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1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "intern_table.h"
18 
19 #include "base/hash_set.h"
20 #include "common_runtime_test.h"
21 #include "gc_root-inl.h"
22 #include "mirror/object.h"
23 #include "handle_scope-inl.h"
24 #include "mirror/string.h"
25 #include "scoped_thread_state_change-inl.h"
26 #include "utf.h"
27 
28 namespace art {
29 
30 class InternTableTest : public CommonRuntimeTest {};
31 
TEST_F(InternTableTest,Intern)32 TEST_F(InternTableTest, Intern) {
33   ScopedObjectAccess soa(Thread::Current());
34   InternTable intern_table;
35   StackHandleScope<4> hs(soa.Self());
36   Handle<mirror::String> foo_1(hs.NewHandle(intern_table.InternStrong(3, "foo")));
37   Handle<mirror::String> foo_2(hs.NewHandle(intern_table.InternStrong(3, "foo")));
38   Handle<mirror::String> foo_3(
39       hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
40   Handle<mirror::String> bar(hs.NewHandle(intern_table.InternStrong(3, "bar")));
41   ASSERT_TRUE(foo_1 != nullptr);
42   ASSERT_TRUE(foo_2 != nullptr);
43   ASSERT_TRUE(foo_3 != nullptr);
44   ASSERT_TRUE(bar != nullptr);
45   EXPECT_EQ(foo_1.Get(), foo_2.Get());
46   EXPECT_TRUE(foo_1->Equals("foo"));
47   EXPECT_TRUE(foo_2->Equals("foo"));
48   EXPECT_TRUE(foo_3->Equals("foo"));
49   EXPECT_NE(foo_1.Get(), bar.Get());
50   EXPECT_NE(foo_2.Get(), bar.Get());
51   EXPECT_NE(foo_3.Get(), bar.Get());
52 }
53 
TEST_F(InternTableTest,Size)54 TEST_F(InternTableTest, Size) {
55   ScopedObjectAccess soa(Thread::Current());
56   InternTable t;
57   EXPECT_EQ(0U, t.Size());
58   t.InternStrong(3, "foo");
59   StackHandleScope<1> hs(soa.Self());
60   Handle<mirror::String> foo(
61       hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
62   t.InternWeak(foo.Get());
63   EXPECT_EQ(1U, t.Size());
64   t.InternStrong(3, "bar");
65   EXPECT_EQ(2U, t.Size());
66 }
67 
68 // Check if table indexes match on 64 and 32 bit machines.
69 // This is done by ensuring hash values are the same on every machine and limited to 32-bit wide.
70 // Otherwise cross compilation can cause a table to be filled on host using one indexing algorithm
71 // and later on a device with different sizeof(size_t) can use another indexing algorithm.
72 // Thus the table may provide wrong data.
TEST_F(InternTableTest,CrossHash)73 TEST_F(InternTableTest, CrossHash) {
74   ScopedObjectAccess soa(Thread::Current());
75   InternTable t;
76 
77   // A string that has a negative hash value.
78   GcRoot<mirror::String> str(mirror::String::AllocFromModifiedUtf8(soa.Self(), "00000000"));
79 
80   MutexLock mu(Thread::Current(), *Locks::intern_table_lock_);
81   for (InternTable::Table::UnorderedSet& table : t.strong_interns_.tables_) {
82     // The negative hash value shall be 32-bit wide on every host.
83     ASSERT_TRUE(IsUint<32>(table.hashfn_(str)));
84   }
85 }
86 
87 class TestPredicate : public IsMarkedVisitor {
88  public:
IsMarked(mirror::Object * s)89   mirror::Object* IsMarked(mirror::Object* s) OVERRIDE REQUIRES_SHARED(Locks::mutator_lock_) {
90     bool erased = false;
91     for (auto it = expected_.begin(), end = expected_.end(); it != end; ++it) {
92       if (*it == s) {
93         expected_.erase(it);
94         erased = true;
95         break;
96       }
97     }
98     EXPECT_TRUE(erased);
99     return nullptr;
100   }
101 
Expect(const mirror::String * s)102   void Expect(const mirror::String* s) {
103     expected_.push_back(s);
104   }
105 
~TestPredicate()106   ~TestPredicate() {
107     EXPECT_EQ(0U, expected_.size());
108   }
109 
110  private:
111   mutable std::vector<const mirror::String*> expected_;
112 };
113 
TEST_F(InternTableTest,SweepInternTableWeaks)114 TEST_F(InternTableTest, SweepInternTableWeaks) {
115   ScopedObjectAccess soa(Thread::Current());
116   InternTable t;
117   t.InternStrong(3, "foo");
118   t.InternStrong(3, "bar");
119   StackHandleScope<5> hs(soa.Self());
120   Handle<mirror::String> hello(
121       hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "hello")));
122   Handle<mirror::String> world(
123       hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "world")));
124   Handle<mirror::String> s0(hs.NewHandle(t.InternWeak(hello.Get())));
125   Handle<mirror::String> s1(hs.NewHandle(t.InternWeak(world.Get())));
126 
127   EXPECT_EQ(4U, t.Size());
128 
129   // We should traverse only the weaks...
130   TestPredicate p;
131   p.Expect(s0.Get());
132   p.Expect(s1.Get());
133   {
134     ReaderMutexLock mu(soa.Self(), *Locks::heap_bitmap_lock_);
135     t.SweepInternTableWeaks(&p);
136   }
137 
138   EXPECT_EQ(2U, t.Size());
139 
140   // Just check that we didn't corrupt the map.
141   Handle<mirror::String> still_here(
142       hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "still here")));
143   t.InternWeak(still_here.Get());
144   EXPECT_EQ(3U, t.Size());
145 }
146 
TEST_F(InternTableTest,ContainsWeak)147 TEST_F(InternTableTest, ContainsWeak) {
148   ScopedObjectAccess soa(Thread::Current());
149   {
150     // Strongs are never weak.
