Merge commit 'c70b3198' into thread-next [lots of conflicts]

There were more conflicts that I'd like to see, most notably in route
export. If a bisect identifies this commit with something related, it
may be simply true that this commit introduces that bug. Let's hope it
doesn't happen.

5 files changed, 676 insertions, 168 deletions

diff --git a/nest/config.Y b/nest/config.Y
index 525829b3..e894f7c4 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -386,7 +386,7 @@ debug_default:
    DEBUG PROTOCOLS debug_mask { new_config->proto_default_debug = $3; }
  | DEBUG CHANNELS debug_mask { new_config->channel_default_debug = $3; }
  | DEBUG COMMANDS expr { new_config->cli_debug = $3; }
- | DEBUG PIPE bool { new_config->pipe_debug = $3; }
+ | DEBUG TABLES bool { new_config->table_debug = $3; }
  ;
 
 /* MRTDUMP PROTOCOLS is in systep/unix/config.Y */
diff --git a/nest/proto.c b/nest/proto.c
index 72e479d7..3a80ab0e 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -697,8 +697,6 @@ channel_do_stop(struct channel *c)
 
   CALL(c->channel->shutdown, c);
 
-  /* This have to be done in here, as channel pool is freed before channel_do_down() */
-  c->out_table = NULL;
 }
 
 static void
diff --git a/nest/rt-show.c b/nest/rt-show.c
index 1dbfaec2..6dfb85f6 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -79,8 +79,8 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
   if (d->verbose)
   {
     ea_show_list(c, a);
-    cli_printf(c, -1008, "\tInternal route handling values: %uL %uG %uS",
-	e->src->private_id, e->src->global_id, e->stale_cycle);
+    cli_printf(c, -1008, "\tInternal route handling values: %uL %uG %uS id %u",
+	e->src->private_id, e->src->global_id, e->stale_cycle, e->id);
   }
   else if (dest == RTD_UNICAST)
     ea_show_nexthop_list(c, nhad);
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 5e07c129..85a6faf7 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -110,6 +110,8 @@
 #include "proto/bgp/bgp.h"
 #endif
 
+#include <stdatomic.h>
+
 pool *rt_table_pool;
 
 static linpool *rte_update_pool;
@@ -117,6 +119,16 @@ static linpool *rte_update_pool;
 list routing_tables;
 list deleted_routing_tables;
 
+/* Data structures for export journal */
+#define RT_PENDING_EXPORT_ITEMS		(page_size - sizeof(struct rt_export_block)) / sizeof(struct rt_pending_export)
+
+struct rt_export_block {
+  node n;
+  _Atomic u32 end;
+  _Atomic _Bool not_last;
+  struct rt_pending_export export[];
+};
+
 static void rt_free_hostcache(rtable *tab);
 static void rt_notify_hostcache(rtable *tab, net *net);
 static void rt_update_hostcache(rtable *tab);
@@ -133,6 +145,14 @@ static void rt_feed_equal(void *);
 static void rt_feed_for(void *);
 static uint rt_feed_net(struct rt_export_hook *c, net *n);
 
+static inline void rt_export_used(struct rt_exporter *);
+static void rt_export_cleanup(rtable *tab);
+
+static inline void rte_update_lock(void);
+static inline void rte_update_unlock(void);
+
+static int rte_same(rte *x, rte *y);
+
 const char *rt_import_state_name_array[TIS_MAX] = {
   [TIS_DOWN] = "DOWN",
   [TIS_UP] = "UP",
@@ -685,8 +705,9 @@ rte_mergable(rte *pri, rte *sec)
 static void
 rte_trace(const char *name, const rte *e, int dir, const char *msg)
 {
-  log(L_TRACE "%s %c %s %N %uL %uG %s",
-      name, dir, msg, e->net, e->src->private_id, e->src->global_id,
+  log(L_TRACE "%s %c %s %N src %uL %uG %uS id %u %s",
+      name, dir, msg, e->net,
+      e->src->private_id, e->src->global_id, e->stale_cycle, e->id,
       rta_dest_name(rte_dest(e)));
 }
 
@@ -848,6 +869,16 @@ do_rt_notify(struct channel *c, const net_addr *net, rte *new, const rte *old)
 static void
 rt_notify_basic(struct channel *c, const net_addr *net, rte *new, rte *old)
 {
+  if (new && old && rte_same(new, old))
+  {
+    if ((new->id != old->id) && bmap_test(&c->export_map, old->id))
+    {
+      bmap_set(&c->export_map, new->id);
+      bmap_clear(&c->export_map, old->id);
+    }
+    return;
+  }
+
   if (new)
     new = export_filter(c, new, 0);
 
@@ -860,6 +891,16 @@ rt_notify_basic(struct channel *c, const net_addr *net, rte *new, rte *old)
   do_rt_notify(c, net, new, old);
 }
 
+static void
+channel_rpe_mark_seen(struct rt_export_request *req, struct rt_pending_export *rpe)
+{
+  struct channel *c = SKIP_BACK(struct channel, out_req, req);
+
+  rpe_mark_seen(req->hook, rpe);
+  if (rpe->old)
+    bmap_clear(&c->export_reject_map, rpe->old->rte.id);
+}
+
 void
 rt_notify_accepted(struct rt_export_request *req, const net_addr *n, struct rt_pending_export *rpe,
     struct rte **feed, uint count)
@@ -903,38 +944,30 @@ rt_notify_accepted(struct rt_export_request *req, const net_addr *n, struct rt_p
     }
   }
 
+done:
   /* Check obsolete routes for previously exported */
-  if (!old_best)
-    if (rpe && rpe->old && bmap_test(&c->export_map, rpe->old->rte.id))
-      old_best = &rpe->old->rte;
-
-/*    for (; rpe; rpe = atomic_load_explicit(&rpe->next, memory_order_relaxed))
+  while (rpe)
+  {
+    channel_rpe_mark_seen(req, rpe);
+    if (rpe->old)
     {
-      if (rpe->old && bmap_test(&hook->accept_map, rpe->old->id))
+      if (bmap_test(&c->export_map, rpe->old->rte.id))
       {
-	old_best = &rpe->old.rte;
-	break;
+	ASSERT_DIE(old_best == NULL);
+	old_best = &rpe->old->rte;
       }
-
-      if (rpe == rpe_last)
-	break;
     }
-    */
+    rpe = rpe_next(rpe, NULL);
+  }
 
