Re: [lwip-users] DNS thread-safe functions

[address@hidden]

Am 29.01.2020 um 16:37 schrieb address@hidden:
> Dear all,
>
> I would like to ask some questions about the thread-safe functions.
>
> According the http://www.nongnu.org/lwip/2_0_x/pitfalls.html page, in
> the OS mode, all the callback-style APIs function must only be called
> from the TCPIP thread.
> In the OS mode, the functions belongs to NETIF, DHCP, DNS, … modules
> require corresponding thread-safe functions to be used from threads
> different from TCPIP thread.
> For example instead of calling directly the /netif_set_up/ function it’s
> necessary use the /netifapi_netif_set_up/ function, or instead of
> calling directly the /dhcp_start/ function it’s necessary use the
> /netifapi_dhcp_start/ function.
>
> I am looking for the thread-safe function corresponding to the
> /dns_setserver /function. I am using LwIP 2.1.2, but I don’t find it.

I don't think such a function exists.

> At this point I would know if there is a thread-safe function
> corresponding to the /dns_setserver/ or if I should build a similar
> function myself. In this last case, which function could I take as a model?.

The simple solution would be to enable LWIP_TCPIP_CORE_LOCKING and
surround your call with LOCK_TCPIP_CORE()/UNLOCK_TCPIP_CORE().

Regards,
Simon

> Thanks in advance for your attention and for your suggestions.
> Regards