1 files changed, 255 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testWeakMap.cpp b/js/src/jsapi-tests/testWeakMap.cpp
new file mode 100644
index 0000000000..95a291a8a0
--- /dev/null
+++ b/js/src/jsapi-tests/testWeakMap.cpp
@@ -0,0 +1,255 @@
+/* -*- 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 "gc/Zone.h"
+#include "js/Array.h"               // JS::GetArrayLength
+#include "js/GlobalObject.h"        // JS_NewGlobalObject
+#include "js/PropertyAndElement.h"  // JS_DefineProperty
+#include "js/WeakMap.h"
+#include "jsapi-tests/tests.h"
+#include "vm/Realm.h"
+
+using namespace js;
+
+JSObject* keyDelegate = nullptr;
+
+BEGIN_TEST(testWeakMap_basicOperations) {
+  JS::RootedObject map(cx, JS::NewWeakMapObject(cx));
+  CHECK(IsWeakMapObject(map));
+
+  JS::RootedObject key(cx, newKey());
+  CHECK(key);
+  CHECK(!IsWeakMapObject(key));
+
+  JS::RootedValue r(cx);
+  CHECK(GetWeakMapEntry(cx, map, key, &r));
+  CHECK(r.isUndefined());
+
+  CHECK(checkSize(map, 0));
+
+  JS::RootedValue val(cx, JS::Int32Value(1));
+  CHECK(SetWeakMapEntry(cx, map, key, val));
+
+  CHECK(GetWeakMapEntry(cx, map, key, &r));
+  CHECK(r == val);
+  CHECK(checkSize(map, 1));
+
+  JS_GC(cx);
+
+  CHECK(GetWeakMapEntry(cx, map, key, &r));
+  CHECK(r == val);
+  CHECK(checkSize(map, 1));
+
+  key = nullptr;
+  JS_GC(cx);
+
+  CHECK(checkSize(map, 0));
+
+  return true;
+}
+
+JSObject* newKey() { return JS_NewPlainObject(cx); }
+
+bool checkSize(JS::HandleObject map, uint32_t expected) {
+  JS::RootedObject keys(cx);
+  CHECK(JS_NondeterministicGetWeakMapKeys(cx, map, &keys));
+
+  uint32_t length;
+  CHECK(JS::GetArrayLength(cx, keys, &length));
+  CHECK(length == expected);
+
+  return true;
+}
+END_TEST(testWeakMap_basicOperations)
+
+BEGIN_TEST(testWeakMap_keyDelegates) {
+  AutoLeaveZeal nozeal(cx);
+
+  AutoGCParameter param(cx, JSGC_INCREMENTAL_GC_ENABLED, true);
+  JS_GC(cx);
+  JS::RootedObject map(cx, JS::NewWeakMapObject(cx));
+  CHECK(map);
+
+  JS::RootedObject delegate(cx, newDelegate());
+  JS::RootedObject key(cx, delegate);
+  if (!JS_WrapObject(cx, &key)) {
+    return false;
+  }
+  CHECK(key);
+  CHECK(delegate);
+
+  keyDelegate = delegate;
+
+  JS::RootedObject delegateRoot(cx);
+  {
+    JSAutoRealm ar(cx, delegate);
+    delegateRoot = JS_NewPlainObject(cx);
+    CHECK(delegateRoot);
+    JS::RootedValue delegateValue(cx, JS::ObjectValue(*delegate));
+    CHECK(JS_DefineProperty(cx, delegateRoot, "delegate", delegateValue, 0));
+  }
+  delegate = nullptr;
+
+  /*
+   * Perform an incremental GC, introducing an unmarked CCW to force the map
+   * zone to finish marking before the delegate zone.
+   */
+  CHECK(newCCW(map, delegateRoot));
+  performIncrementalGC();
+#ifdef DEBUG
+  CHECK(map->zone()->lastSweepGroupIndex() <
+        delegateRoot->zone()->lastSweepGroupIndex());
+#endif
+
+  /* Add our entry to the weakmap. */
+  JS::RootedValue val(cx, JS::Int32Value(1));
+  CHECK(SetWeakMapEntry(cx, map, key, val));
+  CHECK(checkSize(map, 1));
+
+  /*
+   * Check the delegate keeps the entry alive even if the key is not reachable.
+   */
+  key = nullptr;
+  CHECK(newCCW(map, delegateRoot));
+  performIncrementalGC();
+  CHECK(checkSize(map, 1));
+
+  /*
+   * Check that the zones finished marking at the same time, which is
+   * necessary because of the presence of the delegate and the CCW.
