[lwip-users] Re: [lwip] memp_malloc

[Kieran Mansley]

On Thu, 7 Mar 2002, Mumtaz Ahmad wrote:

> Hi
>
> Why does the code use memp_malloc at some places and memp_mallocp at others
> . I think if the code has to be run in mutithreading environment then
> memp_mallocp must always be used since this function is gaurded by
> semaphores .

...unless you know that resource will only be accessed by one thread.
Having had a look at the code (I don't know if this is right, but it looks
this way to me) the only places that use memp_malloc are in api_lib.c and
they are all requesting memory of the same type (MEMP_API_MSG).  This type
is not requested from anywhere else, and the code in api_lib.c is always
executed by the same thread (I think!), so by not protecting it with
semaphores you should get a significant increase in performance.  (API
msgs are still a big bottleneck, but it'd be worse otherwise)

Could all be wrong though.  Adam will be along shortly to correct me...

Kieran

[This message was sent through the lwip discussion list.]