1 /* 2 * Copyright (C) 2015 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 "profiling_info.h" 18 19 #include "art_method-inl.h" 20 #include "dex_instruction.h" 21 #include "jit/jit.h" 22 #include "jit/jit_code_cache.h" 23 #include "scoped_thread_state_change.h" 24 #include "thread.h" 25 26 namespace art { 27 28 ProfilingInfo::ProfilingInfo(ArtMethod* method, const std::vector<uint32_t>& entries) 29 : number_of_inline_caches_(entries.size()), 30 method_(method), 31 is_method_being_compiled_(false), 32 is_osr_method_being_compiled_(false), 33 current_inline_uses_(0), 34 saved_entry_point_(nullptr) { 35 memset(&cache_, 0, number_of_inline_caches_ * sizeof(InlineCache)); 36 for (size_t i = 0; i < number_of_inline_caches_; ++i) { 37 cache_[i].dex_pc_ = entries[i]; 38 } 39 if (method->IsCopied()) { 40 // GetHoldingClassOfCopiedMethod is expensive, but creating a profiling info for a copied method 41 // appears to happen very rarely in practice. 42 holding_class_ = GcRoot<mirror::Class>( 43 Runtime::Current()->GetClassLinker()->GetHoldingClassOfCopiedMethod(method)); 44 } else { 45 holding_class_ = GcRoot<mirror::Class>(method->GetDeclaringClass()); 46 } 47 DCHECK(!holding_class_.IsNull()); 48 } 49 50 bool ProfilingInfo::Create(Thread* self, ArtMethod* method, bool retry_allocation) { 51 // Walk over the dex instructions of the method and keep track of 52 // instructions we are interested in profiling. 53 DCHECK(!method->IsNative()); 54 55 const DexFile::CodeItem& code_item = *method->GetCodeItem(); 56 const uint16_t* code_ptr = code_item.insns_; 57 const uint16_t* code_end = code_item.insns_ + code_item.insns_size_in_code_units_; 58 59 uint32_t dex_pc = 0; 60 std::vector<uint32_t> entries; 61 while (code_ptr < code_end) { 62 const Instruction& instruction = *Instruction::At(code_ptr); 63 switch (instruction.Opcode()) { 64 case Instruction::INVOKE_VIRTUAL: 65 case Instruction::INVOKE_VIRTUAL_RANGE: 66 case Instruction::INVOKE_VIRTUAL_QUICK: 67 case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: 68 case Instruction::INVOKE_INTERFACE: 69 case Instruction::INVOKE_INTERFACE_RANGE: 70 entries.push_back(dex_pc); 71 break; 72 73 default: 74 break; 75 } 76 dex_pc += instruction.SizeInCodeUnits(); 77 code_ptr += instruction.SizeInCodeUnits(); 78 } 79 80 // We always create a `ProfilingInfo` object, even if there is no instruction we are 81 // interested in. The JIT code cache internally uses it. 82 83 // Allocate the `ProfilingInfo` object int the JIT's data space. 84 jit::JitCodeCache* code_cache = Runtime::Current()->GetJit()->GetCodeCache(); 85 return code_cache->AddProfilingInfo(self, method, entries, retry_allocation) != nullptr; 86 } 87 88 InlineCache* ProfilingInfo::GetInlineCache(uint32_t dex_pc) { 89 InlineCache* cache = nullptr; 90 // TODO: binary search if array is too long. 91 for (size_t i = 0; i < number_of_inline_caches_; ++i) { 92 if (cache_[i].dex_pc_ == dex_pc) { 93 cache = &cache_[i]; 94 break; 95 } 96 } 97 return cache; 98 } 99 100 void ProfilingInfo::AddInvokeInfo(uint32_t dex_pc, mirror::Class* cls) { 101 InlineCache* cache = GetInlineCache(dex_pc); 102 CHECK(cache != nullptr) << PrettyMethod(method_) << "@" << dex_pc; 103 for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) { 104 mirror::Class* existing = cache->classes_[i].Read(); 105 if (existing == cls) { 106 // Receiver type is already in the cache, nothing else to do. 107 return; 108 } else if (existing == nullptr) { 109 // Cache entry is empty, try to put `cls` in it. 110 GcRoot<mirror::Class> expected_root(nullptr); 111 GcRoot<mirror::Class> desired_root(cls); 112 if (!reinterpret_cast<Atomic<GcRoot<mirror::Class>>*>(&cache->classes_[i])-> 113 CompareExchangeStrongSequentiallyConsistent(expected_root, desired_root)) { 114 // Some other thread put a class in the cache, continue iteration starting at this 115 // entry in case the entry contains `cls`. 116 --i; 117 } else { 118 // We successfully set `cls`, just return. 119 // Since the instrumentation is marked from the declaring class we need to mark the card so 120 // that mod-union tables and card rescanning know about the update. 121 // Note that the declaring class is not necessarily the holding class if the method is 122 // copied. We need the card mark to be in the holding class since that is from where we 123 // will visit the profiling info. 124 if (!holding_class_.IsNull()) { 125 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(holding_class_.Read()); 126 } 127 return; 128 } 129 } 130 } 131 // Unsuccessfull - cache is full, making it megamorphic. We do not DCHECK it though, 132 // as the garbage collector might clear the entries concurrently. 133 } 134 135 } // namespace art 136
