1 // Copyright 2012 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "src/profiler/cpu-profiler.h" 6 7 #include <unordered_map> 8 #include <utility> 9 10 #include "src/base/lazy-instance.h" 11 #include "src/base/platform/mutex.h" 12 #include "src/base/template-utils.h" 13 #include "src/debug/debug.h" 14 #include "src/deoptimizer.h" 15 #include "src/frames-inl.h" 16 #include "src/locked-queue-inl.h" 17 #include "src/log-inl.h" 18 #include "src/profiler/cpu-profiler-inl.h" 19 #include "src/vm-state-inl.h" 20 21 namespace v8 { 22 namespace internal { 23 24 static const int kProfilerStackSize = 64 * KB; 25 26 class CpuSampler : public sampler::Sampler { 27 public: 28 CpuSampler(Isolate* isolate, ProfilerEventsProcessor* processor) 29 : sampler::Sampler(reinterpret_cast<v8::Isolate*>(isolate)), 30 processor_(processor) {} 31 32 void SampleStack(const v8::RegisterState& regs) override { 33 TickSample* sample = processor_->StartTickSample(); 34 if (sample == nullptr) return; 35 Isolate* isolate = reinterpret_cast<Isolate*>(this->isolate()); 36 sample->Init(isolate, regs, TickSample::kIncludeCEntryFrame, true); 37 if (is_counting_samples_ && !sample->timestamp.IsNull()) { 38 if (sample->state == JS) ++js_sample_count_; 39 if (sample->state == EXTERNAL) ++external_sample_count_; 40 } 41 processor_->FinishTickSample(); 42 } 43 44 private: 45 ProfilerEventsProcessor* processor_; 46 }; 47 48 ProfilerEventsProcessor::ProfilerEventsProcessor(Isolate* isolate, 49 ProfileGenerator* generator, 50 base::TimeDelta period) 51 : Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)), 52 generator_(generator), 53 sampler_(new CpuSampler(isolate, this)), 54 running_(1), 55 period_(period), 56 last_code_event_id_(0), 57 last_processed_code_event_id_(0) { 58 sampler_->IncreaseProfilingDepth(); 59 } 60 61 ProfilerEventsProcessor::~ProfilerEventsProcessor() { 62 sampler_->DecreaseProfilingDepth(); 63 } 64 65 void ProfilerEventsProcessor::Enqueue(const CodeEventsContainer& event) { 66 event.generic.order = ++last_code_event_id_; 67 events_buffer_.Enqueue(event); 68 } 69 70 71 void ProfilerEventsProcessor::AddDeoptStack(Isolate* isolate, Address from, 72 int fp_to_sp_delta) { 73 TickSampleEventRecord record(last_code_event_id_); 74 RegisterState regs; 75 Address fp = isolate->c_entry_fp(isolate->thread_local_top()); 76 regs.sp = reinterpret_cast<void*>(fp - fp_to_sp_delta); 77 regs.fp = reinterpret_cast<void*>(fp); 78 regs.pc = reinterpret_cast<void*>(from); 79 record.sample.Init(isolate, regs, TickSample::kSkipCEntryFrame, false, false); 80 ticks_from_vm_buffer_.Enqueue(record); 81 } 82 83 void ProfilerEventsProcessor::AddCurrentStack(Isolate* isolate, 84 bool update_stats) { 85 TickSampleEventRecord record(last_code_event_id_); 86 RegisterState regs; 87 StackFrameIterator it(isolate); 88 if (!it.done()) { 89 StackFrame* frame = it.frame(); 90 regs.sp = reinterpret_cast<void*>(frame->sp()); 91 regs.fp = reinterpret_cast<void*>(frame->fp()); 92 regs.pc = reinterpret_cast<void*>(frame->pc()); 93 } 94 record.sample.Init(isolate, regs, TickSample::kSkipCEntryFrame, update_stats, 95 false); 96 ticks_from_vm_buffer_.Enqueue(record); 97 } 98 99 100 void ProfilerEventsProcessor::StopSynchronously() { 101 if (!base::Relaxed_AtomicExchange(&running_, 0)) return; 102 Join(); 103 } 104 105 106 bool ProfilerEventsProcessor::ProcessCodeEvent() { 107 CodeEventsContainer record; 108 if (events_buffer_.Dequeue(&record)) { 109 switch (record.generic.type) { 110 #define PROFILER_TYPE_CASE(type, clss) \ 111 case CodeEventRecord::type: \ 112 record.clss##_.UpdateCodeMap(generator_->code_map()); \ 113 break; 114 115 CODE_EVENTS_TYPE_LIST(PROFILER_TYPE_CASE) 116 117 #undef PROFILER_TYPE_CASE 118 default: return true; // Skip record. 