dart::PendingDeopts Class Reference

#include <pending_deopts.h>

Public Types
enum	ClearReason { kClearDueToThrow , kClearDueToDeopt }

Public Member Functions
	PendingDeopts ()
	~PendingDeopts ()
bool	HasPendingDeopts ()
void	AddPendingDeopt (uword fp, uword pc)
uword	FindPendingDeopt (uword fp)
void	ClearPendingDeoptsBelow (uword fp, ClearReason reason)
void	ClearPendingDeoptsAtOrBelow (uword fp, ClearReason reason)
uword	RemapExceptionPCForDeopt (uword program_counter, uword frame_pointer, bool *clear_deopt)

Detailed Description

Definition at line 28 of file pending_deopts.h.

Member Enumeration Documentation

ClearReason

enum dart::PendingDeopts::ClearReason

Enumerator
kClearDueToThrow
kClearDueToDeopt

Definition at line 30 of file pending_deopts.h.

                   {
    kClearDueToThrow,
    kClearDueToDeopt,
  };

Constructor & Destructor Documentation

PendingDeopts()

dart::PendingDeopts::PendingDeopts

(

)

Definition at line 14 of file pending_deopts.cc.

    : pending_deopts_(new MallocGrowableArray<PendingLazyDeopt>()) {}

~PendingDeopts()

dart::PendingDeopts::~PendingDeopts

(

)

Definition at line 16 of file pending_deopts.cc.

                              {
  delete pending_deopts_;
  pending_deopts_ = nullptr;
}

Member Function Documentation

AddPendingDeopt()

void dart::PendingDeopts::AddPendingDeopt	(	uword	fp,
		uword	pc
	)

Definition at line 21 of file pending_deopts.cc.

                                                      {
  // GrowableArray::Add is not atomic and may be interrupted by a profiler
  // stack walk.
  MallocGrowableArray<PendingLazyDeopt>* old_pending_deopts = pending_deopts_;
  MallocGrowableArray<PendingLazyDeopt>* new_pending_deopts =
      new MallocGrowableArray<PendingLazyDeopt>(old_pending_deopts->length() +
                                                1);
  for (intptr_t i = 0; i < old_pending_deopts->length(); i++) {
    ASSERT((*old_pending_deopts)[i].fp() != fp);
    new_pending_deopts->Add((*old_pending_deopts)[i]);
  }
  PendingLazyDeopt deopt(fp, pc);
  new_pending_deopts->Add(deopt);
 
  pending_deopts_ = new_pending_deopts;
  delete old_pending_deopts;
}

ClearPendingDeoptsAtOrBelow()

void dart::PendingDeopts::ClearPendingDeoptsAtOrBelow	(	uword	fp,
		ClearReason	reason
	)

Definition at line 79 of file pending_deopts.cc.

                                                                            {
  ClearPendingDeoptsBelow(fp + kWordSize, reason);
}

ClearPendingDeoptsBelow()

void dart::PendingDeopts::ClearPendingDeoptsBelow	(	uword	fp,
		ClearReason	reason
	)

Definition at line 57 of file pending_deopts.cc.

                                                                        {
  for (intptr_t i = pending_deopts_->length() - 1; i >= 0; i--) {
    if ((*pending_deopts_)[i].fp() < fp) {
      if (FLAG_trace_deoptimization) {
        switch (reason) {
          case kClearDueToThrow:
            THR_Print(
                "Lazy deopt skipped due to throw for "
                "fp=%" Pp ", pc=%" Pp "\n",
                (*pending_deopts_)[i].fp(), (*pending_deopts_)[i].pc());
            break;
          case kClearDueToDeopt:
            THR_Print("Lazy deopt fp=%" Pp " pc=%" Pp "\n",
                      (*pending_deopts_)[i].fp(), (*pending_deopts_)[i].pc());
            break;
        }
      }
      pending_deopts_->RemoveAt(i);
    }
  }
}

FindPendingDeopt()

uword dart::PendingDeopts::FindPendingDeopt

(

uword

fp

)

Definition at line 48 of file pending_deopts.cc.

                                              {
  auto record = FindPendingDeoptRecord(fp);
  if (record != nullptr) {
    return record->pc();
  }
  FATAL("Missing pending deopt entry");
  return 0;
}

HasPendingDeopts()

bool dart::PendingDeopts::HasPendingDeopts ( )

inline

Definition at line 37 of file pending_deopts.h.

{ return pending_deopts_->length() > 0; }

RemapExceptionPCForDeopt()

uword dart::PendingDeopts::RemapExceptionPCForDeopt	(	uword	program_counter,
		uword	frame_pointer,
		bool *	clear_deopt
	)

Definition at line 83 of file pending_deopts.cc.

                                                                 {
  *clear_deopt = false;
 
  // Do not attempt to deopt at async exception handler as it doesn't
  // belong to the function code. Async handler never continues execution
  // in the same frame - it either rethrows exception to the caller or
  // tail calls Dart handler, leaving the function frame before the call.
  if (program_counter == StubCode::AsyncExceptionHandler().EntryPoint()) {
    *clear_deopt = true;
    return program_counter;
  }
 
  // Check if the target frame is scheduled for lazy deopt.
  if (FindPendingDeoptRecord(frame_pointer) != nullptr) {
#if defined(DEBUG)
    // Ensure the frame references optimized code.
    ObjectPtr pc_marker = *(reinterpret_cast<ObjectPtr*>(
        frame_pointer + runtime_frame_layout.code_from_fp * kWordSize));
    Code& code = Code::Handle(Code::RawCast(pc_marker));
    ASSERT(code.is_optimized() && !code.is_force_optimized());
#endif
    if (FLAG_trace_deoptimization) {
      THR_Print("Throwing to frame scheduled for lazy deopt fp=%" Pp "\n",
                frame_pointer);
    }
    return StubCode::DeoptimizeLazyFromThrow().EntryPoint();
  }
 
  return program_counter;
}

---

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

• third_party/dart-lang/sdk/runtime/vm/pending_deopts.h
• third_party/dart-lang/sdk/runtime/vm/pending_deopts.cc