The R13B03 release.OTP_R13B03

1 files changed, 963 insertions, 0 deletions

diff --git a/lib/appmon/src/appmon_info.erl b/lib/appmon/src/appmon_info.erl
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+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+%%----------------------------------------------------------------------
+%%
+%% Information centre for appmon. Must be present on each node
+%% monitored.
+%%
+%%
+%%	A worklist is maintained that contain all current work that
+%%	should be performed at each timeout. Each entry in the
+%%	worklist describes where the result shall be sent and a list
+%%	of options relevant for that particular task
+%%
+%%
+%% Maintenance Note:
+%%
+%%	This module is supposed to be updated by any who would like to
+%%	subscribe for information. The idea is that several tools
+%%	could use this module for their core information gathering
+%%	services.
+%%
+%%	The module is based on the notion of tasks. Each task should
+%%	have a nice public interface function which should handle task
+%%	administration. Tasks are identified by a "key" consisting of
+%%	three items, the requesting pid, the name of the task and the
+%%	task auxillary parameter. The requesting pid is the pid of the
+%%	callee (in the appmon case it can be the node window for
+%%	instance), the task name is whatever name the task is given
+%%	(in the appmon case it can be app, app_ctrl or load). The task
+%%	name can be seen as the type of the task. The task auxillary
+%%	parameter is an all purpose parameter that have a different
+%%	meaning for each type of task so in appmon the Aux for app
+%%	contains the root pid of the monitored application and in
+%%	app_ctrl it contains the node name (just to distinguish from
+%%	the other app_ctrl tasks, if any) while the Aux parameter is
+%%	not used for the load task at all.
+%%
+%%	Each task also carries a list of options for
+%%	customisation. The options valid for a task is completely
+%%	internal to that task type except for the timeout option which
+%%	is used by do_work to determine the interval at which to
+%%	perform the task. The timeout option may also have the value
+%%	at_most_once that indicates that the task should not be done
+%%	more than once, in appmon the remote port (or process) info
+%%	(pinfo) task is such a task that is only done once for each
+%%	call. Note that the only way to change or update options is to
+%%	call the public interface function for the task, this will
+%%	merge the old options with the new ones and also force the
+%%	task to be executed.
+%%
+%%	All tasks are managed by the do_work function. The basic
+%%	functionality being that the result of the task is compared to
+%%	the previous result and a delivery is sent to the callee if
+%%	they differ. Most tasks are then done on a regular basis using
+%%	the timer module for a delay.
+%%	
+%%	There are a limited number of places where the module need to
+%%	be updated when new services are added, they are all marked
+%%	with "Maintenance Note", and here is a quick guide:
+%%
+%%	First implement the task. Put the functions in this module
+%%	among the other task implementations. Currently all task
+%%	implementations should be put in this file to make it simple
+%%	to monitor a node, this module should be the only one
+%%	needed. Then add your implementation to the do_work2 function
+%%	and finally add a public interface function among the other
+%%	public interface functions. Voila.
+%%
+%%
+%%
+%%	Future ideas:
+%%
+%%	Appmon should maybe be enhanced to show all processes on a
+%%	node. First put all processes in an ets P, then pick those
+%%	that belong to applications (the normal way), then try to find
+%%	those processes that are roots in process link trees and pick
+%%	them. The final step would be to do something with those
+%%	processes that are left.
+%%
+%%----------------------------------------------------------------------
+-module(appmon_info).
+-behaviour(gen_server).
+
+%% Exported functions
+-export([start_link/3, app/4, pinfo/4, load/4, app_ctrl/4]).
+
+%% For internal use (RPC call)
+-export([start_link2/3]).
+
+%% For debugging
+-export([status/0]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+	 terminate/2, code_change/3]).
+
+
+%%----------------------------------------------------------------------
+%% The records
+%%
+%%	state is used for keeping track of all tasks.
+%%
+%%	db is the database used in the app task.
+%%
+
+-record(state, {starter, opts=[], work=[], clients=[]}).
+-record(db, {q, p, links, links2}).
+
+
+%%----------------------------------------------------------------------
+%% Macros
+%%
+
+-define(MK_KEY(CMD, AUX, FROM, OPTS), {CMD, AUX, FROM}).
+-define(MK_DOIT(KEY), {do_it, KEY}).
+-define(ifthen(P,S), if P -> S; true -> ok end).