   /* Nothing to export */
   if (!new_best && !old_best)
   {
     DBG("rt_notify_accepted: nothing to export\n");
-    goto done;
+    return;
   }
 
   do_rt_notify(c, n, new_best, old_best);
-
-done:
-  /* Drop the old stored rejection if applicable.
-   * new->id == old->id happens when updating hostentries. */
-  if (rpe && rpe->old && (!rpe->new || (rpe->new->rte.id != rpe->old->rte.id)))
-    bmap_clear(&c->export_reject_map, rpe->old->rte.id);
 }
 
 rte *
@@ -1026,33 +1059,25 @@ rt_notify_merged(struct rt_export_request *req, const net_addr *n, struct rt_pen
     }
 
   /* Check obsolete routes for previously exported */
-  if (!old_best)
-    if (rpe && rpe->old && bmap_test(&c->export_map, rpe->old->rte.id))
-      old_best = &rpe->old->rte;
-
-/*    for (; rpe; rpe = atomic_load_explicit(&rpe->next, memory_order_relaxed))
+  while (rpe)
+  {
+    channel_rpe_mark_seen(req, rpe);
+    if (rpe->old)
     {
-      if (rpe->old && bmap_test(&hook->accept_map, rpe->old->id))
+      if (bmap_test(&c->export_map, rpe->old->rte.id))
       {
-	old_best = &rpe->old.rte;
-	break;
+	ASSERT_DIE(old_best == NULL);
+	old_best = &rpe->old->rte;
       }
-
-      if (rpe == rpe_last)
-	break;
     }
-    */
+    rpe = rpe_next(rpe, NULL);
+  }
 
   /* Prepare new merged route */
   rte *new_merged = count ? rt_export_merged(c, feed, count, rte_update_pool, 0) : NULL;
 
   if (new_merged || old_best)
     do_rt_notify(c, n, new_merged, old_best);
-
-  /* Drop the old stored rejection if applicable.
-   * new->id == old->id happens when updating hostentries. */
-  if (rpe && rpe->old && (!rpe->new || (rpe->new->rte.id != rpe->old->rte.id)))
-    bmap_clear(&c->export_reject_map, rpe->old->rte.id);
 }
 
 void
@@ -1060,19 +1085,19 @@ rt_notify_optimal(struct rt_export_request *req, const net_addr *net, struct rt_
 {
   struct channel *c = SKIP_BACK(struct channel, out_req, req);
 
-  if (rpe->new_best != rpe->old_best)
-  {
-    rte n0 = RTE_COPY_VALID(rpe->new_best);
-    rte *o = RTE_VALID_OR_NULL(rpe->old_best);
+  rte *o = RTE_VALID_OR_NULL(rpe->old_best);
+  struct rte_storage *new_best = rpe->new_best;
 
-    if (n0.src || o)
-      rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
+  while (rpe)
+  {
+    channel_rpe_mark_seen(req, rpe);
+    new_best = rpe->new_best;
+    rpe = rpe_next(rpe, NULL);
   }
 
-  /* Drop the old stored rejection if applicable.
-   * new->id == old->id happens when updating hostentries. */
-  if (rpe->old && (!rpe->new || (rpe->new->rte.id != rpe->old->rte.id)))
-    bmap_clear(&c->export_reject_map, rpe->old->rte.id);
+  rte n0 = RTE_COPY_VALID(new_best);
+  if (n0.src || o)
+    rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
 }
 
 void
@@ -1080,18 +1105,28 @@ rt_notify_any(struct rt_export_request *req, const net_addr *net, struct rt_pend
 {
   struct channel *c = SKIP_BACK(struct channel, out_req, req);
 
-  if (rpe->new != rpe->old)
+  rte *n = RTE_VALID_OR_NULL(rpe->new);
+  rte *o = RTE_VALID_OR_NULL(rpe->old);
+
+  if (!n && !o)
   {
-    rte n0 = RTE_COPY_VALID(rpe->new);
-    rte *o = RTE_VALID_OR_NULL(rpe->old);
-    if (n0.src || o)
-      rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
+    channel_rpe_mark_seen(req, rpe);
+    return;
   }
 
-  /* Drop the old stored rejection if applicable.
-   * new->id == old->id happens when updating hostentries. */
-  if (rpe->old && (!rpe->new || (rpe->new->rte.id != rpe->old->rte.id)))
-    bmap_clear(&c->export_reject_map, rpe->old->rte.id);
+  struct rte_src *src = n ? n->src : o->src;
+  struct rte_storage *new_latest = rpe->new;
+
+  while (rpe)
+  {
+    channel_rpe_mark_seen(req, rpe);
+    new_latest = rpe->new;
+    rpe = rpe_next(rpe, src);
+  }
+
+  rte n0 = RTE_COPY_VALID(new_latest);
+  if (n0.src || o)
+    rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
 }
 
 void
@@ -1107,6 +1142,98 @@ rt_feed_any(struct rt_export_request *req, const net_addr *net, struct rt_pendin
     }
 }
 
