C++ DataLayout::bci方法代码示例

ciProfileData* ciMethodData::bci_to_extra_data(int bci, ciMethod* m, bool& two_free_slots) {
  DataLayout* dp  = extra_data_base();
  DataLayout* end = args_data_limit();
  two_free_slots = false;
  for (;dp < end; dp = MethodData::next_extra(dp)) {
    switch(dp->tag()) {
    case DataLayout::no_tag:
      _saw_free_extra_data = true;  // observed an empty slot (common case)
      two_free_slots = (MethodData::next_extra(dp)->tag() == DataLayout::no_tag);
      return NULL;
    case DataLayout::arg_info_data_tag:
      return NULL; // ArgInfoData is at the end of extra data section.
    case DataLayout::bit_data_tag:
      if (m == NULL && dp->bci() == bci) {
        return new ciBitData(dp);
      }
      break;
    case DataLayout::speculative_trap_data_tag: {
      ciSpeculativeTrapData* data = new ciSpeculativeTrapData(dp);
      // data->method() might be null if the MDO is snapshotted
      // concurrently with a trap
      if (m != NULL && data->method() == m && dp->bci() == bci) {
        return data;
      }
      break;
    }
    default:
      fatal(err_msg("bad tag = %d", dp->tag()));
    }
  }
  return NULL;
}

// Translate a bci to its corresponding extra data, or NULL.
ProfileData* methodDataOopDesc::bci_to_extra_data(int bci, bool create_if_missing) {
  DataLayout* dp    = extra_data_base();
  DataLayout* end   = extra_data_limit();
  DataLayout* avail = NULL;
  for (; dp < end; dp = next_extra(dp)) {
    // No need for "OrderAccess::load_acquire" ops,
    // since the data structure is monotonic.
    if (dp->tag() == DataLayout::no_tag)  break;
    if (dp->tag() == DataLayout::arg_info_data_tag) {
      dp = end; // ArgInfoData is at the end of extra data section.
      break;
    }
    if (dp->bci() == bci) {
      assert(dp->tag() == DataLayout::bit_data_tag, "sane");
      return new BitData(dp);
    }
  }
  if (create_if_missing && dp < end) {
    // Allocate this one.  There is no mutual exclusion,
    // so two threads could allocate different BCIs to the
    // same data layout.  This means these extra data
    // records, like most other MDO contents, must not be
    // trusted too much.
    DataLayout temp;
    temp.initialize(DataLayout::bit_data_tag, bci, 0);
    dp->release_set_header(temp.header());
    assert(dp->tag() == DataLayout::bit_data_tag, "sane");
    //NO: assert(dp->bci() == bci, "no concurrent allocation");
    return new BitData(dp);
  }
  return NULL;
}

// Translate a bci to its corresponding data, or NULL.
ciProfileData* ciMethodData::bci_to_data(int bci) {
  ciProfileData* data = data_before(bci);
  for ( ; is_valid(data); data = next_data(data)) {
    if (data->bci() == bci) {
      set_hint_di(dp_to_di(data->dp()));
      return data;
    } else if (data->bci() > bci) {
      break;
    }
  }
  // bci_to_extra_data(bci) ...
  DataLayout* dp  = data_layout_at(data_size());
  DataLayout* end = data_layout_at(data_size() + extra_data_size());
  for (; dp < end; dp = methodDataOopDesc::next_extra(dp)) {
    if (dp->tag() == DataLayout::no_tag) {
      _saw_free_extra_data = true;  // observed an empty slot (common case)
      return NULL;
    }
    if (dp->tag() == DataLayout::arg_info_data_tag) {
      break; // ArgInfoData is at the end of extra data section.
    }
    if (dp->bci() == bci) {
      assert(dp->tag() == DataLayout::bit_data_tag, "sane");
      return new ciBitData(dp);
    }
  }
  return NULL;
}