[WIP]Create a V8 sampler library and tracing controller.

src/v8-sampler.cc

Index: src/v8-sampler.cc
diff --git a/src/profiler/sampler.cc b/src/v8-sampler.cc
similarity index 53%
copy from src/profiler/sampler.cc
copy to src/v8-sampler.cc
index 45f1d4d3efcfd726409b16ec2aa80f0b673b0d92..8c66561066c652a00d851d8cd70d6e3a1c1bb4c6 100644
--- a/src/profiler/sampler.cc
+++ b/src/v8-sampler.cc
@@ -1,13 +1,14 @@
-// Copyright 2013 the V8 project authors. All rights reserved.
+// 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/profiler/sampler.h"
+#include "include/v8.h"
+#include "include/v8-sampler.h"
+#include "src/base/platform/time.h"
+#include <iostream>
 
 #if V8_OS_POSIX && !V8_OS_CYGWIN
 
-#define USE_SIGNALS
-
 #include <errno.h>
 #include <pthread.h>
 #include <signal.h>
@@ -155,92 +156,27 @@ enum { REG_RBP = 10, REG_RSP = 15, REG_RIP = 16 };
 
 #endif  // V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T)
 
-
 namespace v8 {
-namespace internal {
 
 namespace {
 
-class PlatformDataCommon : public Malloced {
+class PlatformDataCommon : public i::Malloced {
  public:
-  PlatformDataCommon() : profiled_thread_id_(ThreadId::Current()) {}
-  ThreadId profiled_thread_id() { return profiled_thread_id_; }
+  PlatformDataCommon() : profiled_thread_id_(i::ThreadId::Current()) {}
+  i::ThreadId profiled_thread_id() { return profiled_thread_id_; }
 
  protected:
   ~PlatformDataCommon() {}
 
  private:
-  ThreadId profiled_thread_id_;
+  i::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 {
+class V8Sampler::PlatformData : public PlatformDataCommon {
  public:
   PlatformData() : vm_tid_(pthread_self()) {}
   pthread_t vm_tid() const { return vm_tid_; }
@@ -255,7 +191,7 @@ class Sampler::PlatformData : public PlatformDataCommon {
 // Win32 profiler support. On Cygwin we use the same sampler implementation as
 // on Win32.
 
-class Sampler::PlatformData : public PlatformDataCommon {
+class V8Sampler::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
@@ -287,21 +223,21 @@ class Sampler::PlatformData : public PlatformDataCommon {
 #if defined(USE_SIMULATOR)
 class SimulatorHelper {
  public:
-  inline bool Init(Isolate* isolate) {
+  inline bool Init(i::Isolate* isolate) {
     simulator_ = isolate->thread_local_top()->simulator_;
     // Check if there is active simulator.
     return simulator_ != NULL;
   }
 
-  inline void FillRegisters(v8::RegisterState* state) {
+  inline void FillRegisters(RegisterState* state) {
 #if V8_TARGET_ARCH_ARM
     if (!simulator_->has_bad_pc()) {
-      state->pc = reinterpret_cast<Address>(simulator_->get_pc());
+      state->pc = reinterpret_cast<i::Address>(simulator_->get_pc());
     }
-    state->sp = reinterpret_cast<Address>(simulator_->get_register(
-        Simulator::sp));
-    state->fp = reinterpret_cast<Address>(simulator_->get_register(
-        Simulator::r11));
+    state->sp = reinterpret_cast<i::Address>(simulator_->get_register(
+        i::Simulator::sp));
+    state->fp = reinterpret_cast<i::Address>(simulator_->get_register(
+        i::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
@@ -317,37 +253,37 @@ class SimulatorHelper {
       // 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());
+    state->pc = reinterpret_cast<i::Address>(simulator_->pc());
+    state->sp = reinterpret_cast<i::Address>(simulator_->sp());
+    state->fp = reinterpret_cast<i::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->pc = reinterpret_cast<i::Address>(simulator_->get_pc());
     }
-    state->sp = reinterpret_cast<Address>(simulator_->get_register(
-        Simulator::sp));
-    state->fp = reinterpret_cast<Address>(simulator_->get_register(
-        Simulator::fp));
+    state->sp = reinterpret_cast<i::Address>(simulator_->get_register(
+        i::Simulator::sp));
+    state->fp = reinterpret_cast<i::Address>(simulator_->get_register(
+        i::Simulator::fp));
 #elif V8_TARGET_ARCH_PPC
     if (!simulator_->has_bad_pc()) {
-      state->pc = reinterpret_cast<Address>(simulator_->get_pc());
+      state->pc = reinterpret_cast<i::Address>(simulator_->get_pc());
     }
     state->sp =
-        reinterpret_cast<Address>(simulator_->get_register(Simulator::sp));
+        reinterpret_cast<i::Address>(simulator_->get_register(i::Simulator::sp));
     state->fp =
-        reinterpret_cast<Address>(simulator_->get_register(Simulator::fp));
+        reinterpret_cast<i::Address>(simulator_->get_register(i::Simulator::fp));
 #endif
   }
 
