extcap: discover interfaces in a parallel

Split interface discovery in three stages: discover available programs
(extcap_get_extcap_paths), obtain outputs for each (extcap_run_all) and
processing of the output (process_new_extcap). The second step is most
expensive, do it in parallel in multiple threads.

extcap_foreach used to call extcap_if_exists, but as "cb_info.ifname" is
always NULL for interface discovery, it would always pass. Remove this
check and all other unused functions.

This saves 100ms startup time on Linux with 7 extcap tools.

Change-Id: I511e491d3b23c0a7f2fe2447842e87a9bd75adbe
Ping-Bug: 15295
Reviewed-on: https://code.wireshark.org/review/30766
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 0 insertions, 4 deletions

diff --git a/extcap.h b/extcap.h
index 386955dd61..55f4af7f69 100644
--- a/extcap.h
+++ b/extcap.h
@@ -65,10 +65,6 @@ struct _extcap_arg;
 extern "C" {
 #endif /* __cplusplus */
 
-/* Count the number of extcap binaries */
-guint
-extcap_count(void);
-
 /* Registers preferences for all interfaces */
 void
 extcap_register_preferences(void);