Fix race condition in STM DAG generation (in debug mode).

The same file name for .dot graphs could be used by concurrent processes.

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/system.ml b/lib/system.ml
index 4b99de707b..1817aed1fc 100644
--- a/lib/system.ml
+++ b/lib/system.ml
@@ -309,6 +309,7 @@ let with_time time f x =
     raise e
 
 let process_id () =
-  if Flags.async_proofs_is_worker () then !Flags.async_proofs_worker_id
-  else Printf.sprintf "master:%d" (Thread.id (Thread.self ()))
-    
+  Printf.sprintf "%d:%s:%d" (Unix.getpid ())
+    (if Flags.async_proofs_is_worker () then !Flags.async_proofs_worker_id
+     else "master")
+    (Thread.id (Thread.self ()))