%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions 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},
ok
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 ->
{ok,_} = 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 ->
erlang:min(trunc(load_range()*(Td/Tot+Q/6)),
load_range());
prog ->
erlang:min(trunc(load_range()*prog(Td/Tot+Q/6)),
load_range())
end;
queue ->
case get_opt(load_scale, Opts) of
linear ->
erlang:min(trunc(load_range()*Q/6), load_range());
prog ->
erlang:min(trunc(load_range()*prog(Q/6)), load_range())
end
end.
%%
%% 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].
