction() description:
If a process sets the action for the SIGCHLD signal to SIG_IGN, the behaviour is unspecified [UX[ except as specified below.
If the action for the SIGCHLD signal is set to SIG_IGN, child processes of the calling processes will not be transformed into zombie processes when they terminate. If the calling process subsequently waits for its children, and the process has no unwaited for children that were transformed into zombie processes, it will block until all of its children terminate, and wait(), wait3(), waitid() and waitpid() will fail and set errno to [ECHILD]. ]]
The part between the [UX[ and ]] is a 'Unix extension' to the base X/Open spec.
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