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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 
CreateFromRuntimeArguments(const RuntimeArgumentMap & options)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 
ShouldUsePriorityThreadWeight()122 bool Jit::ShouldUsePriorityThreadWeight() {
123   return Runtime::Current()->InJankPerceptibleProcessState()
124       && Thread::Current()->IsJitSensitiveThread();
125 }
126 
DumpInfo(std::ostream & os)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 
DumpForSigQuit(std::ostream & os)134 void Jit::DumpForSigQuit(std::ostream& os) {
135   DumpInfo(os);
136   ProfileSaver::DumpInstanceInfo(os);
137 }
138 
AddTimingLogger(const TimingLogger & logger)139 void Jit::AddTimingLogger(const TimingLogger& logger) {
140   cumulative_timings_.AddLogger(logger);
141 }
142 
Jit()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 
Create(JitOptions * options,std::string * error_msg)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 
LoadCompilerLibrary(std::string * error_msg)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 
LoadCompiler(std::string * error_msg)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 
CompileMethod(ArtMethod * method,Thread * self,bool osr)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 
CreateThreadPool()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 
DeleteThreadPool()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 
StartProfileSaver(const std::string & filename,const std::vector<std::string> & code_paths,const std::string & foreign_dex_profile_path,const std::string & app_dir)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 
StopProfileSaver()318 void Jit::StopProfileSaver() {
319   if (save_profiling_info_ && ProfileSaver::IsStarted()) {
320     ProfileSaver::Stop(dump_info_on_shutdown_);
321   }
322 }
323 
JitAtFirstUse()324 bool Jit::JitAtFirstUse() {
325   return HotMethodThreshold() == 0;
326 }
327 
CanInvokeCompiledCode(ArtMethod * method)328 bool Jit::CanInvokeCompiledCode(ArtMethod* method) {
329   return code_cache_->ContainsPc(method->GetEntryPointFromQuickCompiledCode());
330 }
331 
~Jit()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 
NewTypeLoadedIfUsingJit(mirror::Class * type)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 
DumpTypeInfoForLoadedTypes(ClassLinker * linker)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 
MaybeDoOnStackReplacement(Thread * thread,ArtMethod * method,uint32_t dex_pc,int32_t dex_pc_offset,JValue * result)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 
AddMemoryUsage(ArtMethod * method,size_t bytes)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 
JitCompileTask(ArtMethod * method,TaskKind kind)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 
~JitCompileTask()558   ~JitCompileTask() {
559     ScopedObjectAccess soa(Thread::Current());
560     soa.Vm()->DeleteGlobalRef(soa.Self(), klass_);
561   }
562 
Run(Thread * self)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 
Finalize()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 
AddSamples(Thread * self,ArtMethod * method,uint16_t count,bool with_backedges)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 
MethodEntered(Thread * thread,ArtMethod * method)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 
InvokeVirtualOrInterface(Thread * thread,mirror::Object * this_object,ArtMethod * caller,uint32_t dex_pc,ArtMethod * callee ATTRIBUTE_UNUSED)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 
WaitForCompilationToFinish(Thread * self)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