JuliaLang/julia
`JULIA_NUM_THREADS` ignored when embedding Julia on a Windows system
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#55.468 aperta il 12 ago 2024
bughelp wantedsystem:windows
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Descrizione
The following c# code...
Environment.SetEnvironmentVariable("JULIA_NUM_THREADS", "4");
jl_init_with_image__threading(mBinPath, mSysImg);
jl_eval_string("println(\"Threads=$(Threads.nthreads())\")");
jl_eval_string("println(\"JULIA_NUM_THREADS=$(ENV[\"JULIA_NUM_THREADS\"])\")");
Produces the following output
Threads=1
JULIA_NUM_THREADS=4
In discussions with the Jeff and Keno it appears this happens in Windows because there are several environment stores in Windows, and the threads are created by reading with getenv (which access the machine level environment), while later in Julia the ENV is retrieved using getenvw (which access the process level environment).