Make the loop public and let the display drive it

An application that has its own descriptors and timers needed a second
loop next to yasl's, and could not see yasl's key-repeat timer, clipboard
pipes or reconnect timer. Now there is one wait: the application owns a
yasl_loop, and yasl_init can run the display on it.

- Public yasl_loop_*: descriptors, timers and signals. Descriptor
  callbacks return void. Timer IDs are 64 bits and never reused; a zero
  delay runs in the next step. A nested step or run fails with EBUSY, a
  step off the loop's thread with EPERM, and a quit made before a run ends
  it at once. An interrupted wait keeps its deadline. Creating a loop
  fails when it cannot make its wake pipe.
- The display drives the loop through prepare, wait and check hooks
  instead of wrapping its step. Wayland finishes its read before any
  callback runs, so loop callbacks may create surfaces and do roundtrips.
  Readiness (queued events, an owed REFRESH) is derived in the step, so
  the wait never blocks over pending work. A draw that cannot proceed for
  want of a buffer is no longer counted as work.
- yasl_init takes struct yasl_options. With loop and on_event, each step
  delivers events to on_event and yasl_wait_event fails with EBUSY.
  EALREADY only for the same options, EBUSY for others.
- yasl_surface_request_frame: a REFRESH once the window can show a new
  frame, for pacing animation.
- DISPLAY_LOST reports whether the display reconnects. Pull waits still
  fail with ENOTCONN after a final loss.
- Events pushed from another thread wake the loop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/platform/wayland/api.h b/src/platform/wayland/api.h
index 69f61b1..1fb6d5c 100644
--- a/src/platform/wayland/api.h
+++ b/src/platform/wayland/api.h
@@ -6,10 +6,11 @@
 struct wayland_display;
 struct wayland_surface;
 
-struct wayland_display *wayland_display_open(struct yasl_private_loop *loop, const struct yasl_private_display_spec *spec);
+struct wayland_display *wayland_display_open(struct yasl_loop *loop, const struct yasl_private_display_spec *spec);
 void wayland_display_close(struct wayland_display *d);
 uint32_t wayland_display_caps(const struct wayland_display *d);
-int wayland_display_dispatch_timeout(struct wayland_display *d, int timeout_ms);
+bool wayland_display_prepare(struct wayland_display *d);
+void wayland_display_check(struct wayland_display *d);
 void wayland_display_flush(struct wayland_display *d);
 int wayland_display_modifiers(const struct wayland_display *d);
 bool wayland_display_copy_text(struct wayland_display *d, enum yasl_private_selection sel, const char *text);