1 // Copyright 2013 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #include "sampler.h" 29 30 #if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) \ 31 || defined(__NetBSD__) || defined(__sun) || defined(__ANDROID__) \ 32 || defined(__native_client__) 33 34 #define USE_SIGNALS 35 36 #include <errno.h> 37 #include <pthread.h> 38 #include <signal.h> 39 #include <sys/time.h> 40 #include <sys/syscall.h> 41 // OpenBSD doesn't have <ucontext.h>. ucontext_t lives in <signal.h> 42 // and is a typedef for struct sigcontext. There is no uc_mcontext. 43 #if (!defined(__ANDROID__) || defined(__BIONIC_HAVE_UCONTEXT_T)) \ 44 && !defined(__OpenBSD__) 45 #include <ucontext.h> 46 #endif 47 #include <unistd.h> 48 49 // GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'. 50 // Old versions of the C library <signal.h> didn't define the type. 51 #if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T) && \ 52 defined(__arm__) && !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT) 53 #include <asm/sigcontext.h> 54 #endif 55 56 #elif defined(__MACH__) 57 58 #include <mach/mach.h> 59 60 #elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__) 61 62 #include "win32-headers.h" 63 64 #endif 65 66 #include "v8.h" 67 68 #include "cpu-profiler.h" 69 #include "flags.h" 70 #include "frames-inl.h" 71 #include "log.h" 72 #include "platform.h" 73 #include "simulator.h" 74 #include "v8threads.h" 75 #include "vm-state-inl.h" 76 77 78 #if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T) 79 80 // Not all versions of Android's C library provide ucontext_t. 81 // Detect this and provide custom but compatible definitions. Note that these 82 // follow the GLibc naming convention to access register values from 83 // mcontext_t. 84 // 85 // See http://code.google.com/p/android/issues/detail?id=34784 86 87 #if defined(__arm__) 88 89 typedef struct sigcontext mcontext_t; 90 91 typedef struct ucontext { 92 uint32_t uc_flags; 93 struct ucontext* uc_link; 94 stack_t uc_stack; 95 mcontext_t uc_mcontext; 96 // Other fields are not used by V8, don't define them here. 97 } ucontext_t; 98 99 #elif defined(__mips__) 100 // MIPS version of sigcontext, for Android bionic. 101 typedef struct { 102 uint32_t regmask; 103 uint32_t status; 104 uint64_t pc; 105 uint64_t gregs[32]; 106 uint64_t fpregs[32]; 107 uint32_t acx; 108 uint32_t fpc_csr; 109 uint32_t fpc_eir; 110 uint32_t used_math; 111 uint32_t dsp; 112 uint64_t mdhi; 113 uint64_t mdlo; 114 uint32_t hi1; 115 uint32_t lo1; 116 uint32_t hi2; 117 uint32_t lo2; 118 uint32_t hi3; 119 uint32_t lo3; 120 } mcontext_t; 121 122 typedef struct ucontext { 123 uint32_t uc_flags; 124 struct ucontext* uc_link; 125 stack_t uc_stack; 126 mcontext_t uc_mcontext; 127 // Other fields are not used by V8, don't define them here. 128 } ucontext_t; 129 130 #elif defined(__i386__) 131 // x86 version for Android. 132 typedef struct { 133 uint32_t gregs[19]; 134 void* fpregs; 135 uint32_t oldmask; 136 uint32_t cr2; 137 } mcontext_t; 138 139 typedef uint32_t kernel_sigset_t[2]; // x86 kernel uses 64-bit signal masks 140 typedef struct ucontext { 141 uint32_t uc_flags; 142 struct ucontext* uc_link; 143 stack_t uc_stack; 144 mcontext_t uc_mcontext; 145 // Other fields are not used by V8, don't define them here. 146 } ucontext_t; 147 enum { REG_EBP = 6, REG_ESP = 7, REG_EIP = 14 }; 148 #endif 149 150 #endif // __ANDROID__ && !defined(__BIONIC_HAVE_UCONTEXT_T) 151 152 153 namespace v8 { 154 namespace internal { 155 156 namespace { 157 158 class PlatformDataCommon : public Malloced { 159 public: 160 PlatformDataCommon() : profiled_thread_id_(ThreadId::Current()) {} 161 ThreadId profiled_thread_id() { return profiled_thread_id_; } 162 163 protected: 164 ~PlatformDataCommon() {} 165 166 private: 167 ThreadId profiled_thread_id_; 168 }; 169 170 } // namespace 171 172 #if defined(USE_SIGNALS) 173 174 class Sampler::PlatformData : public PlatformDataCommon { 175 public: 176 PlatformData() : vm_tid_(pthread_self()) {} 177 pthread_t vm_tid() const { return vm_tid_; } 178 179 private: 180 pthread_t vm_tid_; 181 }; 182 183 #elif defined(__MACH__) 184 185 class Sampler::PlatformData : public PlatformDataCommon { 186 public: 187 PlatformData() : profiled_thread_(mach_thread_self()) {} 188 189 ~PlatformData() { 190 // Deallocate Mach port for thread. 191 mach_port_deallocate(mach_task_self(), profiled_thread_); 192 } 193 194 thread_act_t profiled_thread() { return profiled_thread_; } 195 196 private: 197 // Note: for profiled_thread_ Mach primitives are used instead of PThread's 198 // because the latter doesn't provide thread manipulation primitives required. 199 // For details, consult "Mac OS X Internals" book, Section 7.3. 200 thread_act_t profiled_thread_; 201 }; 202 203 #elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__) 204 205 // ---------------------------------------------------------------------------- 206 // Win32 profiler support. On Cygwin we use the same sampler implementation as 207 // on Win32. 208 209 class Sampler::PlatformData : public PlatformDataCommon { 210 public: 211 // Get a handle to the calling thread. This is the thread that we are 212 // going to profile. We need to make a copy of the handle because we are 213 // going to use it in the sampler thread. Using GetThreadHandle() will 214 // not work in this case. We're using OpenThread because DuplicateHandle 215 // for some reason doesn't work in Chrome's sandbox. 216 PlatformData() 217 : profiled_thread_(OpenThread(THREAD_GET_CONTEXT | 218 THREAD_SUSPEND_RESUME | 219 THREAD_QUERY_INFORMATION, 220 false, 221 GetCurrentThreadId())) {} 222 223 ~PlatformData() { 224 if (profiled_thread_ != NULL) { 225 CloseHandle(profiled_thread_); 226 profiled_thread_ = NULL; 227 } 228 } 229 230 HANDLE profiled_thread() { return profiled_thread_; } 231 232 private: 233 HANDLE profiled_thread_; 234 }; 235 #endif 236 237 238 #if defined(USE_SIMULATOR) 239 class SimulatorHelper { 240 public: 241 inline bool Init(Sampler* sampler, Isolate* isolate) { 242 ThreadId thread_id = sampler->platform_data()->profiled_thread_id(); 243 Isolate::PerIsolateThreadData* per_thread_data = isolate-> 244 FindPerThreadDataForThread(thread_id); 245 if (!per_thread_data) return false; 246 simulator_ = per_thread_data->simulator(); 247 // Check if there is active simulator. 248 return simulator_ != NULL; 249 } 250 251 inline void FillRegisters(RegisterState* state) { 252 state->pc = reinterpret_cast<Address>(simulator_->get_pc()); 253 state->sp = reinterpret_cast<Address>(simulator_->get_register( 254 Simulator::sp)); 255 #if V8_TARGET_ARCH_ARM 256 state->fp = reinterpret_cast<Address>(simulator_->get_register( 257 Simulator::r11)); 258 #elif V8_TARGET_ARCH_MIPS 259 state->fp = reinterpret_cast<Address>(simulator_->get_register( 260 Simulator::fp)); 261 #endif 262 } 263 264 private: 265 Simulator* simulator_; 266 }; 267 #endif // USE_SIMULATOR 268 269 270 #if defined(USE_SIGNALS) 271 272 class SignalHandler : public AllStatic { 273 public: 274 static inline void EnsureInstalled() { 275 if (signal_handler_installed_) return; 