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
ProfilingInfo(ArtMethod * method,const std::vector<uint32_t> & entries)28 ProfilingInfo::ProfilingInfo(ArtMethod* method, const std::vector<uint32_t>& entries)
29 : baseline_hotness_count_(0),
30 method_(method),
31 number_of_inline_caches_(entries.size()),
32 current_inline_uses_(0) {
33 memset(&cache_, 0, number_of_inline_caches_ * sizeof(InlineCache));
34 for (size_t i = 0; i < number_of_inline_caches_; ++i) {
35 cache_[i].dex_pc_ = entries[i];
36 }
37 }
38
Create(Thread * self,ArtMethod * method)39 ProfilingInfo* ProfilingInfo::Create(Thread* self, ArtMethod* method) {
40 // Walk over the dex instructions of the method and keep track of
41 // instructions we are interested in profiling.
42 DCHECK(!method->IsNative());
43
44 std::vector<uint32_t> entries;
45 for (const DexInstructionPcPair& inst : method->DexInstructions()) {
46 switch (inst->Opcode()) {
47 case Instruction::INVOKE_VIRTUAL:
48 case Instruction::INVOKE_VIRTUAL_RANGE:
49 case Instruction::INVOKE_INTERFACE:
50 case Instruction::INVOKE_INTERFACE_RANGE:
51 entries.push_back(inst.DexPc());
52 break;
53
54 default:
55 break;
56 }
57 }
58
59 // We always create a `ProfilingInfo` object, even if there is no instruction we are
60 // interested in. The JIT code cache internally uses it.
61
62 // Allocate the `ProfilingInfo` object int the JIT's data space.
63 jit::JitCodeCache* code_cache = Runtime::Current()->GetJit()->GetCodeCache();
64 return code_cache->AddProfilingInfo(self, method, entries);
65 }
66
GetInlineCache(uint32_t dex_pc)67 InlineCache* ProfilingInfo::GetInlineCache(uint32_t dex_pc) {
68 // TODO: binary search if array is too long.
69 for (size_t i = 0; i < number_of_inline_caches_; ++i) {
70 if (cache_[i].dex_pc_ == dex_pc) {
71 return &cache_[i];
72 }
73 }
74 ScopedObjectAccess soa(Thread::Current());
75 LOG(FATAL) << "No inline cache found for " << ArtMethod::PrettyMethod(method_) << "@" << dex_pc;
76 UNREACHABLE();
77 }
78
AddInvokeInfo(uint32_t dex_pc,mirror::Class * cls)79 void ProfilingInfo::AddInvokeInfo(uint32_t dex_pc, mirror::Class* cls) {
80 InlineCache* cache = GetInlineCache(dex_pc);
81 for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) {
82 mirror::Class* existing = cache->classes_[i].Read<kWithoutReadBarrier>();
83 mirror::Class* marked = ReadBarrier::IsMarked(existing);
84 if (marked == cls) {
85 // Receiver type is already in the cache, nothing else to do.
86 return;
87 } else if (marked == nullptr) {
88 // Cache entry is empty, try to put `cls` in it.
89 // Note: it's ok to spin on 'existing' here: if 'existing' is not null, that means
90 // it is a stalled heap address, which will only be cleared during SweepSystemWeaks,
91 // *after* this thread hits a suspend point.
92 GcRoot<mirror::Class> expected_root(existing);
93 GcRoot<mirror::Class> desired_root(cls);
94 auto atomic_root = reinterpret_cast<Atomic<GcRoot<mirror::Class>>*>(&cache->classes_[i]);
95 if (!atomic_root->CompareAndSetStrongSequentiallyConsistent(expected_root, desired_root)) {
96 // Some other thread put a class in the cache, continue iteration starting at this
97 // entry in case the entry contains `cls`.
98 --i;
99 } else {
100 // We successfully set `cls`, just return.
101 return;
102 }
103 }
104 }
105 // Unsuccessfull - cache is full, making it megamorphic. We do not DCHECK it though,
106 // as the garbage collector might clear the entries concurrently.
107 }
108
ScopedProfilingInfoUse(jit::Jit * jit,ArtMethod * method,Thread * self)109 ScopedProfilingInfoUse::ScopedProfilingInfoUse(jit::Jit* jit, ArtMethod* method, Thread* self)
110 : jit_(jit),
111 method_(method),
112 self_(self),
113 // Fetch the profiling info ahead of using it. If it's null when fetching,
114 // we should not call JitCodeCache::DoneCompilerUse.
115 profiling_info_(jit->GetCodeCache()->NotifyCompilerUse(method, self)) {
116 }
117
~ScopedProfilingInfoUse()118 ScopedProfilingInfoUse::~ScopedProfilingInfoUse() {
119 if (profiling_info_ != nullptr) {
120 jit_->GetCodeCache()->DoneCompilerUse(method_, self_);
121 }
122 }
123
124 } // namespace art
125