--- /dev/null
+VEdit::render checking out
+Cache::check_out 1
+Cache::check_out 2
+ VEdit::draw checking out
+ Cache::check_out 1
+VEdit::render checking in
+ ATrack::render checking out
+ Cache::check_out 1
+Cache::check_in 1
+ Cache::check_out 2
+Cache::check_in 2
+VEdit::render done
+ VRender::process_buffer age video
+ Cache::age_type 1
+ Cache::lock_all 1
+ Cache::lock_all 2
+but ATrack::render has locked check_out at this point.
+ VEdit::draw checking in
+ Cache::check_in 1
+but Cache::age_type has locked check_in and check_out can't be unlocked until
+VEdit completes