151     InternTable t;
152     StackHandleScope<2> hs(soa.Self());
153     Handle<mirror::String> interned_foo_1(hs.NewHandle(t.InternStrong(3, "foo")));
154     EXPECT_FALSE(t.ContainsWeak(interned_foo_1.Get()));
155     Handle<mirror::String> interned_foo_2(hs.NewHandle(t.InternStrong(3, "foo")));
156     EXPECT_FALSE(t.ContainsWeak(interned_foo_2.Get()));
157     EXPECT_EQ(interned_foo_1.Get(), interned_foo_2.Get());
158   }
159 
160   {
161     // Weaks are always weak.
162     InternTable t;
163     StackHandleScope<4> hs(soa.Self());
164     Handle<mirror::String> foo_1(
165         hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
166     Handle<mirror::String> foo_2(
167         hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
168     EXPECT_NE(foo_1.Get(), foo_2.Get());
169     Handle<mirror::String> interned_foo_1(hs.NewHandle(t.InternWeak(foo_1.Get())));
170     Handle<mirror::String> interned_foo_2(hs.NewHandle(t.InternWeak(foo_2.Get())));
171     EXPECT_TRUE(t.ContainsWeak(interned_foo_2.Get()));
172     EXPECT_EQ(interned_foo_1.Get(), interned_foo_2.Get());
173   }
174 
175   {
176     // A weak can be promoted to a strong.
177     InternTable t;
178     StackHandleScope<3> hs(soa.Self());
179     Handle<mirror::String> foo(
180         hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
181     Handle<mirror::String> interned_foo_1(hs.NewHandle(t.InternWeak(foo.Get())));
182     EXPECT_TRUE(t.ContainsWeak(interned_foo_1.Get()));
183     Handle<mirror::String> interned_foo_2(hs.NewHandle(t.InternStrong(3, "foo")));
184     EXPECT_FALSE(t.ContainsWeak(interned_foo_2.Get()));
185     EXPECT_EQ(interned_foo_1.Get(), interned_foo_2.Get());
186   }
187 
188   {
189     // Interning a weak after a strong gets you the strong.
190     InternTable t;
191     StackHandleScope<3> hs(soa.Self());
192     Handle<mirror::String> interned_foo_1(hs.NewHandle(t.InternStrong(3, "foo")));
193     EXPECT_FALSE(t.ContainsWeak(interned_foo_1.Get()));
194     Handle<mirror::String> foo(
195         hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "foo")));
196     Handle<mirror::String> interned_foo_2(hs.NewHandle(t.InternWeak(foo.Get())));
197     EXPECT_FALSE(t.ContainsWeak(interned_foo_2.Get()));
198     EXPECT_EQ(interned_foo_1.Get(), interned_foo_2.Get());
199   }
200 }
201 
TEST_F(InternTableTest,LookupStrong)202 TEST_F(InternTableTest, LookupStrong) {
203   ScopedObjectAccess soa(Thread::Current());
204   InternTable intern_table;
205   StackHandleScope<3> hs(soa.Self());
206   Handle<mirror::String> foo(hs.NewHandle(intern_table.InternStrong(3, "foo")));
207   Handle<mirror::String> bar(hs.NewHandle(intern_table.InternStrong(3, "bar")));
208   Handle<mirror::String> foobar(hs.NewHandle(intern_table.InternStrong(6, "foobar")));
209   ASSERT_TRUE(foo != nullptr);
210   ASSERT_TRUE(bar != nullptr);
211   ASSERT_TRUE(foobar != nullptr);
212   ASSERT_TRUE(foo->Equals("foo"));
213   ASSERT_TRUE(bar->Equals("bar"));
214   ASSERT_TRUE(foobar->Equals("foobar"));
215   ASSERT_NE(foo.Get(), bar.Get());
216   ASSERT_NE(foo.Get(), foobar.Get());
217   ASSERT_NE(bar.Get(), foobar.Get());
218   ObjPtr<mirror::String> lookup_foo = intern_table.LookupStrong(soa.Self(), 3, "foo");
219   EXPECT_OBJ_PTR_EQ(lookup_foo, foo.Get());
220   ObjPtr<mirror::String> lookup_bar = intern_table.LookupStrong(soa.Self(), 3, "bar");
221   EXPECT_OBJ_PTR_EQ(lookup_bar, bar.Get());
222   ObjPtr<mirror::String> lookup_foobar = intern_table.LookupStrong(soa.Self(), 6, "foobar");
223   EXPECT_OBJ_PTR_EQ(lookup_foobar, foobar.Get());
224   ObjPtr<mirror::String> lookup_foox = intern_table.LookupStrong(soa.Self(), 4, "foox");
225   EXPECT_TRUE(lookup_foox == nullptr);
226   ObjPtr<mirror::String> lookup_fooba = intern_table.LookupStrong(soa.Self(), 5, "fooba");
227   EXPECT_TRUE(lookup_fooba == nullptr);
228   ObjPtr<mirror::String> lookup_foobaR = intern_table.LookupStrong(soa.Self(), 6, "foobaR");
229   EXPECT_TRUE(lookup_foobaR == nullptr);
230   // Try a hash conflict.
231   ASSERT_EQ(ComputeUtf16HashFromModifiedUtf8("foobar", 6),
232             ComputeUtf16HashFromModifiedUtf8("foobbS", 6));
233   ObjPtr<mirror::String> lookup_foobbS = intern_table.LookupStrong(soa.Self(), 6, "foobbS");
234   EXPECT_TRUE(lookup_foobbS == nullptr);
235 }
236 
237 }  // namespace art
238