+void
+rpe_mark_seen(struct rt_export_hook *hook, struct rt_pending_export *rpe)
+{
+  bmap_set(&hook->seq_map, rpe->seq);
+}
+
+struct rt_pending_export *
+rpe_next(struct rt_pending_export *rpe, struct rte_src *src)
+{
+  struct rt_pending_export *next = atomic_load_explicit(&rpe->next, memory_order_acquire);
+
+  if (!next)
+    return NULL;
+
+  if (!src)
+    return next;
+
+  while (rpe = next)
+    if (src == (rpe->new ? rpe->new->rte.src : rpe->old->rte.src))
+      return rpe;
+    else
+      next = atomic_load_explicit(&rpe->next, memory_order_acquire);
+
+  return NULL;
+}
+
+static struct rt_pending_export * rt_next_export_fast(struct rt_pending_export *last);
+static void
+rte_export(struct rt_export_hook *hook, struct rt_pending_export *rpe)
+{
+  if (bmap_test(&hook->seq_map, rpe->seq))
+    goto ignore;	/* Seen already */
+
+  const net_addr *n = rpe->new_best ? rpe->new_best->rte.net : rpe->old_best->rte.net;
+
+  switch (hook->req->addr_mode)
+    {
+      case TE_ADDR_NONE:
+	break;
+
+      case TE_ADDR_IN:
+	if (!net_in_netX(n, hook->req->addr))
+	  goto ignore;
+	break;
+
+      case TE_ADDR_EQUAL:
+	if (!net_equal(n, hook->req->addr))
+	  goto ignore;
+	break;
+
+      case TE_ADDR_FOR:
+	bug("Continuos export of best prefix match not implemented yet.");
+
+      default:
+	bug("Strange table export address mode: %d", hook->req->addr_mode);
+    }
+
+  if (rpe->new)
+    hook->stats.updates_received++;
+  else
+    hook->stats.withdraws_received++;
+
+  if (hook->req->export_one)
+    hook->req->export_one(hook->req, n, rpe);
+  else if (hook->req->export_bulk)
+  {
+    net *net = SKIP_BACK(struct network, n.addr, (net_addr (*)[0]) n);
+    uint count = rte_feed_count(net);
+    rte **feed = NULL;
+    if (count)
+    {
+      feed = alloca(count * sizeof(rte *));
+      rte_feed_obtain(net, feed, count);
+    }
+    hook->req->export_bulk(hook->req, n, rpe, feed, count);
+  }
+  else
+    bug("Export request must always provide an export method");
+
+ignore:
+  /* Get the next export if exists */
+  hook->rpe_next = rt_next_export_fast(rpe);
+
+  /* The last block may be available to free */
+  if (PAGE_HEAD(hook->rpe_next) != PAGE_HEAD(rpe))
+    CALL(hook->table->used, hook->table);
+
+  /* Releasing this export for cleanup routine */
+  DBG("store hook=%p last_export=%p seq=%lu\n", hook, rpe, rpe->seq);
+  atomic_store_explicit(&hook->last_export, rpe, memory_order_release);
+}
+
 /**
  * rte_announce - announce a routing table change
  * @tab: table the route has been added to
@@ -1145,7 +1272,7 @@ rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage
   int new_best_valid = rte_is_valid(RTE_OR_NULL(new_best));
   int old_best_valid = rte_is_valid(RTE_OR_NULL(old_best));
 
-  if (!new && !old && !new_best && !old_best)
+  if ((new == old) && (new_best == old_best))
     return;
 
   if (new_best_valid || old_best_valid)
@@ -1164,57 +1291,198 @@ rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage
 
   rt_schedule_notify(tab);
 
-  struct rt_pending_export rpe = { .new = new, .old = old, .new_best = new_best, .old_best = old_best };
-  uint count = rte_feed_count(net);
-  rte **feed = NULL;
-  if (count)
+  if (EMPTY_LIST(tab->exporter.hooks) && EMPTY_LIST(tab->exporter.pending))
+  {
+    /* No export hook and no pending exports to cleanup. We may free the route immediately. */
+    if (!old)
+      return;
+
+    hmap_clear(&tab->id_map, old->rte.id);
+    rte_free(old);
+    return;
+  }
+
+  /* Get the pending export structure */
+  struct rt_export_block *rpeb = NULL, *rpebsnl = NULL;
+  u32 end = 0;
+
+  if (!EMPTY_LIST(tab->exporter.pending))
   {
-    feed = alloca(count * sizeof(rte *));
-    rte_feed_obtain(net, feed, count);
+    rpeb = TAIL(tab->exporter.pending);
+    end = atomic_load_explicit(&rpeb->end, memory_order_relaxed);
+    if (end >= RT_PENDING_EXPORT_ITEMS)
+    {
+      ASSERT_DIE(end == RT_PENDING_EXPORT_ITEMS);
+      rpebsnl = rpeb;
+
+      rpeb = NULL;
+      end = 0;
+    }
   }
 
