Minor scheduler optimization

1 files changed, 5 insertions, 4 deletions

diff --git a/build2/scheduler.txx b/build2/scheduler.txx
index 3410b6f..684409c 100644
--- a/build2/scheduler.txx
+++ b/build2/scheduler.txx
@@ -70,14 +70,15 @@ namespace build2
         size_t om (m);
         m = task_queue_depth_;
 
+        ql.unlock ();
+        forward<F> (f) (forward<A> (a)...); // Should not throw.
+
+        if (om != task_queue_depth_)
         {
-          ql.unlock ();
-          forward<F> (f) (forward<A> (a)...); // Should not throw.
           ql.lock ();
+          m = s == 0 ? t : om;
         }
 
-        m = s == 0 ? t : om;
-
         return false;
       }
     }