Hi,
Sorry for the late reply.
On Thu, Jul 6, 2023 at 4:54 PM stsp <stsp2@xxxxxxxxx> wrote:
>
>
> 06.07.2023 13:41, Murphy Zhou пишет:
> > Signed-off-by: Stas Sergeev <stsp2@xxxxxxxxx>
> > ---
> > src/t_ofd_locks.c | 73 ++++++++++++++++++++++++++++++-----------------
> > 1 file changed, 47 insertions(+), 26 deletions(-)
> >
> > diff --git a/src/t_ofd_locks.c b/src/t_ofd_locks.c
> > index e77f2659..daa6f96c 100644
> > --- a/src/t_ofd_locks.c
> > +++ b/src/t_ofd_locks.c
> > @@ -297,6 +297,7 @@ int main(int argc, char **argv)
> > semid = semget(semkey, 2, IPC_CREAT|IPC_EXCL);
> > if (semid < 0 && errno == EEXIST) {
> > /* remove sem set after one round of test */
> > + semid = semget(semkey, 2, IPC_CREAT);
> > if (semctl(semid, 2, IPC_RMID, semu) == -1)
> > Good catch. This RMID is useless unless we have got the existing
> > semaphore. According to SEMGET(2), seems should be:
> >
> > semid = semget(semkey, 2, 0);
> >
> > to obtain an existing semaphore?
>
> Yes, I just wanted to avoid the purely
> theoretical condition when someone
> else removed this sem right before we
> did second semget(). So I added IPC_CREAT
> just as a safety measure.
> Should I remove it?
>
> > The while loop makes sure we get the semaphore before continuing
> > the test. It's been some time, I'm not sure but now I really can't see
> > this really hurts.
> What while loop do you mean and what
> doesn't hurt? Does the rest of the patch
> look ok?
I mean the do-while loop ensures a new semaphore is created.
And in most of the test scenarios, this program runs only once and
there is no semaphore left behind, unless debugging this program
itself.
So I don't think there are any race conditions being opened up.
Much appreciated!
Thanks,
Murphy
