The debounce timer added for flicker prevention was armed from the IPC
listener thread via Glib::signal_timeout().connect(), while its timeout
lambda and the m_updatePending flag ran on the GTK main thread — an
unsynchronized cross-thread data race on GLib timer/main-loop state.
Additionally ~Workspaces() never disconnected the timer, so a pending
timeout could fire on a freed 'this' (use-after-free).
Restore the pre-refactor threading model: onEvent now only mutates state
under m_mutex on the IPC thread and calls dp.emit() (Glib::Dispatcher is
thread-safe). The debounce timer is owned entirely by the main-thread
update() path, which arms/re-arms it on each dispatch and coalesces
bursts into a single refresh. ~Workspaces() disconnects the timer
(guarded) so none outlives the object. Debounce behavior is preserved.
Alex
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