add original source

source/listing_5.1.cpp

@@ -0,0 +1,16 @@
+class spinlock_mutex
+{
+    std::atomic_flag flag;
+public:
+    spinlock_mutex():
+        flag(ATOMIC_FLAG_INIT)
+    {}
+    void lock()
+    {
+        while(flag.test_and_set(std::memory_order_acquire));
+    }
+    void unlock()
+    {
+        flag.clear(std::memory_order_release);
+    }
+};