1 files changed, 89 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testThreadingExclusiveData.cpp b/js/src/jsapi-tests/testThreadingExclusiveData.cpp
new file mode 100644
index 000000000..bf04b8a8e
--- /dev/null
+++ b/js/src/jsapi-tests/testThreadingExclusiveData.cpp
@@ -0,0 +1,89 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/IntegerRange.h"
+#include "js/Vector.h"
+#include "jsapi-tests/tests.h"
+#include "threading/ExclusiveData.h"
+#include "threading/Thread.h"
+
+// One thread for each bit in our counter.
+const static uint8_t NumThreads = 64;
+const static bool ShowDiagnostics = false;
+
+struct CounterAndBit
+{
+    uint8_t bit;
+    const js::ExclusiveData<uint64_t>& counter;
+
+    CounterAndBit(uint8_t bit, const js::ExclusiveData<uint64_t>& counter)
+      : bit(bit)
+      , counter(counter)
+    {
+        MOZ_ASSERT(bit < NumThreads);
+    }
+};
+
+void
+printDiagnosticMessage(uint8_t bit, uint64_t seen)
+{
+    if (!ShowDiagnostics)
+        return;
+
+    fprintf(stderr, "Thread %d saw ", bit);
+    for (auto i : mozilla::MakeRange(NumThreads)) {
+        if (seen & (uint64_t(1) << i))
+            fprintf(stderr, "1");
+        else
+            fprintf(stderr, "0");
+    }
+    fprintf(stderr, "\n");
+}
+
+void
+setBitAndCheck(CounterAndBit* counterAndBit)
+{
+    while (true) {
+        {
+            // Set our bit. Repeatedly setting it is idempotent.
+            auto guard = counterAndBit->counter.lock();
+            printDiagnosticMessage(counterAndBit->bit, guard);
+            guard |= (uint64_t(1) << counterAndBit->bit);
+        }
+
+        {
+            // Check to see if we have observed all the other threads setting
+            // their bit as well.
+            auto guard = counterAndBit->counter.lock();
+            printDiagnosticMessage(counterAndBit->bit, guard);
+            if (guard == UINT64_MAX) {
+                js_delete(counterAndBit);
+                return;
+            }
+        }
+    }
+}
+
+BEGIN_TEST(testExclusiveData)
+{
+    js::ExclusiveData<uint64_t> counter(js::mutexid::TestMutex, 0);
+
+    js::Vector<js::Thread> threads(cx);
+    CHECK(threads.reserve(NumThreads));
+
+    for (auto i : mozilla::MakeRange(NumThreads)) {
+        auto counterAndBit = js_new<CounterAndBit>(i, counter);
+        CHECK(counterAndBit);
+        CHECK(threads.emplaceBack());
+        CHECK(threads.back().init(setBitAndCheck, counterAndBit));
+    }
+
+    for (auto& thread : threads)
+        thread.join();
+
+    return true;
+}
+END_TEST(testExclusiveData)