1 /*
2  * Copyright (C) 2014 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 <type_traits>
18 
19 #include "base/enums.h"
20 #include "class_linker-inl.h"
21 #include "common_runtime_test.h"
22 #include "gtest/gtest.h"
23 #include "handle.h"
24 #include "handle_scope-inl.h"
25 #include "mirror/class-alloc-inl.h"
26 #include "mirror/class-inl.h"
27 #include "mirror/object.h"
28 #include "scoped_thread_state_change-inl.h"
29 #include "thread.h"
30 
31 namespace art {
32 
33 // Handles are value objects and should be trivially copyable.
34 static_assert(std::is_trivially_copyable<Handle<mirror::Object>>::value,
35               "Handle should be trivially copyable");
36 static_assert(std::is_trivially_copyable<MutableHandle<mirror::Object>>::value,
37               "MutableHandle should be trivially copyable");
38 static_assert(std::is_trivially_copyable<ScopedNullHandle<mirror::Object>>::value,
39               "ScopedNullHandle should be trivially copyable");
40 
41 class HandleScopeTest : public CommonRuntimeTest {};
42 
43 // Test the offsets computed for members of HandleScope. Because of cross-compiling
44 // it is impossible the use OFFSETOF_MEMBER, so we do some reasonable computations ourselves. This
45 // test checks whether we do the right thing.
TEST_F(HandleScopeTest,Offsets)46 TEST_F(HandleScopeTest, Offsets) {
47   ScopedObjectAccess soa(Thread::Current());
48   ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
49   // As the members of HandleScope are private, we cannot use OFFSETOF_MEMBER
50   // here. So do the inverse: set some data, and access it through pointers created from the offsets.
51   StackHandleScope<0x1> hs0(soa.Self());
52   static const size_t kNumReferences = 0x9ABC;
53   StackHandleScope<kNumReferences> test_table(soa.Self());
54   ObjPtr<mirror::Class> c = class_linker->FindSystemClass(soa.Self(), "Ljava/lang/Object;");
55   test_table.SetReference(0, c.Ptr());
56 
57   uint8_t* table_base_ptr = reinterpret_cast<uint8_t*>(&test_table);
58 
59   {
60     BaseHandleScope** link_ptr = reinterpret_cast<BaseHandleScope**>(table_base_ptr +
61         HandleScope::LinkOffset(kRuntimePointerSize));
62     EXPECT_EQ(*link_ptr, &hs0);
63   }
64 
65   {
66     uint32_t* num_ptr = reinterpret_cast<uint32_t*>(table_base_ptr +
67         HandleScope::NumberOfReferencesOffset(kRuntimePointerSize));
68     EXPECT_EQ(*num_ptr, static_cast<size_t>(kNumReferences));
69   }
70 
71   {
72     auto* ref_ptr = reinterpret_cast<StackReference<mirror::Object>*>(table_base_ptr +
73         HandleScope::ReferencesOffset(kRuntimePointerSize));
74     EXPECT_OBJ_PTR_EQ(ref_ptr->AsMirrorPtr(), c);
75   }
76 }
77 
78 class CollectVisitor {
79  public:
VisitRootIfNonNull(StackReference<mirror::Object> * ref)80   void VisitRootIfNonNull(StackReference<mirror::Object>* ref) {
81     if (!ref->IsNull()) {
82       visited.insert(ref);
83     }
84     ++total_visited;
85   }
86 
87   std::set<StackReference<mirror::Object>*> visited;
88   size_t total_visited = 0;  // including null.
89 };
90 
91 // Test functionality of variable sized handle scopes.
TEST_F(HandleScopeTest,VariableSized)92 TEST_F(HandleScopeTest, VariableSized) {
93   ScopedObjectAccess soa(Thread::Current());
94   VariableSizedHandleScope hs(soa.Self());
95   ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
96   Handle<mirror::Class> c =
97       hs.NewHandle(class_linker->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
98   // Test nested scopes.
99   StackHandleScope<1> inner(soa.Self());
100   inner.NewHandle(c->AllocObject(soa.Self()));
101   // Add a bunch of handles and make sure callbacks work.
102   static const size_t kNumHandles = 100;
103   std::vector<Handle<mirror::Object>> handles;
104   for (size_t i = 0; i < kNumHandles; ++i) {
105     BaseHandleScope* base = &hs;
106     ObjPtr<mirror::Object> o = c->AllocObject(soa.Self());
107     handles.push_back(hs.NewHandle(o));
108     EXPECT_OBJ_PTR_EQ(o, handles.back().Get());
109     EXPECT_TRUE(hs.Contains(handles.back().GetReference()));
110     EXPECT_TRUE(base->Contains(handles.back().GetReference()));
111     EXPECT_EQ(hs.NumberOfReferences(), base->NumberOfReferences());
112   }
113   CollectVisitor visitor;
114   BaseHandleScope* base = &hs;
115   base->VisitRoots(visitor);
116   EXPECT_LE(visitor.visited.size(), base->NumberOfReferences());
117   EXPECT_EQ(visitor.total_visited, base->NumberOfReferences());
118   for (StackReference<mirror::Object>* ref : visitor.visited) {
119     EXPECT_TRUE(base->Contains(ref));
120   }
121 }
122 
123 }  // namespace art
124