1 files changed, 84 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testThreadingExclusiveData.cpp b/js/src/jsapi-tests/testThreadingExclusiveData.cpp
new file mode 100644
index 0000000000..0a72a639ac
--- /dev/null
+++ b/js/src/jsapi-tests/testThreadingExclusiveData.cpp
@@ -0,0 +1,84 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * 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::IntegerRange(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::IntegerRange(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)