Posix queues

[Rami]

I have problems with removing queues. Manual says that mq_unlink does not
remove named queue before all references are released. While developing my
process, it may happen that mq_close is not not called in every thread which
has opened queue... Are those references to queue removed when process is
terminated, even if mq_close was not called ?

And manual says:
However, the mq_unlink() call need not block until all references have
been closed; it may return immediately.

What does these 'need not' and 'may return' mean? Seems like my mq_unlink
call blocks.

Now when I call mq_open with flags O_RDWR | O_CREAT, seems like also open
call blocks, is this because mq_unlink was called and queue is not actually
yet removed ?

Solaris 8.0

BR,
Rami

[Marc Rochkind]

On Tue, 15 Jul 2003 07:31:35 GMT, Rami <oo.oo@oo.com> wrote:

> I have problems with removing queues. Manual says that mq_unlink does not
> remove named queue before all references are released. While developing
> my
> process, it may happen that mq_close is not not called in every thread
> which
> has opened queue... Are those references to queue removed when process is
> terminated, even if mq_close was not called ?

Yes. Open mqs are closed when process exits.

>
> And manual says:
> However, the mq_unlink() call need not block until all references
> have
> been closed; it may return immediately.
>
> What does these 'need not' and 'may return' mean? Seems like my mq_unlink
> call blocks.

The word "may" "describes a feature or behavior that is optional for an
implementation." So, as a programmer, you can't depend on it being one way
or the other.

>
> Now when I call mq_open with flags O_RDWR | O_CREAT, seems like also open
> call blocks, is this because mq_unlink was called and queue is not
> actually
> yet removed ?

That is a possibility. Standard specifically says this may happen.

>
> Solaris 8.0
>
> BR,
> Rami
>
>
>