| // Copyright 2013 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/profiler/sampler.h" |
| |
| #if V8_OS_POSIX && !V8_OS_CYGWIN |
| |
| #define USE_SIGNALS |
| |
| #include <errno.h> |
| #include <pthread.h> |
| #include <signal.h> |
| #include <sys/time.h> |
| |
| #if !V8_OS_QNX && !V8_OS_NACL && !V8_OS_AIX |
| #include <sys/syscall.h> // NOLINT |
| #endif |
| |
| #if V8_OS_MACOSX |
| #include <mach/mach.h> |
| // OpenBSD doesn't have <ucontext.h>. ucontext_t lives in <signal.h> |
| // and is a typedef for struct sigcontext. There is no uc_mcontext. |
| #elif(!V8_OS_ANDROID || defined(__BIONIC_HAVE_UCONTEXT_T)) && \ |
| !V8_OS_OPENBSD && !V8_OS_NACL |
| #include <ucontext.h> |
| #endif |
| |
| #include <unistd.h> |
| |
| // GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'. |
| // Old versions of the C library <signal.h> didn't define the type. |
| #if V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T) && \ |
| (defined(__arm__) || defined(__aarch64__)) && \ |
| !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT) |
| #include <asm/sigcontext.h> // NOLINT |
| #endif |
| |
| #elif V8_OS_WIN || V8_OS_CYGWIN |
| |
| #include "src/base/win32-headers.h" |
| |
| #endif |
| |
| #include "src/base/platform/platform.h" |
| #include "src/flags.h" |
| #include "src/frames-inl.h" |
| #include "src/log.h" |
| #include "src/profiler/cpu-profiler-inl.h" |
| #include "src/simulator.h" |
| #include "src/v8threads.h" |
| #include "src/vm-state-inl.h" |
| |
| |
| #if V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T) |
| |
| // Not all versions of Android's C library provide ucontext_t. |
| // Detect this and provide custom but compatible definitions. Note that these |
| // follow the GLibc naming convention to access register values from |
| // mcontext_t. |
| // |
| // See http://code.google.com/p/android/issues/detail?id=34784 |
| |
| #if defined(__arm__) |
| |
| typedef struct sigcontext mcontext_t; |
| |
| typedef struct ucontext { |
| uint32_t uc_flags; |
| struct ucontext* uc_link; |
| stack_t uc_stack; |
| mcontext_t uc_mcontext; |
| // Other fields are not used by V8, don't define them here. |
| } ucontext_t; |
| |
| #elif defined(__aarch64__) |
| |
| typedef struct sigcontext mcontext_t; |
| |
| typedef struct ucontext { |
| uint64_t uc_flags; |
| struct ucontext *uc_link; |
| stack_t uc_stack; |
| mcontext_t uc_mcontext; |
| // Other fields are not used by V8, don't define them here. |
| } ucontext_t; |
| |
| #elif defined(__mips__) |
| // MIPS version of sigcontext, for Android bionic. |
| typedef struct { |
| uint32_t regmask; |
| uint32_t status; |
| uint64_t pc; |
| uint64_t gregs[32]; |
| uint64_t fpregs[32]; |
| uint32_t acx; |
| uint32_t fpc_csr; |
| uint32_t fpc_eir; |
| uint32_t used_math; |
| uint32_t dsp; |
| uint64_t mdhi; |
| uint64_t mdlo; |
| uint32_t hi1; |
| uint32_t lo1; |
| uint32_t hi2; |
| uint32_t lo2; |
| uint32_t hi3; |
| uint32_t lo3; |
| } mcontext_t; |
| |
| typedef struct ucontext { |
| uint32_t uc_flags; |
| struct ucontext* uc_link; |
| stack_t uc_stack; |
| mcontext_t uc_mcontext; |
| // Other fields are not used by V8, don't define them here. |
| } ucontext_t; |
| |
| #elif defined(__i386__) |
| // x86 version for Android. |
| typedef struct { |
| uint32_t gregs[19]; |
| void* fpregs; |
| uint32_t oldmask; |
| uint32_t cr2; |
| } mcontext_t; |
| |
| typedef uint32_t kernel_sigset_t[2]; // x86 kernel uses 64-bit signal masks |
| typedef struct ucontext { |
