1 files changed, 48 insertions, 0 deletions
diff --git a/lib/remoteCounter.ml b/lib/remoteCounter.ml
new file mode 100644
index 00000000..f4d7bb7b
--- /dev/null
+++ b/lib/remoteCounter.ml
@@ -0,0 +1,48 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+type 'a getter = unit -> 'a
+type 'a installer = ('a getter) -> unit
+
+type remote_counters_status = (string * Obj.t) list
+
+let counters : remote_counters_status ref = ref []
+
+let (!!) x = !(!x)
+
+let new_counter ~name a ~incr ~build =
+  assert(not (List.mem_assoc name !counters));
+  let data = ref (ref a) in
+  counters := (name, Obj.repr data) :: !counters;
+  let m = Mutex.create () in
+  let mk_thsafe_getter f () =
+    (* - slaves must use a remote counter getter, not this one! *)
+    (* - in the main process there is a race condition between slave
+         managers (that are threads) and the main thread, hence the mutex *)
+    if Flags.async_proofs_is_worker () then
+      Errors.anomaly(Pp.str"Slave processes must install remote counters");
+    Mutex.lock m; let x = f () in Mutex.unlock m;
+    build x in
+  let getter = ref(mk_thsafe_getter (fun () -> !data := incr !!data; !!data)) in
+  let installer f =
+    if not (Flags.async_proofs_is_worker ()) then
+      Errors.anomaly(Pp.str"Only slave processes can install a remote counter");
+    getter := f in
+  (fun () -> !getter ()), installer
+
+let backup () = !counters
+
+let snapshot () =
+  List.map (fun (n,v) -> n, Obj.repr (ref (ref !!(Obj.obj v)))) !counters
+
+let restore l =
+  List.iter (fun (name, data) ->
+    assert(List.mem_assoc name !counters);
+    let dataref = Obj.obj (List.assoc name !counters) in
+    !dataref := !!(Obj.obj data))
+  l