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1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 //     * Redistributions of source code must retain the above copyright
7 //       notice, this list of conditions and the following disclaimer.
8 //     * Redistributions in binary form must reproduce the above
9 //       copyright notice, this list of conditions and the following
10 //       disclaimer in the documentation and/or other materials provided
11 //       with the distribution.
12 //     * Neither the name of Google Inc. nor the names of its
13 //       contributors may be used to endorse or promote products derived
14 //       from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #include "v8.h"
29 
30 #include "global-handles.h"
31 #include "snapshot.h"
32 #include "cctest.h"
33 
34 using namespace v8::internal;
35 
36 
GetIsolateFrom(LocalContext * context)37 static Isolate* GetIsolateFrom(LocalContext* context) {
38   return reinterpret_cast<Isolate*>((*context)->GetIsolate());
39 }
40 
41 
AllocateJSWeakMap(Isolate * isolate)42 static Handle<JSWeakMap> AllocateJSWeakMap(Isolate* isolate) {
43   Factory* factory = isolate->factory();
44   Heap* heap = isolate->heap();
45   Handle<Map> map = factory->NewMap(JS_WEAK_MAP_TYPE, JSWeakMap::kSize);
46   Handle<JSObject> weakmap_obj = factory->NewJSObjectFromMap(map);
47   Handle<JSWeakMap> weakmap(JSWeakMap::cast(*weakmap_obj));
48   // Do not use handles for the hash table, it would make entries strong.
49   Object* table_obj = ObjectHashTable::Allocate(heap, 1)->ToObjectChecked();
50   ObjectHashTable* table = ObjectHashTable::cast(table_obj);
51   weakmap->set_table(table);
52   weakmap->set_next(Smi::FromInt(0));
53   return weakmap;
54 }
55 
PutIntoWeakMap(Handle<JSWeakMap> weakmap,Handle<JSObject> key,Handle<Object> value)56 static void PutIntoWeakMap(Handle<JSWeakMap> weakmap,
57                            Handle<JSObject> key,
58                            Handle<Object> value) {
59   Handle<ObjectHashTable> table = ObjectHashTable::Put(
60       Handle<ObjectHashTable>(ObjectHashTable::cast(weakmap->table())),
61       Handle<JSObject>(JSObject::cast(*key)),
62       value);
63   weakmap->set_table(*table);
64 }
65 
66 static int NumberOfWeakCalls = 0;
WeakPointerCallback(v8::Isolate * isolate,v8::Persistent<v8::Value> * handle,void * id)67 static void WeakPointerCallback(v8::Isolate* isolate,
68                                 v8::Persistent<v8::Value>* handle,
69                                 void* id) {
70   ASSERT(id == reinterpret_cast<void*>(1234));
71   NumberOfWeakCalls++;
72   handle->Reset();
73 }
74 
75 
TEST(Weakness)76 TEST(Weakness) {
77   FLAG_incremental_marking = false;
78   LocalContext context;
79   Isolate* isolate = GetIsolateFrom(&context);
80   Factory* factory = isolate->factory();
81   Heap* heap = isolate->heap();
82   HandleScope scope(isolate);
83   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
84   GlobalHandles* global_handles = isolate->global_handles();
85 
86   // Keep global reference to the key.
87   Handle<Object> key;
88   {
89     HandleScope scope(isolate);
90     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
91     Handle<JSObject> object = factory->NewJSObjectFromMap(map);
92     key = global_handles->Create(*object);
93   }
94   CHECK(!global_handles->IsWeak(key.location()));
95 
96   // Put entry into weak map.
97   {
98     HandleScope scope(isolate);
99     PutIntoWeakMap(weakmap,
100                    Handle<JSObject>(JSObject::cast(*key)),
101                    Handle<Smi>(Smi::FromInt(23), isolate));
102   }
103   CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
104 
105   // Force a full GC.
106   heap->CollectAllGarbage(false);
107   CHECK_EQ(0, NumberOfWeakCalls);
108   CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
109   CHECK_EQ(
110       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
111 
112   // Make the global reference to the key weak.
113   {
114     HandleScope scope(isolate);
115     global_handles->MakeWeak(key.location(),
116                              reinterpret_cast<void*>(1234),
117                              &WeakPointerCallback);
118   }
119   CHECK(global_handles->IsWeak(key.location()));
120 
121   // Force a full GC.
