Initialize the array in C, cuts 70% of creation time

Author: haesbaert

lib/iomux_stubs.c

@@ -113,6 +113,23 @@ caml_iomux_poll_set_index(value v_fds, value v_index, value v_fd, value v_events
 	return (Val_unit);
 }
 
+value
+caml_iomux_poll_init(value v_fds, value v_maxfds)
+{
+	CAMLparam1(v_fds);
+	struct pollfd *pfd = pollfd_of_index(v_fds, Val_int(0));
+	int maxfds = Int_val(v_maxfds);
+	int i;
+
+	for (i = 0; i < maxfds; i++, pfd++) {
+		pfd->fd = -1;
+		pfd->events = 0;
+	}
+
+	CAMLreturn(Val_unit);
+}
+
+
 value /* noalloc */
 caml_iomux_poll_get_revents(value v_fds, value v_index)
 {

lib/poll.ml

@@ -22,6 +22,7 @@ module Raw = struct
   external poll : buffer -> int -> int -> int = "caml_iomux_poll"
   external ppoll : buffer -> int -> int64 -> int list -> int = "caml_iomux_ppoll"
   external set_index : buffer -> int -> int -> int -> unit = "caml_iomux_poll_set_index" [@@noalloc]
+  external init : buffer -> int -> unit = "caml_iomux_poll_init"
   external get_revents : buffer -> int -> int = "caml_iomux_poll_get_revents" [@@noalloc]
   external get_fd : buffer -> int -> int = "caml_iomux_poll_get_fd" [@@noalloc]
 end
@@ -117,9 +118,7 @@ let create ?(maxfds=Util.max_open_files ()) () =
   let len = maxfds * Config.sizeof_pollfd in
   let buffer = Bigarray.(Array1.create char c_layout len) in
   let t = { buffer; maxfds } in
-  for i = 0 to maxfds - 1 do
-    invalidate_index t i
-  done;
+  Raw.init buffer maxfds;
   t
 
 let maxfds t = t.maxfds