DragonFly commits List (threaded) for 2004-12
[
Date Prev][
Date Next]
[
Thread Prev][
Thread Next]
[
Date Index][
Thread Index]
Re: cvs commit: src/sys/i386/include
On Wed, Dec 08, 2004 at 03:57:22PM -0800, Matthew Dillon wrote:
> What's this for ? Generally speaking I don't think we want to abstract
> this. Atomicy requirements for generation counters is going to be highly
> dependant on the situation, all these functions will do is confuse
> matters.
The problem is that we don't have a useful set of atomic ops for 64bit
values. IMO we have the following constraints on _any_ kind of generation
counter:
1. It must be atomically incrementable.
2. It must be atomically fetchable with the constraint that the returned
value is between the value before the _get function is called and the
value after the _get function is called.
3. It must be possible to compare two counters.
This is what I tried to provide, with the possibility to just implement
it via atomic instructions on platforms providing those.
Joerg
[
Date Prev][
Date Next]
[
Thread Prev][
Thread Next]
[
Date Index][
Thread Index]