| uint32_t uc_flags; |
| struct ucontext* uc_link; |
| stack_t uc_stack; |
| mcontext_t uc_mcontext; |
| // Other fields are not used by V8, don't define them here. |
| } ucontext_t; |
| enum { REG_EBP = 6, REG_ESP = 7, REG_EIP = 14 }; |
| |
| #elif defined(__x86_64__) |
| // x64 version for Android. |
| typedef struct { |
| uint64_t gregs[23]; |
| void* fpregs; |
| uint64_t __reserved1[8]; |
| } mcontext_t; |
| |
| typedef struct ucontext { |
| uint64_t uc_flags; |
| struct ucontext *uc_link; |
| stack_t uc_stack; |
| mcontext_t uc_mcontext; |
| // Other fields are not used by V8, don't define them here. |
| } ucontext_t; |
| enum { REG_RBP = 10, REG_RSP = 15, REG_RIP = 16 }; |
| #endif |
| |
| #endif // V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T) |
| |
| |
| namespace v8 { |
| namespace internal { |
| |
| namespace { |
| |
| class PlatformDataCommon : public Malloced { |
| public: |
| PlatformDataCommon() : profiled_thread_id_(ThreadId::Current()) {} |
| ThreadId profiled_thread_id() { return profiled_thread_id_; } |
| |
| protected: |
| ~PlatformDataCommon() {} |
| |
| private: |
| ThreadId profiled_thread_id_; |
| }; |
| |
| |
| bool IsSamePage(byte* ptr1, byte* ptr2) { |
| const uint32_t kPageSize = 4096; |
| uintptr_t mask = ~static_cast<uintptr_t>(kPageSize - 1); |
| return (reinterpret_cast<uintptr_t>(ptr1) & mask) == |
| (reinterpret_cast<uintptr_t>(ptr2) & mask); |
| } |
| |
| |
| // Check if the code at specified address could potentially be a |
| // frame setup code. |
| bool IsNoFrameRegion(Address address) { |
| struct Pattern { |
| int bytes_count; |
| byte bytes[8]; |
| int offsets[4]; |
| }; |
| byte* pc = reinterpret_cast<byte*>(address); |
| static Pattern patterns[] = { |
| #if V8_HOST_ARCH_IA32 |
| // push %ebp |
| // mov %esp,%ebp |
| {3, {0x55, 0x89, 0xe5}, {0, 1, -1}}, |
| // pop %ebp |
| // ret N |
| {2, {0x5d, 0xc2}, {0, 1, -1}}, |
| // pop %ebp |
| // ret |
| {2, {0x5d, 0xc3}, {0, 1, -1}}, |
| #elif V8_HOST_ARCH_X64 |
| // pushq %rbp |
| // movq %rsp,%rbp |
| {4, {0x55, 0x48, 0x89, 0xe5}, {0, 1, -1}}, |
| // popq %rbp |
| // ret N |
| {2, {0x5d, 0xc2}, {0, 1, -1}}, |
| // popq %rbp |
| // ret |
| {2, {0x5d, 0xc3}, {0, 1, -1}}, |
| #endif |
| {0, {}, {}} |
| }; |
| for (Pattern* pattern = patterns; pattern->bytes_count; ++pattern) { |
| for (int* offset_ptr = pattern->offsets; *offset_ptr != -1; ++offset_ptr) { |
| int offset = *offset_ptr; |
| if (!offset || IsSamePage(pc, pc - offset)) { |
| MSAN_MEMORY_IS_INITIALIZED(pc - offset, pattern->bytes_count); |
| if (!memcmp(pc - offset, pattern->bytes, pattern->bytes_count)) |
| return true; |
| } else { |
| // It is not safe to examine bytes on another page as it might not be |
| // allocated thus causing a SEGFAULT. |
| // Check the pattern part that's on the same page and |
| // pessimistically assume it could be the entire pattern match. |
| MSAN_MEMORY_IS_INITIALIZED(pc, pattern->bytes_count - offset); |
| if (!memcmp(pc, pattern->bytes + offset, pattern->bytes_count - offset)) |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| } // namespace |
| |
| #if defined(USE_SIGNALS) |
| |
| class Sampler::PlatformData : public PlatformDataCommon { |
| public: |
| PlatformData() : vm_tid_(pthread_self()) {} |
| pthread_t vm_tid() const { return vm_tid_; } |
| |
| private: |
| pthread_t vm_tid_; |
| }; |
| |
| #elif V8_OS_WIN || V8_OS_CYGWIN |
| |
| // ---------------------------------------------------------------------------- |
