1 /*
2  * Copyright 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 "jit_instrumentation.h"
18 
19 #include "art_method-inl.h"
20 #include "jit.h"
21 #include "jit_code_cache.h"
22 #include "scoped_thread_state_change.h"
23 
24 namespace art {
25 namespace jit {
26 
27 class JitCompileTask : public Task {
28  public:
JitCompileTask(ArtMethod * method,JitInstrumentationCache * cache)29   explicit JitCompileTask(ArtMethod* method, JitInstrumentationCache* cache)
30       : method_(method), cache_(cache) {
31   }
32 
Run(Thread * self)33   virtual void Run(Thread* self) OVERRIDE {
34     ScopedObjectAccess soa(self);
35     VLOG(jit) << "JitCompileTask compiling method " << PrettyMethod(method_);
36     if (Runtime::Current()->GetJit()->CompileMethod(method_, self)) {
37       cache_->SignalCompiled(self, method_);
38     } else {
39       VLOG(jit) << "Failed to compile method " << PrettyMethod(method_);
40     }
41   }
42 
Finalize()43   virtual void Finalize() OVERRIDE {
44     delete this;
45   }
46 
47  private:
48   ArtMethod* const method_;
49   JitInstrumentationCache* const cache_;
50 
51   DISALLOW_IMPLICIT_CONSTRUCTORS(JitCompileTask);
52 };
53 
JitInstrumentationCache(size_t hot_method_threshold)54 JitInstrumentationCache::JitInstrumentationCache(size_t hot_method_threshold)
55     : lock_("jit instrumentation lock"), hot_method_threshold_(hot_method_threshold) {
56 }
57 
CreateThreadPool()58 void JitInstrumentationCache::CreateThreadPool() {
59   thread_pool_.reset(new ThreadPool("Jit thread pool", 1));
60 }
61 
DeleteThreadPool()62 void JitInstrumentationCache::DeleteThreadPool() {
63   thread_pool_.reset();
64 }
65 
SignalCompiled(Thread * self,ArtMethod * method)66 void JitInstrumentationCache::SignalCompiled(Thread* self, ArtMethod* method) {
67   ScopedObjectAccessUnchecked soa(self);
68   jmethodID method_id = soa.EncodeMethod(method);
69   MutexLock mu(self, lock_);
70   auto it = samples_.find(method_id);
71   if (it != samples_.end()) {
72     samples_.erase(it);
73   }
74 }
75 
AddSamples(Thread * self,ArtMethod * method,size_t count)76 void JitInstrumentationCache::AddSamples(Thread* self, ArtMethod* method, size_t count) {
77   ScopedObjectAccessUnchecked soa(self);
78   // Since we don't have on-stack replacement, some methods can remain in the interpreter longer
79   // than we want resulting in samples even after the method is compiled.
80   if (method->IsClassInitializer() || method->IsNative() ||
81       Runtime::Current()->GetJit()->GetCodeCache()->ContainsMethod(method)) {
82     return;
83   }
84   jmethodID method_id = soa.EncodeMethod(method);
85   bool is_hot = false;
86   {
87     MutexLock mu(self, lock_);
88     size_t sample_count = 0;
89     auto it = samples_.find(method_id);
90     if (it != samples_.end()) {
91       it->second += count;
92       sample_count = it->second;
93     } else {
94       sample_count = count;
95       samples_.insert(std::make_pair(method_id, count));
96     }
97     // If we have enough samples, mark as hot and request Jit compilation.
98     if (sample_count >= hot_method_threshold_ && sample_count - count < hot_method_threshold_) {
99       is_hot = true;
100     }
101   }
102   if (is_hot) {
103     if (thread_pool_.get() != nullptr) {
104       thread_pool_->AddTask(self, new JitCompileTask(
105           method->GetInterfaceMethodIfProxy(sizeof(void*)), this));
106       thread_pool_->StartWorkers(self);
107     } else {
108       VLOG(jit) << "Compiling hot method " << PrettyMethod(method);
109       Runtime::Current()->GetJit()->CompileMethod(
110           method->GetInterfaceMethodIfProxy(sizeof(void*)), self);
111     }
112   }
113 }
114 
JitInstrumentationListener(JitInstrumentationCache * cache)115 JitInstrumentationListener::JitInstrumentationListener(JitInstrumentationCache* cache)
116     : instrumentation_cache_(cache) {
117   CHECK(instrumentation_cache_ != nullptr);
118 }
119 
120 }  // namespace jit
121 }  // namespace art
122