+
+
+%%----------------------------------------------------------------------
+%% Public interface
+%%
+%%	The Aux parameter is an auxillary parameter that can be used
+%%	freely by the requesting process, it is included in the work
+%%	task key. appmon uses it for storing the node name when
+%%	requesting load and app_ctrl tasks, and appmon_a uses it for
+%%	storing application name when requesting app task.
+%%
+%%	Maintenance Note: Put new tasks at the end, please.
+%%
+
+
+%% Do not use gen_server:start_link because we do not want the
+%% appmon_info to die when initiating process dies unless special
+%% conditions apply.
+%% Uhu, we don't??? Made a fix so that this proces DOES indeed die
+%% if it's starter dies. /Gunilla
+start_link(Node, Client, Opts) ->
+    rpc:call(Node, ?MODULE, start_link2, [self(), Client, Opts]).
+start_link2(Starter, Client, Opts) ->
+    Name = {local, ?MODULE},
+    Args = {Starter, Opts, Client},
+    case gen_server:start(Name, ?MODULE, Args, []) of
+	{ok, Pid} ->
+	    {ok, Pid};
+	{error, {already_started, Pid}} -> 
+	    register_client(Pid, Client),
+	    {ok, Pid}
+    end.
+	
+
+%% app_ctrl
+%%
+%%	Monitors which applications exist on a node
+%%
+app_ctrl(Serv, Aux, OnOff, Opts) ->
+    gen_server:cast(Serv, {self(), app_ctrl, Aux, OnOff, Opts}).
+
+
+%% load
+%%
+%%	Monitors load on a node
+%%
+load(Serv, Aux, OnOff, Opts) ->
+    gen_server:cast(Serv, {self(), load, Aux, OnOff, Opts}).
+
+
+%% app
+%%
+%%	Monitors one application given by name (this ends up in a
+%%	process tree
+%%
+app(Serv, AppName, OnOff, Opts) ->
+    gen_server:cast(Serv, {self(), app, AppName, OnOff, Opts}).
+
+%% pinfo
+%%
+%%	Process or Port info
+%%
+pinfo(Serv, Pid, OnOff, Opt) ->
+    gen_server:cast(Serv, {self(), pinfo, Pid, OnOff, Opt}).
+
+%% register_client
+%%
+%%	Registers a client (someone subscribing for information)
+%%
+
+register_client(Serv, P) ->
+    link(Serv),
+    gen_server:call(Serv, {register_client, P}).
+
+%% status
+%%
+%%	Status of appmon_info
+%%
+
+status() ->
+    gen_server:cast(?MODULE, status).
+
+%%----------------------------------------------------------------------
+%%
+%% Gen server administration
+%%
+%%----------------------------------------------------------------------
+
+init({Starter, Opts, Pid}) ->
+    link(Pid),
+    process_flag(trap_exit, true),
+    WorkStore = ets:new(workstore, [set, public]),
+    {ok, #state{starter=Starter, opts=Opts, work=WorkStore,
+		clients=[Pid]}}.
+
+terminate(_Reason, State) ->
+    ets:delete(State#state.work),
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+
+%%----------------------------------------------------------------------
+%%
+%% Gen server calls
+%%
+%%----------------------------------------------------------------------
+
+handle_call({register_client, Pid}, _From, State) ->
+    NewState = case lists:member(Pid, State#state.clients) of
+		   true -> State;
+		   _ -> State#state{clients=[Pid | State#state.clients]}
+	       end,
+    {reply, ok, NewState};
+handle_call(_Other, _From, State) ->
+    {reply, ok, State}.
+
+%%----------------------------------------------------------------------
+%%
+%% Gen server casts
+%%
+%%----------------------------------------------------------------------
+
+%% Cmd = app_ctrl | load | app | pinfo
+handle_cast({From, Cmd, Aux, OnOff, Opts}, State) ->
+    NewState = update_worklist(Cmd, Aux, From, OnOff, Opts, State),
+    {noreply, NewState};
+handle_cast(status, State) ->
+    print_state(State),
+    {noreply, State};
+handle_cast(_Other, State) ->
+    {noreply, State}.
