Atomic guard impromenents (#9473)

* Read atomic before doing CAS in the constructor.

* Typo

* Code style fix.

Co-authored-by: Roman Slivinskyi <rsl@keepit.com>

src/core/src/atomic_guard.hpp

@@ -12,7 +12,7 @@ class AtomicGuard {
 public:
     AtomicGuard(std::atomic_bool& b) : m_atomic(b) {
         bool exp = false;
-        while (!m_atomic.compare_exchange_strong(exp, true)) {
+        while (m_atomic.load(std::memory_order_relaxed) || !m_atomic.compare_exchange_strong(exp, true)) {
             exp = false;
         }
     }