Revert of Create libsampler as V8 sampler library.

src/libsampler/v8-sampler.cc

Index: src/libsampler/v8-sampler.cc
diff --git a/src/libsampler/v8-sampler.cc b/src/libsampler/v8-sampler.cc
deleted file mode 100644
index a7798b5b8ee89e9c3a9e0d53def463987d383c3e..0000000000000000000000000000000000000000
--- a/src/libsampler/v8-sampler.cc
+++ /dev/null
@@ -1,678 +0,0 @@
-// Copyright 2016 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/libsampler/v8-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 <algorithm>
-#include <vector>
-#include <map>
-
-#include "src/base/atomic-utils.h"
-#include "src/base/platform/platform.h"
-#include "src/libsampler/hashmap.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 sampler {
-
-namespace {
-
-#if defined(USE_SIGNALS)
-typedef std::vector<Sampler*> SamplerList;
-typedef SamplerList::iterator SamplerListIterator;
-
-class AtomicGuard {
- public:
-  explicit AtomicGuard(base::AtomicValue<int>* atomic, bool is_block = true)
-      : atomic_(atomic),
-        is_success_(false) {
-    do {
-      // Use Acquire_Load to gain mutual exclusion.
-      USE(atomic_->Value());
-      is_success_ = atomic_->TrySetValue(0, 1);
-    } while (is_block && !is_success_);
-  }
-
-  bool is_success() { return is_success_; }
-
-  ~AtomicGuard() {
-    if (is_success_) {
-      atomic_->SetValue(0);
-    }
-    atomic_ = NULL;
-  }
-
- private:
-  base::AtomicValue<int>* atomic_;
-  bool is_success_;
-};
-
-
-// Returns key for hash map.
-void* ThreadKey(pthread_t thread_id) {
-  return reinterpret_cast<void*>(thread_id);
-}
-
-
-// Returns hash value for hash map.
-uint32_t ThreadHash(pthread_t thread_id) {
-#if V8_OS_MACOSX
-  return static_cast<uint32_t>(reinterpret_cast<intptr_t>(thread_id));
-#else
-  return static_cast<uint32_t>(thread_id);
-#endif
-}
-
-#endif  // USE_SIGNALS
-
-}  // namespace
-
-#if defined(USE_SIGNALS)
-
-class Sampler::PlatformData {
- public:
-  PlatformData() : vm_tid_(pthread_self()) {}
-  pthread_t vm_tid() const { return vm_tid_; }
-
- private:
-  pthread_t vm_tid_;
-};
-
-
-class SamplerManager {
- public:
-  static void AddSampler(Sampler* sampler) {
-    AtomicGuard atomic_guard(&samplers_access_counter_);
-    DCHECK(sampler->IsActive() || !sampler->IsRegistered());
-    // Add sampler into map if needed.
-    pthread_t thread_id = sampler->platform_data()->vm_tid();
-    HashMap::Entry* entry =
-        sampler_map_.Pointer()->LookupOrInsert(ThreadKey(thread_id),
-                                               ThreadHash(thread_id));
-    DCHECK(entry != NULL);
-    if (entry->value == NULL) {
-      SamplerList* samplers = new SamplerList();
-      samplers->push_back(sampler);
-      entry->value = samplers;
-    } else {
-      SamplerList* samplers = reinterpret_cast<SamplerList*>(entry->value);
-      bool exists = false;
-      for (SamplerListIterator iter = samplers->begin();
-           iter != samplers->end(); ++iter) {
-        if (*iter == sampler) {
-          exists = true;
-          break;
-        }
-      }
-      if (!exists) {
-        samplers->push_back(sampler);
-      }
-    }
-  }
-
-  static void RemoveSampler(Sampler* sampler) {
-    AtomicGuard atomic_guard(&samplers_access_counter_);
-    DCHECK(sampler->IsActive() || sampler->IsRegistered());
-    // Remove sampler from map.
