v8::internal::TickSample Struct Reference

#include <sampler.h>

Collaboration diagram for v8::internal::TickSample:

Public Member Functions
	TickSample ()
void	Init (Isolate *isolate, const RegisterState &state)

Public Attributes
StateTag	state
Address	pc
union {
Address   tos
Address   external_callback
};
Address	stack [kMaxFramesCount]
base::TimeTicks	timestamp
unsigned	frames_count: kMaxFramesCountLog2
bool	has_external_callback: 1
StackFrame::Type	top_frame_type: 4

Static Public Attributes
static const unsigned	kMaxFramesCountLog2 = 8
static const unsigned	kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1

Detailed Description

Definition at line 32 of file sampler.h.

Constructor & Destructor Documentation

TickSample()

v8::internal::TickSample::TickSample ( )

inline

Definition at line 33 of file sampler.h.

      : state(OTHER),
        pc(NULL),
        external_callback(NULL),
        frames_count(0),
        has_external_callback(false),
        top_frame_type(StackFrame::NONE) {}

Member Function Documentation

Init()

DISABLE_ASAN void v8::internal::TickSample::Init	(	Isolate *	isolate,
		const RegisterState &	state
	)

Definition at line 579 of file sampler.cc.

                                                              {
  DCHECK(isolate->IsInitialized());
  timestamp = base::TimeTicks::HighResolutionNow();
  pc = 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) {
    // Not executing JS now.
    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 {
    // Sample potential return address value for frameless invocation of
    // stubs (we'll figure out later, if this value makes sense).
    tos = Memory::Address_at(regs.sp);
    has_external_callback = false;
  }
 
  SafeStackFrameIterator it(isolate, regs.fp, regs.sp, js_entry_sp);
  top_frame_type = it.top_frame_type();
  unsigned i = 0;
  while (!it.done() && i < TickSample::kMaxFramesCount) {
    stack[i++] = it.frame()->pc();
    it.Advance();
  }
  frames_count = i;
}

References v8::internal::Memory::Address_at(), v8::internal::SafeStackFrameIterator::Advance(), DCHECK, external_callback, v8::internal::RegisterState::fp, v8::internal::SafeStackFrameIterator::frame(), frames_count, v8::internal::GC, v8::internal::Isolate::handler(), has_external_callback, v8::internal::Isolate::IsInitialized(), v8::internal::Isolate::js_entry_sp(), kMaxFramesCount, v8::internal::RegisterState::pc, pc, v8::internal::RegisterState::sp, stack, state, v8::internal::Isolate::thread_local_top(), timestamp, v8::internal::SafeStackFrameIterator::top_frame_type(), top_frame_type, and tos.

Referenced by v8::internal::ProfilerEventsProcessor::AddCurrentStack(), and v8::internal::Sampler::SampleStack().

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Member Data Documentation

union { ... }

external_callback

Address v8::internal::TickSample::external_callback

Definition at line 45 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), and v8::internal::Logger::TickEvent().

frames_count

unsigned v8::internal::TickSample::frames_count

Definition at line 51 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), and v8::internal::Logger::TickEvent().

has_external_callback

bool v8::internal::TickSample::has_external_callback

Definition at line 52 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), and v8::internal::Logger::TickEvent().

kMaxFramesCount

const unsigned v8::internal::TickSample::kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1

static

Definition at line 48 of file sampler.h.

Referenced by Init().

kMaxFramesCountLog2

const unsigned v8::internal::TickSample::kMaxFramesCountLog2 = 8

static

Definition at line 47 of file sampler.h.

pc

Address v8::internal::TickSample::pc

Definition at line 42 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), and v8::internal::Logger::TickEvent().

stack

Address v8::internal::TickSample::stack[kMaxFramesCount]

Definition at line 49 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), and v8::internal::Logger::TickEvent().

state

StateTag v8::internal::TickSample::state

Definition at line 41 of file sampler.h.

Referenced by Init(), v8::internal::ProfileGenerator::RecordTickSample(), v8::internal::Sampler::SampleStack(), and v8::internal::Logger::TickEvent().

timestamp

base::TimeTicks v8::internal::TickSample::timestamp

Definition at line 50 of file sampler.h.

Referenced by Init(), and v8::internal::ProfileGenerator::RecordTickSample().

top_frame_type

StackFrame::Type v8::internal::TickSample::top_frame_type

Definition at line 53 of file sampler.h.

Referenced by Init(), and v8::internal::ProfileGenerator::RecordTickSample().

tos

Address v8::internal::TickSample::tos

Definition at line 44 of file sampler.h.

Referenced by Init(), and v8::internal::Logger::TickEvent().

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The documentation for this struct was generated from the following files:

• /mnt/V8SourceCode/src/sampler.h
• /mnt/V8SourceCode/src/sampler.cc