ES6: Implement WeakSet

test/cctest/test-weaksets.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 21 matching lines @@
 #include "cctest.h"
 
 using namespace v8::internal;
 
 
 static Isolate* GetIsolateFrom(LocalContext* context) {
   return reinterpret_cast<Isolate*>((*context)->GetIsolate());
 }
 
 
-static Handle<JSWeakMap> AllocateJSWeakMap(Isolate* isolate) {
+static Handle<JSWeakSet> AllocateJSWeakSet(Isolate* isolate) {
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
-  Handle<Map> map = factory->NewMap(JS_WEAK_MAP_TYPE, JSWeakMap::kSize);
-  Handle<JSObject> weakmap_obj = factory->NewJSObjectFromMap(map);
-  Handle<JSWeakMap> weakmap(JSWeakMap::cast(*weakmap_obj));
+  Handle<Map> map = factory->NewMap(JS_WEAK_SET_TYPE, JSWeakSet::kSize);
+  Handle<JSObject> weakset_obj = factory->NewJSObjectFromMap(map);
+  Handle<JSWeakSet> weakset(JSWeakSet::cast(*weakset_obj));
   // Do not use handles for the hash table, it would make entries strong.
   Object* table_obj = ObjectHashTable::Allocate(heap, 1)->ToObjectChecked();
   ObjectHashTable* table = ObjectHashTable::cast(table_obj);
-  weakmap->set_table(table);
-  weakmap->set_next(Smi::FromInt(0));
-  return weakmap;
+  weakset->set_table(table);
+  weakset->set_next(Smi::FromInt(0));
+  return weakset;
 }
 
-static void PutIntoWeakMap(Handle<JSWeakMap> weakmap,
+static void PutIntoWeakSet(Handle<JSWeakSet> weakset,
                            Handle<JSObject> key,
                            Handle<Object> value) {
   Handle<ObjectHashTable> table = PutIntoObjectHashTable(
-      Handle<ObjectHashTable>(ObjectHashTable::cast(weakmap->table())),
+      Handle<ObjectHashTable>(ObjectHashTable::cast(weakset->table())),
       Handle<JSObject>(JSObject::cast(*key)),
       value);
-  weakmap->set_table(*table);
+  weakset->set_table(*table);
 }
 
 static int NumberOfWeakCalls = 0;
 static void WeakPointerCallback(v8::Isolate* isolate,
                                 v8::Persistent<v8::Value>* handle,
                                 void* id) {
   ASSERT(id == reinterpret_cast<void*>(1234));
   NumberOfWeakCalls++;
   handle->Dispose(isolate);
 }
 
 
-TEST(Weakness) {
+TEST(WeakSet_Weakness) {
   FLAG_incremental_marking = false;
   LocalContext context;
   Isolate* isolate = GetIsolateFrom(&context);
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   HandleScope scope(isolate);
-  Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
+  Handle<JSWeakSet> weakset = AllocateJSWeakSet(isolate);
   GlobalHandles* global_handles = isolate->global_handles();
 
   // Keep global reference to the key.
   Handle<Object> key;
   {
     HandleScope scope(isolate);
     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
     Handle<JSObject> object = factory->NewJSObjectFromMap(map);
     key = global_handles->Create(*object);
   }
   CHECK(!global_handles->IsWeak(key.location()));
 
-  // Put entry into weak map.
+  // Put entry into weak set.
   {
     HandleScope scope(isolate);
-    PutIntoWeakMap(weakmap,
+    PutIntoWeakSet(weakset,
                    Handle<JSObject>(JSObject::cast(*key)),
                    Handle<Smi>(Smi::FromInt(23), isolate));
   }
-  CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(1, ObjectHashTable::cast(weakset->table())->NumberOfElements());
 
   // Force a full GC.
   heap->CollectAllGarbage(false);
   CHECK_EQ(0, NumberOfWeakCalls);
-  CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(1, ObjectHashTable::cast(weakset->table())->NumberOfElements());
   CHECK_EQ(
-      0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
+      0, ObjectHashTable::cast(weakset->table())->NumberOfDeletedElements());
 
   // Make the global reference to the key weak.
   {
     HandleScope scope(isolate);
     global_handles->MakeWeak(key.location(),
                              reinterpret_cast<void*>(1234),
                              &WeakPointerCallback);
   }
   CHECK(global_handles->IsWeak(key.location()));
 
   // Force a full GC.
   // Perform two consecutive GCs because the first one will only clear
-  // weak references whereas the second one will also clear weak maps.
+  // weak references whereas the second one will also clear weak sets.
   heap->CollectAllGarbage(false);
   CHECK_EQ(1, NumberOfWeakCalls);
-  CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(1, ObjectHashTable::cast(weakset->table())->NumberOfElements());
   CHECK_EQ(
-      0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
+      0, ObjectHashTable::cast(weakset->table())->NumberOfDeletedElements());
   heap->CollectAllGarbage(false);
   CHECK_EQ(1, NumberOfWeakCalls);
-  CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(0, ObjectHashTable::cast(weakset->table())->NumberOfElements());
   CHECK_EQ(
-      1, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
+      1, ObjectHashTable::cast(weakset->table())->NumberOfDeletedElements());
 }
 