+
+
+%%----------------------------------------------------------------------
+%%
+%% Gen server info's
+%%
+%%----------------------------------------------------------------------
+
+handle_info({do_it, Key}, State) ->
+    ok = do_work(Key, State),
+    {noreply, State};
+
+handle_info({'EXIT', Pid, Reason}, State) ->
+    case State#state.starter of
+	Pid ->
+	    {stop, Reason, State};
+	_Other ->
+	    Work = State#state.work,
+	    del_work(ets:match(Work, {{'$1','$2',Pid}, '_', '_', '_'}),
+		     Pid, Work),
+	    case lists:delete(Pid, State#state.clients) of
+		[] -> case get_opt(stay_resident, State#state.opts) of
+			  true -> {noreply, State#state{clients=[]}};
+			  _ -> {stop, normal, State}
+		      end;
+		NewClients -> {noreply, State#state{clients=NewClients}}
+	    end
+    end;
+handle_info(_Other, State) ->
+    {noreply, State}.
+
+
+%%----------------------------------------------------------------------
+%%
+%% Doing actual work
+%%
+%%----------------------------------------------------------------------
+
+do_work(Key, State) ->
+    WorkStore = State#state.work,
+    {Cmd, Aux, From, _OldRef, Old, Opts} = retrieve(WorkStore, Key),
+    {ok, Result} = do_work2(Cmd, Aux, From, Old, Opts),
+    if
+	Result==Old -> ok;
+	true ->
+	    From ! {delivery, self(), Cmd, Aux, Result}
+    end,
+    case get_opt(timeout, Opts) of
+	at_most_once ->
+	    del_task(Key, WorkStore);
+	T when is_integer(T) ->
+	    {ok, Ref} = timer:send_after(T, ?MK_DOIT(Key)),
+	    store(WorkStore, Key, Ref, Result, Opts)
+    end,
+    ok.
+
+
+%%----------------------------------------------------------------------
+%%
+%% Name: do_work2
+%%
+%% Maintenance Note: Add a clause here for each new task.
+%%
+do_work2(load, _Aux, _From, Old, Opts) ->
+    calc_load(Old, Opts);
+do_work2(app_ctrl, _Aux, _From, _Old, _Opts) ->
+    calc_app_on_node();
+do_work2(app, Aux, _From, _Old, Opts) ->
+    calc_app_tree(Aux, Opts);
+do_work2(pinfo, Aux, _From, _Old, _Opts) ->
+    calc_pinfo(pinfo, Aux);
+do_work2(Cmd, Aux, _From, _Old, _Opts) ->
+    {Cmd, Aux}.
+
+
+retrieve(Tab, Key) ->
+    case ets:lookup(Tab, Key) of
+	[{{Cmd, Aux, From}, Ref, Old, Opts}] ->
+	    {Cmd, Aux, From, Ref, Old, Opts};
+	_Other ->
+	    false
+    end.
+
+store(Tab, Key, Ref, Old, Opts) ->
+    ets:insert(Tab, {Key, Ref, Old, Opts}),
+    Key.
+
+
+%%----------------------------------------------------------------------
+%%
+%% WorkStore handling
+%%
+%%----------------------------------------------------------------------
+
+update_worklist(Cmd, Aux, From, true, Opts, State) ->
+    add_task(Cmd, Aux, From, Opts, State),
+    State;
+update_worklist(Cmd, Aux, From, _Other, _Opts, State) ->
+    del_task(Cmd, Aux, From, State#state.work),
+    State.
+
+%% First check if a task like this already exists and if so cancel its
+%% timer and make really sure that no stray do it command will come
+%% later. Then start a new timer for the task and store it i
+%% WorkStorage
+add_task(Cmd, Aux, From, Opts, State) ->
+    WorkStore = State#state.work,
+    Key = ?MK_KEY(Cmd, Aux, From, Opts),
+    OldOpts = del_task(Key, WorkStore),
+    store(WorkStore, Key, nil, nil, ins_opts(Opts, OldOpts)),
+    catch do_work(Key, State),
+    ok.
+
+%% Delete a list of tasks belonging to a pid
+del_work([[Cmd, Aux] | Ws], Pid, Work) ->
+    del_task(Cmd, Aux, Pid, Work),
+    del_work(Ws, Pid, Work);
+del_work([], _Pid, _Work) -> ok.
+
+%% Must return old options or empty list
+del_task(Cmd, Aux, From, WorkStore) ->
+    del_task(?MK_KEY(Cmd, Aux, From, []), WorkStore).