276 struct sigaction sa; 277 sa.sa_sigaction = &HandleProfilerSignal; 278 sigemptyset(&sa.sa_mask); 279 sa.sa_flags = SA_RESTART | SA_SIGINFO; 280 signal_handler_installed_ = 281 (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0); 282 } 283 284 static inline void Restore() { 285 if (signal_handler_installed_) { 286 sigaction(SIGPROF, &old_signal_handler_, 0); 287 signal_handler_installed_ = false; 288 } 289 } 290 291 static inline bool Installed() { 292 return signal_handler_installed_; 293 } 294 295 private: 296 static void HandleProfilerSignal(int signal, siginfo_t* info, void* context); 297 static bool signal_handler_installed_; 298 static struct sigaction old_signal_handler_; 299 }; 300 301 struct sigaction SignalHandler::old_signal_handler_; 302 bool SignalHandler::signal_handler_installed_ = false; 303 304 305 void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info, 306 void* context) { 307 #if defined(__native_client__) 308 // As Native Client does not support signal handling, profiling 309 // is disabled. 310 return; 311 #else 312 USE(info); 313 if (signal != SIGPROF) return; 314 Isolate* isolate = Isolate::UncheckedCurrent(); 315 if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) { 316 // We require a fully initialized and entered isolate. 317 return; 318 } 319 if (v8::Locker::IsActive() && 320 !isolate->thread_manager()->IsLockedByCurrentThread()) { 321 return; 322 } 323 324 Sampler* sampler = isolate->logger()->sampler(); 325 if (sampler == NULL || !sampler->IsActive()) return; 326 327 RegisterState state; 328 329 #if defined(USE_SIMULATOR) 330 SimulatorHelper helper; 331 if (!helper.Init(sampler, isolate)) return; 332 helper.FillRegisters(&state); 333 #else 334 // Extracting the sample from the context is extremely machine dependent. 335 ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context); 336 #if !defined(__OpenBSD__) 337 mcontext_t& mcontext = ucontext->uc_mcontext; 338 #endif 339 #if defined(__linux__) || defined(__ANDROID__) 340 #if V8_HOST_ARCH_IA32 341 state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]); 342 state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]); 343 state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]); 344 #elif V8_HOST_ARCH_X64 345 state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]); 346 state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]); 347 state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]); 348 #elif V8_HOST_ARCH_ARM 349 #if defined(__GLIBC__) && !defined(__UCLIBC__) && \ 350 (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3)) 351 // Old GLibc ARM versions used a gregs[] array to access the register 352 // values from mcontext_t. 353 state.pc = reinterpret_cast<Address>(mcontext.gregs[R15]); 354 state.sp = reinterpret_cast<Address>(mcontext.gregs[R13]); 355 state.fp = reinterpret_cast<Address>(mcontext.gregs[R11]); 356 #else 357 state.pc = reinterpret_cast<Address>(mcontext.arm_pc); 358 state.sp = reinterpret_cast<Address>(mcontext.arm_sp); 359 state.fp = reinterpret_cast<Address>(mcontext.arm_fp); 360 #endif // defined(__GLIBC__) && !defined(__UCLIBC__) && 361 // (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3)) 362 #elif V8_HOST_ARCH_MIPS 363 state.pc = reinterpret_cast<Address>(mcontext.pc); 364 state.sp = reinterpret_cast<Address>(mcontext.gregs[29]); 365 state.fp = reinterpret_cast<Address>(mcontext.gregs[30]); 366 #endif // V8_HOST_ARCH_* 367 #elif defined(__FreeBSD__) 368 #if V8_HOST_ARCH_IA32 369 state.pc = reinterpret_cast<Address>(mcontext.mc_eip); 