| // Win32 profiler support. On Cygwin we use the same sampler implementation as |
| // on Win32. |
| |
| class Sampler::PlatformData : public PlatformDataCommon { |
| public: |
| // Get a handle to the calling thread. This is the thread that we are |
| // going to profile. We need to make a copy of the handle because we are |
| // going to use it in the sampler thread. Using GetThreadHandle() will |
| // not work in this case. We're using OpenThread because DuplicateHandle |
| // for some reason doesn't work in Chrome's sandbox. |
| PlatformData() |
| : profiled_thread_(OpenThread(THREAD_GET_CONTEXT | |
| THREAD_SUSPEND_RESUME | |
| THREAD_QUERY_INFORMATION, |
| false, |
| GetCurrentThreadId())) {} |
| |
| ~PlatformData() { |
| if (profiled_thread_ != NULL) { |
| CloseHandle(profiled_thread_); |
| profiled_thread_ = NULL; |
| } |
| } |
| |
| HANDLE profiled_thread() { return profiled_thread_; } |
| |
| private: |
| HANDLE profiled_thread_; |
| }; |
| #endif |
| |
| |
| #if defined(USE_SIMULATOR) |
| class SimulatorHelper { |
| public: |
| inline bool Init(Isolate* isolate) { |
| simulator_ = isolate->thread_local_top()->simulator_; |
| // Check if there is active simulator. |
| return simulator_ != NULL; |
| } |
| |
| inline void FillRegisters(v8::RegisterState* state) { |
| #if V8_TARGET_ARCH_ARM |
| if (!simulator_->has_bad_pc()) { |
| state->pc = reinterpret_cast<Address>(simulator_->get_pc()); |
| } |
| state->sp = reinterpret_cast<Address>(simulator_->get_register( |
| Simulator::sp)); |
| state->fp = reinterpret_cast<Address>(simulator_->get_register( |
| Simulator::r11)); |
| #elif V8_TARGET_ARCH_ARM64 |
| if (simulator_->sp() == 0 || simulator_->fp() == 0) { |
| // It's possible that the simulator is interrupted while it is updating |
| // the sp or fp register. ARM64 simulator does this in two steps: |
| // first setting it to zero and then setting it to a new value. |
| // Bailout if sp/fp doesn't contain the new value. |
| // |
| // FIXME: The above doesn't really solve the issue. |
| // If a 64-bit target is executed on a 32-bit host even the final |
| // write is non-atomic, so it might obtain a half of the result. |
| // Moreover as long as the register set code uses memcpy (as of now), |
| // it is not guaranteed to be atomic even when both host and target |
| // are of same bitness. |
| return; |
| } |
| state->pc = reinterpret_cast<Address>(simulator_->pc()); |
| state->sp = reinterpret_cast<Address>(simulator_->sp()); |
| state->fp = reinterpret_cast<Address>(simulator_->fp()); |
| #elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 |
| if (!simulator_->has_bad_pc()) { |
| state->pc = reinterpret_cast<Address>(simulator_->get_pc()); |
| } |
| state->sp = reinterpret_cast<Address>(simulator_->get_register( |
| Simulator::sp)); |
| state->fp = reinterpret_cast<Address>(simulator_->get_register( |
| Simulator::fp)); |
| #elif V8_TARGET_ARCH_PPC |
| if (!simulator_->has_bad_pc()) { |
| state->pc = reinterpret_cast<Address>(simulator_->get_pc()); |
| } |
| state->sp = |
| reinterpret_cast<Address>(simulator_->get_register(Simulator::sp)); |
| state->fp = |
| reinterpret_cast<Address>(simulator_->get_register(Simulator::fp)); |
| #endif |
| } |
| |
| private: |
| Simulator* simulator_; |
| }; |
| #endif // USE_SIMULATOR |
| |
| |
| #if defined(USE_SIGNALS) |
| |
| class SignalHandler : public AllStatic { |
| public: |
| static void SetUp() { if (!mutex_) mutex_ = new base::Mutex(); } |
