summaryrefslogtreecommitdiffstats
path: root/js/src/tests/js1_8/extensions/dekker.js
diff options
context:
space:
mode:
Diffstat (limited to 'js/src/tests/js1_8/extensions/dekker.js')
-rw-r--r--js/src/tests/js1_8/extensions/dekker.js68
1 files changed, 68 insertions, 0 deletions
diff --git a/js/src/tests/js1_8/extensions/dekker.js b/js/src/tests/js1_8/extensions/dekker.js
new file mode 100644
index 000000000..26d93d4fe
--- /dev/null
+++ b/js/src/tests/js1_8/extensions/dekker.js
@@ -0,0 +1,68 @@
+// |reftest| skip
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ * Contributor: Jason Orendorff
+ */
+
+//-----------------------------------------------------------------------------
+
+var summary = "Dekker's algorithm for mutual exclusion";
+// Adapted from pseudocode in Wikipedia:
+// http://en.wikipedia.org/wiki/Dekker%27s_algorithm
+
+printStatus (summary);
+
+var N = 500; // number of iterations
+
+// the mutex mechanism
+var f = [false, false];
+var turn = 0;
+
+// resource being protected
+var counter = 0;
+
+function worker(me) {
+ let him = 1 - me;
+
+ for (let i = 0; i < N; i++) {
+ // enter the mutex
+ f[me] = true;
+ while (f[him]) {
+ if (turn != me) {
+ f[me] = false;
+ while (turn != me)
+ ; // busy wait
+ f[me] = true;
+ }
+ }
+
+ // critical section
+ let x = counter;
+ sleep(0.003);
+ counter = x + 1;
+
+ // leave the mutex
+ turn = him;
+ f[me] = false;
+ }
+
+ return 'ok';
+}
+
+var expect;
+var actual;
+
+if (typeof scatter == 'undefined' || typeof sleep == 'undefined') {
+ print('Test skipped. scatter or sleep not defined.');
+ expect = actual = 'Test skipped.';
+} else {
+ var results = scatter([function () { return worker(0); },
+ function () { return worker(1); }]);
+
+ expect = "Thread status: [ok,ok], counter: " + (2 * N);
+ actual = "Thread status: [" + results + "], counter: " + counter;
+}
+
+reportCompare(expect, actual, summary);