-  struct rt_export_hook *eh;
-  WALK_LIST(eh, tab->exporter.hooks)
+  if (!rpeb)
+  {
+    rpeb = alloc_page();
+    *rpeb = (struct rt_export_block) {};
+    add_tail(&tab->exporter.pending, &rpeb->n);
+  }
+
+  /* Fill the pending export */
+  struct rt_pending_export *rpe = &rpeb->export[rpeb->end];
+  *rpe = (struct rt_pending_export) {
+    .new = new,
+    .new_best = new_best,
+    .old = old,
+    .old_best = old_best,
+    .seq = tab->exporter.next_seq++,
+  };
+
+  DBGL("rte_announce: table=%s net=%N new=%p id %u from %s old=%p id %u from %s new_best=%p id %u old_best=%p id %u seq=%lu",
+      tab->name, net->n.addr,
+      new, new ? new->rte.id : 0, new ? new->rte.sender->req->name : NULL,
+      old, old ? old->rte.id : 0, old ? old->rte.sender->req->name : NULL,
+      new_best, old_best, rpe->seq);
+
+  ASSERT_DIE(atomic_fetch_add_explicit(&rpeb->end, 1, memory_order_release) == end);
+
+  if (rpebsnl)
   {
-    if (eh->export_state == TES_STOP)
+    _Bool f = 0;
+    ASSERT_DIE(atomic_compare_exchange_strong_explicit(&rpebsnl->not_last, &f, 1,
+	  memory_order_release, memory_order_relaxed));
+  }
+
+  /* Append to the same-network squasher list */
+  if (net->last)
+  {
+    struct rt_pending_export *rpenull = NULL;
+    ASSERT_DIE(atomic_compare_exchange_strong_explicit(
+	  &net->last->next, &rpenull, rpe,
+	  memory_order_relaxed,
+	  memory_order_relaxed));
+    
+  }
+
+  net->last = rpe;
+
+  if (!net->first)
+    net->first = rpe;
+
+  if (tab->exporter.first == NULL)
+    tab->exporter.first = rpe;
+
+  if (!tm_active(tab->exporter.export_timer))
+    tm_start(tab->exporter.export_timer, tab->config->export_settle_time);
+}
+
+static struct rt_pending_export *
+rt_next_export_fast(struct rt_pending_export *last)
+{
+  /* Get the whole export block and find our position in there. */
+  struct rt_export_block *rpeb = PAGE_HEAD(last);
+  u32 pos = (last - &rpeb->export[0]);
+  u32 end = atomic_load_explicit(&rpeb->end, memory_order_acquire);
+  ASSERT_DIE(pos < end);
+
+  /* Next is in the same block. */
+  if (++pos < end)
+    return &rpeb->export[pos];
+
+  /* There is another block. */
+  if (atomic_load_explicit(&rpeb->not_last, memory_order_acquire))
+  {
+    /* This is OK to do non-atomically because of the not_last flag. */
+    rpeb = NODE_NEXT(rpeb);
+    return &rpeb->export[0];
+  }
+
+  /* There is nothing more. */
+  return NULL;
+}
+
+static struct rt_pending_export *
+rt_next_export(struct rt_export_hook *hook, struct rt_exporter *tab)
+{
+  /* As the table is locked, it is safe to reload the last export pointer */
+  struct rt_pending_export *last = atomic_load_explicit(&hook->last_export, memory_order_acquire);
+
+  /* It is still valid, let's reuse it */
+  if (last)
+    return rt_next_export_fast(last);
+
+  /* No, therefore we must process the table's first pending export */
+  else
+    return tab->first;
+}
+
+static void
+rt_announce_exports(timer *tm)
+{
+  rtable *tab = tm->data;
+
+  struct rt_export_hook *c; node *n;
+  WALK_LIST2(c, n, tab->exporter.hooks, n)
+  {
+    if (atomic_load_explicit(&c->export_state, memory_order_acquire) != TES_READY)
       continue;
 
-    switch (eh->req->addr_mode)
-    {
-      case TE_ADDR_NONE:
-	break;
+    ev_schedule_work(c->event);
+  }
+}
 
-      case TE_ADDR_IN:
-	if (!net_in_netX(net->n.addr, eh->req->addr))
-	  continue;
-	break;
+static struct rt_pending_export *
+rt_last_export(struct rt_exporter *tab)
+{
+  struct rt_pending_export *rpe = NULL;
 
-      case TE_ADDR_EQUAL:
-	if (!net_equal(net->n.addr, eh->req->addr))
-	  continue;
-	break;
+  if (!EMPTY_LIST(tab->pending))
+  {
+    /* We'll continue processing exports from this export on */
+    struct rt_export_block *reb = TAIL(tab->pending);
+    ASSERT_DIE(reb->end);
+    rpe = &reb->export[reb->end - 1];
+  }
 
-      case TE_ADDR_FOR:
-	bug("Continuos export of best prefix match not implemented yet.");
+  return rpe;
+}
 
-      default:
-	bug("Strange table export address mode: %d", eh->req->addr_mode);
+#define RT_EXPORT_BULK	1024
+
+static void
+rt_export_hook(void *_data)
+{
+  struct rt_export_hook *c = _data;
+
+  ASSERT_DIE(atomic_load_explicit(&c->export_state, memory_order_relaxed) == TES_READY);
+
+  if (!c->rpe_next)
+  {
+    c->rpe_next = rt_next_export(c, c->table);
+
+    if (!c->rpe_next)
+    {
+      CALL(c->table->used, c->table);
+      return;
     }
+  }
 
-    if (new)
-      eh->stats.updates_received++;
-    else
-      eh->stats.withdraws_received++;
+  /* Process the export */
+  for (uint i=0; i<RT_EXPORT_BULK; i++)
+  {
+    rte_update_lock();
 
-    if (eh->req->export_one)
-      eh->req->export_one(eh->req, net->n.addr, &rpe);
-    else if (eh->req->export_bulk)
-      eh->req->export_bulk(eh->req, net->n.addr, &rpe, feed, count);
-    else
-      bug("Export request must always provide an export method");
+    rte_export(c, c->rpe_next);
+
+    if (!c->rpe_next)
+      break;
+
+    rte_update_unlock();
   }
+
+  ev_schedule_work(c->event);
 }
 
+
 static inline int
 rte_validate(struct channel *ch, rte *e)
 {
@@ -1459,14 +1727,8 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
   if (new_stored)
     {
       new_stored->rte.lastmod = current_time();
-
-      if (!old)
-        {
-	  new_stored->rte.id = hmap_first_zero(&table->id_map);
-	  hmap_set(&table->id_map, new_stored->rte.id);
-	}
-      else
-	new_stored->rte.id = old->id;
+      new_stored->rte.id = hmap_first_zero(&table->id_map);
+      hmap_set(&table->id_map, new_stored->rte.id);
     }
 
   /* Log the route change */
@@ -1498,13 +1760,6 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
     p->rte_insert(net, &new_stored->rte);
 #endif
 
-  if (old)
-    {
-      if (!new_stored)
-	hmap_clear(&table->id_map, old->id);
-
-      rte_free(old_stored);
-    }
 }
 
 static int rte_update_nest_cnt;		/* Nesting counter to allow recursive updates */
@@ -1711,16 +1966,19 @@ rt_export_stopped(void *data)
   struct rt_export_hook *hook = data;
   struct rt_exporter *tab = hook->table;
 
+  /* Drop pending exports */
+  CALL(tab->used, tab);
+
   /* Unlist */
   rem_node(&hook->n);
 
-  /* Reporting the channel as stopped. */
+  /* Report the channel as stopped. */
   hook->stopped(hook->req);
 