| static void TearDown() { delete mutex_; mutex_ = NULL; } |
| |
| static void IncreaseSamplerCount() { |
| base::LockGuard<base::Mutex> lock_guard(mutex_); |
| if (++client_count_ == 1) Install(); |
| } |
| |
| static void DecreaseSamplerCount() { |
| base::LockGuard<base::Mutex> lock_guard(mutex_); |
| if (--client_count_ == 0) Restore(); |
| } |
| |
| static bool Installed() { |
| return signal_handler_installed_; |
| } |
| |
| private: |
| static void Install() { |
| #if !V8_OS_NACL |
| struct sigaction sa; |
| sa.sa_sigaction = &HandleProfilerSignal; |
| sigemptyset(&sa.sa_mask); |
| #if V8_OS_QNX |
| sa.sa_flags = SA_SIGINFO; |
| #else |
| sa.sa_flags = SA_RESTART | SA_SIGINFO; |
| #endif |
| signal_handler_installed_ = |
| (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0); |
| #endif |
| } |
| |
| static void Restore() { |
| #if !V8_OS_NACL |
| if (signal_handler_installed_) { |
| sigaction(SIGPROF, &old_signal_handler_, 0); |
| signal_handler_installed_ = false; |
| } |
| #endif |
| } |
| |
| #if !V8_OS_NACL |
| static void HandleProfilerSignal(int signal, siginfo_t* info, void* context); |
| #endif |
| // Protects the process wide state below. |
| static base::Mutex* mutex_; |
| static int client_count_; |
| static bool signal_handler_installed_; |
| static struct sigaction old_signal_handler_; |
| }; |
| |
| |
| base::Mutex* SignalHandler::mutex_ = NULL; |
| int SignalHandler::client_count_ = 0; |
| struct sigaction SignalHandler::old_signal_handler_; |
| bool SignalHandler::signal_handler_installed_ = false; |
| |
| |
| // As Native Client does not support signal handling, profiling is disabled. |
| #if !V8_OS_NACL |
| void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info, |
| void* context) { |
| USE(info); |
| if (signal != SIGPROF) return; |
| Isolate* isolate = Isolate::UnsafeCurrent(); |
| if (isolate == NULL || !isolate->IsInUse()) { |
| // We require a fully initialized and entered isolate. |
| return; |
| } |
| if (v8::Locker::IsActive() && |
| !isolate->thread_manager()->IsLockedByCurrentThread()) { |
| return; |
| } |
| |
| Sampler* sampler = isolate->logger()->sampler(); |
| if (sampler == NULL) return; |
| |
| v8::RegisterState state; |
| |
| #if defined(USE_SIMULATOR) |
| SimulatorHelper helper; |
| if (!helper.Init(isolate)) return; |
| helper.FillRegisters(&state); |
| // It possible that the simulator is interrupted while it is updating |
| // the sp or fp register. ARM64 simulator does this in two steps: |
| // first setting it to zero and then setting it to the new value. |
| // Bailout if sp/fp doesn't contain the new value. |
| if (state.sp == 0 || state.fp == 0) return; |
| #else |
| // Extracting the sample from the context is extremely machine dependent. |
| ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context); |
| #if !(V8_OS_OPENBSD || (V8_OS_LINUX && V8_HOST_ARCH_PPC)) |
| mcontext_t& mcontext = ucontext->uc_mcontext; |
| #endif |
| #if V8_OS_LINUX |
| #if V8_HOST_ARCH_IA32 |
| state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]); |
| #elif V8_HOST_ARCH_X64 |
| state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]); |
| #elif V8_HOST_ARCH_ARM |
| #if V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4) |
| // Old GLibc ARM versions used a gregs[] array to access the register |
| // values from mcontext_t. |
| state.pc = reinterpret_cast<Address>(mcontext.gregs[R15]); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[R13]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[R11]); |
