private static synchronized void initialize(TypeDataBase db) {
    Type type = db.lookupType("InterpreterCodelet");

    sizeField = type.getCIntegerField("_size");
    descriptionField = type.getAddressField("_description");
    isSafepointSafeField = type.getJIntField("_is_safepoint_safe");
    bytecodeField = type.getCIntegerField("_bytecode");

    instanceSize = type.getSize();
  }