Function print_handles_data

deps/v8/tools/windbg.js:682–741

(print_handles = false)

    Handles
-----------------------------------------------------------------------------*/
function print_handles_data(print_handles = false) {
  if (isolate_address == 0) {
    print("Please call !set_iso(isolate_address) first.");
    return;
  }

  let iso = cast(isolate_address, "v8::internal::Isolate");
  let hsd = iso.handle_scope_data_;
  let hsimpl = iso.handle_scope_implementer_;

  // depth level
  print(`Nested depth level: ${hsd.level}`);

  // count of handles
  const ptr_size = pointer_size();
  let blocks = hsimpl.blocks_;
  const block_size = 1022; // v8::internal::KB - 2
  const first_block = blocks.data_.address;
  const last_block = (blocks.size_ == 0)
                     ? first_block
                     : first_block + ptr_size * (blocks.size_ - 1);

  const count = (blocks.size_ == 0)
              ? 0
              : (blocks.size_ - 1) * block_size +
                (hsd.next.address - poi(last_block))/ptr_size;
  print(`Currently tracking ${count} local handles`);

  // print the handles
  if (print_handles && count > 0) {
    for (let block = first_block; block < last_block;
         block += block_size * ptr_size) {
      print(`Handles in block at ${hex(block)}`);
      for (let i = 0; i < block_size; i++) {
        const location = poi(block + i * ptr_size);
        print(`  ${hex(location)}->${hex(poi(location))}`);
      }
    }

    let location = poi(last_block);
    print(`Handles in block at ${hex(last_block)}`);
    for (let location = poi(last_block); location < hsd.next.address;
         location += ptr_size) {
      print(`  ${hex(location)}->${hex(poi(location))}`);
    }
  }

  // where will the next handle allocate at?
  const prefix = "Next handle's location will be";
  if (hsd.next.address < hsd.limit.address) {
    print(`${prefix} at ${hex(hsd.next.address)}`);
  }
  else if (hsimpl.spare_) {
    const location = hsimpl.spare_.address;
    print(`${prefix} from the spare block at ${hex(location)}`);
  }
  else {
    print(`${prefix} from a new block to be allocated`);