From 12b14f9c79cdf097a53fe783d8dc1163ece5f591 Mon Sep 17 00:00:00 2001
From: Nick Vatamaniuc <vatamane@gmail.com>
Date: Thu, 6 May 2021 15:35:14 -0400
Subject: [PATCH] Introduce an option to not trap process exits in worker
 processes

When worker processes are part of an external connection pool it may make sense
to rely on automatic cleanup based on links. Since by default worker processes
trap exits, linked proceses would fail to terminate the ibrowse worker and
instead it would generate an '{'EXIT', Pid, Reason}' which is handled in
handle_info/2 with a warning to stdout.

Add a new option to allow users to control worker process link behavior via an
ibrowse config parameter. The default stays the same (=true).
---
 src/ibrowse_http_client.erl | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/ibrowse_http_client.erl b/src/ibrowse_http_client.erl
index e59228c..5443fe7 100644
--- a/src/ibrowse_http_client.erl
+++ b/src/ibrowse_http_client.erl
@@ -133,7 +133,7 @@ send_req(Conn_Pid, Url, Headers, Method, Body, Options, Timeout) ->
 %%          {stop, Reason}
 %%--------------------------------------------------------------------
 init({Lb_Tid, #url{host = Host, port = Port}, {SSLOptions, Is_ssl}}) ->
-    process_flag(trap_exit, true),
+    maybe_trap_exits(),
     State = #state{host = Host,
                    port = Port,
                    ssl_options = SSLOptions,
@@ -143,7 +143,7 @@ init({Lb_Tid, #url{host = Host, port = Port}, {SSLOptions, Is_ssl}}) ->
     put(my_trace_flag, ibrowse_lib:get_trace_status(Host, Port)),
     {ok, set_inac_timer(State)};
 init(Url) when is_list(Url) ->
-    process_flag(trap_exit, true),
+    maybe_trap_exits(),
     case catch ibrowse_lib:parse_url(Url) of
         #url{protocol = Protocol} = Url_rec ->
             init({undefined, Url_rec, {[], Protocol == https}});
@@ -151,7 +151,7 @@ init(Url) when is_list(Url) ->
             {error, invalid_url}
     end;
 init({Host, Port}) ->
-    process_flag(trap_exit, true),
+    maybe_trap_exits(),
     State = #state{host = Host,
                    port = Port},
     put(ibrowse_trace_token, [Host, $:, integer_to_list(Port)]),
@@ -2187,3 +2187,9 @@ get_header_value(Name, Headers, Default_val) ->
 
 delayed_stop_timer() ->
     erlang:send_after(500, self(), delayed_stop).
+
+maybe_trap_exits() ->
+    case ibrowse:get_config_value(worker_trap_exits, true) of
+        true -> process_flag(trap_exit, true);
+        false -> ok
+    end.