-
Pl
chevron_right
Christian Hergert: Dedicated Threads with Futures
news.movim.eu / PlanetGnome • 5 September
There are often needs to integrate with blocking APIs that do not fit well into the async or future-based models of the GNOME ecosystem. In those cases, you may want to use a dedicated thread for blocking calls so that you do not disrupt main loops, timeouts, or fiber scheduling.
This is ideal when doing things like interacting with
libflatpak
or even
libgit2
.
Creating a Dedicated Thread
Use the dex_thread_spawn() function to spawn a new thread. When the thread completes the resulting future will either resolve or reject.
typedef DexFuture *(*DexThreadFunc) (gpointer user_data); DexFuture *future = dex_thread_spawn ("[my-thredad]", thread_func, thread_data, (GDestroyNotify)thread_data_free);
Waiting for Future Completion
Since dedicated threads do not have a Dex.Scheduler on them and are not a fiber, you may not await futures. Awaiting would suspend a fiber stack but there is no such fiber to suspend.
To make integration easier, you may use dex_thread_wait_for() to wait for a future to complete. The mechanism used in this case is a mutex and condition variable which will be signaled when the dependent future completes.