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27 
28 #include <utility>
29 
30 #include "src/v8.h"
31 
32 #include "src/global-handles.h"
33 #include "test/cctest/cctest.h"
34 #include "test/cctest/heap/utils-inl.h"
35 
36 using namespace v8::internal;
37 
GetIsolateFrom(LocalContext * context)38 static Isolate* GetIsolateFrom(LocalContext* context) {
39   return reinterpret_cast<Isolate*>((*context)->GetIsolate());
40 }
41 
42 
AllocateJSWeakMap(Isolate * isolate)43 static Handle<JSWeakMap> AllocateJSWeakMap(Isolate* isolate) {
44   Handle<JSWeakMap> weakmap = isolate->factory()->NewJSWeakMap();
45   // Do not leak handles for the hash table, it would make entries strong.
46   {
47     HandleScope scope(isolate);
48     Handle<ObjectHashTable> table = ObjectHashTable::New(isolate, 1);
49     weakmap->set_table(*table);
50   }
51   return weakmap;
52 }
53 
54 static int NumberOfWeakCalls = 0;
WeakPointerCallback(const v8::WeakCallbackData<v8::Value,void> & data)55 static void WeakPointerCallback(
56     const v8::WeakCallbackData<v8::Value, void>& data) {
57   std::pair<v8::Persistent<v8::Value>*, int>* p =
58       reinterpret_cast<std::pair<v8::Persistent<v8::Value>*, int>*>(
59           data.GetParameter());
60   CHECK_EQ(1234, p->second);
61   NumberOfWeakCalls++;
62   p->first->Reset();
63 }
64 
65 
TEST(Weakness)66 TEST(Weakness) {
67   FLAG_incremental_marking = false;
68   LocalContext context;
69   Isolate* isolate = GetIsolateFrom(&context);
70   Factory* factory = isolate->factory();
71   Heap* heap = isolate->heap();
72   HandleScope scope(isolate);
73   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
74   GlobalHandles* global_handles = isolate->global_handles();
75 
76   // Keep global reference to the key.
77   Handle<Object> key;
78   {
79     HandleScope scope(isolate);
80     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
81     Handle<JSObject> object = factory->NewJSObjectFromMap(map);
82     key = global_handles->Create(*object);
83   }
84   CHECK(!global_handles->IsWeak(key.location()));
85 
86   // Put two chained entries into weak map.
87   {
88     HandleScope scope(isolate);
89     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
90     Handle<JSObject> object = factory->NewJSObjectFromMap(map);
91     Handle<Smi> smi(Smi::FromInt(23), isolate);
92     int32_t hash = Object::GetOrCreateHash(isolate, key)->value();
93     JSWeakCollection::Set(weakmap, key, object, hash);
94     int32_t object_hash = Object::GetOrCreateHash(isolate, object)->value();
95     JSWeakCollection::Set(weakmap, object, smi, object_hash);
96   }
97   CHECK_EQ(2, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
98 
99   // Force a full GC.
100   heap->CollectAllGarbage(false);
101   CHECK_EQ(0, NumberOfWeakCalls);
102   CHECK_EQ(2, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
103   CHECK_EQ(
104       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
105 
106   // Make the global reference to the key weak.
107   {
108     HandleScope scope(isolate);
109     std::pair<Handle<Object>*, int> handle_and_id(&key, 1234);
110     GlobalHandles::MakeWeak(key.location(),
111                             reinterpret_cast<void*>(&handle_and_id),
112                             &WeakPointerCallback);
113   }
114   CHECK(global_handles->IsWeak(key.location()));
115 
116   // Force a full GC.
117   // Perform two consecutive GCs because the first one will only clear
118   // weak references whereas the second one will also clear weak maps.
119   heap->CollectAllGarbage(false);
120   CHECK_EQ(1, NumberOfWeakCalls);
121   CHECK_EQ(2, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
122   CHECK_EQ(
123       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
124   heap->CollectAllGarbage(false);
125   CHECK_EQ(1, NumberOfWeakCalls);
126   CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
127   CHECK_EQ(2,
128            ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
129 }
130 
131 
TEST(Shrinking)132 TEST(Shrinking) {
133   LocalContext context;
134   Isolate* isolate = GetIsolateFrom(&context);
135   Factory* factory = isolate->factory();
136   Heap* heap = isolate->heap();
137   HandleScope scope(isolate);
138   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
139 
140   // Check initial capacity.
141   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
142 
143   // Fill up weak map to trigger capacity change.