370 state.sp = reinterpret_cast<Address>(mcontext.mc_esp); 371 state.fp = reinterpret_cast<Address>(mcontext.mc_ebp); 372 #elif V8_HOST_ARCH_X64 373 state.pc = reinterpret_cast<Address>(mcontext.mc_rip); 374 state.sp = reinterpret_cast<Address>(mcontext.mc_rsp); 375 state.fp = reinterpret_cast<Address>(mcontext.mc_rbp); 376 #elif V8_HOST_ARCH_ARM 377 state.pc = reinterpret_cast<Address>(mcontext.mc_r15); 378 state.sp = reinterpret_cast<Address>(mcontext.mc_r13); 379 state.fp = reinterpret_cast<Address>(mcontext.mc_r11); 380 #endif // V8_HOST_ARCH_* 381 #elif defined(__NetBSD__) 382 #if V8_HOST_ARCH_IA32 383 state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_EIP]); 384 state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_ESP]); 385 state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_EBP]); 386 #elif V8_HOST_ARCH_X64 387 state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_RIP]); 388 state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RSP]); 389 state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RBP]); 390 #endif // V8_HOST_ARCH_* 391 #elif defined(__OpenBSD__) 392 #if V8_HOST_ARCH_IA32 393 state.pc = reinterpret_cast<Address>(ucontext->sc_eip); 394 state.sp = reinterpret_cast<Address>(ucontext->sc_esp); 395 state.fp = reinterpret_cast<Address>(ucontext->sc_ebp); 396 #elif V8_HOST_ARCH_X64 397 state.pc = reinterpret_cast<Address>(ucontext->sc_rip); 398 state.sp = reinterpret_cast<Address>(ucontext->sc_rsp); 399 state.fp = reinterpret_cast<Address>(ucontext->sc_rbp); 400 #endif // V8_HOST_ARCH_* 401 #elif defined(__sun) 402 state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_PC]); 403 state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_SP]); 404 state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_FP]); 405 #endif // __sun 406 #endif // USE_SIMULATOR 407 sampler->SampleStack(state); 408 #endif // __native_client__ 409 } 410 411 #endif 412 413 414 class SamplerThread : public Thread { 415 public: 416 static const int kSamplerThreadStackSize = 64 * KB; 417 418 explicit SamplerThread(int interval) 419 : Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)), 420 interval_(interval) {} 421 422 static void SetUp() { if (!mutex_) mutex_ = OS::CreateMutex(); } 423 static void TearDown() { delete mutex_; } 424 425 static void AddActiveSampler(Sampler* sampler) { 426 bool need_to_start = false; 427 ScopedLock lock(mutex_); 428 if (instance_ == NULL) { 429 // Start a thread that will send SIGPROF signal to VM threads, 430 // when CPU profiling will be enabled. 431 instance_ = new SamplerThread(sampler->interval()); 432 need_to_start = true; 433 } 434 435 ASSERT(sampler->IsActive()); 436 ASSERT(!instance_->active_samplers_.Contains(sampler)); 437 ASSERT(instance_->interval_ == sampler->interval()); 438 instance_->active_samplers_.Add(sampler); 439 440 #if defined(USE_SIGNALS) 441 SignalHandler::EnsureInstalled(); 442 #endif 443 if (need_to_start) instance_->StartSynchronously(); 444 } 445 446 static void RemoveActiveSampler(Sampler* sampler) { 447 SamplerThread* instance_to_remove = NULL; 448 { 449 ScopedLock lock(mutex_); 450 451 ASSERT(sampler->IsActive()); 452 bool removed = instance_->active_samplers_.RemoveElement(sampler); 453 ASSERT(removed); 454 USE(removed); 455 456 // We cannot delete the instance immediately as we need to Join() the 457 // thread but we are holding mutex_ and the thread may try to acquire it. 458 if (instance_->active_samplers_.is_empty()) { 459 instance_to_remove = instance_; 460 instance_ = NULL; 461 #if defined(USE_SIGNALS) 462 SignalHandler::Restore(); 463 #endif 464 } 465 } 466 467 if (!instance_to_remove) return; 468 instance_to_remove->Join(); 469 delete instance_to_remove; 470 } 471 472 // Implement Thread::Run(). 