Home | History | Annotate | Download | only in jit
      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.h"
     18 
     19 #include <dlfcn.h>
     20 
     21 #include "art_method-inl.h"
     22 #include "debugger.h"
     23 #include "entrypoints/runtime_asm_entrypoints.h"
     24 #include "interpreter/interpreter.h"
     25 #include "jit_code_cache.h"
     26 #include "oat_file_manager.h"
     27 #include "oat_quick_method_header.h"
     28 #include "offline_profiling_info.h"
     29 #include "profile_saver.h"
     30 #include "runtime.h"
     31 #include "runtime_options.h"
     32 #include "stack_map.h"
     33 #include "thread_list.h"
     34 #include "utils.h"
     35 
     36 namespace art {
     37 namespace jit {
     38 
     39 static constexpr bool kEnableOnStackReplacement = true;
     40 // At what priority to schedule jit threads. 9 is the lowest foreground priority on device.
     41 static constexpr int kJitPoolThreadPthreadPriority = 9;
     42 
     43 // JIT compiler
     44 void* Jit::jit_library_handle_= nullptr;
     45 void* Jit::jit_compiler_handle_ = nullptr;
     46 void* (*Jit::jit_load_)(bool*) = nullptr;
     47 void (*Jit::jit_unload_)(void*) = nullptr;
     48 bool (*Jit::jit_compile_method_)(void*, ArtMethod*, Thread*, bool) = nullptr;
     49 void (*Jit::jit_types_loaded_)(void*, mirror::Class**, size_t count) = nullptr;
     50 bool Jit::generate_debug_info_ = false;
     51 
     52 JitOptions* JitOptions::CreateFromRuntimeArguments(const RuntimeArgumentMap& options) {
     53   auto* jit_options = new JitOptions;
     54   jit_options->use_jit_compilation_ = options.GetOrDefault(RuntimeArgumentMap::UseJitCompilation);
     55 
     56   jit_options->code_cache_initial_capacity_ =
     57       options.GetOrDefault(RuntimeArgumentMap::JITCodeCacheInitialCapacity);
     58   jit_options->code_cache_max_capacity_ =
     59       options.GetOrDefault(RuntimeArgumentMap::JITCodeCacheMaxCapacity);
     60   jit_options->dump_info_on_shutdown_ =
     61       options.Exists(RuntimeArgumentMap::DumpJITInfoOnShutdown);
     62   jit_options->save_profiling_info_ =
     63       options.GetOrDefault(RuntimeArgumentMap::JITSaveProfilingInfo);
     64 
     65   jit_options->compile_threshold_ = options.GetOrDefault(RuntimeArgumentMap::JITCompileThreshold);
     66   if (jit_options->compile_threshold_ > std::numeric_limits<uint16_t>::max()) {
     67     LOG(FATAL) << "Method compilation threshold is above its internal limit.";
     68   }
     69 
     70   if (options.Exists(RuntimeArgumentMap::JITWarmupThreshold)) {
     71     jit_options->warmup_threshold_ = *options.Get(RuntimeArgumentMap::JITWarmupThreshold);
     72     if (jit_options->warmup_threshold_ > std::numeric_limits<uint16_t>::max()) {
     73       LOG(FATAL) << "Method warmup threshold is above its internal limit.";
     74     }
     75   } else {
     76     jit_options->warmup_threshold_ = jit_options->compile_threshold_ / 2;
     77   }
     78 
     79   if (options.Exists(RuntimeArgumentMap::JITOsrThreshold)) {
     80     jit_options->osr_threshold_ = *options.Get(RuntimeArgumentMap::JITOsrThreshold);
     81     if (jit_options->osr_threshold_ > std::numeric_limits<uint16_t>::max()) {
     82       LOG(FATAL) << "Method on stack replacement threshold is above its internal limit.";
     83     }
     84   } else {
     85     jit_options->osr_threshold_ = jit_options->compile_threshold_ * 2;
     86     if (jit_options->osr_threshold_ > std::numeric_limits<uint16_t>::max()) {
     87       jit_options->osr_threshold_ = std::numeric_limits<uint16_t>::max();
     88     }
     89   }
     90 
     91   if (options.Exists(RuntimeArgumentMap::JITPriorityThreadWeight)) {
     92     jit_options->priority_thread_weight_ =
     93         *options.Get(RuntimeArgumentMap::JITPriorityThreadWeight);
     94     if (jit_options->priority_thread_weight_ > jit_options->warmup_threshold_) {
     95       LOG(FATAL) << "Priority thread weight is above the warmup threshold.";
