Use relaxed atomics for FastOS_ThreadInterface break flag

2 files changed, 5 insertions, 4 deletions

diff --git a/fastos/src/vespa/fastos/thread.cpp b/fastos/src/vespa/fastos/thread.cpp
index 5e3400b70e3..3df8fa584a7 100644
--- a/fastos/src/vespa/fastos/thread.cpp
+++ b/fastos/src/vespa/fastos/thread.cpp
@@ -266,7 +266,7 @@ void FastOS_ThreadInterface::Hook ()
             }
             _owner = nullptr;
             _startArg = nullptr;
-            _breakFlag = false;
+            _breakFlag.store(false, std::memory_order_relaxed);
             finished = _pool->isClosed();
 
             dispatchedGuard.unlock();      // END lock
@@ -322,7 +322,7 @@ void FastOS_ThreadInterface::Dispatch(FastOS_Runnable *newOwner, void *arg)
 void FastOS_ThreadInterface::SetBreakFlag()
 {
     std::lock_guard<std::mutex> dispatchedGuard(_dispatchedMutex);
-    _breakFlag = true;
+    _breakFlag.store(true, std::memory_order_relaxed);
     _dispatchedCond.notify_one();
 }
 
diff --git a/fastos/src/vespa/fastos/thread.h b/fastos/src/vespa/fastos/thread.h
index 2726efe3cf0..c025a48d563 100644
--- a/fastos/src/vespa/fastos/thread.h
+++ b/fastos/src/vespa/fastos/thread.h
@@ -12,6 +12,7 @@
 
 
 #include "types.h"
+#include <atomic>
 #include <mutex>
 #include <condition_variable>
 
@@ -294,7 +295,7 @@ protected:
     /**
      * Break flag. If true, the thread should exit.
      */
-    bool _breakFlag;
+    std::atomic<bool> _breakFlag;
 
     /**
      * Is this thread active or free in the threadpool?
@@ -385,7 +386,7 @@ public:
      */
     bool GetBreakFlag () const
     {
-        return _breakFlag;
+        return _breakFlag.load(std::memory_order_relaxed);
     }
 
     /**