Unofficial wish list status.(Jul 2008)

[Me Here]

Walter Bright wrote:

> Yes, but the onus will be on you (the programmer) to prevent data races and
> do proper synchronization.   

In the scenario described, the main thread initialises the array of data. Then,
non-overlapping slices of that are portioned out to N worker threads. Only one
thread ever modifies any given segment. When the worker threads are complete,
the 'results' are left in the original array available in its entirety only to
the main thread.

>You have to be very wary of cache effects when
> writing data in one thread and expecting to see it in another.

Are you saying that there is some combination of OS and/or hardware L1/L2
caching that would allow one thread to read a memory location (previously)
modified by another thread, and see 'old data'?

Cos if you are, its a deeply serious bug that if its not already very well
documented by the OS writer or hardware manufacturers, then here's your chance
to get slashdotted (and diggited and redited etc. all concurrently) as the
discoveerer of a fatel processor flaw.

b.

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