Fixed tests and improve multithread sync

lib/main/concurrent/executor.h

@@ -21,6 +21,7 @@
 #define PIP_TESTS_EXECUTOR_H
 
 #include "piblockingdequeue.h"
+#include <atomic>
 
 /**
  * @brief Thread pools address two different problems: they usually provide improved performance when executing large
@@ -51,11 +52,11 @@ public:
 	 */
 	void shutdown();
 
-	volatile bool isShutdown() const;
+	bool isShutdown() const;
 
 	bool awaitTermination(int timeoutMs);
 private:
-	volatile bool isShutdown_;
+	std::atomic_bool isShutdown_;
 	PIBlockingDequeue<std::function<void()> >* taskQueue;
 	PIVector<PIThread*> threadPool;
 };