From 91d500baf89664187c3a98380263a1d77a646148 Mon Sep 17 00:00:00 2001
From: Matthew Parkinson <mattpark@microsoft.com>
Date: Fri, 17 Dec 2021 11:46:06 +0000
Subject: [PATCH] Fix flag lock race condition in Debug.

---
 src/ds/flaglock.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ds/flaglock.h b/src/ds/flaglock.h
index 954adc0..6155d2b 100644
--- a/src/ds/flaglock.h
+++ b/src/ds/flaglock.h
@@ -63,7 +63,7 @@ namespace snmalloc
      * std::thread::id can be another solution but it does not
      * support `constexpr` initialisation on some platforms.
      */
-    ThreadIdentity owner = nullptr;
+    std::atomic<ThreadIdentity> owner = nullptr;
 
     /**
      * @brief get_thread_identity