122   // Perform two consecutive GCs because the first one will only clear
123   // weak references whereas the second one will also clear weak maps.
124   heap->CollectAllGarbage(false);
125   CHECK_EQ(1, NumberOfWeakCalls);
126   CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
127   CHECK_EQ(
128       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
129   heap->CollectAllGarbage(false);
130   CHECK_EQ(1, NumberOfWeakCalls);
131   CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
132   CHECK_EQ(
133       1, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
134 }
135 
136 
TEST(Shrinking)137 TEST(Shrinking) {
138   LocalContext context;
139   Isolate* isolate = GetIsolateFrom(&context);
140   Factory* factory = isolate->factory();
141   Heap* heap = isolate->heap();
142   HandleScope scope(isolate);
143   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
144 
145   // Check initial capacity.
146   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
147 
148   // Fill up weak map to trigger capacity change.
149   {
150     HandleScope scope(isolate);
151     Handle<Map> map = factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
152     for (int i = 0; i < 32; i++) {
153       Handle<JSObject> object = factory->NewJSObjectFromMap(map);
154       PutIntoWeakMap(weakmap, object, Handle<Smi>(Smi::FromInt(i), isolate));
155     }
156   }
157 
158   // Check increased capacity.
159   CHECK_EQ(128, ObjectHashTable::cast(weakmap->table())->Capacity());
160 
161   // Force a full GC.
162   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
163   CHECK_EQ(
164       0, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
165   heap->CollectAllGarbage(false);
166   CHECK_EQ(0, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
167   CHECK_EQ(
168       32, ObjectHashTable::cast(weakmap->table())->NumberOfDeletedElements());
169 
170   // Check shrunk capacity.
171   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
172 }
173 
174 
175 // Test that weak map values on an evacuation candidate which are not reachable
176 // by other paths are correctly recorded in the slots buffer.
TEST(Regress2060a)177 TEST(Regress2060a) {
178   FLAG_always_compact = true;
179   LocalContext context;
180   Isolate* isolate = GetIsolateFrom(&context);
181   Factory* factory = isolate->factory();
182   Heap* heap = isolate->heap();
183   HandleScope scope(isolate);
184   Handle<JSFunction> function =
185       factory->NewFunction(factory->function_string(), factory->null_value());
186   Handle<JSObject> key = factory->NewJSObject(function);
187   Handle<JSWeakMap> weakmap = AllocateJSWeakMap(isolate);
188 
189   // Start second old-space page so that values land on evacuation candidate.
190   Page* first_page = heap->old_pointer_space()->anchor()->next_page();
191   factory->NewFixedArray(900 * KB / kPointerSize, TENURED);
192 
193   // Fill up weak map with values on an evacuation candidate.
194   {
195     HandleScope scope(isolate);
196     for (int i = 0; i < 32; i++) {
197       Handle<JSObject> object = factory->NewJSObject(function, TENURED);
198       CHECK(!heap->InNewSpace(object->address()));
199       CHECK(!first_page->Contains(object->address()));
200       PutIntoWeakMap(weakmap, key, object);
201     }
202   }
203 
204   // Force compacting garbage collection.
205   CHECK(FLAG_always_compact);
206   heap->CollectAllGarbage(Heap::kNoGCFlags);
207 }
208 
209 
210 // Test that weak map keys on an evacuation candidate which are reachable by
211 // other strong paths are correctly recorded in the slots buffer.
TEST(Regress2060b)212 TEST(Regress2060b) {
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 =
224       factory->NewFunction(factory->function_string(), factory->null_value());
225 
226   // Start second old-space page so that keys land on evacuation candidate.
227   Page* first_page = heap->old_pointer_space()->anchor()->next_page();
228   factory->NewFixedArray(900 * KB / kPointerSize, TENURED);
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     PutIntoWeakMap(weakmap,
240                    keys[i],
241                    Handle<Smi>(Smi::FromInt(i), isolate));
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(Heap::kNoGCFlags);
248   heap->CollectAllGarbage(Heap::kNoGCFlags);
249   heap->CollectAllGarbage(Heap::kNoGCFlags);
250 }
251