   /* Reporting the hook as finished. */
   CALL(tab->done, hook);
 
-  /* Freeing the hook together with its coroutine. */
+  /* Free the hook together with its coroutine. */
   rfree(hook->pool);
 }
 
@@ -1738,7 +1996,7 @@ void
 rt_set_export_state(struct rt_export_hook *hook, u8 state)
 {
   hook->last_state_change = current_time();
-  hook->export_state = state;
+  atomic_store_explicit(&hook->export_state, state, memory_order_release);
 
   if (hook->req->log_state_change)
     hook->req->log_state_change(hook->req, state);
@@ -1784,7 +2042,6 @@ rt_table_export_start(struct rt_exporter *re, struct rt_export_request *req)
   pool *p = rp_new(tab->rp, "Export hook");
   struct rt_export_hook *hook = mb_allocz(p, sizeof(struct rt_export_hook));
   hook->pool = p;
-  hook->lp = lp_new_default(p);
 
   /* stats zeroed by mb_allocz */
   switch (req->addr_mode)
@@ -1829,6 +2086,12 @@ rt_request_export(struct rt_exporter *re, struct rt_export_request *req)
   hook->req = req;
   hook->table = re;
 
+  bmap_init(&hook->seq_map, hook->pool, 1024);
+
+  struct rt_pending_export *rpe = rt_last_export(hook->table);
+  DBG("store hook=%p last_export=%p seq=%lu\n", hook, rpe, rpe ? rpe->seq : 0);
+  atomic_store_explicit(&hook->last_export, rpe, memory_order_relaxed);
+
   hook->n = (node) {};
   add_tail(&re->hooks, &hook->n);
 
@@ -1842,7 +2105,7 @@ rt_table_export_stop(struct rt_export_hook *hook)
 {
   rtable *tab = SKIP_BACK(rtable, exporter, hook->table);
 
-  if (hook->export_state != TES_FEEDING)
+  if (atomic_load_explicit(&hook->export_state, memory_order_relaxed) != TES_FEEDING)
     return;
 
   switch (hook->req->addr_mode)
@@ -2037,8 +2300,8 @@ rt_dump_hooks(rtable *tab)
   {
     eh->req->dump_req(eh->req);
     debug("  Export hook %p requested by %p:"
-       " refeed_pending=%u last_state_change=%t export_state=%u stopped=%p\n",
-       eh, eh->req, eh->refeed_pending, eh->last_state_change, eh->export_state, eh->stopped);
+       " refeed_pending=%u last_state_change=%t export_state=%u\n",
+       eh, eh->req, eh->refeed_pending, eh->last_state_change, atomic_load_explicit(&eh->export_state, memory_order_relaxed));
   }
   debug("\n");
 }
@@ -2091,6 +2354,20 @@ rt_schedule_prune(rtable *tab)
   tab->prune_state |= 1;
 }
 
+static void
+rt_export_used(struct rt_exporter *e)
+{
+  rtable *tab = SKIP_BACK(rtable, exporter, e);
+
+  if (config->table_debug)
+    log(L_TRACE "%s: Export cleanup requested", tab->name);
+
+  if (tab->export_used)
+    return;
+
+  tab->export_used = 1;
+  ev_schedule(tab->rt_event);
+}
 
 static void
 rt_event(void *ptr)
@@ -2099,6 +2376,9 @@ rt_event(void *ptr)
 
   rt_lock_table(tab);
 
+  if (tab->export_used)
+    rt_export_cleanup(tab);
+
   if (tab->hcu_scheduled)
     rt_update_hostcache(tab);
 
@@ -2362,8 +2642,11 @@ rt_setup(pool *pp, struct rtable_config *cf)
     .start = rt_table_export_start,
     .stop = rt_table_export_stop,
     .done = rt_table_export_done,
+    .used = rt_export_used,
   };
+
   init_list(&t->exporter.hooks);
+  init_list(&t->exporter.pending);
 
   init_list(&t->imports);
 
@@ -2374,7 +2657,9 @@ rt_setup(pool *pp, struct rtable_config *cf)
 
   t->rt_event = ev_new_init(p, rt_event, t);
   t->prune_timer = tm_new_init(p, rt_prune_timer, t, 0, 0);
+  t->exporter.export_timer = tm_new_init(p, rt_announce_exports, t, 0, 0);
   t->last_rt_change = t->gc_time = current_time();
+  t->exporter.next_seq = 1;
 
   t->rl_pipe = (struct tbf) TBF_DEFAULT_LOG_LIMITS;
 
@@ -2488,7 +2773,7 @@ again:
 	  }
       }
 
-      if (!n->routes)		/* Orphaned FIB entry */
+      if (!n->routes && !n->first)		/* Orphaned FIB entry */
 	{
 	  FIB_ITERATE_PUT(fit);
 	  fib_delete(&tab->fib, n);
@@ -2543,15 +2828,15 @@ again:
 
   rt_prune_sources();
 