119 } 120 last_processed_code_event_id_ = record.generic.order; 121 return true; 122 } 123 return false; 124 } 125 126 ProfilerEventsProcessor::SampleProcessingResult 127 ProfilerEventsProcessor::ProcessOneSample() { 128 TickSampleEventRecord record1; 129 if (ticks_from_vm_buffer_.Peek(&record1) && 130 (record1.order == last_processed_code_event_id_)) { 131 TickSampleEventRecord record; 132 ticks_from_vm_buffer_.Dequeue(&record); 133 generator_->RecordTickSample(record.sample); 134 return OneSampleProcessed; 135 } 136 137 const TickSampleEventRecord* record = ticks_buffer_.Peek(); 138 if (record == nullptr) { 139 if (ticks_from_vm_buffer_.IsEmpty()) return NoSamplesInQueue; 140 return FoundSampleForNextCodeEvent; 141 } 142 if (record->order != last_processed_code_event_id_) { 143 return FoundSampleForNextCodeEvent; 144 } 145 generator_->RecordTickSample(record->sample); 146 ticks_buffer_.Remove(); 147 return OneSampleProcessed; 148 } 149 150 151 void ProfilerEventsProcessor::Run() { 152 while (!!base::Relaxed_Load(&running_)) { 153 base::TimeTicks nextSampleTime = 154 base::TimeTicks::HighResolutionNow() + period_; 155 base::TimeTicks now; 156 SampleProcessingResult result; 157 // Keep processing existing events until we need to do next sample 158 // or the ticks buffer is empty. 159 do { 160 result = ProcessOneSample(); 161 if (result == FoundSampleForNextCodeEvent) { 162 // All ticks of the current last_processed_code_event_id_ are 163 // processed, proceed to the next code event. 164 ProcessCodeEvent(); 165 } 166 now = base::TimeTicks::HighResolutionNow(); 167 } while (result != NoSamplesInQueue && now < nextSampleTime); 168 169 if (nextSampleTime > now) { 170 #if V8_OS_WIN 171 if (nextSampleTime - now < base::TimeDelta::FromMilliseconds(100)) { 172 // Do not use Sleep on Windows as it is very imprecise, with up to 16ms 173 // jitter, which is unacceptable for short profile intervals. 174 while (base::TimeTicks::HighResolutionNow() < nextSampleTime) { 175 } 176 } else // NOLINT 177 #endif 178 { 179 base::OS::Sleep(nextSampleTime - now); 180 } 181 } 182 183 // Schedule next sample. sampler_ is nullptr in tests. 184 if (sampler_) sampler_->DoSample(); 185 } 186 187 // Process remaining tick events. 188 do { 189 SampleProcessingResult result; 190 do { 191 result = ProcessOneSample(); 192 } while (result == OneSampleProcessed); 193 } while (ProcessCodeEvent()); 194 } 195 196 197 void* ProfilerEventsProcessor::operator new(size_t size) { 198 return AlignedAlloc(size, V8_ALIGNOF(ProfilerEventsProcessor)); 199 } 200 201 202 void ProfilerEventsProcessor::operator delete(void* ptr) { 203 AlignedFree(ptr); 204 } 205 206 207 int CpuProfiler::GetProfilesCount() { 208 // The count of profiles doesn't depend on a security token. 