144   {
145     HandleScope scope(isolate);
146     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
147     for (int i = 0; i < 32; i++) {
148       Handle<JSObject> object = factory->NewJSObjectFromMap(map);
149       Handle<Smi> smi(Smi::FromInt(i), isolate);
150       int32_t object_hash = Object::GetOrCreateHash(isolate, object)->value();
151       JSWeakCollection::Set(weakmap, object, smi, object_hash);
152     }
153   }
154 
155   // Check increased capacity.
156   CHECK_EQ(128, ObjectHashTable::cast(weakmap->table())->Capacity());
157 
158   // Force a full GC.
159   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
160   CHECK_EQ(
161       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
162   heap->CollectAllGarbage(false);
163   CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
164   CHECK_EQ(
165       32, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
166 
167   // Check shrunk capacity.
168   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
169 }
170 
171 
172 // Test that weak map values on an evacuation candidate which are not reachable
173 // by other paths are correctly recorded in the slots buffer.
TEST(Regress2060a)174 TEST(Regress2060a) {
175   if (i::FLAG_never_compact) return;
176   FLAG_always_compact = true;
177   LocalContext context;
178   Isolate* isolate = GetIsolateFrom(&context);
179   Factory* factory = isolate->factory();
180   Heap* heap = isolate->heap();
181   HandleScope scope(isolate);
182   Handle<JSFunction> function = factory->NewFunction(
183       factory->function_string());
184   Handle<JSObject> key = factory->NewJSObject(function);
185   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
186 
187   // Start second old-space page so that values land on evacuation candidate.
188   Page* first_page = heap->old_space()->anchor()->next_page();
189   SimulateFullSpace(heap->old_space());
190 
191   // Fill up weak map with values on an evacuation candidate.
192   {
193     HandleScope scope(isolate);
194     for (int i = 0; i < 32; i++) {
195       Handle<JSObject> object = factory->NewJSObject(function, TENURED);
196       CHECK(!heap->InNewSpace(object->address()));
197       CHECK(!first_page->Contains(object->address()));
198       int32_t hash = Object::GetOrCreateHash(isolate, key)->value();
199       JSWeakCollection::Set(weakmap, key, object, hash);
200     }
201   }
202 
203   // Force compacting garbage collection.
204   CHECK(FLAG_always_compact);
205   heap->CollectAllGarbage();
206 }
207 
208 
209 // Test that weak map keys on an evacuation candidate which are reachable by
210 // other strong paths are correctly recorded in the slots buffer.
TEST(Regress2060b)211 TEST(Regress2060b) {
212   if (i::FLAG_never_compact) return;
213   FLAG_always_compact = true;
214 #ifdef VERIFY_HEAP
215   FLAG_verify_heap = true;
216 #endif
217 
218   LocalContext context;
219   Isolate* isolate = GetIsolateFrom(&context);
220   Factory* factory = isolate->factory();
221   Heap* heap = isolate->heap();
222   HandleScope scope(isolate);
223   Handle<JSFunction> function = factory->NewFunction(
224       factory->function_string());
225 
226   // Start second old-space page so that keys land on evacuation candidate.
227   Page* first_page = heap->old_space()->anchor()->next_page();
228   SimulateFullSpace(heap->old_space());
229 
230   // Fill up weak map with keys on an evacuation candidate.
231   Handle<JSObject> keys[32];
232   for (int i = 0; i < 32; i++) {
233     keys[i] = factory->NewJSObject(function, TENURED);
234     CHECK(!heap->InNewSpace(keys[i]->address()));
235     CHECK(!first_page->Contains(keys[i]->address()));
236   }
237   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
238   for (int i = 0; i < 32; i++) {
239     Handle<Smi> smi(Smi::FromInt(i), isolate);
240     int32_t hash = Object::GetOrCreateHash(isolate, keys[i])->value();
241     JSWeakCollection::Set(weakmap, keys[i], smi, hash);
242   }
243 
244   // Force compacting garbage collection. The subsequent collections are used
245   // to verify that key references were actually updated.
246   CHECK(FLAG_always_compact);
247   heap->CollectAllGarbage();
248   heap->CollectAllGarbage();
249   heap->CollectAllGarbage();
250 }
251 
252 
TEST(Regress399527)253 TEST(Regress399527) {
254   CcTest::InitializeVM();
255   v8::HandleScope scope(CcTest::isolate());
256   Isolate* isolate = CcTest::i_isolate();
257   Heap* heap = isolate->heap();
258   {
259     HandleScope scope(isolate);
260     AllocateJSWeakMap(isolate);
261     SimulateIncrementalMarking(heap);
262   }
263   // The weak map is marked black here but leaving the handle scope will make
264   // the object unreachable. Aborting incremental marking will clear all the
265   // marking bits which makes the weak map garbage.
266   heap->CollectAllGarbage();
267 }
268