PSA: Thread-local state is no longer recommended; Common misconceptions about threadid() and nthreads()

General Usage
26

task_local_storage isn’t going anywhere. It’s just not particularly useful or nice for implementing reductions.

For an example of something that task_local_storage does well in the context of @threads, here’s some code @GunnarFarneback shared on Zulip:

Threads.@threads for j in axes(x, 2)
    temp = get!(() -> Vector{Int}(undef, N), task_local_storage(), :temp)::Vector{Int}
    # fill in temp with j-dependent data
    for i in axes(x, 1)
        y[i, j] = # some computation with x, i, j, temp
    end
end