Re: [lwip-users] Is netconn/socket fullduplex still "really alpha"?

[Simon Goldschmidt]

On 16.11.2021 19:44, Grant Edwards wrote:
> On 2021-11-16, Simon Goldschmidt <goldsimon@gmx.de> wrote:
> > On 16.11.2021 18:47, Grant Edwards wrote:
> > > I've been reading up on netconn/sockets and thread-safety. At
> > > https://www.nongnu.org/lwip/2_1_x/group__lwip__opts__netconn.html
> > > it says this about the "fullduplex" option:
> > >
> > >           "ATTENTION: This is currently really alpha!"
> > >
> > > Is that accurate?
> >
> > No, that comment is outdated and should be deleted by now.
>
> Thanks, that's good news. :)
>
> On that same page it says that for the fullduplex option to work...
>
>     sys_mbox_free() has to unblock receive tasks waiting on
>     recvmbox/acceptmbox and prevent a task pending on this during/after
>     deletion
>
> Is that really required? I can't see how the freeRTOS port does that,
> and AFAICT from reading freeRTOS docs and info, deleting a queue that
> has a non-empty wait list is not allowed/undefined.
>
> > From what I've gleaned from the bugtracker, that mbox_free() behavior
> might not be needed because a "closing" message is now sent through
> the mailbox and the mailbox is not freed until later?

Yeah, well, that comment is outdated as well. Turned out that nearly no
OS supports this, so it got implemented in a different way.

Sorry for all the outdated comments.

Regards,
Simon