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|
(* TEST
include unix;
libunix;
{
bytecode;
}{
native;
}
*)
let () = Random.init 42
let domain_count = 10
let delays =
(* These Random calls are intentionally:
- taken from an independent Random state, not the global state we are testing
- initialized with make_self_init, to return different delays on each tst run
*)
let delay_rng = Random.State.make_self_init () in
List.init domain_count (fun _i -> Random.State.float delay_rng 0.5)
(* Each domain will start by waiting a random amount, to ensure that
the Random.int functions we are testing execute in
non-deterministic order. The Random.int result should remain
deterministic, as domains are spawned in a deterministic order and
each domain state is obtaind by splitting the global Random state
that was initialized with a fixed seed. *)
let f delay () =
Unix.sleepf delay;
let a = Random.int 100 in
let b = Random.int 100 in
let c = Random.int 100 in
(a, b, c)
let () =
delays
|> List.map (fun delay -> Domain.spawn (f delay))
|> List.map Domain.join
|> List.iter (fun (a, b, c) -> Printf.printf "%d %d %d\n%!" a b c)
let () =
print_endline
"Note: we observe in this output that the random numbers of each child domain\n\
appear uncorrelated, yet are produced deterministically."
|