+del_task(Key, WorkStore) ->
+    OldStuff = retrieve(WorkStore, Key),
+    ets:delete(WorkStore, Key),
+    case OldStuff of
+	{_Cmd, _Aux, _From, Ref, _Old, Opts} ->
+	    if
+		Ref /= nil ->
+		    timer:cancel(Ref),
+		    receive
+			{do_it, Key} ->
+			    Opts
+		    after 10 ->
+			    Opts
+		    end;
+		true -> Opts
+	    end;
+	_ ->
+	    []
+    end.
+
+
+%%
+%% Maintenance Note:
+%%
+%% Add new task implementations somewhere here below.
+%%
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% BEGIN OF calc_app_tree
+%%
+%%	App tree is the process tree shown in the application window
+%%
+%%	The top (root) pid is found by calling
+%%	application_controller:get_master(AppName) and this is done in
+%%	calc_app_on_node (before the call to calc_app_tree).
+%%
+%%	We are going to add processes to the P ets and we are doing it
+%%	in a two step process. First all prospect processes are put on
+%%	the queue Q. Then we examine the front of Q and add this
+%%	process to P if it's not already in P. Then all children of
+%%	the process is put on the queue Q and the process is repeated.
+%%
+%%	We also maintain two link ets'es, one for primary links and
+%%	one for secondary links. These databases are updated at the
+%%	same time as the queue is updated with children.
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+
+calc_app_tree(Name, Opts) ->
+    Mode = get_opt(info_type, Opts),
+    case application_controller:get_master(Name) of
+	Pid when is_pid(Pid) ->
+	    DB = new_db(Mode, Pid),
+	    GL = groupl(Pid),
+	    R = case catch do_find_proc(Mode, DB, GL, find_avoid()) of
+		    {ok, DB2} ->
+			{ok, {format(Pid),
+			      format(ets:tab2list(DB2#db.p)),
+			      format(ets:tab2list(DB2#db.links)), 
+			      format(ets:tab2list(DB2#db.links2))}};
+		    {error, Reason} -> 
+			{error, Reason};
+		    Other ->
+			{error, Other}
+		end,
+	    ets:delete(DB#db.p),
+	    ets:delete(DB#db.links),
+	    ets:delete(DB#db.links2),
+	    R;
+	_ ->
+	    {ok, {[], [], [], []}}
+    end.
+
+get_pid(P) when is_pid(P) -> P;
+get_pid(P) when is_port(P) -> P;
+get_pid(X) when is_tuple(X) -> element(2, X).
+
+
+%----------------------------------------------------------------------
+%%---------------------------------------------------------------------
+%% Handling process trees of processses that are linked to each other
+
+do_find_proc(Mode, DB, GL, Avoid) ->
+    case get_next(DB) of
+	{{value, V}, DB2} ->
+	    do_find_proc2(V, Mode, DB2, GL, Avoid);
+	{empty, DB2} ->
+	    {ok, DB2}
+    end.
+
+do_find_proc2(X, Mode, DB, GL, Avoid) when is_port(X) ->
+    %% There used to be a broken attempt here to handle ports,
+    %% but the rest of appmon can't handle ports, so now we
+    %% explicitly ignore ports.
+    do_find_proc(Mode, DB, GL, Avoid);
+do_find_proc2(X, Mode, DB, GL, Avoid) ->
+    Xpid = get_pid(X),
+    DB2 = case is_proc(DB, Xpid) of
+	      false ->
+		  add_proc(DB, Xpid),
+		  C1 = find_children(X, Mode),
+		  add_children(C1, Xpid, DB, GL, Avoid, Mode);
+	      _ -> 
+		  DB
+	  end,
+    do_find_proc(Mode, DB2, GL, Avoid).
+
+
+%% Find children finds the children of a process. The method varies
+%% with the selected mode (sup or link) and there are also some
+%% processes that must be treated differently, notably the application
+%% master.
+%% 
+find_children(X, sup) when is_pid(X) ->
+    %% This is the first (root) process of a supervision tree and it
+    %% better be a supervisor, we are smoked otherwise
+    supervisor:which_children(X);
+find_children(X, link) when is_pid(X), node(X) /= node() ->
+    [];
+find_children(X, link) when is_pid(X) ->
+    case process_info(X, links) of
+	{links, Links} ->
+	    lists:reverse(Links); % OTP-4082
+	_ -> []
+    end;
+find_children({master, X}, sup) -> 
+    case application_master:get_child(X) of
+	{Pid, _Name} when is_pid(Pid) -> [Pid];
+	Pid when is_pid(Pid) -> [Pid]
+    end;
+find_children({_, _X, worker, _}, sup) -> [];
+find_children({_, X, supervisor, _}, sup) ->
+    lists:filter(fun(Thing) -> 
+			 Pid = get_pid(Thing),
+			 if
+			     is_pid(Pid) -> true;
+			     true -> false
+			 end
+		 end,
+		 supervisor:which_children(X)).