     96     } else if (jit_options->priority_thread_weight_ == 0) {
     97       LOG(FATAL) << "Priority thread weight cannot be 0.";
     98     }
     99   } else {
    100     jit_options->priority_thread_weight_ = std::max(
    101         jit_options->warmup_threshold_ / Jit::kDefaultPriorityThreadWeightRatio,
    102         static_cast<size_t>(1));
    103   }
    104 
    105   if (options.Exists(RuntimeArgumentMap::JITInvokeTransitionWeight)) {
    106     jit_options->invoke_transition_weight_ =
    107         *options.Get(RuntimeArgumentMap::JITInvokeTransitionWeight);
    108     if (jit_options->invoke_transition_weight_ > jit_options->warmup_threshold_) {
    109       LOG(FATAL) << "Invoke transition weight is above the warmup threshold.";
    110     } else if (jit_options->invoke_transition_weight_  == 0) {
    111       LOG(FATAL) << "Invoke transition weight cannot be 0.";
    112     }
    113   } else {
    114     jit_options->invoke_transition_weight_ = std::max(
    115         jit_options->warmup_threshold_ / Jit::kDefaultInvokeTransitionWeightRatio,
    116         static_cast<size_t>(1));;
    117   }
    118 
    119   return jit_options;
    120 }
    121 
    122 bool Jit::ShouldUsePriorityThreadWeight() {
    123   return Runtime::Current()->InJankPerceptibleProcessState()
    124       && Thread::Current()->IsJitSensitiveThread();
    125 }
    126 
    127 void Jit::DumpInfo(std::ostream& os) {
    128   code_cache_->Dump(os);
    129   cumulative_timings_.Dump(os);
    130   MutexLock mu(Thread::Current(), lock_);
    131   memory_use_.PrintMemoryUse(os);
    132 }
    133 
    134 void Jit::DumpForSigQuit(std::ostream& os) {
    135   DumpInfo(os);
    136   ProfileSaver::DumpInstanceInfo(os);
    137 }
    138 
    139 void Jit::AddTimingLogger(const TimingLogger& logger) {
    140   cumulative_timings_.AddLogger(logger);
    141 }
    142 
    143 Jit::Jit() : dump_info_on_shutdown_(false),
    144              cumulative_timings_("JIT timings"),
    145              memory_use_("Memory used for compilation", 16),
    146              lock_("JIT memory use lock"),
    147              use_jit_compilation_(true),
    148              save_profiling_info_(false) {}
    149 
    150 Jit* Jit::Create(JitOptions* options, std::string* error_msg) {
    151   DCHECK(options->UseJitCompilation() || options->GetSaveProfilingInfo());
    152   std::unique_ptr<Jit> jit(new Jit);
    153   jit->dump_info_on_shutdown_ = options->DumpJitInfoOnShutdown();
    154   if (jit_compiler_handle_ == nullptr && !LoadCompiler(error_msg)) {
    155     return nullptr;
    156   }
    157   jit->code_cache_.reset(JitCodeCache::Create(
    158       options->GetCodeCacheInitialCapacity(),
    159       options->GetCodeCacheMaxCapacity(),
    160       jit->generate_debug_info_,
    161       error_msg));
    162   if (jit->GetCodeCache() == nullptr) {
    163     return nullptr;
    164   }
    165   jit->use_jit_compilation_ = options->UseJitCompilation();
    166   jit->save_profiling_info_ = options->GetSaveProfilingInfo();
    167   VLOG(jit) << "JIT created with initial_capacity="
    168       << PrettySize(options->GetCodeCacheInitialCapacity())
    169       << ", max_capacity=" << PrettySize(options->GetCodeCacheMaxCapacity())
    170       << ", compile_threshold=" << options->GetCompileThreshold()
    171       << ", save_profiling_info=" << options->GetSaveProfilingInfo();
    172 
    173 
    174   jit->hot_method_threshold_ = options->GetCompileThreshold();
    175   jit->warm_method_threshold_ = options->GetWarmupThreshold();
    176   jit->osr_method_threshold_ = options->GetOsrThreshold();
    177   jit->priority_thread_weight_ = options->GetPriorityThreadWeight();
    178   jit->invoke_transition_weight_ = options->GetInvokeTransitionWeight();
    179 
    180   jit->CreateThreadPool();
    181 
    182   // Notify native debugger about the classes already loaded before the creation of the jit.
