using System; using System.Threading; class Test { public static int result; public static volatile bool finished; static void Thread2() { result = 143; finished = true; } static void Main() { finished = false; // Run Thread2() in a new thread new Thread(new ThreadStart(Thread2)).Start(); // Wait for Thread2 to signal that it has a result by setting // finished to true. for (;;) { if (finished) { Console.WriteLine("result = {0}", result); return; } } } }produces the output:
result = 143In this example, the method Main starts a new thread that runs the method Thread2. This method stores a value into a non-volatile field called result, then stores true in the volatile field finished. The main thread waits for the field finished to be set to true, then reads the field result. Since result has been declared volatile, the main thread must read the value 143 from the field result. If the field finished had not been declared volatile, then it would be permissible for the store to result to be visible to the main thread after the store to finished, and hence for the main thread to read the value 0 from the field result. Declaring finished as a volatile field prevents any such inconsistency. end example]
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