Erlang et (Event Tracer)

et_helper.erl

-module(et_helper).
-compile([export_all]).

-include_lib("et/include/et.hrl").

start() ->
    start([]).

start(ExtraOptions) ->
    Options = [{trace_global, true},
               {parent_pid, undefined},
               {max_actors, infinity},
               {max_events, 1000},
               {active_filter, module_as_actor}],
    et_viewer:start_link(filters() ++ Options ++ ExtraOptions).

trace(Mod) ->
    dbg:p(all, [call, timestamp]),
    dbg:tpl(Mod, [{'_', [], [{message, {caller}}, {return_trace}]}]).

filters() ->
    [{dict_insert, {filter, module_as_actor},
      fun module_as_actor/1},
     {dict_insert, {filter, plain_process_info},
      fun plain_process_info/1},
     {dict_insert, {filter, named_process_info},
      fun named_process_info/1}].

module_as_actor(E) when is_record(E, event) ->
    case lists:keysearch(mfa, 1, E#event.contents) of
        {value, {mfa, {M, F, _A}}} ->
            case lists:keysearch(pam_result, 1, E#event.contents) of
                {value, {pam_result, {M2, _F2, _A2}}} ->
                    {true, E#event{label = F, from = M2, to = M}};
                _ ->
                    {true, E#event{label = F, from = M, to = M}}
            end;
        _ ->
            false
    end.

named_process_info(E) when is_record(E, event) ->
    case plain_process_info(E) of
        true ->
            {true, E#event{to    = pid_to_name(E#event.to),
                           from  = pid_to_name(E#event.from),
                           label = msg_to_label(E)}};
        false ->
            false
    end.

plain_process_info(E) when is_record(E, event) ->
    case E#event.label of
        send                          -> true;
        send_to_non_existing_process  -> true;
        'receive'                     -> true;
        spawn                         -> true;
        exit                          -> true;
        link                          -> true;
        unlink                        -> true;
        getting_linked                -> true;
        {seq_send, _Label}            -> true;
        {seq_receive, _Label}         -> true;
        {seq_print, _Label}           -> true;
        {drop, _N}                    -> true;
        _                             -> false
    end.

pid_to_name(Pid) when is_pid(Pid) ->
    case process_info(Pid, registered_name) of
        {registered_name, Name} ->
            Name;
        _ ->
            Pid
    end;
pid_to_name({Name, Node}) when Node == node() ->
    Name;
pid_to_name(Other) ->
    Other.

msg_to_label(E) when is_record(E, event) ->
    case lists:keysearch(msg, 1, E#event.contents) of
        {value, {msg, Msg}} ->
            mnesia_msg_to_label(Msg, E#event.label);
        false ->
            E#event.label
    end.

mnesia_msg_to_label(Msg, Label) ->
    case Msg of
        {mnesia_tm, _Node, Reply} ->
            case Reply of
                ok                                 -> ok;
                store_erased                       -> store_erased;
                unblocked                          -> unblocked;
                {_From, _Ref, start_outer}         -> start_outer;
                {aborted, _Tid}                    -> aborted;
                {committed, _Tid}                  -> committed;
                {dirty_res, _Res}                  -> dirty_res;
                {error, _Reason}                   -> error;
                {info, _Part, _Coord}              -> info;
                {mnesia_tm, _Node, {'EXIT', _Reason}}   -> 'EXIT';
                {mnesia_tm, _Node, {dirty_res, _Reply}} -> dirty_res;
                {new_store, _Etab}                 -> new_store;
                {new_tid, _Tid, _Etab}             -> new_tid;
                {ok, _Name, _IgnoreNew, _Node}     -> ok;
                {restarted, _Tid}                  -> restarted;
                {vote_yes, _Tid, _Self}            -> vote_yes;
                {vote_yes, _Tid}                   -> vote_yes;
                {acc_pre_commit, _Tid, _Self, _Expect} -> acc_pre_commit;
                {schema_commit, _Tid, _Self}       -> schema_commit;
                {vote_no, _Tid, _Reason}           -> vote_no
            end;
        {'$gen_cast', allow_garb}                  -> allow_garb;
        {'$gen_cast', {release_schema_commit_lock, _Pid}} -> release_schema_commit_lock;
        {'$gen_call', _Ref, {mktab, _Name,_Args}}  -> mktab;
        {'$gen_call', _Ref, wait_for_schema_commit_lock} -> wait_for_schema_commit_lock;
        {'$gen_call', _Ref, {set_lock, _Key}}      -> set_global_lock;
        {'$gen_call', _Ref, {del_lock, _Key}}      -> del_global_lock;
        {'$gen_call', _Ref, {what_happened, _Decision, _Tid}} -> what_happened;
        {async_dump_log, _Reason}                  -> async_dump_log;
        check_overload                             -> check_overload;
        {dumper_done, _Pid, dumped}                -> dumper_done;
        garb_decisions                             -> garb_decisions;
        timeout                                    -> timeout;
        {mnesia_locker, _Node, granted}            -> granted;
        {mnesia_locker, _Node, {granted, _Lookup}} -> granted;
        {'EXIT', _Pid, _Reason}                    -> 'EXIT';
        {_From, info}                              -> info;
        {_From, start_outer}                       -> start_outer;
        {_From, {add_store, _Tid}}                 -> add_store;
        {_From, {ask_commit, _Prot, _Tid, _Commit, _DiscNs, _RamNs}} -> ask_commit;
        {_From, {async_dirty, _Tid, _Commit, _Tab}} -> async_dirty;
        {_From, {block_tab, _Tab}} -> block_tab;
        {_From, {del_store, _Tid, _Current, _Obsolete, _Prop}} -> del_store;
        {_From, {prepare_checkpoint, _Cp}}         ->prepare_checkpoint;
        {_From, {read, _Tid, _Oid}}                -> try_read_lock;
        {_From, {read_write, _Tid, _Oid}}          -> try_read_write_lock;
        {_From, {restart, _Tid, _Store}}           -> restart;
        {_From, {sync_dirty, _Tid, _Commit, _Tab}} -> sync_dirty;
        {_From, {unblock_me, _Tab}}                -> unblock_me;
        {_From, {unblock_tab, _Tab}}               -> unblock_tab;
        {_From, {write, _Tid, _Oid}}               -> try_write_lock;
        {_Tid, committed}                          -> committed;
        {_Tid, do_commit}                          -> do_commit;
        {_Tid, pre_commit}                         -> pre_commit;
        {_Tid, simple_commit}                      -> simple_commit;
        {_Tid, {do_abort, _Reason}}                -> do_abort;
        {activity_ended, _, _Pid}                  -> activity_ended;
        {ask_commit, _Protocol, _Tid, _Bin, _DiscNs, _RamNs} -> ask_commit;
        {delete_transaction, _Tid}                 -> delete_transaction;
        {mnesia_down, _Node}                       -> mnesia_down;
        {release_tid, _Tid}                        -> release_tid;
        {sync_trans_serial, _Tid}                  -> sync_trans_serial;
        {system, _From, _Msg}                      -> system;
        {transaction_done, _Res, _Pid}             -> transaction_done;
        {_Tid, {do_abort, _Reason}}                -> do_abort;
        {_Ref, granted}                            -> granted;
        _                                          -> Label
    end.

snippets.erl

code:add_path("/path/to/et_helper").
et_helper:start([]).
InitialModule = ejabberd_c2s.
et_helper:trace(InitialModule).