    183   jit->DumpTypeInfoForLoadedTypes(Runtime::Current()->GetClassLinker());
    184   return jit.release();
    185 }
    186 
    187 bool Jit::LoadCompilerLibrary(std::string* error_msg) {
    188   jit_library_handle_ = dlopen(
    189       kIsDebugBuild ? "libartd-compiler.so" : "libart-compiler.so", RTLD_NOW);
    190   if (jit_library_handle_ == nullptr) {
    191     std::ostringstream oss;
    192     oss << "JIT could not load libart-compiler.so: " << dlerror();
    193     *error_msg = oss.str();
    194     return false;
    195   }
    196   jit_load_ = reinterpret_cast<void* (*)(bool*)>(dlsym(jit_library_handle_, "jit_load"));
    197   if (jit_load_ == nullptr) {
    198     dlclose(jit_library_handle_);
    199     *error_msg = "JIT couldn't find jit_load entry point";
    200     return false;
    201   }
    202   jit_unload_ = reinterpret_cast<void (*)(void*)>(
    203       dlsym(jit_library_handle_, "jit_unload"));
    204   if (jit_unload_ == nullptr) {
    205     dlclose(jit_library_handle_);
    206     *error_msg = "JIT couldn't find jit_unload entry point";
    207     return false;
    208   }
    209   jit_compile_method_ = reinterpret_cast<bool (*)(void*, ArtMethod*, Thread*, bool)>(
    210       dlsym(jit_library_handle_, "jit_compile_method"));
    211   if (jit_compile_method_ == nullptr) {
    212     dlclose(jit_library_handle_);
    213     *error_msg = "JIT couldn't find jit_compile_method entry point";
    214     return false;
    215   }
    216   jit_types_loaded_ = reinterpret_cast<void (*)(void*, mirror::Class**, size_t)>(
    217       dlsym(jit_library_handle_, "jit_types_loaded"));
    218   if (jit_types_loaded_ == nullptr) {
    219     dlclose(jit_library_handle_);
    220     *error_msg = "JIT couldn't find jit_types_loaded entry point";
    221     return false;
    222   }
    223   return true;
    224 }
    225 
    226 bool Jit::LoadCompiler(std::string* error_msg) {
    227   if (jit_library_handle_ == nullptr && !LoadCompilerLibrary(error_msg)) {
    228     return false;
    229   }
    230   bool will_generate_debug_symbols = false;
    231   VLOG(jit) << "Calling JitLoad interpreter_only="
    232       << Runtime::Current()->GetInstrumentation()->InterpretOnly();
    233   jit_compiler_handle_ = (jit_load_)(&will_generate_debug_symbols);
    234   if (jit_compiler_handle_ == nullptr) {
    235     dlclose(jit_library_handle_);
    236     *error_msg = "JIT couldn't load compiler";
    237     return false;
    238   }
    239   generate_debug_info_ = will_generate_debug_symbols;
    240   return true;
    241 }
    242 
    243 bool Jit::CompileMethod(ArtMethod* method, Thread* self, bool osr) {
    244   DCHECK(Runtime::Current()->UseJitCompilation());
    245   DCHECK(!method->IsRuntimeMethod());
    246 
    247   // Don't compile the method if it has breakpoints.