  private:
-  Simulator* simulator_;
+  i::Simulator* simulator_;
 };
 #endif  // USE_SIMULATOR
 
 
 #if defined(USE_SIGNALS)
 
-class SignalHandler : public AllStatic {
+class SignalHandler {
  public:
   static void SetUp() { if (!mutex_) mutex_ = new base::Mutex(); }
   static void TearDown() { delete mutex_; mutex_ = NULL; }
@@ -370,7 +306,7 @@ class SignalHandler : public AllStatic {
   static void Install() {
 #if !V8_OS_NACL
     struct sigaction sa;
-    sa.sa_sigaction = &HandleProfilerSignal;
+    sa.sa_sigaction = &SignalHandler::HandleProfilerSignal;
     sigemptyset(&sa.sa_mask);
 #if V8_OS_QNX
     sa.sa_flags = SA_SIGINFO;
@@ -401,12 +337,113 @@ class SignalHandler : public AllStatic {
   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;
 
+class SamplerThread : public base::Thread {
+ public:
+  static const int kSamplerThreadStackSize = 64 * i::KB;
+
+  explicit SamplerThread()
+      : Thread(base::Thread::Options("V8::SamplerThread",
+                                     kSamplerThreadStackSize)) {}
+
+  static void SetUp(int interval) {
+    if (!mutex_)
+      mutex_ = new base::Mutex();
+    SamplerThread::interval_ = interval;
+  }
+  static void TearDown() { delete mutex_; mutex_ = NULL; }
+
+  static void SetInterval(int interval) {
+    SamplerThread::interval_ = interval;
+  }
+
+  static void AddActiveSampler(V8Sampler* 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();
+      need_to_start = true;
+    }
+
+    DCHECK(sampler->IsActive());
+    DCHECK(!instance_->active_samplers_.Contains(sampler));
+    instance_->active_samplers_.Add(sampler);
+
+    if (need_to_start) instance_->StartSynchronously();
+  }
+
+  static void RemoveActiveSampler(V8Sampler* 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;
+  }
+
+  static V8Sampler* FetchActiveSampler(void* isolate) {
+    for (int i = 0; i < instance_->active_samplers_.length(); ++i) {
+      V8Sampler* sampler = instance_->active_samplers_.at(i);
+      if (reinterpret_cast<void*>(sampler->isolate()) == isolate)
+        return sampler;
+    }
+    return NULL;
+  }
+
+  // Implement Thread::Run().
+  void Run() override {
+    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) {
+          V8Sampler* sampler = active_samplers_.at(i);
+          if (!sampler->IsProfiling()) continue;
+          sampler->DoSample();
+        }
+      }
+      base::OS::Sleep(
+          base::TimeDelta::FromMilliseconds(SamplerThread::interval_));
+    }
+  }
+
+ private:
+  // Protects the process wide state below.
+  static base::Mutex* mutex_;
+  static SamplerThread* instance_;
+
+  static int interval_;
+  i::List<V8Sampler*> active_samplers_;
+
+  DISALLOW_COPY_AND_ASSIGN(SamplerThread);
+};
+
+base::Mutex* SamplerThread::mutex_ = NULL;
+SamplerThread* SamplerThread::instance_ = NULL;
+int SamplerThread::interval_ = 0;
+
 
