Rate-limit scheduling of work-events

In general, events are code handling some some condition, which is
scheduled when such condition happened and executed independently from
I/O loop. Work-events are a subgroup of events that are scheduled
repeatedly until some (often significant) work is done (e.g. feeding
routes to protocol). All scheduled events are executed during each
I/O loop iteration.

Separate work-events from regular events to a separate queue and
rate limit their execution to a fixed number per I/O loop iteration.
That should prevent excess latency when many work-events are
scheduled at one time (e.g. simultaneous reload of many BGP sessions).

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/event.h b/lib/event.h
index 03735c3f..5f3b78d8 100644
--- a/lib/event.h
+++ b/lib/event.h
@@ -21,14 +21,17 @@ typedef struct event {
 typedef list event_list;
 
 extern event_list global_event_list;
+extern event_list global_work_list;
 
 event *ev_new(pool *);
 void ev_run(event *);
 #define ev_init_list(el) init_list(el)
 void ev_enqueue(event_list *, event *);
 void ev_schedule(event *);
+void ev_schedule_work(event *);
 void ev_postpone(event *);
 int ev_run_list(event_list *);
+int ev_run_list_limited(event_list *, uint);
 
 static inline int
 ev_active(event *e)