add trace to pid other than group_leader()
diff --git a/README.md b/README.md
index 7663acf..afd0e1b 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,8 @@
`recon:proc_window`.
- Fix doc typos
- Fix potential race condition on waiting for death of tracing process
+ - Add an option which allows sending tracing output somewhere other than
+ group_leader().
- 2.2.1
- Fixing type specs for `recon:port_types/0` and `recon_lib:count/1`,
thanks to @lucafavatella
diff --git a/src/recon_trace.erl b/src/recon_trace.erl
index 7c9a78f..b012269 100644
--- a/src/recon_trace.erl
+++ b/src/recon_trace.erl
@@ -152,6 +152,20 @@
%%% In case the operator is tracing from a remote shell which gets
%%% disconnected, the links between the shell and the tracer should make it
%%% so tracing is automatically turned off once you disconnect.
+%%%
+%%% If sending output to the Group Leader is not desired, you may specify
+%%% a different pid() via the option `output' in the {@link calls/3} function.
+%%% For instance to write the traces to a file you can do something like
+%%%
+%%% 1> {ok, Dev} = file:open("/tmp/trace",[write]).
+%%% 2> recon_trace:calls({queue, in, fun(_) -> return_trace() end}, 3, [{output, Dev}]).
+%%% 1
+%%% 3>
+%%% Recon tracer rate limit tripped.
+%%% 4> file:close(Dev).
+%%%
+%%% The only output still sent to the Group Leader is the rate limit being
+%%% tripped, and any errors.
%%% @end
-module(recon_trace).
@@ -161,7 +175,7 @@
-export([format/1]).
%% Internal exports
--export([count_tracer/1, rate_tracer/2, formatter/4]).
+-export([count_tracer/1, rate_tracer/2, formatter/5]).
-type matchspec() :: [{[term()], [term()], [term()]}].
-type shellfun() :: fun((_) -> term()).
@@ -177,6 +191,7 @@
| {args, args | arity} % default: args
%% match pattern options
| {scope, global | local} % default: global
+ | {output, pid()} % default: group_leader()
].
-type mod() :: '_' | module().
@@ -305,10 +320,12 @@
calls({Mod, Fun, Args}, Max, Opts, FormatterFun) ->
calls([{Mod,Fun,Args}], Max, Opts, FormatterFun);
calls(TSpecs = [_|_], {Max, Time}, Opts, FormatterFun) ->
- Pid = setup(rate_tracer, [Max, Time], FormatterFun),
+ OutputTo = validate_output_to (Opts),
+ Pid = setup(rate_tracer, [Max, Time], FormatterFun, OutputTo),
trace_calls(TSpecs, Pid, Opts);
calls(TSpecs = [_|_], Max, Opts, FormatterFun) ->
- Pid = setup(count_tracer, [Max], FormatterFun),
+ OutputTo = validate_output_to (Opts),
+ Pid = setup(count_tracer, [Max], FormatterFun, OutputTo),
trace_calls(TSpecs, Pid, Opts).
%%%%%%%%%%%%%%%%%%%%%%%
@@ -345,11 +362,11 @@
end.
%% @private Formats traces to be output
-formatter(Tracer, Parent, Ref, FormatterFun) ->
+formatter(Tracer, Parent, Ref, FormatterFun, OutputTo) ->
process_flag(trap_exit, true),
link(Tracer),
Parent ! {Ref, linked},
- formatter(Tracer, group_leader(), FormatterFun).
+ formatter(Tracer, OutputTo, FormatterFun).
formatter(Tracer, Leader, FormatterFun) ->
receive
@@ -370,12 +387,12 @@
%% starts the tracer and formatter processes, and
%% cleans them up before each call.
-setup(TracerFun, TracerArgs, FormatterFun) ->
+setup(TracerFun, TracerArgs, FormatterFun, OutputTo) ->
clear(),
Ref = make_ref(),
Tracer = spawn_link(?MODULE, TracerFun, TracerArgs),
register(recon_trace_tracer, Tracer),
- Format = spawn(?MODULE, formatter, [Tracer, self(), Ref, FormatterFun]),
+ Format = spawn(?MODULE, formatter, [Tracer, self(), Ref, FormatterFun, OutputTo]),
register(recon_trace_formatter, Format),
receive
{Ref, linked} -> Tracer
@@ -449,6 +466,13 @@
_ when Args >= 0, Args =< 255 -> {Args, true}
end.
+validate_output_to(Opts) ->
+ OutputTo = proplists:get_value(output, Opts, undefined),
+ case OutputTo of
+ P when is_pid(OutputTo) -> P;
+ _ -> group_leader()
+ end.
+
%%%%%%%%%%%%%%%%%%%%%%%%
%%% TRACE FORMATTING %%%
%%%%%%%%%%%%%%%%%%%%%%%%
