Parallel execution

par.jl

macro par(expr)
    thunk = esc(:(()->($expr)))
    quote
        local task = Task($thunk)
        task.sticky = false
        schedule(task)
        task
    end
end

function fib(n)
    if n ≤ 1
        return 1
    else
        return fib(n-1) + fib(n-2)
    end
end

fetch(@par fib(3))  # compile

const N = 40
const N_TASKS = 128

println("Sequential:")
@time [fib(N) for _ in 1:N_TASKS]

println("Parallel:")
@time fetch.([@par fib(N) for _ in 1:N_TASKS])

~/w/julia (master|…) [1] $ env JULIA_NUM_THREADS=4 ./julia par.jl
Sequential:
 61.244795 seconds (51.93 k allocations: 2.690 MiB)
Parallel:
 16.178837 seconds (471.02 k allocations: 24.798 MiB)