event loop and timers

[Peter Harris]

On 2024-09-01 9:30 a.m., Steven J Abner wrote:
>   Having an issue with using timers with 'beginner loop'.

>   Any insight would be greatly appreciated!

Events are difficult to get right, and your proposed solution has a 
battery-eating busy-loop. The general way to handle timers is to use 
xcb_get_file_descriptor() with select/poll/epoll.

Something like (pseudocode):

while (running) {
   while (ev = xcb_poll_for_event(c)) {
     process_event(ev);
   }
   // process_timers runs any timers that are immediately pending,
   // and returns the number of milliseconds until the next timer
   // in the queue is ready.
   // process_timers returns INT_MAX if there are no timers.
   timeout = process_timers();
   poll(xcb_get_file_descriptor(c), timeout);
}

Note that if process_timers() calls (even indirectly) any xcb_*_reply 
functions, you'll need a xcb_poll_for_queued_event() loop before calling 
poll().

Peter Harris