[lwip-users] Do functions like sys_mbox_invalid() need to be thread safe?

[Grant Edwards]

I'm workikng on a port done by somebody else, and they seem to have
assumed that functions like sys_mbox_set_invalid() don't need to be
thread-safe.  But, they did add mutexes to make sure that some other
functions like like sys_mbox_free() and _new() are thread-safe.

The documentation I've found at https://www.nongnu.org/lwip/2_1_x/
seems to be mute on that subject.

Do the varios sys_* functions for mutex, semaphore, mailbox functions
in the "OS abstraction layer" need to be thread safe?

Or are they only called under some sort of mutex/protection?

Is this documented somewhere I should have looked and didn't?

--
Grant