From fbad420240c2247e0ebf792404876c17a7b88c2b Mon Sep 17 00:00:00 2001
From: Weiyi Wang <wwylele@gmail.com>
Date: Wed, 19 Dec 2018 19:44:11 -0500
Subject: [PATCH] Common/Barrier: add method to get current generation

---
 src/common/thread.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/common/thread.h b/src/common/thread.h
index e84db99a0..38532a190 100644
--- a/src/common/thread.h
+++ b/src/common/thread.h
@@ -79,9 +79,14 @@ public:
         }
     }
 
+    std::size_t Generation() const {
+        std::unique_lock<std::mutex> lk(mutex);
+        return generation;
+    }
+
 private:
     std::condition_variable condvar;
-    std::mutex mutex;
+    mutable std::mutex mutex;
     std::size_t count;
     std::size_t waiting = 0;
     std::size_t generation = 0; // Incremented once each time the barrier is used