 
-TEST(Shrinking) {
+TEST(WeakSet_Shrinking) {
   LocalContext context;
   Isolate* isolate = GetIsolateFrom(&context);
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   HandleScope scope(isolate);
-  Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
+  Handle<JSWeakSet> weakset = AllocateJSWeakSet(isolate);
 
   // Check initial capacity.
-  CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
+  CHECK_EQ(32, ObjectHashTable::cast(weakset->table())->Capacity());
 
-  // Fill up weak map to trigger capacity change.
+  // Fill up weak set to trigger capacity change.
   {
     HandleScope scope(isolate);
     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
     for (int i = 0; i < 32; i++) {
       Handle<JSObject> object = factory->NewJSObjectFromMap(map);
-      PutIntoWeakMap(weakmap, object, Handle<Smi>(Smi::FromInt(i), isolate));
+      PutIntoWeakSet(weakset, object, Handle<Smi>(Smi::FromInt(i), isolate));
     }
   }
 
   // Check increased capacity.
-  CHECK_EQ(128, ObjectHashTable::cast(weakmap->table())->Capacity());
+  CHECK_EQ(128, ObjectHashTable::cast(weakset->table())->Capacity());
 
   // Force a full GC.
-  CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(32, ObjectHashTable::cast(weakset->table())->NumberOfElements());
   CHECK_EQ(
-      0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
+      0, ObjectHashTable::cast(weakset->table())->NumberOfDeletedElements());
   heap->CollectAllGarbage(false);
-  CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
+  CHECK_EQ(0, ObjectHashTable::cast(weakset->table())->NumberOfElements());
   CHECK_EQ(
-      32, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
+      32, ObjectHashTable::cast(weakset->table())->NumberOfDeletedElements());
 
   // Check shrunk capacity.
-  CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
+  CHECK_EQ(32, ObjectHashTable::cast(weakset->table())->Capacity());
 }
 
 
-// Test that weak map values on an evacuation candidate which are not reachable
+// Test that weak set values on an evacuation candidate which are not reachable
 // by other paths are correctly recorded in the slots buffer.
-TEST(Regress2060a) {
+TEST(WeakSet_Regress2060a) {
   FLAG_always_compact = true;
   LocalContext context;
   Isolate* isolate = GetIsolateFrom(&context);
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   HandleScope scope(isolate);
   Handle<JSFunction> function =
       factory->NewFunction(factory->function_string(), factory->null_value());
   Handle<JSObject> key = factory->NewJSObject(function);
-  Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
+  Handle<JSWeakSet> weakset = AllocateJSWeakSet(isolate);
 
   // Start second old-space page so that values land on evacuation candidate.
   Page* first_page = heap->old_pointer_space()->anchor()->next_page();
   factory->NewFixedArray(900 * KB / kPointerSize, TENURED);
 
-  // Fill up weak map with values on an evacuation candidate.
+  // Fill up weak set with values on an evacuation candidate.
   {
     HandleScope scope(isolate);
     for (int i = 0; i < 32; i++) {
       Handle<JSObject> object = factory->NewJSObject(function, TENURED);
       CHECK(!heap->InNewSpace(object->address()));
       CHECK(!first_page->Contains(object->address()));
-      PutIntoWeakMap(weakmap, key, object);
+      PutIntoWeakSet(weakset, key, object);
     }
   }
 
   // Force compacting garbage collection.
   CHECK(FLAG_always_compact);
   heap->CollectAllGarbage(Heap::kNoGCFlags);
 }
 
 
-// Test that weak map keys on an evacuation candidate which are reachable by
+// Test that weak set keys on an evacuation candidate which are reachable by
 // other strong paths are correctly recorded in the slots buffer.
-TEST(Regress2060b) {
+TEST(WeakSet_Regress2060b) {
   FLAG_always_compact = true;
 #ifdef VERIFY_HEAP
   FLAG_verify_heap = true;
 #endif
 
   LocalContext context;
   Isolate* isolate = GetIsolateFrom(&context);
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   HandleScope scope(isolate);
   Handle<JSFunction> function =
       factory->NewFunction(factory->function_string(), factory->null_value());
 
   // Start second old-space page so that keys land on evacuation candidate.
   Page* first_page = heap->old_pointer_space()->anchor()->next_page();
   factory->NewFixedArray(900 * KB / kPointerSize, TENURED);
 
-  // Fill up weak map with keys on an evacuation candidate.
+  // Fill up weak set with keys on an evacuation candidate.
   Handle<JSObject> keys[32];
   for (int i = 0; i < 32; i++) {
     keys[i] = factory->NewJSObject(function, TENURED);
     CHECK(!heap->InNewSpace(keys[i]->address()));
     CHECK(!first_page->Contains(keys[i]->address()));
   }
-  Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
+  Handle<JSWeakSet> weakset = AllocateJSWeakSet(isolate);
   for (int i = 0; i < 32; i++) {
-    PutIntoWeakMap(weakmap,
+    PutIntoWeakSet(weakset,
                    keys[i],
                    Handle<Smi>(Smi::FromInt(i), isolate));
   }
 
   // Force compacting garbage collection. The subsequent collections are used
   // to verify that key references were actually updated.
   CHECK(FLAG_always_compact);
   heap->CollectAllGarbage(Heap::kNoGCFlags);
   heap->CollectAllGarbage(Heap::kNoGCFlags);
   heap->CollectAllGarbage(Heap::kNoGCFlags);
 }