The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/js/src/tests/js1_8/extensions/dekker.js	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,68 @@
     1.4 +// |reftest| skip
     1.5 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
     1.6 +/*
     1.7 + * Any copyright is dedicated to the Public Domain.
     1.8 + * http://creativecommons.org/licenses/publicdomain/
     1.9 + * Contributor: Jason Orendorff
    1.10 + */
    1.11 +
    1.12 +//-----------------------------------------------------------------------------
    1.13 +
    1.14 +var summary = "Dekker's algorithm for mutual exclusion";
    1.15 +// Adapted from pseudocode in Wikipedia:
    1.16 +// http://en.wikipedia.org/wiki/Dekker%27s_algorithm
    1.17 +
    1.18 +printStatus (summary);
    1.19 +
    1.20 +var N = 500;  // number of iterations
    1.21 +
    1.22 +// the mutex mechanism
    1.23 +var f = [false, false];
    1.24 +var turn = 0;
    1.25 +
    1.26 +// resource being protected
    1.27 +var counter = 0;
    1.28 +
    1.29 +function worker(me) {
    1.30 +  let him = 1 - me;
    1.31 +
    1.32 +  for (let i = 0; i < N; i++) {
    1.33 +    // enter the mutex
    1.34 +    f[me] = true;
    1.35 +    while (f[him]) {
    1.36 +      if (turn != me) {
    1.37 +        f[me] = false;
    1.38 +        while (turn != me)
    1.39 +          ;  // busy wait
    1.40 +        f[me] = true;
    1.41 +      }
    1.42 +    }
    1.43 +
    1.44 +    // critical section
    1.45 +    let x = counter;
    1.46 +    sleep(0.003);
    1.47 +    counter = x + 1;
    1.48 +
    1.49 +    // leave the mutex
    1.50 +    turn = him;
    1.51 +    f[me] = false;
    1.52 +  }
    1.53 +
    1.54 +  return 'ok';
    1.55 +}
    1.56 +
    1.57 +var expect;
    1.58 +var actual;
    1.59 +
    1.60 +if (typeof scatter == 'undefined' || typeof sleep == 'undefined') {
    1.61 +  print('Test skipped. scatter or sleep not defined.');
    1.62 +  expect = actual = 'Test skipped.';
    1.63 +} else {
    1.64 +  var results = scatter([function () { return worker(0); },
    1.65 +                         function () { return worker(1); }]);
    1.66 +
    1.67 +  expect = "Thread status: [ok,ok], counter: " + (2 * N);
    1.68 +  actual = "Thread status: [" + results + "], counter: " + counter;
    1.69 +}
    1.70 +
    1.71 +reportCompare(expect, actual, summary);