RE: [lwip-users] Destruction of socksem and selectsem in sockets.c

[Goldschmidt Simon]

Hi Clive,

> Dear All,
> 
> In sockets.c, there are two semaphores that are created on 
> first invocation, that are never destroyed - these are 
> socksem and selectsem, created in alloc_socket() and 
> event_callback() respectively. If I want to completely free 
> all heap memory taken by the stack, these sems need to be 
> destroyed as semaphore creation allocates memory on my OS.
> 
> The question is, where is it safe for them to be destroyed? 
> My hunch is that it would be OK at the end of lwip_close(), 
> immediately before the return statement.
> 
> Does anyone have any views on this?

This seems to be a general problem of the stack. Because in embedded
systems, you normally don't need to shut down anything but just turn of
power, this is not a problem for most lwIP-users. If you wanted to
safely shut down the complete stack, you would need shutdown-functions
corresponding to all the *_init() functions... But who would need that
;-)

Simon.