    248   if (Dbg::IsDebuggerActive() && Dbg::MethodHasAnyBreakpoints(method)) {
    249     VLOG(jit) << "JIT not compiling " << PrettyMethod(method) << " due to breakpoint";
    250     return false;
    251   }
    252 
    253   // Don't compile the method if we are supposed to be deoptimized.
    254   instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
    255   if (instrumentation->AreAllMethodsDeoptimized() || instrumentation->IsDeoptimized(method)) {
    256     VLOG(jit) << "JIT not compiling " << PrettyMethod(method) << " due to deoptimization";
    257     return false;
    258   }
    259 
    260   // If we get a request to compile a proxy method, we pass the actual Java method
    261   // of that proxy method, as the compiler does not expect a proxy method.
    262   ArtMethod* method_to_compile = method->GetInterfaceMethodIfProxy(sizeof(void*));
    263   if (!code_cache_->NotifyCompilationOf(method_to_compile, self, osr)) {
    264     return false;
    265   }
    266 
    267   VLOG(jit) << "Compiling method "
    268             << PrettyMethod(method_to_compile)
    269             << " osr=" << std::boolalpha << osr;
    270   bool success = jit_compile_method_(jit_compiler_handle_, method_to_compile, self, osr);
    271   code_cache_->DoneCompiling(method_to_compile, self, osr);
    272   if (!success) {
    273     VLOG(jit) << "Failed to compile method "
    274               << PrettyMethod(method_to_compile)
    275               << " osr=" << std::boolalpha << osr;
    276   }
    277   return success;
    278 }
    279 
    280 void Jit::CreateThreadPool() {
    281   // There is a DCHECK in the 'AddSamples' method to ensure the tread pool
    282   // is not null when we instrument.
    283   thread_pool_.reset(new ThreadPool("Jit thread pool", 1));
    284   thread_pool_->SetPthreadPriority(kJitPoolThreadPthreadPriority);
    285   thread_pool_->StartWorkers(Thread::Current());
    286 }
    287 
    288 void Jit::DeleteThreadPool() {
    289   Thread* self = Thread::Current();
    290   DCHECK(Runtime::Current()->IsShuttingDown(self));
    291   if (thread_pool_ != nullptr) {
    292     ThreadPool* cache = nullptr;
    293     {
    294       ScopedSuspendAll ssa(__FUNCTION__);
    295       // Clear thread_pool_ field while the threads are suspended.
    296       // A mutator in the 'AddSamples' method will check against it.
    297       cache = thread_pool_.release();
    298     }
    299     cache->StopWorkers(self);
    300     cache->RemoveAllTasks(self);
    301     // We could just suspend all threads, but we know those threads
    302     // will finish in a short period, so it's not worth adding a suspend logic
    303     // here. Besides, this is only done for shutdown.
    304     cache->Wait(self, false, false);
    305     delete cache;
    306   }
    307 }
    308 
    309 void Jit::StartProfileSaver(const std::string& filename,
    310                             const std::vector<std::string>& code_paths,
    311                             const std::string& foreign_dex_profile_path,
    312                             const std::string& app_dir) {
    313   if (save_profiling_info_) {
    314     ProfileSaver::Start(filename, code_cache_.get(), code_paths, foreign_dex_profile_path, app_dir);
    315   }
    316 }
    317 
    318 void Jit::StopProfileSaver() {
    319   if (save_profiling_info_ && ProfileSaver::IsStarted()) {
    320     ProfileSaver::Stop(dump_info_on_shutdown_);
    321   }
    322 }
    323 
    324 bool Jit::JitAtFirstUse() {
    325   return HotMethodThreshold() == 0;
    326 }
    327 
    328 bool Jit::CanInvokeCompiledCode(ArtMethod* method) {
    329   return code_cache_->ContainsPc(method->GetEntryPointFromQuickCompiledCode());
    330 }
    331 
    332 Jit::~Jit() {
    333   DCHECK(!save_profiling_info_ || !ProfileSaver::IsStarted());
    334   if (dump_info_on_shutdown_) {
    335     DumpInfo(LOG(INFO));
    336   }
    337   DeleteThreadPool();
    338   if (jit_compiler_handle_ != nullptr) {
    339     jit_unload_(jit_compiler_handle_);
    340     jit_compiler_handle_ = nullptr;
    341   }
    342   if (jit_library_handle_ != nullptr) {
    343     dlclose(jit_library_handle_);
    344     jit_library_handle_ = nullptr;
    345   }
    346 }
    347 
    348 void Jit::NewTypeLoadedIfUsingJit(mirror::Class* type) {
    349   if (!Runtime::Current()->UseJitCompilation()) {
    350     // No need to notify if we only use the JIT to save profiles.