 // As Native Client does not support signal handling, profiling is disabled.
 #if !V8_OS_NACL
@@ -414,20 +451,21 @@ void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
                                          void* context) {
   USE(info);
   if (signal != SIGPROF) return;
-  Isolate* isolate = Isolate::UnsafeCurrent();
+  i::Isolate* isolate = i::Isolate::UnsafeCurrent();
   if (isolate == NULL || !isolate->IsInUse()) {
     // We require a fully initialized and entered isolate.
     return;
   }
-  if (v8::Locker::IsActive() &&
+  if (Locker::IsActive() &&
       !isolate->thread_manager()->IsLockedByCurrentThread()) {
     return;
   }
 
-  Sampler* sampler = isolate->logger()->sampler();
+  V8Sampler* sampler = SamplerThread::FetchActiveSampler(
+      reinterpret_cast<void*>(isolate));
   if (sampler == NULL) return;
 
-  v8::RegisterState state;
+  RegisterState state;
 
 #if defined(USE_SIMULATOR)
   SimulatorHelper helper;
@@ -446,117 +484,117 @@ void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
 #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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.gregs[REG_EIP]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[REG_ESP]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.gregs[REG_RIP]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[REG_RSP]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.gregs[R15]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[R13]);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.arm_pc);
+  state.sp = reinterpret_cast<i::Address>(mcontext.arm_sp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.pc);
+  state.sp = reinterpret_cast<i::Address>(mcontext.sp);
   // FP is an alias for x29.
-  state.fp = reinterpret_cast<Address>(mcontext.regs[29]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.pc);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[29]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.pc);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[29]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(ucontext->uc_mcontext.regs->nip);
+  state.sp = reinterpret_cast<i::Address>(ucontext->uc_mcontext.regs->gpr[PT_R1]);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext->__ss.__rip);
+  state.sp = reinterpret_cast<i::Address>(mcontext->__ss.__rsp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext->ss.rip);
+  state.sp = reinterpret_cast<i::Address>(mcontext->ss.rsp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext->__ss.__eip);
+  state.sp = reinterpret_cast<i::Address>(mcontext->__ss.__esp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext->ss.eip);
+  state.sp = reinterpret_cast<i::Address>(mcontext->ss.esp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.mc_eip);
+  state.sp = reinterpret_cast<i::Address>(mcontext.mc_esp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.mc_rip);
+  state.sp = reinterpret_cast<i::Address>(mcontext.mc_rsp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.mc_r15);
+  state.sp = reinterpret_cast<i::Address>(mcontext.mc_r13);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.__gregs[_REG_EIP]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.__gregs[_REG_ESP]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.__gregs[_REG_RIP]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.__gregs[_REG_RSP]);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(ucontext->sc_eip);
+  state.sp = reinterpret_cast<i::Address>(ucontext->sc_esp);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(ucontext->sc_rip);
+  state.sp = reinterpret_cast<i::Address>(ucontext->sc_rsp);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.gregs[REG_PC]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.gregs[REG_SP]);
+  state.fp = reinterpret_cast<i::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);
+  state.pc = reinterpret_cast<i::Address>(mcontext.cpu.eip);
+  state.sp = reinterpret_cast<i::Address>(mcontext.cpu.esp);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.cpu.gpr[ARM_REG_PC]);
+  state.sp = reinterpret_cast<i::Address>(mcontext.cpu.gpr[ARM_REG_SP]);
+  state.fp = reinterpret_cast<i::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]);
+  state.pc = reinterpret_cast<i::Address>(mcontext.jmp_context.iar);
+  state.sp = reinterpret_cast<i::Address>(mcontext.jmp_context.gpr[1]);
+  state.fp = reinterpret_cast<i::Address>(mcontext.jmp_context.gpr[31]);
 #endif  // V8_OS_AIX
 #endif  // USE_SIMULATOR
   sampler->SampleStack(state);
@@ -566,188 +604,39 @@ void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
 #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,
-                                   bool update_stats) {
-  timestamp = base::TimeTicks::HighResolutionNow();
-  pc = reinterpret_cast<Address>(regs.pc);
-  state = isolate->current_vm_state();
-  this->update_stats = update_stats;
-
-  // 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() {
+void V8Sampler::SetUp() {
 #if defined(USE_SIGNALS)
   SignalHandler::SetUp();
 #endif
-  SamplerThread::SetUp();
+  SamplerThread::SetUp(kSamplingIntervalMs);
 }
 
-
-void Sampler::TearDown() {
+void V8Sampler::TearDown() {
   SamplerThread::TearDown();
 #if defined(USE_SIGNALS)
   SignalHandler::TearDown();
 #endif
 }
 