-    pthread_t thread_id = sampler->platform_data()->vm_tid();
-    void* thread_key = ThreadKey(thread_id);
-    uint32_t thread_hash = ThreadHash(thread_id);
-    HashMap::Entry* entry = sampler_map_.Get().Lookup(thread_key, thread_hash);
-    DCHECK(entry != NULL);
-    SamplerList* samplers = reinterpret_cast<SamplerList*>(entry->value);
-    for (SamplerListIterator iter = samplers->begin(); iter != samplers->end();
-         ++iter) {
-      if (*iter == sampler) {
-        samplers->erase(iter);
-        break;
-      }
-    }
-    if (samplers->empty()) {
-      sampler_map_.Pointer()->Remove(thread_key, thread_hash);
-      delete samplers;
-    }
-  }
-
- private:
-  struct HashMapCreateTrait {
-    static void Construct(HashMap* allocated_ptr) {
-      new (allocated_ptr) HashMap(HashMap::PointersMatch);
-    }
-  };
-  friend class SignalHandler;
-  static base::LazyInstance<HashMap, HashMapCreateTrait>::type
-      sampler_map_;
-  static base::AtomicValue<int> samplers_access_counter_;
-};
-
-base::LazyInstance<HashMap, SamplerManager::HashMapCreateTrait>::type
-    SamplerManager::sampler_map_ = LAZY_INSTANCE_INITIALIZER;
-base::AtomicValue<int> SamplerManager::samplers_access_counter_(0);
-
-
-#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:
-  // 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  // USE_SIGNALS
-
-
-#if defined(USE_SIGNALS)
-class SignalHandler {
- 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  // !V8_OS_NACL
-  }
-
-  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 FillRegisterState(void* context, RegisterState* regs);
-  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;
-  AtomicGuard atomic_guard(&SamplerManager::samplers_access_counter_, false);
-  if (!atomic_guard.is_success()) return;
-  pthread_t thread_id = pthread_self();
-  HashMap::Entry* entry =
-      SamplerManager::sampler_map_.Pointer()->Lookup(ThreadKey(thread_id),
-                                                     ThreadHash(thread_id));
-  if (entry == NULL) return;
-  SamplerList* samplers = reinterpret_cast<SamplerList*>(entry->value);
-
-  v8::RegisterState state;
-  FillRegisterState(context, &state);
-
-  for (int i = 0; i < samplers->size(); ++i) {
-    Sampler* sampler = (*samplers)[i];
-    Isolate* isolate = sampler->isolate();
-
-    // We require a fully initialized and entered isolate.
-    if (isolate == NULL || !isolate->IsInUse()) return;
-
-    if (v8::Locker::IsActive() && !Locker::IsLocked(isolate)) return;
-
-    sampler->SampleStack(state);
-  }
-}
-
-void SignalHandler::FillRegisterState(void* context, RegisterState* state) {
-  // 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 || V8_HOST_ARCH_S390)))
-  mcontext_t& mcontext = ucontext->uc_mcontext;
-#endif
-#if V8_OS_LINUX
-#if V8_HOST_ARCH_IA32
-  state->pc = reinterpret_cast<void*>(mcontext.gregs[REG_EIP]);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[REG_ESP]);
-  state->fp = reinterpret_cast<void*>(mcontext.gregs[REG_EBP]);
-#elif V8_HOST_ARCH_X64
-  state->pc = reinterpret_cast<void*>(mcontext.gregs[REG_RIP]);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[REG_RSP]);
-  state->fp = reinterpret_cast<void*>(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<void*>(mcontext.gregs[R15]);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[R13]);
-  state->fp = reinterpret_cast<void*>(mcontext.gregs[R11]);
-#else
-  state->pc = reinterpret_cast<void*>(mcontext.arm_pc);
-  state->sp = reinterpret_cast<void*>(mcontext.arm_sp);
-  state->fp = reinterpret_cast<void*>(mcontext.arm_fp);
-#endif  // V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4)
-#elif V8_HOST_ARCH_ARM64
-  state->pc = reinterpret_cast<void*>(mcontext.pc);
-  state->sp = reinterpret_cast<void*>(mcontext.sp);
-  // FP is an alias for x29.
-  state->fp = reinterpret_cast<void*>(mcontext.regs[29]);
-#elif V8_HOST_ARCH_MIPS
-  state->pc = reinterpret_cast<void*>(mcontext.pc);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[29]);
-  state->fp = reinterpret_cast<void*>(mcontext.gregs[30]);
-#elif V8_HOST_ARCH_MIPS64
-  state->pc = reinterpret_cast<void*>(mcontext.pc);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[29]);
-  state->fp = reinterpret_cast<void*>(mcontext.gregs[30]);
-#elif V8_HOST_ARCH_PPC
-  state->pc = reinterpret_cast<void*>(ucontext->uc_mcontext.regs->nip);
-  state->sp =
-      reinterpret_cast<void*>(ucontext->uc_mcontext.regs->gpr[PT_R1]);
-  state->fp =
-      reinterpret_cast<void*>(ucontext->uc_mcontext.regs->gpr[PT_R31]);
-#elif V8_HOST_ARCH_S390
-#if V8_TARGET_ARCH_32_BIT
-  // 31-bit target will have bit 0 (MSB) of the PSW set to denote addressing
-  // mode.  This bit needs to be masked out to resolve actual address.
