Vladimir Marko | 83cc7ae | 2014-02-12 18:02:05 +0000 | [diff] [blame^] | 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 | #ifndef ART_COMPILER_UTILS_DEBUG_STACK_H_ |
| 18 | #define ART_COMPILER_UTILS_DEBUG_STACK_H_ |
| 19 | |
| 20 | #include "base/logging.h" |
| 21 | #include "base/macros.h" |
| 22 | #include "globals.h" |
| 23 | |
| 24 | namespace art { |
| 25 | |
| 26 | // Helper classes for reference counting to enforce construction/destruction order and |
| 27 | // usage of the top element of a stack in debug mode with no overhead in release mode. |
| 28 | |
| 29 | // Reference counter. No references allowed in destructor or in explicitly called CheckNoRefs(). |
| 30 | template <bool kIsDebug> |
| 31 | class DebugStackRefCounterImpl; |
| 32 | // Reference. Allows an explicit check that it's the top reference. |
| 33 | template <bool kIsDebug> |
| 34 | class DebugStackReferenceImpl; |
| 35 | // Indirect top reference. Checks that the reference is the top reference when used. |
| 36 | template <bool kIsDebug> |
| 37 | class DebugStackIndirectTopRefImpl; |
| 38 | |
| 39 | typedef DebugStackRefCounterImpl<kIsDebugBuild> DebugStackRefCounter; |
| 40 | typedef DebugStackReferenceImpl<kIsDebugBuild> DebugStackReference; |
| 41 | typedef DebugStackIndirectTopRefImpl<kIsDebugBuild> DebugStackIndirectTopRef; |
| 42 | |
| 43 | // Non-debug mode specializations. This should be optimized away. |
| 44 | |
| 45 | template <> |
| 46 | class DebugStackRefCounterImpl<false> { |
| 47 | public: |
| 48 | size_t IncrementRefCount() { return 0u; } |
| 49 | void DecrementRefCount() { } |
| 50 | size_t GetRefCount() const { return 0u; } |
| 51 | void CheckNoRefs() const { } |
| 52 | }; |
| 53 | |
| 54 | template <> |
| 55 | class DebugStackReferenceImpl<false> { |
| 56 | public: |
| 57 | explicit DebugStackReferenceImpl(DebugStackRefCounterImpl<false>* counter) { UNUSED(counter); } |
| 58 | DebugStackReferenceImpl(const DebugStackReferenceImpl& other) = default; |
| 59 | DebugStackReferenceImpl& operator=(const DebugStackReferenceImpl& other) = default; |
| 60 | void CheckTop() { } |
| 61 | }; |
| 62 | |
| 63 | template <> |
| 64 | class DebugStackIndirectTopRefImpl<false> { |
| 65 | public: |
| 66 | explicit DebugStackIndirectTopRefImpl(DebugStackReferenceImpl<false>* ref) { UNUSED(ref); } |
| 67 | DebugStackIndirectTopRefImpl(const DebugStackIndirectTopRefImpl& other) = default; |
| 68 | DebugStackIndirectTopRefImpl& operator=(const DebugStackIndirectTopRefImpl& other) = default; |
| 69 | void CheckTop() { } |
| 70 | }; |
| 71 | |
| 72 | // Debug mode versions. |
| 73 | |
| 74 | template <bool kIsDebug> |
| 75 | class DebugStackRefCounterImpl { |
| 76 | public: |
| 77 | DebugStackRefCounterImpl() : ref_count_(0u) { } |
| 78 | ~DebugStackRefCounterImpl() { CheckNoRefs(); } |
| 79 | size_t IncrementRefCount() { return ++ref_count_; } |
| 80 | void DecrementRefCount() { --ref_count_; } |
| 81 | size_t GetRefCount() const { return ref_count_; } |
| 82 | void CheckNoRefs() const { CHECK_EQ(ref_count_, 0u); } |
| 83 | |
| 84 | private: |
| 85 | size_t ref_count_; |
| 86 | }; |
| 87 | |
| 88 | template <bool kIsDebug> |
| 89 | class DebugStackReferenceImpl { |
| 90 | public: |
| 91 | explicit DebugStackReferenceImpl(DebugStackRefCounterImpl<kIsDebug>* counter) |
| 92 | : counter_(counter), ref_count_(counter->IncrementRefCount()) { |
| 93 | } |
| 94 | DebugStackReferenceImpl(const DebugStackReferenceImpl& other) |
| 95 | : counter_(other.counter_), ref_count_(counter_->IncrementRefCount()) { |
| 96 | } |
| 97 | DebugStackReferenceImpl& operator=(const DebugStackReferenceImpl& other) { |
| 98 | CHECK(counter_ == other.counter_); |
| 99 | return *this; |
| 100 | } |
| 101 | ~DebugStackReferenceImpl() { counter_->DecrementRefCount(); } |
| 102 | void CheckTop() { CHECK_EQ(counter_->GetRefCount(), ref_count_); } |
| 103 | |
| 104 | private: |
| 105 | DebugStackRefCounterImpl<true>* counter_; |
| 106 | size_t ref_count_; |
| 107 | }; |
| 108 | |
| 109 | template <bool kIsDebug> |
| 110 | class DebugStackIndirectTopRefImpl { |
| 111 | public: |
| 112 | explicit DebugStackIndirectTopRefImpl(DebugStackReferenceImpl<kIsDebug>* ref) |
| 113 | : ref_(ref) { |
| 114 | CheckTop(); |
| 115 | } |
| 116 | DebugStackIndirectTopRefImpl(const DebugStackIndirectTopRefImpl& other) |
| 117 | : ref_(other.ref_) { |
| 118 | CheckTop(); |
| 119 | } |
| 120 | DebugStackIndirectTopRefImpl& operator=(const DebugStackIndirectTopRefImpl& other) { |
| 121 | CHECK(ref_ == other->ref_); |
| 122 | CheckTop(); |
| 123 | return *this; |
| 124 | } |
| 125 | ~DebugStackIndirectTopRefImpl() { |
| 126 | CheckTop(); |
| 127 | } |
| 128 | void CheckTop() { |
| 129 | ref_->CheckTop(); |
| 130 | } |
| 131 | |
| 132 | private: |
| 133 | DebugStackReferenceImpl<kIsDebug>* ref_; |
| 134 | }; |
| 135 | |
| 136 | } // namespace art |
| 137 | |
| 138 | #endif // ART_COMPILER_UTILS_DEBUG_STACK_H_ |