Re: Spin locks

[Andrew Haley <aph at redhat dot com>]

Vardhan, Sundara (GE Infra, Energy) wrote:

> Thanks for the reply. Please find below a code snippet of the function
> that calls the spin lock. Hope this helps
> 
> int gstas( unsigned char *ip )
> #else
> int gstas(ip)
> unsigned char *ip;
> #endif
> /*
> PURPOSE: To atomically lock a byte.
> 
> DESCRIPTION: This routine is used to atomically lock a lock
> structure which is one byte in size.
> 
> */
> {
> unsigned char   gstas_orig_byte ;
> int             status = RT_SUCCESS ;
> 
> gstas_orig_byte=__sync_lock_test_and_set(ip,0xff);
> if ( 0 != gstas_orig_byte )
>     {
>     status = RT_ERROR ;
>     }
> return( status ) ;
> }
> 
> The above function is called by different processes when the product is
> in runtime. This function returns error in different processes during
> different run cycles. 
> 
> Hope this helps.

Not really, sorry.  The example test case has to run (i.e. has to have a
main() function) and has to demonstrate the problem by failing.  Snippets
don't do it.  This would also be the case if you were paying for gcc
support; the burden on you isn't any less because you're getting
community support for no charge.

Andrew.