I would like to start playing with concurrency in the programs I write (mostly for fun), but I don’t own a multi-core system and can’t afford one any time soon. I run linux. Is there a way to, for example with a Virtual Machine, compare the performance of a multi-threaded implementation of a program with a single-threaded version, without actually running it on hardware with multiple processors or cores?
That is, I would like to be able to implement parallel algorithms and be able to say that, yes, this multithreaded implementation is better-performing than the single-threaded.
Thanks
You can not test multithreaded programs reliably on a single core machine. Race conditions will show up very differently or even be totally hidden on a single core machine. The performance will decrease etc.
If you want to LEARN how to program multiple threads, you can do so on a single core machine for the first steps (i.e how works the API etc.). But you’ll have to test on a multicore machine and its very likely that you will see faults on a multicore machine that you dont see on a single core machine.
Virtual machines are by my experience no help with this. They introduce new bugs, that didnt show up before, but they CANT simulate real concurrency with multiple cores.