Fix JULIA_EXCLUSIVE setting affinity on non-worker threads

[xal-0]

With JULIA_EXCLUSIVE=1, we would try to give both worker and interactive threads an exclusive CPU, causing --threads=auto to produce a "Too many threads requested" error.

Fixes #50702.

[topolarity]

This logic is a little odd to me - e.g. if nthreadsi == 1 and nmutator_threads == 2 we no longer end up setting affinity for any thread

Is that intentional?

[xal-0]

This logic is a little odd to me - e.g. if nthreadsi == 1 and nmutator_threads == 2 we no longer end up setting affinity for any thread

Is that intentional?

It was not intentional! It should be fixed now:

$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 1 -e ''
setting affinity of master thread to 0
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 2 -e ''
setting affinity of master thread to 0
setting affinity of thread 1 to 1
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 3 -e ''
setting affinity of master thread to 0
setting affinity of thread 1 to 1
setting affinity of thread 2 to 2
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 1,1 -e ''
setting affinity of thread 1 to 0
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 1,2 -e ''
setting affinity of thread 2 to 0
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 1,3 -e ''
setting affinity of thread 3 to 0
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 2,1 -e ''
setting affinity of thread 1 to 0
setting affinity of thread 2 to 1
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 2,2 -e ''
setting affinity of thread 2 to 0
setting affinity of thread 3 to 1
$ JULIA_EXCLUSIVE=1 ./usr/bin/julia-debug -t 3,3 -e ''
setting affinity of thread 3 to 0
setting affinity of thread 4 to 1
setting affinity of thread 5 to 2

[Keno]

Thank you!

[Keno]

(I am well known for my hatred of magic integer constants).

[Keno]

Nice work

[topolarity]

Nicely done!

[giordano]

Git history and diff seem to be messed up

[topolarity]

Our CI seems to have fallen over, but this has passed tests repeatedly on all platforms so I'll go ahead and merge it.

Thanks @xal-0 !