DiffArray Performance

[Alastair Reid]

Alastair:
> >never used in multi-threaded situation.

MR K P SCHUPKE:
> Erm, nearly all my code in Haskell is multi-threaded. 

And do you use DiffArrays?

MR K P SCHUPKE:
> I would hesitate to make any type unsafe for multi-threading by default

Sorry to be unclear.  I wasn't actually saying to remove the support.

I was thinking that, if the current mutex implementation is killing 
performance (and it is an assumption - though one of the Simons could 
probably confirm or deny it), we should look to see if mutexes can be made 
cheaper or rewrite the code to avoid it or ...  For example, the Java 
community has done a lot of work on how to make it cheap to take an 
uncontested lock but more expensive to take a contested lock.

--
Alastair Reid