| #else |
| state.pc = reinterpret_cast<Address>(mcontext.arm_pc); |
| state.sp = reinterpret_cast<Address>(mcontext.arm_sp); |
| state.fp = reinterpret_cast<Address>(mcontext.arm_fp); |
| #endif // V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4) |
| #elif V8_HOST_ARCH_ARM64 |
| state.pc = reinterpret_cast<Address>(mcontext.pc); |
| state.sp = reinterpret_cast<Address>(mcontext.sp); |
| // FP is an alias for x29. |
| state.fp = reinterpret_cast<Address>(mcontext.regs[29]); |
| #elif V8_HOST_ARCH_MIPS |
| state.pc = reinterpret_cast<Address>(mcontext.pc); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[29]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[30]); |
| #elif V8_HOST_ARCH_MIPS64 |
| state.pc = reinterpret_cast<Address>(mcontext.pc); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[29]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[30]); |
| #elif V8_HOST_ARCH_PPC |
| state.pc = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->nip); |
| state.sp = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->gpr[PT_R1]); |
| state.fp = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->gpr[PT_R31]); |
| #endif // V8_HOST_ARCH_* |
| #elif V8_OS_MACOSX |
| #if V8_HOST_ARCH_X64 |
| #if __DARWIN_UNIX03 |
| state.pc = reinterpret_cast<Address>(mcontext->__ss.__rip); |
| state.sp = reinterpret_cast<Address>(mcontext->__ss.__rsp); |
| state.fp = reinterpret_cast<Address>(mcontext->__ss.__rbp); |
| #else // !__DARWIN_UNIX03 |
| state.pc = reinterpret_cast<Address>(mcontext->ss.rip); |
| state.sp = reinterpret_cast<Address>(mcontext->ss.rsp); |
| state.fp = reinterpret_cast<Address>(mcontext->ss.rbp); |
| #endif // __DARWIN_UNIX03 |
| #elif V8_HOST_ARCH_IA32 |
| #if __DARWIN_UNIX03 |
| state.pc = reinterpret_cast<Address>(mcontext->__ss.__eip); |
| state.sp = reinterpret_cast<Address>(mcontext->__ss.__esp); |
| state.fp = reinterpret_cast<Address>(mcontext->__ss.__ebp); |
| #else // !__DARWIN_UNIX03 |
| state.pc = reinterpret_cast<Address>(mcontext->ss.eip); |
| state.sp = reinterpret_cast<Address>(mcontext->ss.esp); |
| state.fp = reinterpret_cast<Address>(mcontext->ss.ebp); |
| #endif // __DARWIN_UNIX03 |
| #endif // V8_HOST_ARCH_IA32 |
| #elif V8_OS_FREEBSD |
| #if V8_HOST_ARCH_IA32 |
| state.pc = reinterpret_cast<Address>(mcontext.mc_eip); |
| state.sp = reinterpret_cast<Address>(mcontext.mc_esp); |
| state.fp = reinterpret_cast<Address>(mcontext.mc_ebp); |
| #elif V8_HOST_ARCH_X64 |
| state.pc = reinterpret_cast<Address>(mcontext.mc_rip); |
| state.sp = reinterpret_cast<Address>(mcontext.mc_rsp); |
| state.fp = reinterpret_cast<Address>(mcontext.mc_rbp); |
| #elif V8_HOST_ARCH_ARM |
| state.pc = reinterpret_cast<Address>(mcontext.mc_r15); |
| state.sp = reinterpret_cast<Address>(mcontext.mc_r13); |
| state.fp = reinterpret_cast<Address>(mcontext.mc_r11); |
| #endif // V8_HOST_ARCH_* |
| #elif V8_OS_NETBSD |
| #if V8_HOST_ARCH_IA32 |
| state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_EIP]); |
| state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_ESP]); |
| state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_EBP]); |
| #elif V8_HOST_ARCH_X64 |
| state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_RIP]); |
| state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RSP]); |
| state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RBP]); |
| #endif // V8_HOST_ARCH_* |