+
+
+%% Add links to primary (L1) or secondary (L2) sets and return an
+%% updated queue. A link is considered secondary if its endpoint is in
+%% the queue of un-visited but known processes.
+add_children(CList, Paren, DB, _GL, _Avoid, sup) ->
+    lists:foldr(fun(C, DB2) -> 
+			case get_pid(C) of
+			    P when is_pid(P) -> 
+				add_prim(C, Paren, DB2);
+			    _ -> DB2 end end,
+		DB, CList);
+
+add_children(CList, Paren, DB, GL, Avoid, _Mode) ->
+    lists:foldr(fun(C, DB2) ->
+			maybe_add_child(C, Paren, DB2, GL, Avoid)
+		end, DB, CList).
+
+%% Check if the child is already in P
+maybe_add_child(C, Paren, DB, GL, Avoid) ->
+    case is_proc(DB, C) of
+	false -> 
+	    maybe_add_child_node(C, Paren, DB, GL, Avoid);
+	_ -> DB					% In P: no action
+    end.
+
+%% Check if process on this node
+maybe_add_child_node(C, Paren, DB, GL, Avoid) ->
+    if
+	node(C) /= node() -> 
+	    add_foreign(C, Paren, DB);
+	true -> 
+	    maybe_add_child_avoid(C, Paren, DB, GL, Avoid)
+    end.
+
+%% Check if child is on the avoid list
+maybe_add_child_avoid(C, Paren, DB, GL, Avoid) ->
+    case lists:member(C, Avoid) of
+	true -> DB;
+	false ->
+	    maybe_add_child_port(C, Paren, DB, GL)
+    end.
+
+%% Check if it is a port, then it is added
+maybe_add_child_port(C, Paren, DB, GL) ->
+    if
+	is_port(C) ->
+	    add_prim(C, Paren, DB);
+	true ->
+	    maybe_add_child_sasl(C, Paren, DB, GL)
+    end.
+
+%% Use SASL stuff if present
+maybe_add_child_sasl(C, Paren, DB, GL) ->
+    case check_sasl_ancestor(Paren, C) of
+	yes ->					% Primary
+	    add_prim(C, Paren, DB);
+	no ->					% Secondary
+	    add_sec(C, Paren, DB);
+	dont_know ->
+	    maybe_add_child_gl(C, Paren, DB, GL)
+    end.
+		    
+%% Check group leader
+maybe_add_child_gl(C, Paren, DB, GL) ->
+    case cmp_groupl(GL, groupl(C)) of
+	true -> maybe_add_child_sec(C, Paren, DB);
+	_ -> DB
+    end.
+
+%% Check if the link should be a secondary one. Note that this part is
+%% pretty much a guess.
+maybe_add_child_sec(C, Paren, DB) ->
+    case is_in_queue(DB, C) of
+	true ->					% Yes, secondary
+	    add_sec(C, Paren, DB);
+	_ ->					% Primary link
+	    add_prim(C, Paren, DB)
+    end.
+
+check_sasl_ancestor(Paren, C) ->
+    case lists:keysearch('$ancestors', 1, 
+			 element(2,process_info(C, dictionary))) of
+	{value, {_, L}} when is_list(L) ->
+	    H = if
+		    is_atom(hd(L)) -> whereis(hd(L));
+		    true -> hd(L)
+		end,
+	    if
+		H == Paren -> yes;
+		true -> no
+	    end;
+	_ -> dont_know
+    end.
+
+
+%----------------------------------------------------------------------
+%%---------------------------------------------------------------------
+%% Primitives for the database DB of all links, processes and the
+%% queue of not visited yet processes.
+
+-define(add_link(C, Paren, L), ets:insert(L, {Paren, C})).
+
+new_db(Mode, Pid) ->
+    P  = ets:new(processes, [set, public]),
+    L1 = ets:new(links, [bag, public]),
+    L2 = ets:new(extralinks, [bag, public]),
+    Q = if
+	    Mode =:= sup -> queue:in({master, Pid}, queue:new());
+	    true -> queue:in(Pid, queue:new())
+	end,
+    #db{q=Q, p=P, links=L1, links2=L2}.
