session scheduler now sets -j option for why3server

src/driver/prove_client.ml

 let standalone : bool ref = ref true
 let socket : Unix.file_descr option ref = ref None
+let max_running_provers : int ref = ref 1
+
+let set_max_running_provers x =
+  max_running_provers := x
 
 let client_connect socket_name =
   if Sys.os_type = "Win32" then begin
@@ -70,7 +74,9 @@ let disconnect () =
 let run_server () =
   let exec = Filename.concat Config.libdir "why3server" in
   Unix.create_process exec
-    [|exec; "--socket"; !socket_name; "--single-client"|]
+    [|exec; "--socket"; !socket_name;
+      "--single-client";
+      "-j"; string_of_int !max_running_provers |]
   Unix.stdin Unix.stdout Unix.stderr
 
 let force_connect () =

src/driver/prove_client.mli

 val standalone : bool ref
 
 val set_socket_name : string -> unit
+val set_max_running_provers : int -> unit
 
 val connect : unit -> unit
 

src/session/session_scheduler.ml

@@ -111,11 +111,13 @@ type t =
     }
 
 let set_maximum_running_proofs max sched =
+  Prove_client.set_max_running_provers max;
   (* TODO dequeue actions if maximum_running_proofs increase *)
   sched.maximum_running_proofs <- max
 
 let init max =
   Debug.dprintf debug "[Sched] init scheduler max=%i@." max;
+  Prove_client.set_max_running_provers max;
   { actions_queue = Queue.create ();
     maximum_running_proofs = max;
     running_proofs = [];