sysvsem: Add a timeout argument to the semop.

[dchagin]

Summary

For future use in the Linux emulation layer for the semtimedop syscall
split the sys_semop syscall into two counterparts and add
struct timespec *timeout argument to the last one.

[jhb]

sys/kern/sysv_sem.c

1351–1352

I think this is fine, but I would maybe write this bit instead as something like:

if (error != 0) {
   if (error == ERESTART)
       error = EINTR;
   goto done2;
}

I think that makes the intent clearer overall.

[kib]

sys/kern/sysv_sem.c

1156

There is very similar, if not identical code, both in your recent kern_sig.c changes, and in kern_event.c::kqueue_scan(). Can it be extracted into some common helper? Also it arguably requires a comment so that people easily see how we handle timeout precision.

[dchagin]

sys/kern/sysv_sem.c

1156

Yes, the code is almost identical, I already thought about what you suggested. I'll do it a bit later, first I need to commit my local queue, it's too big.

1351–1352

sure