The following situation can trigger the deadlock:
1) Long time ago a_service was started through rc.d
2) We want to restart a_service and issue service a_service restart
3) rc.subr reads current process PID (via file or process),
sends TERM signal and runs pwait with PID harvested
4) a_service process dies very quickly so it's PID becomes available.
It is possible that while original process was running,
PID counter overflowed and pwait got assigned a_service's PID.
This patch ignores pid(s) to wait that are equal to pwait PID.
Reported by: Dan McGregor, Boris Lytochkin
Submitted by: Boris Lytochkin <lytboris at gmail.com>
Reviewed By: 0mp
MFC after: 2 weeks
PR: 218598
Differential Revision: https://reviews.freebsd.org/D28240
* Add small EXAMPLES section to the man page showing the different
flags and exit codes.
* Complete description for -v flag.
Approved by: manpages (bcr@)
The exit status will be 124, as the timeout(1) utility uses.
Reviewed by: jilles
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D9697
Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.
Reviewed by: ru
Approved by: philip, ed (mentors)
This is similar to the Solaris utility of the same name.
Some use cases:
* rc.subr's wait_for_pids
* interactive use, e.g. to shut down the computer when some task is done
even if the task is already running
Discussed on: hackers@
