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/dex_instruction.h" 21 #include "jit/jit.h" 22 #include "jit/jit_code_cache.h" 23 #include "scoped_thread_state_change-inl.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 } 40 41 bool ProfilingInfo::Create(Thread* self, ArtMethod* method, bool retry_allocation) { 42 // Walk over the dex instructions of the method and keep track of 43 // instructions we are interested in profiling. 44 DCHECK(!method->IsNative()); 45 46 std::vector<uint32_t> entries; 47 for (const DexInstructionPcPair& inst : method->DexInstructions()) { 48 switch (inst->Opcode()) { 49 case Instruction::INVOKE_VIRTUAL: 50 case Instruction::INVOKE_VIRTUAL_RANGE: 51 case Instruction::INVOKE_VIRTUAL_QUICK: 52 case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: 53 case Instruction::INVOKE_INTERFACE: 54 case Instruction::INVOKE_INTERFACE_RANGE: 55 entries.push_back(inst.DexPc()); 56 break; 57 58 default: 59 break; 60 } 61 } 62 63 // We always create a `ProfilingInfo` object, even if there is no instruction we are 64 // interested in. The JIT code cache internally uses it. 65 66 // Allocate the `ProfilingInfo` object int the JIT's data space. 67 jit::JitCodeCache* code_cache = Runtime::Current()->GetJit()->GetCodeCache(); 68 return code_cache->AddProfilingInfo(self, method, entries, retry_allocation) != nullptr; 69 } 70 71 InlineCache* ProfilingInfo::GetInlineCache(uint32_t dex_pc) { 72 // TODO: binary search if array is too long. 73 for (size_t i = 0; i < number_of_inline_caches_; ++i) { 74 if (cache_[i].dex_pc_ == dex_pc) { 75 return &cache_[i]; 76 } 77 } 78 LOG(FATAL) << "No inline cache found for " << ArtMethod::PrettyMethod(method_) << "@" << dex_pc; 79 UNREACHABLE(); 80 } 81 82 void ProfilingInfo::AddInvokeInfo(uint32_t dex_pc, mirror::Class* cls) { 83 InlineCache* cache = GetInlineCache(dex_pc); 84 for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) { 85 mirror::Class* existing = cache->classes_[i].Read<kWithoutReadBarrier>(); 86 mirror::Class* marked = ReadBarrier::IsMarked(existing); 87 if (marked == cls) { 88 // Receiver type is already in the cache, nothing else to do. 89 return; 90 } else if (marked == nullptr) { 91 // Cache entry is empty, try to put `cls` in it. 92 // Note: it's ok to spin on 'existing' here: if 'existing' is not null, that means 93 // it is a stalled heap address, which will only be cleared during SweepSystemWeaks, 94 // *after* this thread hits a suspend point. 95 GcRoot<mirror::Class> expected_root(existing); 96 GcRoot<mirror::Class> desired_root(cls); 97 auto atomic_root = reinterpret_cast<Atomic<GcRoot<mirror::Class>>*>(&cache->classes_[i]); 98 if (!atomic_root->CompareAndSetStrongSequentiallyConsistent(expected_root, desired_root)) { 99 // Some other thread put a class in the cache, continue iteration starting at this 100 // entry in case the entry contains `cls`. 101 --i; 102 } else { 103 // We successfully set `cls`, just return. 104 return; 105 } 106 } 107 } 108 // Unsuccessfull - cache is full, making it megamorphic. We do not DCHECK it though, 109 // as the garbage collector might clear the entries concurrently. 110 } 111 112 } // namespace art 113