Weak memory test.

test_weak_memory.cpp

@@ -0,0 +1,59 @@
+#include <random>
+#include <atomic>
+#include <thread>
+#include <iostream>
+#include <exception>
+
+
+
+int main ( void )
+{try{
+	int shared = 0;
+	std::atomic<int> flag;
+	
+	std::random_device rd;
+	std::default_random_engine el(rd());
+	std::uniform_int_distribution<int> ud(1,10);
+
+	auto f = [&flag, &shared, &el, &ud](){
+
+	    int count = 0;
+	    while (count < 10000000)
+    	{
+			volatile int busy_wait = ud(el)*100;
+			for ( ; busy_wait; --busy_wait );
+			
+	        int expected = 0;
+    	    if (flag.compare_exchange_strong(expected, 1, std::memory_order_relaxed))
+        	{
+	            // Lock was successful
+    	        shared++;
+        	    flag.store(0, std::memory_order_relaxed);
+            	count++;
+	        }
+    	}	
+	};
+
+	std::thread t1( f );
+	std::thread t2( f );
+
+	t1.join();
+	t2.join();
+
+	std::cout << "shared = " << shared << std::endl;
+
+	return 0;
+}
+catch ( const std::exception& e )
+{
+	std::cerr << std::endl
+			<< "std::exception(\"" << e.what() << "\")." << std::endl;
+	return 2;
+}
+catch ( ... )
+{
+	std::cerr  << std::endl
+			<< "unknown exception." << std::endl;
+	return 1;
+}}
+