    351     return;
    352   }
    353   jit::Jit* jit = Runtime::Current()->GetJit();
    354   if (jit->generate_debug_info_) {
    355     DCHECK(jit->jit_types_loaded_ != nullptr);
    356     jit->jit_types_loaded_(jit->jit_compiler_handle_, &type, 1);
    357   }
    358 }
    359 
    360 void Jit::DumpTypeInfoForLoadedTypes(ClassLinker* linker) {
    361   struct CollectClasses : public ClassVisitor {
    362     bool operator()(mirror::Class* klass) override {
    363       classes_.push_back(klass);
    364       return true;
    365     }
    366     std::vector<mirror::Class*> classes_;
    367   };
    368 
    369   if (generate_debug_info_) {
    370     ScopedObjectAccess so(Thread::Current());
    371 
    372     CollectClasses visitor;
    373     linker->VisitClasses(&visitor);
    374     jit_types_loaded_(jit_compiler_handle_, visitor.classes_.data(), visitor.classes_.size());
    375   }
    376 }
    377 
    378 extern "C" void art_quick_osr_stub(void** stack,
    379                                    uint32_t stack_size_in_bytes,
    380                                    const uint8_t* native_pc,
    381                                    JValue* result,
    382                                    const char* shorty,
    383                                    Thread* self);
    384 
    385 bool Jit::MaybeDoOnStackReplacement(Thread* thread,
    386                                     ArtMethod* method,
    387                                     uint32_t dex_pc,
    388                                     int32_t dex_pc_offset,
    389                                     JValue* result) {
    390   if (!kEnableOnStackReplacement) {
    391     return false;
    392   }
    393 
    394   Jit* jit = Runtime::Current()->GetJit();
    395   if (jit == nullptr) {
    396     return false;
    397   }
    398 
    399   if (UNLIKELY(__builtin_frame_address(0) < thread->GetStackEnd())) {
    400     // Don't attempt to do an OSR if we are close to the stack limit. Since
    401     // the interpreter frames are still on stack, OSR has the potential
    402     // to stack overflow even for a simple loop.
    403     // b/27094810.
    404     return false;
    405   }
    406 
    407   // Get the actual Java method if this method is from a proxy class. The compiler
    408   // and the JIT code cache do not expect methods from proxy classes.
    409   method = method->GetInterfaceMethodIfProxy(sizeof(void*));
    410 
    411   // Cheap check if the method has been compiled already. That's an indicator that we should
    412   // osr into it.
    413   if (!jit->GetCodeCache()->ContainsPc(method->GetEntryPointFromQuickCompiledCode())) {
    414     return false;
    415   }
    416 
    417   // Fetch some data before looking up for an OSR method. We don't want thread
    418   // suspension once we hold an OSR method, as the JIT code cache could delete the OSR
    419   // method while we are being suspended.
    420   const size_t number_of_vregs = method->GetCodeItem()->registers_size_;
    421   const char* shorty = method->GetShorty();
    422   std::string method_name(VLOG_IS_ON(jit) ? PrettyMethod(method) : "");
    423   void** memory = nullptr;
    424   size_t frame_size = 0;
    425   ShadowFrame* shadow_frame = nullptr;
    426   const uint8_t* native_pc = nullptr;
    427 
    428   {
    429     ScopedAssertNoThreadSuspension sts(thread, "Holding OSR method");
    430     const OatQuickMethodHeader* osr_method = jit->GetCodeCache()->LookupOsrMethodHeader(method);
    431     if (osr_method == nullptr) {
    432       // No osr method yet, just return to the interpreter.