-Sampler::Sampler(Isolate* isolate, int interval)
+void V8Sampler::SetInterval(int interval) {
+  SamplerThread::SetInterval(interval);
+}
+
+void V8Sampler::CollectStackSample(const RegisterState& regs,
+                                   void** frames, size_t frames_limit,
+                                   SampleInfo* sample_info) {
+  isolate_->GetStackSample(regs, frames, frames_limit, sample_info);
+}
+
+void V8Sampler::SetJitCodeEventHandler(JitCodeEventOptions options,
+                                       void* data) {
+  JitCodeEventHandler handler =
+      reinterpret_cast<JitCodeEventHandler>(data);
+  isolate_->SetJitCodeEventHandler(options, handler);
+}
+
+V8Sampler::V8Sampler(Isolate* isolate)
     : isolate_(isolate),
-      interval_(interval),
       profiling_(false),
       has_processing_thread_(false),
       active_(false),
@@ -757,67 +646,63 @@ Sampler::Sampler(Isolate* isolate, int interval)
   data_ = new PlatformData;
 }
 
-Sampler::~Sampler() {
+V8Sampler::~V8Sampler() {
   DCHECK(!IsActive());
   delete data_;
 }
 
-void Sampler::Start() {
+void V8Sampler::Start() {
   DCHECK(!IsActive());
   SetActive(true);
   SamplerThread::AddActiveSampler(this);
 }
 
-
-void Sampler::Stop() {
+void V8Sampler::Stop() {
   DCHECK(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
-
-void Sampler::IncreaseProfilingDepth() {
+void V8Sampler::IncreaseProfilingDepth() {
   base::NoBarrier_AtomicIncrement(&profiling_, 1);
 #if defined(USE_SIGNALS)
   SignalHandler::IncreaseSamplerCount();
 #endif
 }
 
-
-void Sampler::DecreaseProfilingDepth() {
+void V8Sampler::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;
+void V8Sampler::SampleStack(const RegisterState& state) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate_);
+  i::TickSample* sample = i_isolate->cpu_profiler()->StartTickSample();
+  i::TickSample sample_obj;
   if (sample == NULL) sample = &sample_obj;
-  sample->Init(isolate_, state, TickSample::kIncludeCEntryFrame, true);
+  sample->Init(i_isolate, state, i::TickSample::kIncludeCEntryFrame, true);
   if (is_counting_samples_) {
     if (sample->state == JS) ++js_sample_count_;
     if (sample->state == EXTERNAL) ++external_sample_count_;
   }
   Tick(sample);
   if (sample != &sample_obj) {
-    isolate_->cpu_profiler()->FinishTickSample();
+    i_isolate->cpu_profiler()->FinishTickSample();
   }
 }
 
-
 #if defined(USE_SIGNALS)
 
-void Sampler::DoSample() {
+void V8Sampler::DoSample() {
   if (!SignalHandler::Installed()) return;
   pthread_kill(platform_data()->vm_tid(), SIGPROF);
 }
 
 #elif V8_OS_WIN || V8_OS_CYGWIN
 
-void Sampler::DoSample() {
+void V8Sampler::DoSample() {
   HANDLE profiled_thread = platform_data()->profiled_thread();
   if (profiled_thread == NULL) return;
 
@@ -834,18 +719,18 @@ void Sampler::DoSample() {
   memset(&context, 0, sizeof(context));
   context.ContextFlags = CONTEXT_FULL;
   if (GetThreadContext(profiled_thread, &context) != 0) {
-    v8::RegisterState state;
+    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);
+    state.pc = reinterpret_cast<i::Address>(context.Rip);
+    state.sp = reinterpret_cast<i::Address>(context.Rsp);
+    state.fp = reinterpret_cast<i::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);
+    state.pc = reinterpret_cast<i::Address>(context.Eip);
+    state.sp = reinterpret_cast<i::Address>(context.Esp);
+    state.fp = reinterpret_cast<i::Address>(context.Ebp);
 #endif
 #endif  // USE_SIMULATOR
     SampleStack(state);
@@ -855,6 +740,4 @@ void Sampler::DoSample() {
 
 #endif  // USE_SIGNALS
 
-
-}  // namespace internal
-}  // namespace v8
+}