in reply to Multithreading How do I share hash of hash of arrays
But it has very limited use in CPU-intensive activities,
Utter garbage! (You just can't help yourself can you.)
If I have a cpu-bound process that takes 1 hour; and I can spread that processing across 4 cpus, I can cut that runtime to 15 minutes.
Just because data is shared; it doesn't mean it has to be locked. If only reads are performed no locking is necessary.