-  state->pc =
-      reinterpret_cast<void*>(ucontext->uc_mcontext.psw.addr & 0x7FFFFFFF);
-#else
-  state->pc = reinterpret_cast<void*>(ucontext->uc_mcontext.psw.addr);
-#endif  // V8_TARGET_ARCH_32_BIT
-  state->sp = reinterpret_cast<void*>(ucontext->uc_mcontext.gregs[15]);
-  state->fp = reinterpret_cast<void*>(ucontext->uc_mcontext.gregs[11]);
-#endif  // V8_HOST_ARCH_*
-#elif V8_OS_MACOSX
-#if V8_HOST_ARCH_X64
-#if __DARWIN_UNIX03
-  state->pc = reinterpret_cast<void*>(mcontext->__ss.__rip);
-  state->sp = reinterpret_cast<void*>(mcontext->__ss.__rsp);
-  state->fp = reinterpret_cast<void*>(mcontext->__ss.__rbp);
-#else  // !__DARWIN_UNIX03
-  state->pc = reinterpret_cast<void*>(mcontext->ss.rip);
-  state->sp = reinterpret_cast<void*>(mcontext->ss.rsp);
-  state->fp = reinterpret_cast<void*>(mcontext->ss.rbp);
-#endif  // __DARWIN_UNIX03
-#elif V8_HOST_ARCH_IA32
-#if __DARWIN_UNIX03
-  state->pc = reinterpret_cast<void*>(mcontext->__ss.__eip);
-  state->sp = reinterpret_cast<void*>(mcontext->__ss.__esp);
-  state->fp = reinterpret_cast<void*>(mcontext->__ss.__ebp);
-#else  // !__DARWIN_UNIX03
-  state->pc = reinterpret_cast<void*>(mcontext->ss.eip);
-  state->sp = reinterpret_cast<void*>(mcontext->ss.esp);
-  state->fp = reinterpret_cast<void*>(mcontext->ss.ebp);
-#endif  // __DARWIN_UNIX03
-#endif  // V8_HOST_ARCH_IA32
-#elif V8_OS_FREEBSD
-#if V8_HOST_ARCH_IA32
-  state->pc = reinterpret_cast<void*>(mcontext.mc_eip);
-  state->sp = reinterpret_cast<void*>(mcontext.mc_esp);
-  state->fp = reinterpret_cast<void*>(mcontext.mc_ebp);
-#elif V8_HOST_ARCH_X64
-  state->pc = reinterpret_cast<void*>(mcontext.mc_rip);
-  state->sp = reinterpret_cast<void*>(mcontext.mc_rsp);
-  state->fp = reinterpret_cast<void*>(mcontext.mc_rbp);
-#elif V8_HOST_ARCH_ARM
-  state->pc = reinterpret_cast<void*>(mcontext.mc_r15);
-  state->sp = reinterpret_cast<void*>(mcontext.mc_r13);
-  state->fp = reinterpret_cast<void*>(mcontext.mc_r11);
-#endif  // V8_HOST_ARCH_*
-#elif V8_OS_NETBSD
-#if V8_HOST_ARCH_IA32
-  state->pc = reinterpret_cast<void*>(mcontext.__gregs[_REG_EIP]);
-  state->sp = reinterpret_cast<void*>(mcontext.__gregs[_REG_ESP]);
-  state->fp = reinterpret_cast<void*>(mcontext.__gregs[_REG_EBP]);
-#elif V8_HOST_ARCH_X64
-  state->pc = reinterpret_cast<void*>(mcontext.__gregs[_REG_RIP]);
-  state->sp = reinterpret_cast<void*>(mcontext.__gregs[_REG_RSP]);
-  state->fp = reinterpret_cast<void*>(mcontext.__gregs[_REG_RBP]);
-#endif  // V8_HOST_ARCH_*
-#elif V8_OS_OPENBSD
-#if V8_HOST_ARCH_IA32
-  state->pc = reinterpret_cast<void*>(ucontext->sc_eip);
-  state->sp = reinterpret_cast<void*>(ucontext->sc_esp);
-  state->fp = reinterpret_cast<void*>(ucontext->sc_ebp);
-#elif V8_HOST_ARCH_X64
-  state->pc = reinterpret_cast<void*>(ucontext->sc_rip);
-  state->sp = reinterpret_cast<void*>(ucontext->sc_rsp);
-  state->fp = reinterpret_cast<void*>(ucontext->sc_rbp);