473 virtual void Run() { 474 while (true) { 475 { 476 ScopedLock lock(mutex_); 477 if (active_samplers_.is_empty()) break; 478 // When CPU profiling is enabled both JavaScript and C++ code is 479 // profiled. We must not suspend. 480 for (int i = 0; i < active_samplers_.length(); ++i) { 481 Sampler* sampler = active_samplers_.at(i); 482 if (!sampler->isolate()->IsInitialized()) continue; 483 if (!sampler->IsProfiling()) continue; 484 SampleContext(sampler); 485 } 486 } 487 OS::Sleep(interval_); 488 } 489 } 490 491 private: 492 #if defined(USE_SIGNALS) 493 494 void SampleContext(Sampler* sampler) { 495 if (!SignalHandler::Installed()) return; 496 pthread_t tid = sampler->platform_data()->vm_tid(); 497 pthread_kill(tid, SIGPROF); 498 } 499 500 #elif defined(__MACH__) 501 502 void SampleContext(Sampler* sampler) { 503 thread_act_t profiled_thread = sampler->platform_data()->profiled_thread(); 504 505 #if defined(USE_SIMULATOR) 506 SimulatorHelper helper; 507 Isolate* isolate = sampler->isolate(); 508 if (!helper.Init(sampler, isolate)) return; 509 #endif 510 511 if (KERN_SUCCESS != thread_suspend(profiled_thread)) return; 512 513 #if V8_HOST_ARCH_X64 514 thread_state_flavor_t flavor = x86_THREAD_STATE64; 515 x86_thread_state64_t thread_state; 516 mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT; 517 #if __DARWIN_UNIX03 518 #define REGISTER_FIELD(name) __r ## name 519 #else 520 #define REGISTER_FIELD(name) r ## name 521 #endif // __DARWIN_UNIX03 522 #elif V8_HOST_ARCH_IA32 523 thread_state_flavor_t flavor = i386_THREAD_STATE; 524 i386_thread_state_t thread_state; 525 mach_msg_type_number_t count = i386_THREAD_STATE_COUNT; 526 #if __DARWIN_UNIX03 527 #define REGISTER_FIELD(name) __e ## name 528 #else 529 #define REGISTER_FIELD(name) e ## name 530 #endif // __DARWIN_UNIX03 531 #else 532 #error Unsupported Mac OS X host architecture. 533 #endif // V8_HOST_ARCH 534 535 if (thread_get_state(profiled_thread, 536 flavor, 537 reinterpret_cast<natural_t*>(&thread_state), 538 &count) == KERN_SUCCESS) { 539 RegisterState state; 540 #if defined(USE_SIMULATOR) 541 helper.FillRegisters(&state); 542 #else 543 state.pc = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(ip)); 544 state.sp = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(sp)); 545 state.fp = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(bp)); 546 #endif // USE_SIMULATOR 547 #undef REGISTER_FIELD 548 sampler->SampleStack(state); 549 } 550 thread_resume(profiled_thread); 551 } 552 553 #elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__) 554 555 void SampleContext(Sampler* sampler) { 556 HANDLE profiled_thread = sampler->platform_data()->profiled_thread(); 557 if (profiled_thread == NULL) return; 558 559 Isolate* isolate = sampler->isolate(); 560 #if defined(USE_SIMULATOR) 561 SimulatorHelper helper; 562 if (!helper.Init(sampler, isolate)) return; 563 #endif 564 565 const DWORD kSuspendFailed = static_cast<DWORD>(-1); 566 if (SuspendThread(profiled_thread) == kSuspendFailed) return; 567 568 // Context used for sampling the register state of the profiled thread. 