| #elif V8_OS_OPENBSD |
| #if V8_HOST_ARCH_IA32 |
| state.pc = reinterpret_cast<Address>(ucontext->sc_eip); |
| state.sp = reinterpret_cast<Address>(ucontext->sc_esp); |
| state.fp = reinterpret_cast<Address>(ucontext->sc_ebp); |
| #elif V8_HOST_ARCH_X64 |
| state.pc = reinterpret_cast<Address>(ucontext->sc_rip); |
| state.sp = reinterpret_cast<Address>(ucontext->sc_rsp); |
| state.fp = reinterpret_cast<Address>(ucontext->sc_rbp); |
| #endif // V8_HOST_ARCH_* |
| #elif V8_OS_SOLARIS |
| state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_PC]); |
| state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_SP]); |
| state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_FP]); |
| #elif V8_OS_QNX |
| #if V8_HOST_ARCH_IA32 |
| state.pc = reinterpret_cast<Address>(mcontext.cpu.eip); |
| state.sp = reinterpret_cast<Address>(mcontext.cpu.esp); |
| state.fp = reinterpret_cast<Address>(mcontext.cpu.ebp); |
| #elif V8_HOST_ARCH_ARM |
| state.pc = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_PC]); |
| state.sp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_SP]); |
| state.fp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_FP]); |
| #endif // V8_HOST_ARCH_* |
| #elif V8_OS_AIX |
| state.pc = reinterpret_cast<Address>(mcontext.jmp_context.iar); |
| state.sp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[1]); |
| state.fp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[31]); |
| #endif // V8_OS_AIX |
| #endif // USE_SIMULATOR |
| sampler->SampleStack(state); |
| } |
| #endif // V8_OS_NACL |
| |
| #endif |
| |
| |
| class SamplerThread : public base::Thread { |
| public: |
| static const int kSamplerThreadStackSize = 64 * KB; |
| |
| explicit SamplerThread(int interval) |
| : Thread(base::Thread::Options("SamplerThread", kSamplerThreadStackSize)), |
| interval_(interval) {} |
| |
| static void SetUp() { if (!mutex_) mutex_ = new base::Mutex(); } |
| static void TearDown() { delete mutex_; mutex_ = NULL; } |
| |
| static void AddActiveSampler(Sampler* sampler) { |
| bool need_to_start = false; |
| base::LockGuard<base::Mutex> lock_guard(mutex_); |
| if (instance_ == NULL) { |
| // Start a thread that will send SIGPROF signal to VM threads, |
| // when CPU profiling will be enabled. |
| instance_ = new SamplerThread(sampler->interval()); |
| need_to_start = true; |
| } |
| |
| DCHECK(sampler->IsActive()); |
| DCHECK(!instance_->active_samplers_.Contains(sampler)); |
| DCHECK(instance_->interval_ == sampler->interval()); |
| instance_->active_samplers_.Add(sampler); |
| |
| if (need_to_start) instance_->StartSynchronously(); |
| } |
| |
| static void RemoveActiveSampler(Sampler* sampler) { |
| SamplerThread* instance_to_remove = NULL; |
| { |
| base::LockGuard<base::Mutex> lock_guard(mutex_); |
| |
| DCHECK(sampler->IsActive()); |
| bool removed = instance_->active_samplers_.RemoveElement(sampler); |
| DCHECK(removed); |
| USE(removed); |
| |
| // We cannot delete the instance immediately as we need to Join() the |
| // thread but we are holding mutex_ and the thread may try to acquire it. |
| if (instance_->active_samplers_.is_empty()) { |
| instance_to_remove = instance_; |
| instance_ = NULL; |
| } |
| } |
| |
| if (!instance_to_remove) return; |
| instance_to_remove->Join(); |
| delete instance_to_remove; |
| } |
| |
| // Implement Thread::Run(). |
| virtual void Run() { |
| while (true) { |
| { |
| base::LockGuard<base::Mutex> lock_guard(mutex_); |
