events: loop_schedule() is unclear, rename it loop_schedule_fast()

src/nvim/event/loop.c

@@ -71,7 +71,7 @@ bool loop_poll_events(Loop *loop, int ms)
   return timeout_expired;
 }
 
-/// Schedules an event from another thread.
+/// Schedules a fast event from another thread.
 ///
 /// @note Event is queued into `fast_events`, which is processed outside of the
 ///       primary `events` queue by loop_poll_events(). For `main_loop`, that
@@ -79,7 +79,7 @@ bool loop_poll_events(Loop *loop, int ms)
 ///       (VimState.execute), so redraw and other side-effects are likely to be
 ///       skipped.
 /// @see loop_schedule_deferred
-void loop_schedule(Loop *loop, Event event)
+void loop_schedule_fast(Loop *loop, Event event)
 {
   uv_mutex_lock(&loop->mutex);
   multiqueue_put_event(loop->thread_events, event);
@@ -87,15 +87,15 @@ void loop_schedule(Loop *loop, Event event)
   uv_mutex_unlock(&loop->mutex);
 }
 
-/// Schedules an event from another thread. Unlike loop_schedule(), the event
+/// Schedules an event from another thread. Unlike loop_schedule_fast(), the
-/// is forwarded to `Loop.events`, instead of being processed immediately.
+/// event is forwarded to `Loop.events`, instead of being processed immediately.
 ///
-/// @see loop_schedule
+/// @see loop_schedule_fast
 void loop_schedule_deferred(Loop *loop, Event event)
 {
   Event *eventp = xmalloc(sizeof(*eventp));
   *eventp = event;
-  loop_schedule(loop, event_create(loop_deferred_event, 2, loop, eventp));
+  loop_schedule_fast(loop, event_create(loop_deferred_event, 2, loop, eventp));
 }
 static void loop_deferred_event(void **argv)
 {

src/nvim/message.c

@@ -753,7 +753,7 @@ void msg_schedule_emsgf(const char *const fmt, ...)
   va_end(ap);
 
   char *s = xstrdup((char *)IObuff);
-  loop_schedule(&main_loop, event_create(msg_emsgf_event, 1, s));
+  multiqueue_put(main_loop.events, msg_emsgf_event, 1, s);
 }
 
 /*

src/nvim/tui/input.c

@@ -164,7 +164,7 @@ static void tinput_flush(TermInput *input, bool wait_until_empty)
   size_t drain_boundary = wait_until_empty ? 0 : 0xff;
   do {
     uv_mutex_lock(&input->key_buffer_mutex);
-    loop_schedule(&main_loop, event_create(tinput_wait_enqueue, 1, input));
+    loop_schedule_fast(&main_loop, event_create(tinput_wait_enqueue, 1, input));
     input->waiting = true;
     while (input->waiting) {
       uv_cond_wait(&input->key_buffer_cond, &input->key_buffer_mutex);
@@ -522,7 +522,7 @@ static void tinput_read_cb(Stream *stream, RBuffer *buf, size_t count_,
   TermInput *input = data;
 
   if (eof) {
-    loop_schedule(&main_loop, event_create(tinput_done_event, 0));
+    loop_schedule_fast(&main_loop, event_create(tinput_done_event, 0));
     return;
   }
 

src/nvim/tui/tui.c

@@ -454,7 +454,7 @@ static void tui_scheduler(Event event, void *d)
 {
   UI *ui = d;
   TUIData *data = ui->data;
-  loop_schedule(data->loop, event);  // `tui_loop` local to tui_main().
+  loop_schedule_fast(data->loop, event);  // `tui_loop` local to tui_main().
 }
 
 #ifdef UNIX

src/nvim/ui.c

@@ -228,7 +228,11 @@ static void ui_refresh_event(void **argv)
 
 void ui_schedule_refresh(void)
 {
-  loop_schedule(&main_loop, event_create(ui_refresh_event, 0));
+  // TODO(bfredl): "fast" is not optimal. UI should be refreshed only at
+  // deferred processing plus a few more blocked-on-input situtions like
+  // wait_return(), but not any os_breakcheck(). Alternatively make this
+  // defered and make wait_return() process deferred events already.
+  loop_schedule_fast(&main_loop, event_create(ui_refresh_event, 0));
 }
 
 void ui_default_colors_set(void)