source: benchmark/creation/JavaThread.java@ 6136ecc

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 6136ecc was 6e540ea, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago

additional corrections to harmonize with last benchmark update

  • Property mode set to 100644
File size: 1.9 KB
RevLine 
[50abab9]1public class JavaThread {
[be53b87]2 // Simplistic low-quality Marsaglia Shift-XOR pseudo-random number generator.
3 // Bijective
4 // Cycle length for non-zero values is 4G-1.
5 // 0 is absorbing and should be avoided -- fixed point.
6 // The returned value is typically masked to produce a positive value.
7 static volatile int Ticket = 0 ;
8
9 private static int nextRandom (int x) {
10 if (x == 0) {
11 // reseed the PRNG
12 // Ticket is accessed infrequently and does not constitute a coherence hot-spot.
13 // Note that we use a non-atomic racy increment -- the race is rare and benign.
14 // If the race is a concern switch to an AtomicInteger.
15 // In addition accesses to the RW volatile global "Ticket" variable are not
16 // (readily) predictable at compile-time so the JIT will not be able to elide
17 // nextRandom() invocations.
18 x = ++Ticket ;
19 if (x == 0) x = 1 ;
20 }
21 x ^= x << 6;
22 x ^= x >>> 21;
23 x ^= x << 7;
24 return x ;
25 }
26 static int x = 2;
27
[b4107c8]28 static private int times = Integer.parseInt("10000") ;
[be53b87]29
[50abab9]30 public static class MyThread extends Thread {
31 @Override
32 public void run() {}
33 }
[be53b87]34 public static void helper() throws InterruptedException {
[6e540ea]35 for(int i = 1; i <= times; i += 1) {
[be53b87]36 MyThread m = new MyThread();
37 x = nextRandom( x );
38 m.start();
[50abab9]39 m.join();
40 }
[be53b87]41 }
42 public static void InnerMain() throws InterruptedException {
43 long start = System.nanoTime();
44 helper();
[50abab9]45 long end = System.nanoTime();
[6e540ea]46 System.out.println( (end - start) / times );
[be53b87]47 }
48 public static void main(String[] args) throws InterruptedException {
[b4107c8]49 if ( args.length > 2 ) System.exit( 1 );
50 if ( args.length == 2 ) { times = Integer.parseInt(args[1]); }
51
52 for (int i = Integer.parseInt("5"); --i >= 0 ; ) {
[be53b87]53 InnerMain();
[6e540ea]54 Thread.sleep(2000); // 2 seconds
[be53b87]55 x = nextRandom(x);
56 }
57 if ( x == 0 ) System.out.println(x);
[50abab9]58 }
[be53b87]59}
[b4107c8]60
61// Local Variables: //
62// tab-width: 4 //
63// End: //
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