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