Hi,

 

I’m an experienced software developer, but a bit of a newbie when it comes to parallel processing in any language.

 

I’ve done some multithreading in Java and C++ on a single processor, single core architecture only.

 

First, let me define some terms:

 

Multithreading: this is multiple processes running on one processor and is the conventional way to do parallel programming

Multicore: this is when we have two (or more) cores within the one CPU

Multiprocessor: this is when we have multiple CPUs

 

Question 1:

Is there any programmatic change in dealing with multiple threads as opposed to multiple cores in most languages (specifically Haskell)?

 

That is, to write multiple threads you normally “spin-off” a new thread which runs in parallel along with other threads. Is Haskell smart enough to do this by magic by itself, or would I need to tell it explicitly : Run thread A whilst running thread B

 

Also, what about multicore architectures? Do I have to tell the language to spin off two separate programs to run on each core and then somehow use some kind of communications to exchange data?

 

I also assume that, in theory it would be possible to have multiple threads running on each core. Say, 3 threads spawned from program 1 running on core 1 and 5 threads on program 2 running on core 2

 

Likewise I would suppose that it would be possible to have multiprocessors, each potentially multicore, each core running multiple threads.

 

Question 2:

 

In light of the above  statement, is the programmatic change DIFFERENT for dealing with each of

a)      Multithreading in Haskell versus

b)      Multicores in Haskell verus

c)       Multiprocessors in Haskell

 

 

References or info appreciated.

 

Just curious.

 

Mark