cygserver debug output patch
Thu Jun 13 06:29:00 GMT 2002
> -----Original Message-----
> From: email@example.com
> [mailto:firstname.lastname@example.org] On Behalf Of Conrad Scott
> Sent: Thursday, 13 June 2002 11:24 PM
> Since Chris is thinking that it would be a good idea to put
> my cygserver /
> shm stuff on a branch, I can't think there's much point putting those
> patches I sent you into the main line, they could better go
> on the branch.
> Does that sound reasonable to you?
I'll put them in mainline or the branch when I create it. I'm not sure
yet which they belong in - let me look at them first.
> Anyhow, the ipctests now run successfully on win 95 (thanks
> to Nicholas for
> helping out on the patch, compile, test, report yet another
> abject failure
> test cycle).
> IPC_RMID a segment that processes are still attached to:
"IPC_RMID Remove the shared memory identifier specified by shmid from
the system and
destroy the shared memory segment and shmid_ds data structure associated
with it. IPC_RMID can only be executed by a process that has an
ID equal to either that of a process with appropriate privileges or to
of shm_perm.cuid or shm_perm.uid in the shmid_ds data structure
It seems fairly clear: the shm id is immediately removed from the
system, along with the shm segment and shmid_ds data structure.
> AFAICT it succeeds
> but the memory itself is only deleted on the last detach
> (which I think is
> what the cygserver code does - or does now).
Yes. I wasn't sure if that was right either :}.
> The only issue I
> can't find any
> reference to is what happens if you call shmat() or
> shmctl(IPC_INFO) for
> that shmid after using IPC_RMID but before the segment itself
> is deleted.
> I'll have a look at the netbsd and the linux code and see
> what they do, but
> if anyone has a good idea or any useful specs, I'd welcome the hint.
Good idea. For specs, check the open group, or IEEE 1003.1.
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