1 files changed, 80 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testSharedImmutableStringsCache.cpp b/js/src/jsapi-tests/testSharedImmutableStringsCache.cpp
new file mode 100644
index 000000000..421d9f8f9
--- /dev/null
+++ b/js/src/jsapi-tests/testSharedImmutableStringsCache.cpp
@@ -0,0 +1,80 @@
+/* -*- 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/Thread.h"
+#include "vm/SharedImmutableStringsCache.h"
+
+const int NUM_THREADS = 256;
+const int NUM_ITERATIONS = 256;
+
+const int NUM_STRINGS = 4;
+const char16_t *const STRINGS[NUM_STRINGS] = {
+    u"uno",
+    u"dos",
+    u"tres",
+    u"quattro"
+};
+
+struct CacheAndIndex
+{
+    js::SharedImmutableStringsCache* cache;
+    int index;
+
+    CacheAndIndex(js::SharedImmutableStringsCache* cache, int index)
+      : cache(cache)
+      , index(index)
+    { }
+};
+
+static void
+getString(CacheAndIndex* cacheAndIndex)
+{
+    for (int i = 0; i < NUM_ITERATIONS; i++) {
+        auto str = STRINGS[cacheAndIndex->index % NUM_STRINGS];
+
+        auto dupe = js::DuplicateString(str);
+        MOZ_RELEASE_ASSERT(dupe);
+
+        auto deduped = cacheAndIndex->cache->getOrCreate(mozilla::Move(dupe), js_strlen(str));
+        MOZ_RELEASE_ASSERT(deduped.isSome());
+        MOZ_RELEASE_ASSERT(js_strcmp(str, deduped->chars()) == 0);
+
+        {
+            auto cloned = deduped->clone();
+            // We should be de-duplicating and giving back the same string.
+            MOZ_RELEASE_ASSERT(deduped->chars() == cloned.chars());
+        }
+    }
+
+    js_delete(cacheAndIndex);
+}
+
+BEGIN_TEST(testSharedImmutableStringsCache)
+{
+    auto maybeCache = js::SharedImmutableStringsCache::Create();
+    CHECK(maybeCache.isSome());
+    auto& cache = *maybeCache;
+
+    js::Vector<js::Thread> threads(cx);
+    CHECK(threads.reserve(NUM_THREADS));
+
+    for (auto i : mozilla::MakeRange(NUM_THREADS)) {
+        auto cacheAndIndex = js_new<CacheAndIndex>(&cache, i);
+        CHECK(cacheAndIndex);
+        threads.infallibleEmplaceBack();
+        CHECK(threads.back().init(getString, cacheAndIndex));
+    }
+
+    for (auto& thread : threads)
+        thread.join();
+
+    return true;
+}
+END_TEST(testSharedImmutableStringsCache)