    433       return false;
    434     }
    435 
    436     CodeInfo code_info = osr_method->GetOptimizedCodeInfo();
    437     CodeInfoEncoding encoding = code_info.ExtractEncoding();
    438 
    439     // Find stack map starting at the target dex_pc.
    440     StackMap stack_map = code_info.GetOsrStackMapForDexPc(dex_pc + dex_pc_offset, encoding);
    441     if (!stack_map.IsValid()) {
    442       // There is no OSR stack map for this dex pc offset. Just return to the interpreter in the
    443       // hope that the next branch has one.
    444       return false;
    445     }
    446 
    447     // Before allowing the jump, make sure the debugger is not active to avoid jumping from
    448     // interpreter to OSR while e.g. single stepping. Note that we could selectively disable
    449     // OSR when single stepping, but that's currently hard to know at this point.
    450     if (Dbg::IsDebuggerActive()) {
    451       return false;
    452     }
    453 
    454     // We found a stack map, now fill the frame with dex register values from the interpreter's
    455     // shadow frame.
    456     DexRegisterMap vreg_map =
    457         code_info.GetDexRegisterMapOf(stack_map, encoding, number_of_vregs);
    458 
    459     frame_size = osr_method->GetFrameSizeInBytes();
    460 
    461     // Allocate memory to put shadow frame values. The osr stub will copy that memory to
    462     // stack.
    463     // Note that we could pass the shadow frame to the stub, and let it copy the values there,
    464     // but that is engineering complexity not worth the effort for something like OSR.
    465     memory = reinterpret_cast<void**>(malloc(frame_size));
    466     CHECK(memory != nullptr);
    467     memset(memory, 0, frame_size);
    468 
    469     // Art ABI: ArtMethod is at the bottom of the stack.
    470     memory[0] = method;
    471 
    472     shadow_frame = thread->PopShadowFrame();
    473     if (!vreg_map.IsValid()) {
    474       // If we don't have a dex register map, then there are no live dex registers at
    475       // this dex pc.
    476     } else {
    477       for (uint16_t vreg = 0; vreg < number_of_vregs; ++vreg) {
    478         DexRegisterLocation::Kind location =
    479             vreg_map.GetLocationKind(vreg, number_of_vregs, code_info, encoding);
    480         if (location == DexRegisterLocation::Kind::kNone) {
    481           // Dex register is dead or uninitialized.
    482           continue;
    483         }
    484 
    485         if (location == DexRegisterLocation::Kind::kConstant) {
    486           // We skip constants because the compiled code knows how to handle them.
    487           continue;
    488         }
    489 
    490         DCHECK_EQ(location, DexRegisterLocation::Kind::kInStack);
    491 
    492         int32_t vreg_value = shadow_frame->GetVReg(vreg);
    493         int32_t slot_offset = vreg_map.GetStackOffsetInBytes(vreg,
    494                                                              number_of_vregs,
    495                                                              code_info,
    496                                                              encoding);
    497         DCHECK_LT(slot_offset, static_cast<int32_t>(frame_size));
    498         DCHECK_GT(slot_offset, 0);
    499         (reinterpret_cast<int32_t*>(memory))[slot_offset / sizeof(int32_t)] = vreg_value;
    500       }
    501     }
    502 
    503     native_pc = stack_map.GetNativePcOffset(encoding.stack_map_encoding) +
    504         osr_method->GetEntryPoint();
    505     VLOG(jit) << "Jumping to "
    506               << method_name
    507               << "@"
    508               << std::hex << reinterpret_cast<uintptr_t>(native_pc);
    509   }
    510 
    511   {
    512     ManagedStack fragment;
    513     thread->PushManagedStackFragment(&fragment);
    514     (*art_quick_osr_stub)(memory,
    515                           frame_size,
    516                           native_pc,
    517                           result,
    518                           shorty,
    519                           thread);
    520 
    521     if (UNLIKELY(thread->GetException() == Thread::GetDeoptimizationException())) {
    522       thread->DeoptimizeWithDeoptimizationException(result);
    523     }
    524     thread->PopManagedStackFragment(fragment);
    525   }
    526   free(memory);
    527   thread->PushShadowFrame(shadow_frame);
    528   VLOG(jit) << "Done running OSR code for " << method_name;
    529   return true;
    530 }
    531 
    532 void Jit::AddMemoryUsage(ArtMethod* method, size_t bytes) {
    533   if (bytes > 4 * MB) {
    534     LOG(INFO) << "Compiler allocated "
    535               << PrettySize(bytes)
    536               << " to compile "
    537               << PrettyMethod(method);
    538   }
    539   MutexLock mu(Thread::Current(), lock_);
    540   memory_use_.AddValue(bytes);
    541 }
    542 
    543 class JitCompileTask FINAL : public Task {
    544  public:
    545   enum TaskKind {
    546     kAllocateProfile,
    547     kCompile,
    548     kCompileOsr
    549   };
    550 
    551   JitCompileTask(ArtMethod* method, TaskKind kind) : method_(method), kind_(kind) {
    552     ScopedObjectAccess soa(Thread::Current());
    553     // Add a global ref to the class to prevent class unloading until compilation is done.