+  uint flushed_channels = 0;
+
   /* Close flushed channels */
   WALK_LIST2_DELSAFE(ih, n, x, tab->imports, n)
     if (ih->import_state == TIS_FLUSHING)
     {
-      rt_set_import_state(ih, TIS_CLEARED);
-      ih->stopped(ih->req);
-      rem_node(&ih->n);
-      mb_free(ih);
-      rt_unlock_table(tab);
+      ih->flush_seq = tab->exporter.next_seq;
+      rt_set_import_state(ih, TIS_WAITING);
+      flushed_channels++;
     }
     else if (ih->stale_pruning != ih->stale_pruned)
     {
@@ -2559,6 +2844,184 @@ again:
       if (ih->req->trace_routes & D_STATES)
 	log(L_TRACE "%s: table prune after refresh end [%u]", ih->req->name, ih->stale_pruned);
     }
+
+  /* In some cases, we may want to directly proceed to export cleanup */
+  if (EMPTY_LIST(tab->exporter.hooks) && flushed_channels)
+    rt_export_cleanup(tab);
+}
+
+static void
+rt_export_cleanup(rtable *tab)
+{
+  tab->export_used = 0;
+
+  u64 min_seq = ~((u64) 0);
+  struct rt_pending_export *last_export_to_free = NULL;
+  struct rt_pending_export *first = tab->exporter.first;
+
+  struct rt_export_hook *eh;
+  node *n;
+  WALK_LIST2(eh, n, tab->exporter.hooks, n)
+  {
+    switch (atomic_load_explicit(&eh->export_state, memory_order_acquire))
+    {
+      case TES_DOWN:
+	continue;
+
+      case TES_READY:
+	{
+	  struct rt_pending_export *last = atomic_load_explicit(&eh->last_export, memory_order_acquire);
+	  if (!last)
+	    /* No last export means that the channel has exported nothing since last cleanup */
+	    goto done;
+
+	  else if (min_seq > last->seq)
+	  {
+	    min_seq = last->seq;
+	    last_export_to_free = last;
+	  }
+	  continue;
+	}
+
+      default:
+	/* It's only safe to cleanup when the export state is idle or regular. No feeding or stopping allowed. */
+	goto done;
+    }
+  }
+
+  tab->exporter.first = last_export_to_free ? rt_next_export_fast(last_export_to_free) : NULL;
+
+  if (config->table_debug)
+    log(L_TRACE "%s: Export cleanup, old exporter.first seq %lu, new %lu, min_seq %ld",
+      tab->name,
+      first ? first->seq : 0,
+      tab->exporter.first ? tab->exporter.first->seq : 0,
+      min_seq);
+
+  WALK_LIST2(eh, n, tab->exporter.hooks, n)
+  {
+    if (atomic_load_explicit(&eh->export_state, memory_order_acquire) != TES_READY)
+      continue;
+
+    struct rt_pending_export *last = atomic_load_explicit(&eh->last_export, memory_order_acquire);
+    if (last == last_export_to_free)
+    {
+      /* This may fail when the channel managed to export more inbetween. This is OK. */
+      atomic_compare_exchange_strong_explicit(
+	  &eh->last_export, &last, NULL,
+	  memory_order_release,
+	  memory_order_relaxed);
+
+      DBG("store hook=%p last_export=NULL\n", eh);
+    }
+  }
+
+  while (first && (first->seq <= min_seq))
+  {
+    ASSERT_DIE(first->new || first->old);
+
+    const net_addr *n = first->new ?
+      first->new->rte.net :
+      first->old->rte.net;
+    net *net = SKIP_BACK(struct network, n.addr, (net_addr (*)[0]) n);
+
+    ASSERT_DIE(net->first == first);
+    
+    if (first == net->last)
+      /* The only export here */
+      net->last = net->first = NULL;
+    else
+      /* First is now the next one */
+      net->first = atomic_load_explicit(&first->next, memory_order_relaxed);
+
+    /* For now, the old route may be finally freed */
+    if (first->old)
+    {
+      rt_rte_trace_in(D_ROUTES, first->old->rte.sender->req, &first->old->rte, "freed");
+      hmap_clear(&tab->id_map, first->old->rte.id);
+      rte_free(first->old);
+    }
+
+#ifdef LOCAL_DEBUG
+    memset(first, 0xbd, sizeof(struct rt_pending_export));
+#endif
+
+    struct rt_export_block *reb = HEAD(tab->exporter.pending);
+    ASSERT_DIE(reb == PAGE_HEAD(first));
+
+    u32 pos = (first - &reb->export[0]);
+    u32 end = atomic_load_explicit(&reb->end, memory_order_relaxed);
+    ASSERT_DIE(pos < end);
+
+    struct rt_pending_export *next = NULL;
+    
+    if (++pos < end)
+      next = &reb->export[pos];
+    else
+    {
+      rem_node(&reb->n);
+
+#ifdef LOCAL_DEBUG
+      memset(reb, 0xbe, page_size);
+#endif
+
+      free_page(reb);
+
+      if (EMPTY_LIST(tab->exporter.pending))
+      {
+	if (config->table_debug)
+	  log(L_TRACE "%s: Resetting export seq", tab->name);
+
+	node *n;
+	WALK_LIST2(eh, n, tab->exporter.hooks, n)
+	{
+	  if (atomic_load_explicit(&eh->export_state, memory_order_acquire) != TES_READY)
+	    continue;
+
+	  ASSERT_DIE(atomic_load_explicit(&eh->last_export, memory_order_acquire) == NULL);
+	  bmap_reset(&eh->seq_map, 1024);
+	}
+
+	tab->exporter.next_seq = 1;
+      }
+      else
+      {
+	reb = HEAD(tab->exporter.pending);
+	next = &reb->export[0];
+      }
+    }
+
+    first = next;
+  }
+
+done:;
+  struct rt_import_hook *ih; node *x;
+  _Bool imports_stopped = 0;
+  WALK_LIST2_DELSAFE(ih, n, x, tab->imports, n)
+    if (ih->import_state == TIS_WAITING)
+      if (!first || (first->seq >= ih->flush_seq))
+      {
+	ih->import_state = TIS_CLEARED;
+	ih->stopped(ih->req);
+	rem_node(&ih->n);
+	mb_free(ih);
+	rt_unlock_table(tab);
+	imports_stopped = 1;
+      }
+
+  if (tab->export_used)
+    ev_schedule(tab->rt_event);
+
+  if (imports_stopped)
+  {
+    if (config->table_debug)
+      log(L_TRACE "%s: Sources pruning routine requested", tab->name);
+
+    rt_prune_sources();
+  }
+
+  if (EMPTY_LIST(tab->exporter.pending) && tm_active(tab->exporter.export_timer))
+    tm_stop(tab->exporter.export_timer);
 }
 
 /**
@@ -3040,6 +3503,11 @@ rt_next_hop_update_net(rtable *tab, net *n)
 	/* Replace the route in the list */
 	new->next = e->next;
 	*k = e = new;
+
+	/* Get a new ID for the route */
+	new->rte.lastmod = current_time();
+	new->rte.id = hmap_first_zero(&tab->id_map);
+	hmap_set(&tab->id_map, new->rte.id);
       }
 