569 CONTEXT context; 570 memset(&context, 0, sizeof(context)); 571 context.ContextFlags = CONTEXT_FULL; 572 if (GetThreadContext(profiled_thread, &context) != 0) { 573 RegisterState state; 574 #if defined(USE_SIMULATOR) 575 helper.FillRegisters(&state); 576 #else 577 #if V8_HOST_ARCH_X64 578 state.pc = reinterpret_cast<Address>(context.Rip); 579 state.sp = reinterpret_cast<Address>(context.Rsp); 580 state.fp = reinterpret_cast<Address>(context.Rbp); 581 #else 582 state.pc = reinterpret_cast<Address>(context.Eip); 583 state.sp = reinterpret_cast<Address>(context.Esp); 584 state.fp = reinterpret_cast<Address>(context.Ebp); 585 #endif 586 #endif // USE_SIMULATOR 587 sampler->SampleStack(state); 588 } 589 ResumeThread(profiled_thread); 590 } 591 592 #endif // USE_SIGNALS 593 594 595 // Protects the process wide state below. 596 static Mutex* mutex_; 597 static SamplerThread* instance_; 598 599 const int interval_; 600 List<Sampler*> active_samplers_; 601 602 DISALLOW_COPY_AND_ASSIGN(SamplerThread); 603 }; 604 605 606 Mutex* SamplerThread::mutex_ = NULL; 607 SamplerThread* SamplerThread::instance_ = NULL; 608 609 610 // 611 // StackTracer implementation 612 // 613 DISABLE_ASAN void TickSample::Init(Isolate* isolate, 614 const RegisterState& regs) { 615 ASSERT(isolate->IsInitialized()); 616 pc = regs.pc; 617 state = isolate->current_vm_state(); 618 619 // Avoid collecting traces while doing GC. 620 if (state == GC) return; 621 622 Address js_entry_sp = isolate->js_entry_sp(); 623 if (js_entry_sp == 0) { 624 // Not executing JS now. 625 return; 626 } 627 628 ExternalCallbackScope* scope = isolate->external_callback_scope(); 629 Address handler = Isolate::handler(isolate->thread_local_top()); 630 // If there is a handler on top of the external callback scope then 631 // we have already entrered JavaScript again and the external callback 632 // is not the top function. 633 if (scope && scope->scope_address() < handler) { 634 external_callback = scope->callback(); 635 has_external_callback = true; 636 } else { 637 // Sample potential return address value for frameless invocation of 638 // stubs (we'll figure out later, if this value makes sense). 639 tos = Memory::Address_at(regs.sp); 640 has_external_callback = false; 641 } 642 643 SafeStackFrameIterator it(isolate, regs.fp, regs.sp, js_entry_sp); 644 top_frame_type = it.top_frame_type(); 645 int i = 0; 646 while (!it.done() && i < TickSample::kMaxFramesCount) { 647 stack[i++] = it.frame()->pc(); 648 it.Advance(); 649 } 650 frames_count = i; 651 } 652 653 654 void Sampler::SetUp() { 655 SamplerThread::SetUp(); 656 } 657 658 659 void Sampler::TearDown() { 660 SamplerThread::TearDown(); 661 } 662 663 664 Sampler::Sampler(Isolate* isolate, int interval) 665 : isolate_(isolate), 666 interval_(interval), 667 profiling_(false), 668 active_(false), 669 is_counting_samples_(false), 670 js_and_external_sample_count_(0) { 671 data_ = new PlatformData; 672 } 673 674 675 Sampler::~Sampler() { 676 ASSERT(!IsActive()); 677 delete data_; 678 } 679 680 681 void Sampler::Start() { 682 ASSERT(!IsActive()); 683 SetActive(true); 684 SamplerThread::AddActiveSampler(this); 685 } 686 687 688 void Sampler::Stop() { 689 ASSERT(IsActive()); 690 SamplerThread::RemoveActiveSampler(this); 691 SetActive(false); 692 } 693 694 695 void Sampler::SampleStack(const RegisterState& state) { 696 TickSample* sample = isolate_->cpu_profiler()->TickSampleEvent(); 697 TickSample sample_obj; 698 if (sample == NULL) sample = &sample_obj; 699 sample->Init(isolate_, state); 700 if (is_counting_samples_) { 701 if (sample->state == JS || sample->state == EXTERNAL) { 702 ++js_and_external_sample_count_; 703 } 704 } 705 Tick(sample); 706 } 707 708 } } // namespace v8::internal 709