    554     klass_ = soa.Vm()->AddGlobalRef(soa.Self(), method_->GetDeclaringClass());
    555     CHECK(klass_ != nullptr);
    556   }
    557 
    558   ~JitCompileTask() {
    559     ScopedObjectAccess soa(Thread::Current());
    560     soa.Vm()->DeleteGlobalRef(soa.Self(), klass_);
    561   }
    562 
    563   void Run(Thread* self) OVERRIDE {
    564     ScopedObjectAccess soa(self);
    565     if (kind_ == kCompile) {
    566       Runtime::Current()->GetJit()->CompileMethod(method_, self, /* osr */ false);
    567     } else if (kind_ == kCompileOsr) {
    568       Runtime::Current()->GetJit()->CompileMethod(method_, self, /* osr */ true);
    569     } else {
    570       DCHECK(kind_ == kAllocateProfile);
    571       if (ProfilingInfo::Create(self, method_, /* retry_allocation */ true)) {
    572         VLOG(jit) << "Start profiling " << PrettyMethod(method_);
    573       }
    574     }
    575     ProfileSaver::NotifyJitActivity();
    576   }
    577 
    578   void Finalize() OVERRIDE {
    579     delete this;
    580   }
    581 
    582  private:
    583   ArtMethod* const method_;
    584   const TaskKind kind_;
    585   jobject klass_;
    586 
    587   DISALLOW_IMPLICIT_CONSTRUCTORS(JitCompileTask);
    588 };
    589 
    590 void Jit::AddSamples(Thread* self, ArtMethod* method, uint16_t count, bool with_backedges) {
    591   if (thread_pool_ == nullptr) {
    592     // Should only see this when shutting down.
    593     DCHECK(Runtime::Current()->IsShuttingDown(self));
    594     return;
    595   }
    596 
    597   if (method->IsClassInitializer() || method->IsNative() || !method->IsCompilable()) {
    598     // We do not want to compile such methods.
    599     return;
    600   }
    601   DCHECK(thread_pool_ != nullptr);
    602   DCHECK_GT(warm_method_threshold_, 0);
    603   DCHECK_GT(hot_method_threshold_, warm_method_threshold_);
    604   DCHECK_GT(osr_method_threshold_, hot_method_threshold_);
    605   DCHECK_GE(priority_thread_weight_, 1);
    606   DCHECK_LE(priority_thread_weight_, hot_method_threshold_);
    607 
    608   int32_t starting_count = method->GetCounter();
    609   if (Jit::ShouldUsePriorityThreadWeight()) {
    610     count *= priority_thread_weight_;
    611   }
    612   int32_t new_count = starting_count + count;   // int32 here to avoid wrap-around;
    613   if (starting_count < warm_method_threshold_) {
    614     if ((new_count >= warm_method_threshold_) &&
    615         (method->GetProfilingInfo(sizeof(void*)) == nullptr)) {
    616       bool success = ProfilingInfo::Create(self, method, /* retry_allocation */ false);
    617       if (success) {
    618         VLOG(jit) << "Start profiling " << PrettyMethod(method);
    619       }
    620 
    621       if (thread_pool_ == nullptr) {
    622         // Calling ProfilingInfo::Create might put us in a suspended state, which could
    623         // lead to the thread pool being deleted when we are shutting down.
