Split TickSample and Sampler.

src/profiler/sampler.cc

 // 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
 
@@ skipping 26 matching lines @@
 #endif
 
 #elif V8_OS_WIN || V8_OS_CYGWIN
 
 #include "src/base/win32-headers.h"
 
 #endif
 
 #include "src/base/atomic-utils.h"
 #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/profiler/tick-sample.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
@@ skipping 104 matching lines @@
   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;
-}
-
 typedef List<Sampler*> SamplerList;
 
 #if defined(USE_SIGNALS)
 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.
@@ skipping 74 matching lines @@
   }
 
   HANDLE profiled_thread() { return profiled_thread_; }
 
  private:
   HANDLE profiled_thread_;
 };
 #endif
 
 
-#if defined(USE_SIMULATOR)
-bool SimulatorHelper::FillRegisters(Isolate* isolate,
-                                    v8::RegisterState* state) {
-  Simulator *simulator = isolate->thread_local_top()->simulator_;
-  // Check if there is active simulator.
-  if (simulator == NULL) return false;
-#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
-  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));
-#elif V8_TARGET_ARCH_S390
-  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
-  if (state->sp == 0 || state->fp == 0) {
-    // 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.
-    //
-    // 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 false;
-  }
-  return true;
-}
-#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();
@@ skipping 405 matching lines @@
   SamplerList* samplers = reinterpret_cast<SamplerList*>(entry->value);
   for (int i = 0; i < samplers->length(); ++i) {
     Sampler* sampler = samplers->at(i);
     CollectSample(context, sampler);
   }
 }
 #endif  // !V8_OS_NACL
 #endif  // USE_SIGNALs
 
 
-//
-// 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)) {
-    // Can't collect stack. Mark the sample as spoiled.
-    timestamp = base::TimeTicks();
-    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_entry = *scope->callback_entrypoint_address();
-    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);
-  if (!frames_count) {
-    // It is executing JS but failed to collect a stack trace.
-    // Mark the sample as spoiled.
-    timestamp = base::TimeTicks();
-    pc = 0;
-  }
-}
-
-
-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) {
-    if (it.frame()->is_interpreted()) {
-      // For interpreted frames use the bytecode array pointer as the pc.
-      InterpretedFrame* frame = static_cast<InterpretedFrame*>(it.frame());
-      // Since the sampler can interrupt execution at any point the
-      // bytecode_array might be garbage, so don't dereference it.
-      Address bytecode_array =
-          reinterpret_cast<Address>(frame->GetBytecodeArray()) - kHeapObjectTag;
-      frames[i++] = bytecode_array + BytecodeArray::kHeaderSize +
-                    frame->GetBytecodeOffset();
-    } else {
-      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();
@@ skipping 115 matching lines @@
     SampleStack(state);
   }
   ResumeThread(profiled_thread);
 }
 
 #endif  // USE_SIGNALS
 
 
 }  // namespace internal
 }  // namespace v8