-#endif  // V8_HOST_ARCH_*
-#elif V8_OS_SOLARIS
-  state->pc = reinterpret_cast<void*>(mcontext.gregs[REG_PC]);
-  state->sp = reinterpret_cast<void*>(mcontext.gregs[REG_SP]);
-  state->fp = reinterpret_cast<void*>(mcontext.gregs[REG_FP]);
-#elif V8_OS_QNX
-#if V8_HOST_ARCH_IA32
-  state->pc = reinterpret_cast<void*>(mcontext.cpu.eip);
-  state->sp = reinterpret_cast<void*>(mcontext.cpu.esp);
-  state->fp = reinterpret_cast<void*>(mcontext.cpu.ebp);
-#elif V8_HOST_ARCH_ARM
-  state->pc = reinterpret_cast<void*>(mcontext.cpu.gpr[ARM_REG_PC]);
-  state->sp = reinterpret_cast<void*>(mcontext.cpu.gpr[ARM_REG_SP]);
-  state->fp = reinterpret_cast<void*>(mcontext.cpu.gpr[ARM_REG_FP]);
-#endif  // V8_HOST_ARCH_*
-#elif V8_OS_AIX
-  state->pc = reinterpret_cast<void*>(mcontext.jmp_context.iar);
-  state->sp = reinterpret_cast<void*>(mcontext.jmp_context.gpr[1]);
-  state->fp = reinterpret_cast<void*>(mcontext.jmp_context.gpr[31]);
-#endif  // V8_OS_AIX
-}
-
-#endif  // !V8_OS_NACL
-
-#endif  // USE_SIGNALS
-
-
-void Sampler::SetUp() {
-#if defined(USE_SIGNALS)
-  SignalHandler::SetUp();
-#endif
-}
-
-
-void Sampler::TearDown() {
-#if defined(USE_SIGNALS)
-  SignalHandler::TearDown();
-#endif
-}
-
-Sampler::Sampler(Isolate* isolate)
-    : is_counting_samples_(false),
-      js_sample_count_(0),
-      external_sample_count_(0),
-      isolate_(isolate),
-      profiling_(false),
-      has_processing_thread_(false),
-      active_(false),
-      registered_(false) {
-  data_ = new PlatformData;
-}
-
-Sampler::~Sampler() {
-  DCHECK(!IsActive());
-#if defined(USE_SIGNALS)
-  if (IsRegistered()) {
-    SamplerManager::RemoveSampler(this);
-  }
-#endif
-  delete data_;
-}
-
-void Sampler::Start() {
-  DCHECK(!IsActive());
-  SetActive(true);
-#if defined(USE_SIGNALS)
-  SamplerManager::AddSampler(this);
-#endif
-}
-
-
-void Sampler::Stop() {
-#if defined(USE_SIGNALS)
-  SamplerManager::RemoveSampler(this);
-#endif
-  DCHECK(IsActive());
-  SetActive(false);
-  SetRegistered(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);
-}
-
-
-#if defined(USE_SIGNALS)
-
-void Sampler::DoSample() {
-  if (!SignalHandler::Installed()) return;
-  if (!IsActive() && !IsRegistered()) {
-    SamplerManager::AddSampler(this);
-    SetRegistered(true);
-  }
-  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;
-
-  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 V8_HOST_ARCH_X64
-    state.pc = reinterpret_cast<void*>(context.Rip);
-    state.sp = reinterpret_cast<void*>(context.Rsp);
-    state.fp = reinterpret_cast<void*>(context.Rbp);
-#else
-    state.pc = reinterpret_cast<void*>(context.Eip);
-    state.sp = reinterpret_cast<void*>(context.Esp);
-    state.fp = reinterpret_cast<void*>(context.Ebp);
-#endif
-    SampleStack(state);
-  }
-  ResumeThread(profiled_thread);
-}
-
-#endif  // USE_SIGNALS
-
-}  // namespace sampler
-}  // namespace v8