Replace the shared-global-context design with one where chansrv's
thread never touches libibus directly. All IBus objects (bus, engine,
factory, component) are now owned exclusively by a private
GMainContext/GMainLoop created inside the IBus thread; chansrv hands
off unicode codepoints through a thread-safe GAsyncQueue and wakes the
loop, instead of calling ibus_engine_commit_text() from the wrong
thread or relying on ibus_main()/ibus_quit(), which turned out to
operate on a single loop shared by the whole process rather than one
per connection.
Fixes along the way, found by testing against a live ibus-daemon and
a real focused GTK app rather than just reading the diff:
- xrdp_engine_enable()/disable() now take a real reference on g_engine
(g_object_ref/unref) instead of caching a bare pointer. The old code
unreffed g_engine on teardown without ever having reffed it - IBusEngine
derives from GInitiallyUnowned, so that was releasing a reference it
never owned.
- A custom GSource drains the unicode queue, gated on the engine
actually existing (engine creation is async once XrdpIme is
selected), so a character queued before the engine is ready isn't
lost - it commits as soon as the "enable" signal fires, instead of
racing a one-shot commit against that async setup.
- ibus_engine_commit_text() releases its IBusText argument itself
(it's floating, documented behavior for that specific call) - an
earlier draft of this rewrite added an extra g_object_unref() after
it, which would have been a double-release.
- bus (and anything else that opens a GDBusConnection) must be created
after the private GMainContext is pushed as thread-default, not
before - otherwise its async I/O silently binds to the global
default context, which nothing here iterates, and signals like
"disconnected" simply never fire.
- xrdp_input_unicode_init() now blocks on a condvar until the IBus
thread actually signals ready (or exits), instead of returning
immediately and hoping the engine shows up in time.
- unicode_init()/destroy() no longer touch bus/g_engine from chansrv's
own thread while the IBus thread may still be running against them;
destroy() schedules real teardown on the IBus thread and joins it via
a condvar before returning.
Known limitation, confirmed empirically rather than assumed: this does
NOT make reconnect-after-daemon-restart (#3230) actually work.
ibus_bus_new() returns a process-wide singleton in this libibus
version - two calls in the same process with no disconnect involved
return the identical pointer - so once its connection dies, every
later call just hands back the same dead object; ibus_bus_is_connected()
on it stays permanently false, confirmed not to be a transient state
via repeated retries with delay. The "disconnected" handler still
tears the thread down cleanly so a later xrdp_input_unicode_init()
fails fast instead of hanging or operating on stale state, but a real
fix would mean bypassing IBusBus for a raw GDBusConnection to
ibus-daemon, which isn't justified given how rarely the daemon
actually restarts mid-session.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Liyi Meng
2a77f5f3e8