dart::ProfilerDartStackWalker Class Reference

Inheritance diagram for dart::ProfilerDartStackWalker:

Public Member Functions
	ProfilerDartStackWalker (Thread *thread, Sample *sample, SampleBuffer *sample_buffer, uword pc, uword fp, uword sp, uword lr, bool allocation_sample, intptr_t skip_count=0)
void	walk ()
Public Member Functions inherited from dart::ProfilerStackWalker
	ProfilerStackWalker (Dart_Port port_id, Sample *head_sample, SampleBuffer *sample_buffer, intptr_t skip_count=0)
bool	Append (uword pc, uword fp)
Public Member Functions inherited from dart::ValueObject
	ValueObject ()
	~ValueObject ()

Additional Inherited Members
Protected Attributes inherited from dart::ProfilerStackWalker
Dart_Port	port_id_
Sample *	sample_
SampleBuffer *	sample_buffer_
intptr_t	skip_count_
intptr_t	frames_skipped_
intptr_t	frame_index_
intptr_t	total_frames_

Detailed Description

Definition at line 995 of file profiler.cc.

Constructor & Destructor Documentation

ProfilerDartStackWalker()

dart::ProfilerDartStackWalker::ProfilerDartStackWalker ( Thread *  thread, Sample *  sample, SampleBuffer *  sample_buffer, uword  pc, uword  fp, uword  sp, uword  lr, bool  allocation_sample, intptr_t  skip_count = 0  )

inline

Definition at line 997 of file profiler.cc.

      : ProfilerStackWalker((thread->isolate() != nullptr)
                                ? thread->isolate()->main_port()
                                : ILLEGAL_PORT,
                            sample,
                            sample_buffer,
                            skip_count),
        thread_(thread),
        pc_(reinterpret_cast<uword*>(pc)),
        fp_(reinterpret_cast<uword*>(fp)),
        sp_(reinterpret_cast<uword*>(sp)),
        lr_(reinterpret_cast<uword*>(lr)) {}

Member Function Documentation

walk()

void dart::ProfilerDartStackWalker::walk ( )

inline

Definition at line 1018 of file profiler.cc.

              {
    RELEASE_ASSERT(StubCode::HasBeenInitialized());
    if (thread_->isolate()->IsDeoptimizing()) {
      sample_->set_ignore_sample(true);
      return;
    }
 
    uword* exit_fp = reinterpret_cast<uword*>(thread_->top_exit_frame_info());
    bool has_exit_frame = exit_fp != nullptr;
    if (has_exit_frame) {
      // Exited from compiled code.
      pc_ = nullptr;
      fp_ = exit_fp;
 
      // Skip exit frame.
      pc_ = CallerPC();
      fp_ = CallerFP();
    } else {
      if (thread_->vm_tag() == VMTag::kDartTagId) {
        // Running compiled code.
        // Use the FP and PC from the thread interrupt or simulator; already set
        // in the constructor.
      } else {
        // No Dart on the stack; caller shouldn't use this walker.
        UNREACHABLE();
      }
 
      const bool is_entry_frame =
#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
          StubCode::InInvocationStub(Stack(0)) ||
          StubCode::InInvocationStub(Stack(1));
#else
          StubCode::InInvocationStub(reinterpret_cast<uword>(lr_));
#endif
      if (is_entry_frame) {
        // During the prologue of a function, CallerPC will return the caller's
        // caller. For most frames, the missing PC will be added during profile
        // processing. However, during this stack walk, it can cause us to fail
        // to identify the entry frame and lead the stack walk into the weeds.
        // Do not continue the stalk walk since this might be a false positive
        // from a Smi or unboxed value.
        sample_->set_ignore_sample(true);
        return;
      }
    }
 
    sample_->set_exit_frame_sample(has_exit_frame);
 
    for (;;) {
      // Skip entry frame.
      if (StubCode::InInvocationStub(reinterpret_cast<uword>(pc_))) {
        pc_ = nullptr;
        fp_ = ExitLink();
        if (fp_ == nullptr) {
          break;  // End of Dart stack.
        }
 
        // Skip exit frame.
        pc_ = CallerPC();
        fp_ = CallerFP();
 
        // At least one frame between exit and next entry frame.
        RELEASE_ASSERT(
            !StubCode::InInvocationStub(reinterpret_cast<uword>(pc_)));
      }
 
      if (!Append(reinterpret_cast<uword>(pc_), reinterpret_cast<uword>(fp_))) {
        break;  // Sample is full.
      }
 
      pc_ = CallerPC();
      fp_ = CallerFP();
    }
  }

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The documentation for this class was generated from the following file:

• third_party/dart-lang/sdk/runtime/vm/profiler.cc