(j3.2006) Lock variables

[Malcolm Cohen]

Van Snyder wrote:
>
> For now,
> it would just be a silly program that locks a noncoarray lock -- until
> we implement task parallelism, at which time it will make sense.
>   
It seems highly likely to me that the data structure and locking 
mechanism needed for a task lock and that needed by a coarray lock would 
very likely be significantly different, probably to the extent that 
providing a single lock type that does both jobs would perform 
significantly worse than either kind.  The same applies to critical 
sections.

Certainly if by task parallelism you mean running in the same address 
space (i.e. within a single image) I wouldn't build task locks on top of 
coarray locks, or indeed much of the task parallel infrastructure on any 
of the coarray parallel infrastructure.  Maybe that's just me though.

Of course, it all depends on the hardware, and what kinds of task 
parallelism etc., but since we are not going down that route it is all moot.

Cheers,
-- 
.......................Malcolm Cohen, Nihon NAG, Tokyo.