    624         DCHECK(Runtime::Current()->IsShuttingDown(self));
    625         return;
    626       }
    627 
    628       if (!success) {
    629         // We failed allocating. Instead of doing the collection on the Java thread, we push
    630         // an allocation to a compiler thread, that will do the collection.
    631         thread_pool_->AddTask(self, new JitCompileTask(method, JitCompileTask::kAllocateProfile));
    632       }
    633     }
    634     // Avoid jumping more than one state at a time.
    635     new_count = std::min(new_count, hot_method_threshold_ - 1);
    636   } else if (use_jit_compilation_) {
    637     if (starting_count < hot_method_threshold_) {
    638       if ((new_count >= hot_method_threshold_) &&
    639           !code_cache_->ContainsPc(method->GetEntryPointFromQuickCompiledCode())) {
    640         DCHECK(thread_pool_ != nullptr);
    641         thread_pool_->AddTask(self, new JitCompileTask(method, JitCompileTask::kCompile));
    642       }
    643       // Avoid jumping more than one state at a time.
    644       new_count = std::min(new_count, osr_method_threshold_ - 1);
    645     } else if (starting_count < osr_method_threshold_) {
    646       if (!with_backedges) {
    647         // If the samples don't contain any back edge, we don't increment the hotness.
    648         return;
    649       }
    650       if ((new_count >= osr_method_threshold_) &&  !code_cache_->IsOsrCompiled(method)) {
    651         DCHECK(thread_pool_ != nullptr);
    652         thread_pool_->AddTask(self, new JitCompileTask(method, JitCompileTask::kCompileOsr));
    653       }
    654     }
    655   }
    656   // Update hotness counter
    657   method->SetCounter(new_count);
    658 }
    659 
    660 void Jit::MethodEntered(Thread* thread, ArtMethod* method) {
    661   Runtime* runtime = Runtime::Current();
    662   if (UNLIKELY(runtime->UseJitCompilation() && runtime->GetJit()->JitAtFirstUse())) {
    663     // The compiler requires a ProfilingInfo object.
    664     ProfilingInfo::Create(thread, method, /* retry_allocation */ true);
    665     JitCompileTask compile_task(method, JitCompileTask::kCompile);
    666     compile_task.Run(thread);
    667     return;
    668   }
    669 
    670   ProfilingInfo* profiling_info = method->GetProfilingInfo(sizeof(void*));
    671   // Update the entrypoint if the ProfilingInfo has one. The interpreter will call it
    672   // instead of interpreting the method.
    673   if ((profiling_info != nullptr) && (profiling_info->GetSavedEntryPoint() != nullptr)) {
    674     Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(
    675         method, profiling_info->GetSavedEntryPoint());
    676   } else {
    677     AddSamples(thread, method, 1, /* with_backedges */false);
    678   }
    679 }
    680 
    681 void Jit::InvokeVirtualOrInterface(Thread* thread,
    682                                    mirror::Object* this_object,
    683                                    ArtMethod* caller,
    684                                    uint32_t dex_pc,
    685                                    ArtMethod* callee ATTRIBUTE_UNUSED) {
    686   ScopedAssertNoThreadSuspension ants(thread, __FUNCTION__);
    687   DCHECK(this_object != nullptr);
    688   ProfilingInfo* info = caller->GetProfilingInfo(sizeof(void*));
    689   if (info != nullptr) {
    690     // Since the instrumentation is marked from the declaring class we need to mark the card so
    691     // that mod-union tables and card rescanning know about the update.
    692     Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(caller->GetDeclaringClass());
    693     info->AddInvokeInfo(dex_pc, this_object->GetClass());
    694   }
    695 }
    696 
    697 void Jit::WaitForCompilationToFinish(Thread* self) {
    698   if (thread_pool_ != nullptr) {
    699     thread_pool_->Wait(self, false, false);
    700   }
    701 }
    702 
    703 }  // namespace jit
    704 }  // namespace art
    705