| if (active_samplers_.is_empty()) break; |
| // When CPU profiling is enabled both JavaScript and C++ code is |
| // profiled. We must not suspend. |
| for (int i = 0; i < active_samplers_.length(); ++i) { |
| Sampler* sampler = active_samplers_.at(i); |
| if (!sampler->IsProfiling()) continue; |
| sampler->DoSample(); |
| } |
| } |
| base::OS::Sleep(base::TimeDelta::FromMilliseconds(interval_)); |
| } |
| } |
| |
| private: |
| // Protects the process wide state below. |
| static base::Mutex* mutex_; |
| static SamplerThread* instance_; |
| |
| const int interval_; |
| List<Sampler*> active_samplers_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SamplerThread); |
| }; |
| |
| |
| base::Mutex* SamplerThread::mutex_ = NULL; |
| SamplerThread* SamplerThread::instance_ = NULL; |
| |
| |
| // |
| // StackTracer implementation |
| // |
| DISABLE_ASAN void TickSample::Init(Isolate* isolate, |
| const v8::RegisterState& regs, |
| RecordCEntryFrame record_c_entry_frame) { |
| timestamp = base::TimeTicks::HighResolutionNow(); |
| pc = reinterpret_cast<Address>(regs.pc); |
| state = isolate->current_vm_state(); |
| |
| // Avoid collecting traces while doing GC. |
| if (state == GC) return; |
| |
| Address js_entry_sp = isolate->js_entry_sp(); |
| if (js_entry_sp == 0) return; // Not executing JS now. |
| |
| if (pc && IsNoFrameRegion(pc)) { |
| pc = 0; |
| return; |
| } |
| |
| ExternalCallbackScope* scope = isolate->external_callback_scope(); |
| Address handler = Isolate::handler(isolate->thread_local_top()); |
| // If there is a handler on top of the external callback scope then |
| // we have already entrered JavaScript again and the external callback |
| // is not the top function. |
| if (scope && scope->scope_address() < handler) { |
| external_callback = scope->callback(); |
| has_external_callback = true; |
| } else { |
| // sp register may point at an arbitrary place in memory, make |
| // sure MSAN doesn't complain about it. |
| MSAN_MEMORY_IS_INITIALIZED(regs.sp, sizeof(Address)); |
| // Sample potential return address value for frameless invocation of |
| // stubs (we'll figure out later, if this value makes sense). |
| tos = Memory::Address_at(reinterpret_cast<Address>(regs.sp)); |
| has_external_callback = false; |
| } |
| |
| SafeStackFrameIterator it(isolate, reinterpret_cast<Address>(regs.fp), |
| reinterpret_cast<Address>(regs.sp), js_entry_sp); |
| top_frame_type = it.top_frame_type(); |
| |
| SampleInfo info; |
| GetStackSample(isolate, regs, record_c_entry_frame, |
| reinterpret_cast<void**>(&stack[0]), kMaxFramesCount, &info); |
| frames_count = static_cast<unsigned>(info.frames_count); |
| } |
| |
| |
| void TickSample::GetStackSample(Isolate* isolate, const v8::RegisterState& regs, |
| RecordCEntryFrame record_c_entry_frame, |
| void** frames, size_t frames_limit, |
| v8::SampleInfo* sample_info) { |
| sample_info->frames_count = 0; |
| sample_info->vm_state = isolate->current_vm_state(); |
| if (sample_info->vm_state == GC) return; |
| |
| Address js_entry_sp = isolate->js_entry_sp(); |
| if (js_entry_sp == 0) return; // Not executing JS now. |
| |
| SafeStackFrameIterator it(isolate, reinterpret_cast<Address>(regs.fp), |
| reinterpret_cast<Address>(regs.sp), js_entry_sp); |
| size_t i = 0; |
| if (record_c_entry_frame == kIncludeCEntryFrame && !it.done() && |
| it.top_frame_type() == StackFrame::EXIT) { |
| frames[i++] = isolate->c_function(); |
| } |
| while (!it.done() && i < frames_limit) { |
