Re: Concurrency, again

[Stefan Monnier]

> I thought that "concurrency" and "parallelism" were the same.

They're related and they overlap.

If you use use a pseudo-parallel system (such as the `concurrency`
branch), then you have concurrency but not parallelism.
Vector processing (or GPUs nowadays) on the other hand, offers
parallelism but not concurrency.

To take another example, from the world of memory management:

- A concurrent GC is one where the mutator is not stopped while the
  collector does its job.
- A parallel GC is one where the collector divides its job into chunks
  that can be performed at the same time by different CPUs.  It may be
  concurrent or not.


        Stefan