Dave Hansen wrote: > From: bernard.fou...@kuantic.com <mailto:bernard.fou...@kuantic.com> > > [...re: volatile use cases...] > > In both of these cases, "volatile" is insufficient because it does not > imply "atomic". In the first case, you need an atomic > read-modify-write, and in the second you need an atomic read of a wide > value. In both cases you can achieve that by enclosing the the variable > access in a cli-sei pair. For example, the latter case can be fixed by > changing the routine to something like > > main() // or "int main(void)", yada yada > { > uint32_t ms; // does not need to be volatile > > do{ cli(); ms = Milliseconds; sei(); } while (ms < SOME_LIMIT); > }
No, you can not. You need the macros in util/atomic.h because cli / sei are not memory barriers and accesses to variables done inside a pair like that can be moved out by the compiler. Just search the archives for previous discussions and examples... -- Paulo Marques Software Development Department - Grupo PIE, S.A. Phone: +351 252 290600, Fax: +351 252 290601 Web: www.grupopie.com "There cannot be a crisis today; my schedule is already full." _______________________________________________ AVR-GCC-list mailing list AVR-GCC-list@nongnu.org http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
