From ead883302fe800aec38bb3537d948b8c54a992ea Mon Sep 17 00:00:00 2001 From: Robin Gareus Date: Sat, 28 Mar 2020 17:31:12 +0100 Subject: Don't use shared-pointers in cross thread event structs This fixes a deadlock when closing the session. Session::destroy() takes the engine-lock while removing unhandled session-events. In [1], the event-queue held a last reference to a Track, and releasing that object triggered events (here ~IO) that required the lock. --- [1] #2 0x0041743a in Glib::Threads::Mutex::Lock::Lock at /home/ardour/linux-armhf/stack/include/glibmm-2.4/glibmm/threads.h:643 #3 0xb67433ba in ARDOUR::IO::~IO at ../libs/ardour/io.cc:105 #4 0xb6743612 in ARDOUR::IO::~IO at ../libs/ardour/io.cc:111 #5 0xb6758e66 in boost::checked_delete at /home/ardour/linux-armhf/stack/include/boost/core/checked_delete.hpp:34 #6 0xb675912c in boost::detail::sp_counted_impl_p::dispose at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/sp_counted_impl.hpp:92 #7 0x004178d8 in boost::detail::sp_counted_base::release at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/sp_counted_base_sync.hpp:129 #8 0x00417986 in boost::detail::shared_count::~shared_count at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/shared_count.hpp:426 #9 0xb662343a in boost::shared_ptr::~shared_ptr at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/shared_ptr.hpp:341 #10 0xb6a4af7a in ARDOUR::Route::~Route at ../libs/ardour/route.cc:282 #11 0xb6b9404c in ARDOUR::Track::~Track at ../libs/ardour/track.cc:71 #12 0xb697164a in ARDOUR::MidiTrack::~MidiTrack at ../libs/ardour/midi_track.cc:94 #13 0xb697177a in ARDOUR::MidiTrack::~MidiTrack at ../libs/ardour/midi_track.cc:96 #14 0xb6ac525a in boost::checked_delete at /home/ardour/linux-armhf/stack/include/boost/core/checked_delete.hpp:34 #15 0xb6acde00 in boost::detail::sp_counted_impl_p::dispose at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/sp_counted_impl.hpp:92 #16 0x004178d8 in boost::detail::sp_counted_base::release at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/sp_counted_base_sync.hpp:129 #17 0x00417986 in boost::detail::shared_count::~shared_count at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/detail/shared_count.hpp:426 #18 0xb664dca6 in boost::shared_ptr::~shared_ptr at /home/ardour/linux-armhf/stack/include/boost/smart_ptr/shared_ptr.hpp:341 #19 0xb6aaf67e in ARDOUR::SessionEvent::~SessionEvent at ../libs/ardour/ardour/session_event.h:42 #20 0xb6a91a88 in ARDOUR::Session::destroy at ../libs/ardour/session.cc:753 #21 0xb6a8fb20 in ARDOUR::Session::~Session at ../libs/ardour/session.cc:460 #22 0xb6a9075e in ARDOUR::Session::~Session at ../libs/ardour/session.cc:46 --- libs/ardour/session_process.cc | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'libs/ardour/session_process.cc') diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc index ebdb02f2b2..bc8cb91a51 100644 --- a/libs/ardour/session_process.cc +++ b/libs/ardour/session_process.cc @@ -948,7 +948,9 @@ Session::process_event (SessionEvent* ev) break; case SessionEvent::Overwrite: - overwrite_some_buffers (ev->track, ev->overwrite); + if (boost::shared_ptr track = ev->track.lock()) { + overwrite_some_buffers (track, ev->overwrite); + } break; case SessionEvent::Audition: -- cgit v1.2.3