[PATCH] client: Add acquire-fd API to avoid requiring a polling main thread

[Bill Spitzak]

Can wl_display_acquire_fd be merged into wl_display_dispatch_pending()? 
It looks like you never want to call one without the other, and it also 
appears that wl_display_dispatch releases it so this would be symmetric.

On 04/10/2013 08:16 AM, Kristian Høgsberg wrote:

> 	wl_display_dispatch_pending(display);
>
> 	/* Race here if other thread reads from fd and places events
> 	 * in main eent queue.  We go to sleep in poll while sitting on
> 	 * events that may stall the application if not dispatched. */
>
> 	poll(fds, nfds, -1);
>
> 	/* Race here if other thread reads and doesn't queue any
> 	 * events for main queue. wl_display_dispatch() below will block
> 	 * trying to read from the fd, while other fds in the mainloop
> 	 * are ignored. */
>
> 	wl_display_dispatch(display);
>
> The restriction that only the main thread can read from the fd avoids
> these races, but has the problems described above.
>
> This patch introduces new API to solve both problems.  We add
>
> 	int wl_display_acquire_fd(struct wl_display *display);