Strange behavior of @spawn

New to Julia
1

I do not understand what is going on here:

julia> test(i,j) = println("i = $i , j = $j")
       i = 0 
       for j in 1:4
         global i += 1
         Threads.@spawn test(i,j)
       end

i = 4 , j = 2
julia> i = 4 , j = 1
julia> i = 4 , j = 3
i = 4 , j = 4

Why I get the same i=4 value for all calls?

1 Like
2

Well, I think that the function takes longer to be called in the specific thread than what the loop takes to run… correct?

3

Yes. It is exactly that. You can see the difference if you put a sleep(1) after each @spawn.

2 Likes