+
+get_next(DB) ->
+    {X, Q} = queue:out(DB#db.q),
+    {X, DB#db{q=Q}}.
+add_proc(DB, P) ->
+    ets:insert(DB#db.p, {P}).
+add_prim(C, Paren, DB) ->
+    ?add_link(get_pid(C), Paren, DB#db.links),
+    DB#db{q=queue:in(C, DB#db.q)}.
+add_foreign(C, Paren, DB) ->
+    ?add_link(C, Paren, DB#db.links2),
+    DB#db{q=queue:in(C, DB#db.q)}.
+add_sec(C, Paren, DB) ->
+    ?add_link(C, Paren, DB#db.links2),
+    DB.
+
+is_proc(#db{p=Tab}, P) ->
+    ets:member(Tab, P).
+
+is_in_queue(#db{q=Q}, P) ->
+    queue:member(P, Q).
+
+%% Group leader handling. No processes or Links to processes must be
+%% added when group leaders differ. Note that catch all is needed
+%% because net_sup is undefined when not networked but still present
+%% in the kernel_sup child list. Blahh, didn't like that.
+groupl(P) ->
+    case process_info(P, group_leader) of
+	{group_leader, GL} -> GL;
+	_Other -> nil
+    end.
+
+cmp_groupl(_GL1, nil) -> true;
+cmp_groupl(GL1, GL1) -> true;
+cmp_groupl(_, _) -> false.
+
+
+%% Do some intelligent guessing as to cut in the tree
+find_avoid() ->
+    lists:foldr(fun(X, Accu) -> 
+		       case whereis(X) of
+			   P when is_pid(P) ->
+			       [P|Accu];
+			   _ -> Accu end end,
+		[undefined],
+		[application_controller, init, error_logger, gs, 
+		 node_serv, appmon, appmon_a, appmon_info]).
+
+
+
+%%----------------------------------------------------------------------
+%%
+%% Formats the output strings
+%%
+%%----------------------------------------------------------------------
+format([{P} | Fs]) ->				% Process or port
+    [{P, format(P)} | format(Fs)];
+format([{P1, P2} | Fs]) ->			% Link
+    [{format(P1), format(P2)} | format(Fs)];
+format([]) -> [];
+format(P) when is_pid(P), node(P) /= node() ->
+    pid_to_list(P) ++ " " ++ atom_to_list(node(P));
+format(P) when is_pid(P) ->
+    case process_info(P, registered_name) of
+	{registered_name, Name} -> atom_to_list(Name);
+	_ -> pid_to_list(P)
+    end;
+format(P) when is_port(P) ->
+    "port " ++ integer_to_list(element(2, erlang:port_info(P, id)));
+format(X) ->
+    io:format("What: ~p~n", [X]),
+    "???".
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% END OF calc_app_tree
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% BEGIN OF calc_app_on_node
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+%% Finds all applications on a node
+calc_app_on_node() ->
+    NewApps = reality_check(application:which_applications()),
+    {ok, NewApps}.
+
+
+reality_check([E|Es]) ->
+    N = element(1, E),
+    case catch application_controller:get_master(N) of
+        P when is_pid(P) -> [{P, N, E} | reality_check(Es)];
+        _ -> reality_check(Es)
+    end;
+reality_check([]) -> [].
+
+
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% END OF calc_app_on_node
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% BEGIN OF calc_load
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+calc_load(Old, Opts) ->
+    L = load(Opts),
+    case get_opt(load_average, Opts) of
+	true ->
+	    case Old of
+		{_, L} -> {ok, {L, L}};
+		{_, O2} when abs(L-O2) < 3 -> {ok, {O2, L}};
+		{_, O2}	-> {ok, {O2, trunc((2*L+O2)/3)}};
+		_ -> {ok, {0, L}}
+	    end;
+	_ -> 
+	    case Old of
+		{_, O2} -> {ok, {O2, L}};
+		_ -> {ok, {0, L}}
+	    end
+    end.