+   */
+#ifdef DEBUG
+  CHECK(map->zone()->lastSweepGroupIndex() ==
+        delegateRoot->zone()->lastSweepGroupIndex());
+#endif
+
+  /* Check that when the delegate becomes unreachable the entry is removed. */
+  delegateRoot = nullptr;
+  keyDelegate = nullptr;
+  JS_GC(cx);
+  CHECK(checkSize(map, 0));
+
+  return true;
+}
+
+static size_t DelegateObjectMoved(JSObject* obj, JSObject* old) {
+  if (!keyDelegate) {
+    return 0;  // Object got moved before we set keyDelegate to point to it.
+  }
+
+  MOZ_RELEASE_ASSERT(keyDelegate == old);
+  keyDelegate = obj;
+  return 0;
+}
+
+JSObject* newKey() {
+  static const JSClass keyClass = {
+      "keyWithDelegate", JSCLASS_HAS_RESERVED_SLOTS(1),
+      JS_NULL_CLASS_OPS, JS_NULL_CLASS_SPEC,
+      JS_NULL_CLASS_EXT, JS_NULL_OBJECT_OPS};
+
+  JS::RootedObject key(cx, JS_NewObject(cx, &keyClass));
+  if (!key) {
+    return nullptr;
+  }
+
+  return key;
+}
+
+JSObject* newCCW(JS::HandleObject sourceZone, JS::HandleObject destZone) {
+  /*
+   * Now ensure that this zone will be swept first by adding a cross
+   * compartment wrapper to a new object in the same zone as the
+   * delegate object.
+   */
+  JS::RootedObject object(cx);
+  {
+    JSAutoRealm ar(cx, destZone);
+    object = JS_NewPlainObject(cx);
+    if (!object) {
+      return nullptr;
+    }
+  }
+  {
+    JSAutoRealm ar(cx, sourceZone);
+    if (!JS_WrapObject(cx, &object)) {
+      return nullptr;
+    }
+  }
+
+  // In order to test the SCC algorithm, we need the wrapper/wrappee to be
+  // tenured.
+  cx->runtime()->gc.evictNursery();
+
+  return object;
+}
+
+JSObject* newDelegate() {
+  static const JSClassOps delegateClassOps = {
+      nullptr,                   // addProperty
+      nullptr,                   // delProperty
+      nullptr,                   // enumerate
+      nullptr,                   // newEnumerate
+      nullptr,                   // resolve
+      nullptr,                   // mayResolve
+      nullptr,                   // finalize
+      nullptr,                   // call
+      nullptr,                   // construct
+      JS_GlobalObjectTraceHook,  // trace
+  };
+
+  static const js::ClassExtension delegateClassExtension = {
+      DelegateObjectMoved,  // objectMovedOp
+  };
+
+  static const JSClass delegateClass = {
+      "delegate",
+      JSCLASS_GLOBAL_FLAGS | JSCLASS_HAS_RESERVED_SLOTS(1),
+      &delegateClassOps,
+      JS_NULL_CLASS_SPEC,
+      &delegateClassExtension,
+      JS_NULL_OBJECT_OPS};
+
+  /* Create the global object. */
+  JS::RealmOptions options;
+  JS::RootedObject global(cx,
+                          JS_NewGlobalObject(cx, &delegateClass, nullptr,
+                                             JS::FireOnNewGlobalHook, options));
+  if (!global) {
+    return nullptr;
+  }
+
+  JS_SetReservedSlot(global, 0, JS::Int32Value(42));
+  return global;
+}
+
+bool checkSize(JS::HandleObject map, uint32_t expected) {
+  JS::RootedObject keys(cx);
+  CHECK(JS_NondeterministicGetWeakMapKeys(cx, map, &keys));
+
+  uint32_t length;
+  CHECK(JS::GetArrayLength(cx, keys, &length));
+  CHECK(length == expected);
+
+  return true;
+}
+
+void performIncrementalGC() {
+  JSRuntime* rt = cx->runtime();
+  js::SliceBudget budget(js::WorkBudget(1000));
+  rt->gc.startDebugGC(JS::GCOptions::Normal, budget);
+
+  // Wait until we've started marking before finishing the GC
+  // non-incrementally.
+  while (rt->gc.state() == gc::State::Prepare) {
+    rt->gc.debugGCSlice(budget);
+  }
+  if (JS::IsIncrementalGCInProgress(cx)) {
+    rt->gc.finishGC(JS::GCReason::DEBUG_GC);
+  }
+}
+END_TEST(testWeakMap_keyDelegates)