ardour/livetrax
13
0
Fork 0
Code

clean up functors used in cross-thread call_slot() messages, in case they contain shared_ptr<T>, which could result in a dangling reference

Browse Source
This commit is contained in:
Paul Davis 2016-01-16 09:33:15 -05:00
parent d61cf81997
commit 9d65e6084c
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
libs/pbd/pbd/abstract_ui.cc
View File

@ -224,6 +224,19 @@ AbstractUI<RequestObject>::handle_ui_requests ()
request_buffer_map_lock.unlock ();
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: valid request, calling ::do_request()\n", event_loop_name()));
do_request (vec.buf[0]);
/* if the request was CallSlot, then we need to ensure that we reset the functor in the request, in case it
* held a shared_ptr<>. Failure to do so can lead to dangling references to objects passed to PBD::Signals.
*
* Note that this method (::handle_ui_requests()) is by definition called from the event loop thread, so
* caller_is_self() is true, which means that the execution of the functor has definitely happened after
* do_request() returns and we no longer need the functor for any reason.
*/
if (vec.buf[0]->type == CallSlot) {
vec.buf[0]->the_slot = 0;
}
request_buffer_map_lock.lock ();
if (vec.buf[0]->invalidation) {
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: removing invalidation record for that request\n", event_loop_name()));