   ASSERT_DIE(pos <= count);
@@ -3066,14 +3534,14 @@ rt_next_hop_update_net(rtable *tab, net *n)
   for (int i=0; i<count; i++)
   {
     _Bool nb = (new == updates[i].new), ob = (old_best == updates[i].old);
-    const char *best_indicator[2][2] = { { "updated", "updated [-best]" }, { "updated [+best]", "updated [best]" } };
+    const char *best_indicator[2][2] = {
+      { "autoupdated", "autoupdated [-best]" },
+      { "autoupdated [+best]", "autoupdated [best]" }
+    };
     rt_rte_trace_in(D_ROUTES, updates[i].new->rte.sender->req, &updates[i].new->rte, best_indicator[nb][ob]);
     rte_announce_i(tab, n, updates[i].new, updates[i].old, new, old_best);
   }
 
-  for (int i=0; i<count; i++)
-    rte_free(updates[i].old);
-
   return count;
 }
 
@@ -3252,6 +3720,16 @@ rt_commit(struct config *new, struct config *old)
   DBG("\tdone\n");
 }
 
+static void
+rt_feed_done(struct rt_export_hook *c)
+{
+  c->event->hook = rt_export_hook;
+
+  rt_set_export_state(c, TES_READY);
+
+  ev_schedule_work(c->event);
+}
+
 /**
  * rt_feed_by_fib - advertise all routes to a channel by walking a fib
  * @c: channel to be fed
@@ -3269,7 +3747,7 @@ rt_feed_by_fib(void *data)
   struct fib_iterator *fit = &c->feed_fit;
   int max_feed = 256;
 
-  ASSERT(c->export_state == TES_FEEDING);
+  ASSERT(atomic_load_explicit(&c->export_state, memory_order_relaxed) == TES_FEEDING);
 
   rtable *tab = SKIP_BACK(rtable, exporter, c->table);
 
@@ -3282,14 +3760,15 @@ rt_feed_by_fib(void *data)
 	  return;
 	}
 
-      ASSERT(c->export_state == TES_FEEDING);
+      if (atomic_load_explicit(&c->export_state, memory_order_acquire) != TES_FEEDING)
+	return;
 
       if ((c->req->addr_mode == TE_ADDR_NONE) || net_in_netX(n->n.addr, c->req->addr))
 	max_feed -= rt_feed_net(c, n);
     }
   FIB_ITERATE_END;
 
-  rt_set_export_state(c, TES_READY);
+  rt_feed_done(c);
 }
 
 static void
@@ -3303,7 +3782,7 @@ rt_feed_by_trie(void *data)
 
   int max_feed = 256;
 
-  ASSERT_DIE(c->export_state == TES_FEEDING);
+  ASSERT(atomic_load_explicit(&c->export_state, memory_order_relaxed) == TES_FEEDING);
 
   net_addr addr;
   while (trie_walk_next(ws, &addr))
@@ -3315,7 +3794,8 @@ rt_feed_by_trie(void *data)
     if ((max_feed -= rt_feed_net(c, n)) <= 0)
       return;
 
-    ASSERT_DIE(c->export_state == TES_FEEDING);
+    if (atomic_load_explicit(&c->export_state, memory_order_acquire) != TES_FEEDING)
+      return;
   }
 
   rt_unlock_trie(tab, c->walk_lock);
@@ -3324,7 +3804,7 @@ rt_feed_by_trie(void *data)
   mb_free(c->walk_state);
   c->walk_state = NULL;
 
-  rt_set_export_state(c, TES_READY);
+  rt_feed_done(c);
 }
 
 static void
@@ -3333,14 +3813,14 @@ rt_feed_equal(void *data)
   struct rt_export_hook *c = data;
   rtable *tab = SKIP_BACK(rtable, exporter, c->table);
 
-  ASSERT_DIE(c->export_state == TES_FEEDING);
+  ASSERT_DIE(atomic_load_explicit(&c->export_state, memory_order_relaxed) == TES_FEEDING);
   ASSERT_DIE(c->req->addr_mode == TE_ADDR_EQUAL);
 
   net *n = net_find(tab, c->req->addr);
   if (n)
     rt_feed_net(c, n);
 
-  rt_set_export_state(c, TES_READY);
+  rt_feed_done(c);
 }
 
 static void
@@ -3349,52 +3829,53 @@ rt_feed_for(void *data)
   struct rt_export_hook *c = data;
   rtable *tab = SKIP_BACK(rtable, exporter, c->table);
 
-  ASSERT_DIE(c->export_state == TES_FEEDING);
+  ASSERT_DIE(atomic_load_explicit(&c->export_state, memory_order_relaxed) == TES_FEEDING);
   ASSERT_DIE(c->req->addr_mode == TE_ADDR_FOR);
 
   net *n = net_route(tab, c->req->addr);
   if (n)
     rt_feed_net(c, n);
 
-  rt_set_export_state(c, TES_READY);
+  rt_feed_done(c);
 }
 
 static uint
 rt_feed_net(struct rt_export_hook *c, net *n)
 {
-      if (c->req->export_bulk)
-      {
-	uint count = rte_feed_count(n);
-	if (count)
-	{
-	  rte_update_lock();
-	  rte **feed = alloca(count * sizeof(rte *));
-	  rte_feed_obtain(n, feed, count);
-	  struct rt_pending_export rpe = { .new_best = n->routes };
-	  c->req->export_bulk(c->req, n->n.addr, &rpe, feed, count);
-	  rte_update_unlock();
-	}
-	return count;
-      }
+  uint count = 0;
 
