Hi, a realtime kernel just makes no sense without pthread_suspend and pthread_resume.
About async-thread-safe functions exist just when taking less than one turn in turn based system.
Syncing takes 0 to 1 turn.
Greedy threads takes more than 1 turn.
By implementing Advanced Gtk+ Sequencer I have overtaken gtk's main loop and its greedy it takes more than one turn while doing user interaction.
please consider what I told you