On Monday, 4 August 2014 at 05:14:22 UTC, Philippe Sigaud via
Digitalmars-d-learn wrote:
I have another question: it seems I can spawn hundreds of
threads
(Heck, even 10_000 is accepted), even when I have 4-8 cores. Is
there:
is there a limit to the number of threads? I tried a threadpool
because in my application I feared having to spawn ~100-200
threads
but if that's not the case, I can drastically simplify my code.
Is spawning a thread a slow operation in general?
Most likely those threads either do nothing or are short living
so you don't get actually 10 000 threads running simultaneously.
In general you should expect your operating system to start
stalling at few thousands of concurrent threads competing for
context switches and system resources. Creating new thread is
rather costly operation though you may not spot it in synthetic
snippets, only under actual load.
Modern default approach is to have amount of "worker" threads
identical or close to amount of CPU cores and handle internal
scheduling manually via fibers or some similar solution.
If you are totally new to the topic of concurrent services,
getting familiar with http://en.wikipedia.org/wiki/C10k_problem
may be useful :)
