Example #1
0
inline bool vframeStreamCommon::fill_from_frame() {
  // Interpreted frame
  if (_frame.is_interpreted_frame()) {
    fill_from_interpreter_frame();
    return true;
  }

  // Compiled frame

  if (cb() != NULL && cb()->is_nmethod()) {
    if (nm()->is_native_method()) {
      // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick.
      fill_from_compiled_native_frame();
    } else {
      PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc());
      int decode_offset;
      if (pc_desc == NULL) {
        // Should not happen, but let fill_from_compiled_frame handle it.

        // If we are trying to walk the stack of a thread that is not
        // at a safepoint (like AsyncGetCallTrace would do) then this is an
        // acceptable result. [ This is assuming that safe_for_sender
        // is so bullet proof that we can trust the frames it produced. ]
        //
        // So if we see that the thread is not safepoint safe
        // then simply produce the method and a bci of zero
        // and skip the possibility of decoding any inlining that
        // may be present. That is far better than simply stopping (or
        // asserting. If however the thread is safepoint safe this
        // is the sign of a compiler bug  and we'll let
        // fill_from_compiled_frame handle it.


        JavaThreadState state = _thread->thread_state();

        // in_Java should be good enough to test safepoint safety
        // if state were say in_Java_trans then we'd expect that
        // the pc would have already been slightly adjusted to
        // one that would produce a pcDesc since the trans state
        // would be one that might in fact anticipate a safepoint

        if (state == _thread_in_Java ) {
          // This will get a method a zero bci and no inlining.
          // Might be nice to have a unique bci to signify this
          // particular case but for now zero will do.

          fill_from_compiled_native_frame();

          // There is something to be said for setting the mode to
          // at_end_mode to prevent trying to walk further up the
          // stack. There is evidence that if we walk any further
          // that we could produce a bad stack chain. However until
          // we see evidence that allowing this causes us to find
          // frames bad enough to cause segv's or assertion failures
          // we don't do it as while we may get a bad call chain the
          // probability is much higher (several magnitudes) that we
          // get good data.

          return true;
        }
        decode_offset = DebugInformationRecorder::serialized_null;
      } else {
        decode_offset = pc_desc->scope_decode_offset();
      }
      fill_from_compiled_frame(decode_offset);
    }
    return true;
  }

  // End of stack?
  if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {
    _mode = at_end_mode;
    return true;
  }

  return false;
}