Changes in benchmark/mutex/JavaThread.java [be53b87:bf71cfd]

File:

• benchmark/mutex/JavaThread.java (modified) (1 diff)

benchmark/mutex/JavaThread.java

@@ -1 +1 @@
 public class JavaThread {
-        // Simplistic low-quality Marsaglia Shift-XOR pseudo-random number generator.
-        // Bijective   
-        // Cycle length for non-zero values is 4G-1.
-        // 0 is absorbing and should be avoided -- fixed point.
-        // The returned value is typically masked to produce a positive value.
-        static volatile int Ticket = 0 ; 
+        public synchronized void noop() {}
 
-        private static int nextRandom (int x) {
-                if (x == 0) { 
-                        // reseed the PRNG
-                        // Ticket is accessed infrequently and does not constitute a coherence hot-spot. 
-                        // Note that we use a non-atomic racy increment -- the race is rare and benign. 
-                        // If the race is a concern switch to an AtomicInteger.  
-                        // In addition accesses to the RW volatile global "Ticket"  variable are not 
-                        // (readily) predictable at compile-time so the JIT will not be able to elide 
-                        // nextRandom() invocations.  
-                        x = ++Ticket ; 
-                        if (x == 0) x = 1 ; 
-                }
-                x ^= x << 6;
-                x ^= x >>> 21;
-                x ^= x << 7;
-                return x ;   
-        }
-        static int x = 2;
-
-        static private final int NoOfTimes = Integer.parseInt("100000000") ;
-
-        public synchronized void noop() {
-                x = nextRandom( x );
-        }
-        public static void helper() throws InterruptedException {
+        public static void main(String[] args) {
+                int NoOfTimes = 5000000;
                 JavaThread j = new JavaThread();
-                // Inhibit biased locking ...
-                x = (j.hashCode() ^ System.identityHashCode(j)) | 1 ;     
+                long start = System.nanoTime();
                 for(int i = 1; i <= NoOfTimes; i += 1) {
-                        x = nextRandom(x);
                         j.noop();
                 }
-        }
-        public static void InnerMain() throws InterruptedException {
-                long start = System.nanoTime();
-                helper();
                 long end = System.nanoTime();
-                System.out.println( (end - start) / NoOfTimes );
-        }
-        public static void main(String[] args) throws InterruptedException {
-                for (int n = Integer.parseInt("5"); --n >= 0 ; ) { 
-                        InnerMain();
-                        Thread.sleep(2000);     // 2 seconds
-                        x = nextRandom(x);
-                }
-                if ( x == 0 ) System.out.println(x);
+                System.out.println( (end - start) / NoOfTimes);
         }
 }