Re: lkwt in DragonFly

[David Xu <davidxu@xxxxxxxxxxxxxx>]

Matthew Dillon wrote:
> :Your explanation is interesting, I am sorry that I am new to DFly,
> :but if two threads on same CPU wants to exclusivly access a data 
> :structure, what lock should be used ? does token still work ? on
> :FreeBSD, one can use mutex, but token is holden by CPU on DFly not by 
> :thread, so a thread really does not know if it already held the lock
> :or not, although its CPU already hold the token.
> :
> :David Xu
>
>     If you want something that stays valid through a switch or a blocking
>     condition then you would need to use a lockmgr lock.  If you just
>     need atomicy across a short period of time in which you know the
>     thread will not block, or in a situation where the code does the 
>     right thing if another piece of code operates on the same
>     data structure while the first piece is blocked, then a token
>     would be sufficient.
That's the thing I need, thanks !

And sorry a bit OT, what's the plan of pthread supports in DFly, I am
very interested to work on it in near future.

> 					-Matt
> 					Matthew Dillon 
> 					<dillon@xxxxxxxxxxxxx>

David Xu