Table maintenance is now done in coroutines (c7befcb6) · Commits · 戴 / Bird

nest/route.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -174,14 +174,17 @@ typedef struct rtable {
		* delete as soon as use_count becomes 0 and remove
		* obstacle from this routing table.
		*/
		struct event rt_event; / Routing table event */
		btime last_rt_change; /* Last time when route changed */
		btime base_settle_time; /* Start time of rtable settling interval */
		btime gc_time; /* Time of last GC */
		int gc_counter; /* Number of operations since last GC */

		struct coroutine maint_coro; / Maintenance coroutine */
		struct bsem maint_sem; / Maintenance semaphore */
		byte prune_state; /* Table prune state, 1 -> scheduled, 2-> running */
		byte hcu_scheduled; /* Hostcache update is scheduled */
		byte nhu_state; /* Next Hop Update state */

		struct fib_iterator prune_fit; /* Rtable prune FIB iterator */
		struct fib_iterator nhu_fit; /* Next Hop Update FIB iterator */

nest/rt-table.c

+53 −46

Original line number	Diff line number	Diff line
		@@ -35,7 +35,8 @@
		#include "nest/protocol.h"
		#include "nest/iface.h"
		#include "lib/resource.h"
		#include "lib/event.h"
		#include "lib/coro.h"
		#include "lib/locking.h"
		#include "lib/timer.h"
		#include "lib/string.h"
		#include "conf/conf.h"
		@@ -1754,39 +1755,43 @@ rt_schedule_hcu(rtable *tab)
		return;

		tab->hcu_scheduled = 1;
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);
		}

		static inline void
		rt_schedule_nhu(rtable *tab)
		{
		if (tab->nhu_state == NHU_CLEAN)
		ev_schedule(tab->rt_event);

		/* state change:
		* NHU_CLEAN -> NHU_SCHEDULED
		* NHU_RUNNING -> NHU_DIRTY
		*/
		tab->nhu_state \|= NHU_SCHEDULED;

		if (tab->nhu_state == NHU_SCHEDULED)
		bsem_post(tab->maint_sem);
		}

		void
		rt_schedule_prune(rtable *tab)
		{
		if (tab->prune_state == 0)
		ev_schedule(tab->rt_event);

		/* state change 0->1, 2->3 */
		tab->prune_state \|= 1;

		if (tab->prune_state == 1)
		bsem_post(tab->maint_sem);
		}


		static void
		rt_event(void *ptr)
		rt_maint(void *ptr)
		{
		rtable *tab = ptr;

		rt_lock_table(tab);
		for (_Bool finished = 0; !finished; )
		{
		bsem_wait(tab->maint_sem);

		the_bird_lock();

		if (tab->hcu_scheduled)
		rt_update_hostcache(tab);
		@@ -1797,7 +1802,15 @@ rt_event(void *ptr)
		if (tab->prune_state)
		rt_prune_table(tab);

		rt_unlock_table(tab);
		if (!tab->use_count && tab->deleted)
		{
		rfree(tab);
		the_bird_unlock();
		return;
		}

		the_bird_unlock();
		}
		}


		@@ -1876,6 +1889,7 @@ static void
		rt_free(resource *_r)
		{
		rtable r = (rtable ) _r;
		struct config *conf = r->deleted;

		DBG("Deleting routing table %s\n", r->name);
		ASSERT_DIE(r->use_count == 0);
		@@ -1883,19 +1897,15 @@ rt_free(resource *_r)
		if (r->internal)
		return;

		if (r->hostcache)
		rt_free_hostcache(r);

		r->config->table = NULL;
		rem_node(&r->n);

		if (r->hostcache)
		rt_free_hostcache(r);
		rfree(r->rp);

		/* Freed automagically by the resource pool
		fib_free(&r->fib);
		hmap_free(&r->id_map);
		rfree(r->rt_event);
		rfree(r->settle_timer);
		mb_free(r);
		*/
		config_del_obstacle(conf);
		}

		static void
		@@ -1940,10 +1950,12 @@ rt_setup(pool pp, struct rtable_config cf)
		hmap_init(&t->id_map, p, 1024);
		hmap_set(&t->id_map, 0);

		t->last_rt_change = t->gc_time = current_time();

		init_list(&t->subscribers);

		t->rt_event = ev_new_init(p, rt_event, t);
		t->last_rt_change = t->gc_time = current_time();
		t->maint_sem = bsem_new(p);
		t->maint_coro = coro_run(p, rt_maint, t);
		}

		return t;
		@@ -1971,7 +1983,7 @@ rt_init(void)
		*
		* The prune loop scans routing tables and removes routes belonging to flushing
		* protocols, discarded routes and also stale network entries. It is called from
		* rt_event(). The event is rescheduled if the current iteration do not finish
		* rt_maint(). This loop is rescheduled if the current iteration do not finish
		* the table. The pruning is directed by the prune state (@prune_state),
		* specifying whether the prune cycle is scheduled or running, and there
		* is also a persistent pruning iterator (@prune_fit).
		@@ -2021,7 +2033,7 @@ again:
		if (limit <= 0)
		{
		FIB_ITERATE_PUT(fit);
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);
		return;
		}

		@@ -2036,7 +2048,7 @@ again:
		if (limit <= 0)
		{
		FIB_ITERATE_PUT(fit);
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);
		return;
		}

		@@ -2067,7 +2079,7 @@ again:
		tab->prune_state &= 1;

		if (tab->prune_state > 0)
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);

		/* FIXME: This should be handled in a better way */
		rt_prune_sources();
		@@ -2310,7 +2322,7 @@ rt_next_hop_update(rtable *tab)
		if (max_feed <= 0)
		{
		FIB_ITERATE_PUT(fit);
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);
		return;
		}
		max_feed -= rt_next_hop_update_net(tab, n);
		@@ -2324,7 +2336,7 @@ rt_next_hop_update(rtable *tab)
		tab->nhu_state &= 1;

		if (tab->nhu_state != NHU_CLEAN)
		ev_schedule(tab->rt_event);
		bsem_post(tab->maint_sem);
		}


		@@ -2374,21 +2386,17 @@ rt_lock_table(rtable *r)
		* rt_unlock_table - unlock a routing table
		* @r: routing table to be unlocked
		*
		* Unlock a routing table formerly locked by rt_lock_table(),
		* that is decrease its use count and delete it if it's scheduled
		* for deletion by configuration changes.
		* Unlock a routing table formerly locked by rt_lock_table().
		* If scheduled for deletion, ping the maintenance coroutine to delete
		* the table and finish.
		*/
		void
		rt_unlock_table(rtable *r)
		{
		if (!--r->use_count && r->deleted)
		{
		struct config *conf = r->deleted;
		r->use_count--;

		/* Delete the routing table by freeing its pool */
		rt_shutdown(r);
		config_del_obstacle(conf);
		}
		if (!r->use_count && r->deleted)
		bsem_post(r->maint_sem);
		}

		static struct rtable_config *
		@@ -2438,8 +2446,7 @@ rt_commit(struct config new, struct config old)
		DBG("\t%s: deleted\n", o->name);
		ot->deleted = old;
		config_add_obstacle(old);
		rt_lock_table(ot);
		rt_unlock_table(ot);
		bsem_post(ot->maint_sem); /* Allow the maint_coro to finish. */
		}
		}
		}

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