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bird/lib/event.h
Maria Matejka 0861d3a8a3 Fixing several race-conditions in event code.
After a suggestion by Santiago, I added the direct list pointer into
events and the events are now using this value to check whether the
route is active or not. Also the whole trick with sentinel node unioned
with event list is now gone.

For debugging, there is also an internal circular buffer to store what
has been recently happening in event code before e.g. a crash happened.
By default, this debug is off and must be manually enabled in
lib/event.c as it eats quite some time and space.
2022-09-18 16:33:51 +02:00

77 lines
1.8 KiB
C

/*
* BIRD Library -- Event Processing
*
* (c) 1999 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_EVENT_H_
#define _BIRD_EVENT_H_
#include "lib/resource.h"
#include "lib/locking.h"
#include "lib/rcu.h"
#include <stdatomic.h>
struct birdloop;
typedef struct event {
resource r;
void (*hook)(void *);
void *data;
struct event * _Atomic next;
struct event_list * _Atomic list;
} event;
typedef struct event_list {
event * _Atomic receiver; /* Event receive list */
event * _Atomic _executor; /* Event execute list */
const char *name;
struct birdloop *loop; /* The executor loop */
} event_list;
extern event_list global_event_list;
extern event_list global_work_list;
event *ev_new(pool *);
void ev_run(event *);
void ev_init_list(event_list *, struct birdloop *loop, const char *name);
void ev_enqueue(event_list *, event *);
#define ev_send ev_enqueue
#define ev_send_loop(l, e) ev_send(birdloop_event_list((l)), (e))
#define ev_schedule(e) ({ ASSERT_THE_BIRD_LOCKED; if (!ev_active((e))) ev_send(&global_event_list, (e)); })
#define ev_schedule_work(e) ({ ASSERT_THE_BIRD_LOCKED; if (!ev_active((e))) ev_send(&global_work_list, (e)); })
void ev_postpone(event *);
int ev_run_list_limited(event_list *, uint);
#define ev_run_list(l) ev_run_list_limited((l), ~0)
#define LEGACY_EVENT_LIST(l) (((l) == &global_event_list) || ((l) == &global_work_list))
static inline int
ev_active(event *e)
{
return atomic_load_explicit(&e->list, memory_order_acquire) != NULL;
}
static inline event_list *
ev_get_list(event *e)
{
return atomic_load_explicit(&e->list, memory_order_acquire);
}
static inline event*
ev_new_init(pool *p, void (*hook)(void *), void *data)
{
event *e = ev_new(p);
e->hook = hook;
e->data = data;
return e;
}
#endif