+
+
+load(Opts) ->
+    Q   = get_sample(queue),
+
+    case get_opt(load_method, Opts) of
+	time ->
+	    Td  = get_sample(runtime),
+	    Tot = get_sample(tot_time),
+	    
+	    case get_opt(load_scale, Opts) of
+		linear ->
+		    min(trunc(load_range()*(Td/Tot+Q/6)),
+			load_range());
+		prog ->
+		    min(trunc(load_range()*prog(Td/Tot+Q/6)),
+			load_range())
+	    end;
+	queue ->
+	    case get_opt(load_scale, Opts) of
+		linear ->
+		    min(trunc(load_range()*Q/6), load_range());
+		prog ->
+		    min(trunc(load_range()*prog(Q/6)), load_range())
+		end
+    end.
+
+min(X,Y) when X<Y -> X;
+min(_,Y)->Y.
+
+
+%%
+%% T shall be within 0 and 0.9 for this to work correctly
+prog(T) ->
+    math:sqrt(abs(T)/0.9).
+
+
+get_sample(queue)  -> statistics(run_queue);
+get_sample(runtime)  -> {Rt,Rd} = statistics(runtime), 
+			delta(runtime, Rt, Rd);
+get_sample(tot_time)  -> {Rt,Rd} = statistics(wall_clock), 
+			 delta(tot_time, Rt, Rd).
+
+
+%% Keeps track of differences between calls
+%% Needed because somebody else might have called
+%% statistics/1.
+%%
+%% Note that due to wrap-arounds, we use a cheating 
+%% delta which is correct unless somebody else
+%% uses statistics/1
+delta(KeyWord, Val, CheatDelta) ->
+    RetVal = case get(KeyWord) of 
+		 undefined ->
+		     Val;
+		 Other ->
+		     if
+			 Other > Val ->
+			     CheatDelta;
+			 true ->
+			     Val-Other
+		     end
+	     end,
+    put(KeyWord, Val),
+    RetVal.
+
+
+load_range() -> 16.
+
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% END OF calc_load
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% BEGIN OF calc_pinfo
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+calc_pinfo(pinfo, Pid) when is_pid(Pid) ->
+    Info = process_info(Pid),
+    {ok, io_lib:format("Node: ~p, Process: ~p~n~p~n~n",
+		       [node(), Pid, Info])};
+calc_pinfo(pinfo, Pid) when is_port(Pid) ->
+    Info = lists:map(fun(Key) ->erlang:port_info(Pid, Key) end,
+		     [id, name, connected, links, input, output]),
+    
+    {ok, io_lib:format("Node: ~p, Port: ~p~n~p~n~n", 
+		       [node(),  element(2, erlang:port_info(Pid, id)),
+			Info])};
+calc_pinfo(pinfo, _Pid) ->
+    {ok, ""}.
+
+
+%%----------------------------------------------------------------------
+%%**********************************************************************
+%%
+%%
+%% END OF calc_pinfo
+%%
+%%
+%%**********************************************************************
+%%----------------------------------------------------------------------
+
+
+
+%%----------------------------------------------------------------------
+%%
+%% Print the State
+%%
+%%	-record(state, {opts=[], work=[], clients=[]}).
+%%
+%%----------------------------------------------------------------------
+print_state(State) ->
+    io:format("Status:~n    Opts: ~p~n"
+	      "Clients: ~p~n    WorkStore:~n",
+	      [State#state.opts, State#state.clients]),
+    print_work(ets:tab2list(State#state.work)).
+
+print_work([W|Ws]) ->
+    io:format("        ~p~n", [W]), print_work(Ws);
+print_work([]) -> ok.
+    
+
+%%----------------------------------------------------------------------
+%%
+%% Option handling
+%%
+%%----------------------------------------------------------------------
+
+%% The only options ever set by a user is info_type, timeout,
+%% load_scale and load_method.
+get_opt(Name, Opts) ->
+    case lists:keysearch(Name, 1, Opts) of
+	{value, Val} -> element(2, Val);
+	false -> default(Name)
+    end.
+
+%% not all options have default values
+default(info_type)	-> link;
+default(load_average)	-> true;
+default(load_method)	-> time;
+default(load_scale)	-> prog;
+default(stay_resident)	-> false;
+default(timeout)	-> 2000.
+
+ins_opts([Opt | Opts], Opts2) ->
+    ins_opts(Opts, ins_opt(Opt, Opts2));
+ins_opts([], Opts2) -> Opts2.
+
+ins_opt({Opt, Val}, [{Opt, _} | Os]) -> [{Opt, Val} | Os];
+ins_opt(Opt, [Opt2 | Os]) -> [Opt2 | ins_opt(Opt, Os)];
+ins_opt(Opt, []) -> [Opt].