add create_int_array

lib/task.ml

@@ -12,6 +12,9 @@ type pool =
   {domains : unit Domain.t array;
    task_chan : task_msg Chan.t}
 
+let create_int_array : int -> int array = fun n ->
+    Obj.magic (Array.create_float n)
+
 let do_task f p =
   try
     let res = f () in

lib/task.mli

@@ -7,6 +7,10 @@ type 'a promise
 type pool
 (** Type of task pool *)
 
+val create_int_array : int -> int array
+(** [create_int_array n] returns an uninitialised array of size n. The
+  * uninitialized array can be further initialised in parallel.*)
+
 val setup_pool : num_domains:int -> pool
 (** Sets up a task execution pool with [num_domains]. *)
 

test/dune

@@ -66,3 +66,9 @@
  (libraries domainslib unix)
  (modules prefix_sum)
  (modes native))
+
+(test
+ (name par_init)
+ (libraries domainslib)
+ (modules par_init)
+ (modes native))

test/par_init.ml

@@ -0,0 +1,13 @@
+module T = Domainslib.Task
+
+let num_domains = try int_of_string Sys.argv.(1) with _ -> 4
+let n = try int_of_string Sys.argv.(2) with _ -> 10000
+
+let _ =
+  let arr = T.create_int_array n in
+  let pool = T.setup_pool ~num_domains:(num_domains - 1) in
+  T.parallel_for pool ~chunk_size:(n/num_domains) ~start:0 ~finish:(pred n) ~body:(fun i ->
+    Array.unsafe_set arr i i
+    );
+  Printf.printf "%d\n" (Array.length arr);
+  T.teardown_pool