-      if (n->routes && rte_is_valid(&n->routes->rte))
-      {
-	rte_update_lock();
-	struct rt_pending_export rpe = { .new = n->routes, .new_best = n->routes };
-	c->req->export_one(c->req, n->n.addr, &rpe);
-	rte_update_unlock();
-	return 1;
-      }
+  if (c->req->export_bulk)
+  {
+    count = rte_feed_count(n);
+    if (count)
+    {
+      rte_update_lock();
+      rte **feed = alloca(count * sizeof(rte *));
+      rte_feed_obtain(n, feed, count);
+      c->req->export_bulk(c->req, n->n.addr, NULL, feed, count);
+      rte_update_unlock();
+    }
+  }
 
-      return 0;
-}
+  else if (n->routes)
+  {
+    rte_update_lock();
+    struct rt_pending_export rpe = { .new = n->routes, .new_best = n->routes };
+    c->req->export_one(c->req, n->n.addr, &rpe);
+    rte_update_unlock();
+    count = 1;
+  }
 
+  for (struct rt_pending_export *rpe = n->first; rpe; rpe = rpe_next(rpe, NULL))
+    rpe_mark_seen(c, rpe);
+
+  return count;
+}
 
 /*
  *	Import table
  */
 
-
 void channel_reload_export_bulk(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe UNUSED, rte **feed, uint count)
 {
   struct channel *c = SKIP_BACK(struct channel, reload_req, req);
diff --git a/nest/rt.h b/nest/rt.h
index bdbea05b..20ed0ad0 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -18,6 +18,8 @@
 #include "lib/fib.h"
 #include "lib/route.h"
 
+#include <stdatomic.h>
+
 struct ea_list;
 struct protocol;
 struct proto;
@@ -53,6 +55,7 @@ struct rtable_config {
   byte trie_used;			/* Rtable has attached trie */
   btime min_settle_time;		/* Minimum settle time for notifications */
   btime max_settle_time;		/* Maximum settle time for notifications */
+  btime export_settle_time;		/* Delay before exports are announced */
 };
 
 struct rt_export_hook;
@@ -61,9 +64,17 @@ struct rt_export_request;
 struct rt_exporter {
   list hooks;				/* Registered route export hooks */
   uint addr_type;			/* Type of address data exported (NET_*) */
+
   struct rt_export_hook *(*start)(struct rt_exporter *, struct rt_export_request *);
   void (*stop)(struct rt_export_hook *);
   void (*done)(struct rt_export_hook *);
+  void (*used)(struct rt_exporter *);
+
+  list pending;				/* List of packed struct rt_pending_export */
+  struct timer *export_timer;
+
+  struct rt_pending_export *first;	/* First export to announce */
+  u64 next_seq;				/* The next export will have this ID */
 };
 
 typedef struct rtable {
@@ -98,6 +109,7 @@ typedef struct rtable {
   byte prune_trie;			/* Prune prefix trie during next table prune */
   byte hcu_scheduled;			/* Hostcache update is scheduled */
   byte nhu_state;			/* Next Hop Update state */
+  byte export_used;			/* Pending Export pruning is scheduled */
   struct fib_iterator prune_fit;	/* Rtable prune FIB iterator */
   struct fib_iterator nhu_fit;		/* Next Hop Update FIB iterator */
   struct f_trie *trie_new;		/* New prefix trie defined during pruning */
@@ -132,7 +144,8 @@ struct rt_flowspec_link {
 #define NHU_DIRTY	3
 
 typedef struct network {
-  struct rte_storage *routes;			/* Available routes for this network */
+  struct rte_storage *routes;		/* Available routes for this network */
+  struct rt_pending_export *first, *last;
   struct fib_node n;			/* FIB flags reserved for kernel syncer */
 } net;
 
@@ -200,6 +213,7 @@ struct rt_import_hook {
     u32 withdraws_accepted;		/* Number of route withdraws accepted and processed */
   } stats;
 
+  u64 flush_seq;			/* Table export seq when the channel announced flushing */
   btime last_state_change;		/* Time of last state transition */
 
   u8 import_state;			/* IS_* */
@@ -212,7 +226,9 @@ struct rt_import_hook {
 };
 
 struct rt_pending_export {
+  struct rt_pending_export * _Atomic next;	/* Next export for the same destination */
   struct rte_storage *new, *new_best, *old, *old_best;
+  u64 seq;				/* Sequential ID (table-local) of the pending export */
 };
 
 struct rt_export_request {
@@ -241,7 +257,6 @@ struct rt_export_hook {
   struct rt_exporter *table;		/* The connected table */
 
   pool *pool;
-  linpool *lp;
 
   struct rt_export_request *req;	/* The requestor */
 
@@ -260,10 +275,15 @@ struct rt_export_hook {
     u32 hash_iter;				/* Iterator over hash */
   };
 
+  struct bmap seq_map;			/* Keep track which exports were already procesed */
+
+  struct rt_pending_export * _Atomic last_export;/* Last export processed */
+  struct rt_pending_export *rpe_next;	/* Next pending export to process */
+
   btime last_state_change;		/* Time of last state transition */
 
   u8 refeed_pending;			/* Refeeding and another refeed is scheduled */
-  u8 export_state;			/* Route export state (TES_*, see below) */
+  _Atomic u8 export_state;		/* Route export state (TES_*, see below) */
   u8 feed_type;				/* Which feeding method is used (TFT_*, see below) */
 
   struct event *event;			/* Event running all the export operations */
@@ -314,6 +334,15 @@ void rt_set_export_state(struct rt_export_hook *hook, u8 state);
 
 void rte_import(struct rt_import_request *req, const net_addr *net, rte *new, struct rte_src *src);
 
+/* Get next rpe. If src is given, it must match. */
+struct rt_pending_export *rpe_next(struct rt_pending_export *rpe, struct rte_src *src);
+
+/* Mark the pending export processed */
+void rpe_mark_seen(struct rt_export_hook *hook, struct rt_pending_export *rpe);
+
+/* Get pending export seen status */
+int rpe_get_seen(struct rt_export_hook *hook, struct rt_pending_export *rpe);
+
 /* Types of route announcement, also used as flags */
 #define RA_UNDEF	0		/* Undefined RA type */
 #define RA_OPTIMAL	1		/* Announcement of optimal route change */