209 return static_cast<int>(profiles_->profiles()->size()); 210 } 211 212 213 CpuProfile* CpuProfiler::GetProfile(int index) { 214 return profiles_->profiles()->at(index).get(); 215 } 216 217 218 void CpuProfiler::DeleteAllProfiles() { 219 if (is_profiling_) StopProcessor(); 220 ResetProfiles(); 221 } 222 223 224 void CpuProfiler::DeleteProfile(CpuProfile* profile) { 225 profiles_->RemoveProfile(profile); 226 if (profiles_->profiles()->empty() && !is_profiling_) { 227 // If this was the last profile, clean up all accessory data as well. 228 ResetProfiles(); 229 } 230 } 231 232 void CpuProfiler::CodeEventHandler(const CodeEventsContainer& evt_rec) { 233 switch (evt_rec.generic.type) { 234 case CodeEventRecord::CODE_CREATION: 235 case CodeEventRecord::CODE_MOVE: 236 case CodeEventRecord::CODE_DISABLE_OPT: 237 processor_->Enqueue(evt_rec); 238 break; 239 case CodeEventRecord::CODE_DEOPT: { 240 const CodeDeoptEventRecord* rec = &evt_rec.CodeDeoptEventRecord_; 241 Address pc = rec->pc; 242 int fp_to_sp_delta = rec->fp_to_sp_delta; 243 processor_->Enqueue(evt_rec); 244 processor_->AddDeoptStack(isolate_, pc, fp_to_sp_delta); 245 break; 246 } 247 default: 248 UNREACHABLE(); 249 } 250 } 251 252 namespace { 253 254 class CpuProfilersManager { 255 public: 256 void AddProfiler(Isolate* isolate, CpuProfiler* profiler) { 257 base::LockGuard<base::Mutex> lock(&mutex_); 258 profilers_.emplace(isolate, profiler); 259 } 260 261 void RemoveProfiler(Isolate* isolate, CpuProfiler* profiler) { 262 base::LockGuard<base::Mutex> lock(&mutex_); 263 auto range = profilers_.equal_range(isolate); 264 for (auto it = range.first; it != range.second; ++it) { 265 if (it->second != profiler) continue; 266 profilers_.erase(it); 267 return; 268 } 269 UNREACHABLE(); 270 } 271 272 void CallCollectSample(Isolate* isolate) { 273 base::LockGuard<base::Mutex> lock(&mutex_); 274 auto range = profilers_.equal_range(isolate); 275 for (auto it = range.first; it != range.second; ++it) { 276 it->second->CollectSample(); 277 } 278 } 279 280 private: 281 std::unordered_multimap<Isolate*, CpuProfiler*> profilers_; 282 base::Mutex mutex_; 283 }; 284 285 base::LazyInstance<CpuProfilersManager>::type g_profilers_manager = 286 LAZY_INSTANCE_INITIALIZER; 287 288 } // namespace 289 290 CpuProfiler::CpuProfiler(Isolate* isolate) 291 : CpuProfiler(isolate, new CpuProfilesCollection(isolate), nullptr, 292 nullptr) {} 293 294 CpuProfiler::CpuProfiler(Isolate* isolate, CpuProfilesCollection* test_profiles, 295 ProfileGenerator* test_generator, 296 ProfilerEventsProcessor* test_processor) 297 : isolate_(isolate), 298 sampling_interval_(base::TimeDelta::FromMicroseconds( 299 FLAG_cpu_profiler_sampling_interval)), 300 profiles_(test_profiles), 301 generator_(test_generator), 302 processor_(test_processor), 303 is_profiling_(false) { 304 profiles_->set_cpu_profiler(this); 305 g_profilers_manager.Pointer()->AddProfiler(isolate, this); 306 } 307 308 CpuProfiler::~CpuProfiler() { 309 DCHECK(!is_profiling_); 310 g_profilers_manager.Pointer()->RemoveProfiler(isolate_, this); 311 } 312 313 void CpuProfiler::set_sampling_interval(base::TimeDelta value) { 314 DCHECK(!is_profiling_); 315 sampling_interval_ = value; 316 } 317 318 void CpuProfiler::ResetProfiles() { 319 profiles_.reset(new CpuProfilesCollection(isolate_)); 320 profiles_->set_cpu_profiler(this); 321 profiler_listener_.reset(); 322 generator_.reset(); 323 } 324 325 void CpuProfiler::CreateEntriesForRuntimeCallStats() { 326 RuntimeCallStats* rcs = isolate_->counters()->runtime_call_stats(); 327 CodeMap* code_map = generator_->code_map(); 328 for (int i = 0; i < RuntimeCallStats::kNumberOfCounters; ++i) { 329 RuntimeCallCounter* counter = rcs->GetCounter(i); 330 DCHECK(counter->name()); 331 auto entry = new CodeEntry(CodeEventListener::FUNCTION_TAG, counter->name(), 332 "native V8Runtime"); 333 code_map->AddCode(reinterpret_cast<Address>(counter), entry, 1); 334 } 335 } 336 337 // static 338 void CpuProfiler::CollectSample(Isolate* isolate) { 339 g_profilers_manager.Pointer()->CallCollectSample(isolate); 340 } 341 342 void CpuProfiler::CollectSample() { 343 if (processor_) { 344 processor_->AddCurrentStack(isolate_); 345 } 346 } 347 348 void CpuProfiler::StartProfiling(const char* title, bool record_samples, 349 ProfilingMode mode) { 350 if (profiles_->StartProfiling(title, record_samples, mode)) { 351 TRACE_EVENT0("v8", "CpuProfiler::StartProfiling"); 352 StartProcessorIfNotStarted(); 353 } 354 } 355 356 void CpuProfiler::StartProfiling(String* title, bool record_samples, 357 ProfilingMode mode) { 358 StartProfiling(profiles_->GetName(title), record_samples, mode); 359 isolate_->debug()->feature_tracker()->Track(DebugFeatureTracker::kProfiler); 360 } 361 362 void CpuProfiler::StartProcessorIfNotStarted() { 363 if (processor_) { 364 processor_->AddCurrentStack(isolate_); 365 return; 366 } 367 Logger* logger = isolate_->logger(); 368 // Disable logging when using the new implementation. 369 saved_is_logging_ = logger->is_logging_; 370 logger->is_logging_ = false; 371 372 bool codemap_needs_initialization = false; 373 if (!generator_) { 374 generator_.reset(new ProfileGenerator(profiles_.get())); 375 codemap_needs_initialization = true; 376 CreateEntriesForRuntimeCallStats(); 377 } 378 processor_.reset(new ProfilerEventsProcessor(isolate_, generator_.get(), 379 sampling_interval_)); 380 if (!profiler_listener_) { 381 profiler_listener_.reset(new ProfilerListener(isolate_, this)); 382 } 383 logger->AddCodeEventListener(profiler_listener_.get()); 384 is_profiling_ = true; 385 isolate_->set_is_profiling(true); 386 // Enumerate stuff we already have in the heap. 387 DCHECK(isolate_->heap()->HasBeenSetUp()); 388 if (codemap_needs_initialization) { 389 if (!FLAG_prof_browser_mode) { 390 logger->LogCodeObjects(); 391 } 392 logger->LogCompiledFunctions(); 393 logger->LogAccessorCallbacks(); 394 LogBuiltins(); 395 } 396 // Enable stack sampling. 397 processor_->AddCurrentStack(isolate_); 398 processor_->StartSynchronously(); 399 } 400 401 CpuProfile* CpuProfiler::StopProfiling(const char* title) { 402 if (!is_profiling_) return nullptr; 403 StopProcessorIfLastProfile(title); 404 return profiles_->StopProfiling(title); 405 } 406 407 CpuProfile* CpuProfiler::StopProfiling(String* title) { 408 return StopProfiling(profiles_->GetName(title)); 409 } 410 411 void CpuProfiler::StopProcessorIfLastProfile(const char* title) { 412 if (!profiles_->IsLastProfile(title)) return; 413 StopProcessor(); 414 } 415 416 void CpuProfiler::StopProcessor() { 417 Logger* logger = isolate_->logger(); 418 is_profiling_ = false; 419 isolate_->set_is_profiling(false); 420 logger->RemoveCodeEventListener(profiler_listener_.get()); 421 processor_->StopSynchronously(); 422 processor_.reset(); 423 logger->is_logging_ = saved_is_logging_; 424 } 425 426 427 void CpuProfiler::LogBuiltins() { 428 Builtins* builtins = isolate_->builtins(); 429 DCHECK(builtins->is_initialized()); 430 for (int i = 0; i < Builtins::builtin_count; i++) { 431 CodeEventsContainer evt_rec(CodeEventRecord::REPORT_BUILTIN); 432 ReportBuiltinEventRecord* rec = &evt_rec.ReportBuiltinEventRecord_; 433 Builtins::Name id = static_cast<Builtins::Name>(i); 434 rec->instruction_start = builtins->builtin(id)->InstructionStart(); 435 rec->builtin_id = id; 436 processor_->Enqueue(evt_rec); 437 } 438 } 439 440 } // namespace internal 441 } // namespace v8 442