| frames[i++] = it.frame()->pc(); |
| it.Advance(); |
| } |
| sample_info->frames_count = i; |
| } |
| |
| |
| void Sampler::SetUp() { |
| #if defined(USE_SIGNALS) |
| SignalHandler::SetUp(); |
| #endif |
| SamplerThread::SetUp(); |
| } |
| |
| |
| void Sampler::TearDown() { |
| SamplerThread::TearDown(); |
| #if defined(USE_SIGNALS) |
| SignalHandler::TearDown(); |
| #endif |
| } |
| |
| |
| Sampler::Sampler(Isolate* isolate, int interval) |
| : isolate_(isolate), |
| interval_(interval), |
| profiling_(false), |
| has_processing_thread_(false), |
| active_(false), |
| is_counting_samples_(false), |
| js_and_external_sample_count_(0) { |
| data_ = new PlatformData; |
| } |
| |
| |
| Sampler::~Sampler() { |
| DCHECK(!IsActive()); |
| delete data_; |
| } |
| |
| |
| void Sampler::Start() { |
| DCHECK(!IsActive()); |
| SetActive(true); |
| SamplerThread::AddActiveSampler(this); |
| } |
| |
| |
| void Sampler::Stop() { |
| DCHECK(IsActive()); |
| SamplerThread::RemoveActiveSampler(this); |
| SetActive(false); |
| } |
| |
| |
| void Sampler::IncreaseProfilingDepth() { |
| base::NoBarrier_AtomicIncrement(&profiling_, 1); |
| #if defined(USE_SIGNALS) |
| SignalHandler::IncreaseSamplerCount(); |
| #endif |
| } |
| |
| |
| void Sampler::DecreaseProfilingDepth() { |
| #if defined(USE_SIGNALS) |
| SignalHandler::DecreaseSamplerCount(); |
| #endif |
| base::NoBarrier_AtomicIncrement(&profiling_, -1); |
| } |
| |
| |
| void Sampler::SampleStack(const v8::RegisterState& state) { |
| TickSample* sample = isolate_->cpu_profiler()->StartTickSample(); |
| TickSample sample_obj; |
| if (sample == NULL) sample = &sample_obj; |
| sample->Init(isolate_, state, TickSample::kIncludeCEntryFrame); |
| if (is_counting_samples_) { |
| if (sample->state == JS || sample->state == EXTERNAL) { |
| ++js_and_external_sample_count_; |
| } |
| } |
| Tick(sample); |
| if (sample != &sample_obj) { |
| isolate_->cpu_profiler()->FinishTickSample(); |
| } |
| } |
| |
| |
| #if defined(USE_SIGNALS) |
| |
| void Sampler::DoSample() { |
| if (!SignalHandler::Installed()) return; |
| pthread_kill(platform_data()->vm_tid(), SIGPROF); |
| } |
| |
| #elif V8_OS_WIN || V8_OS_CYGWIN |
| |
| void Sampler::DoSample() { |
| HANDLE profiled_thread = platform_data()->profiled_thread(); |
| if (profiled_thread == NULL) return; |
| |
| #if defined(USE_SIMULATOR) |
| SimulatorHelper helper; |
| if (!helper.Init(isolate())) return; |
| #endif |
| |
| const DWORD kSuspendFailed = static_cast<DWORD>(-1); |
| if (SuspendThread(profiled_thread) == kSuspendFailed) return; |
| |
| // Context used for sampling the register state of the profiled thread. |
| CONTEXT context; |
| memset(&context, 0, sizeof(context)); |
| context.ContextFlags = CONTEXT_FULL; |
| if (GetThreadContext(profiled_thread, &context) != 0) { |
| v8::RegisterState state; |
| #if defined(USE_SIMULATOR) |
| helper.FillRegisters(&state); |
| #else |
| #if V8_HOST_ARCH_X64 |
| state.pc = reinterpret_cast<Address>(context.Rip); |
| state.sp = reinterpret_cast<Address>(context.Rsp); |
| state.fp = reinterpret_cast<Address>(context.Rbp); |
| #else |
| state.pc = reinterpret_cast<Address>(context.Eip); |
| state.sp = reinterpret_cast<Address>(context.Esp); |
| state.fp = reinterpret_cast<Address>(context.Ebp); |
| #endif |
| #endif // USE_SIMULATOR |
| SampleStack(state); |
| } |
| ResumeThread(profiled_thread); |
| } |
| |
| #endif // USE_SIGNALS |
| |
| |
| } // namespace internal |
| } // namespace v8 |