John Baldwin wrote:
>
> On 31-Jan-01 Matthew Emmerton wrote:
> > Hi all,
> >
> > I've taken a look around for an implementation of atomic bit operations in
> > FreeBSD (similar to Linux' asm/bitopt.h, which include clear_bit() and
> > test_and_set_bit()) but haven't found any. The only thing I've found are
> > the atomic clear/set/add/sub routines in machine/atomic.h.
> >
> > Do we have an implementation of atomic bit operations, and if we don't,
> > would we like some?
>
> Erm, atomic_set() sets's bits, and atomic_clear() clear's bits. Anything else
> you might need can be done with atomic_cmpset() anyways. Also, atomic
> operations are very hard to debug, esp. to check for race conditions, so there
> direct use is discouraged. Instead, use a higher level primitive such as a
> mutex or other appropriate lock. There is also talk of a potential abstract
> refcount type so that simple reference counts can be optimized, though that has
> been shot down thus far.
by who?? I really want this....
>
> > --
> > Matt Emmerton
>
> --
>
> John Baldwin <[EMAIL PROTECTED]> -- http://www.FreeBSD.org/~jhb/
> PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
> "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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