-type atom_cache_index() :: 0..2038.

-type atom_cache_ref_entry() :: vdist_new_atom_cache_ref_entry:t() | vdist_old_atom_cache_ref_entry:t().

-type control_message() :: dop_t().

-type dop_t() :: dop_without_payload_t() | dop_with_payload_t().

-type dop_with_payload_t() ::
    vdist_dop_alias_send:t() |
    vdist_dop_alias_send_tt:t() |
    vdist_dop_altact_sig_send:t() |
    vdist_dop_payload_exit:t() |
    vdist_dop_payload_exit_tt:t() |
    vdist_dop_payload_exit2:t() |
    vdist_dop_payload_exit2_tt:t() |
    vdist_dop_payload_monitor_p_exit:t() |
    vdist_dop_reg_send:t() |
    vdist_dop_reg_send_tt:t() |
    vdist_dop_send:t() |
    vdist_dop_send_sender:t() |
    vdist_dop_send_sender_tt:t() |
    vdist_dop_send_tt:t() |
    vdist_dop_spawn_request:t() |
    vdist_dop_spawn_request_tt:t().

-type dop_without_payload_t() ::
    vdist_dop_demonitor_p:t() |
    vdist_dop_exit:t() |
    vdist_dop_exit_tt:t() |
    vdist_dop_exit2:t() |
    vdist_dop_exit2_tt:t() |
    vdist_dop_group_leader:t() |
    vdist_dop_link:t() |
    vdist_dop_monitor_p:t() |
    vdist_dop_monitor_p_exit:t() |
    vdist_dop_spawn_reply:t() |
    vdist_dop_spawn_reply_tt:t() |
    vdist_dop_unlink:t() |
    vdist_dop_unlink_id:t() |
    vdist_dop_unlink_id_ack:t().

-type fragment_id() :: vterm:u64().

-type header_t() ::
    vdist_normal_header:t() |
    vdist_fragment_header:t() |
    vdist_fragment_cont:t() |
    vdist_pass_through_header:t().

-type sequence_id() :: vterm:u64().