diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cowboy_tracer_h.erl | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/src/cowboy_tracer_h.erl b/src/cowboy_tracer_h.erl index 914c678..6c6340d 100644 --- a/src/cowboy_tracer_h.erl +++ b/src/cowboy_tracer_h.erl @@ -21,6 +21,8 @@ -export([terminate/3]). -export([early_error/5]). +-export([set_trace_patterns/0]). + -export([tracer_process/3]). -export([system_continue/3]). -export([system_terminate/4]). @@ -66,6 +68,15 @@ terminate(StreamID, Reason, Next) -> early_error(StreamID, Reason, PartialReq, Resp, Opts) -> cowboy_stream:early_error(StreamID, Reason, PartialReq, Resp, Opts). +%% API. + +%% These trace patterns are most likely not suitable for production. +-spec set_trace_patterns() -> ok. +set_trace_patterns() -> + erlang:trace_pattern({'_', '_', '_'}, [{'_', [], [{return_trace}]}], [local]), + erlang:trace_pattern(on_load, [{'_', [], [{return_trace}]}], [local]), + ok. + %% Internal. init_tracer(StreamID, Req, Opts=#{tracer_match_specs := List, tracer_callback := _}) -> @@ -119,12 +130,15 @@ start_tracer(StreamID, Req, Opts) -> case erlang:trace_info(self(), tracer) of {tracer, []} -> TracerPid = proc_lib:spawn_link(?MODULE, tracer_process, [StreamID, Req, Opts]), - erlang:trace_pattern({'_', '_', '_'}, [{'_', [], [{return_trace}]}], [local]), - erlang:trace_pattern(on_load, [{'_', [], [{return_trace}]}], [local]), - erlang:trace(self(), true, [ - send, 'receive', call, return_to, procs, ports, - monotonic_timestamp, set_on_spawn, {tracer, TracerPid} + %% The default flags are probably not suitable for production. + Flags = maps:get(tracer_flags, Opts, [ + send, 'receive', call, return_to, + procs, ports, monotonic_timestamp, + %% The set_on_spawn flag is necessary to catch events + %% from request processes. + set_on_spawn ]), + erlang:trace(self(), true, [{tracer, TracerPid}|Flags]), ok; _ -> ok |