Route attributes now use the common lockfree usecount

Also route attributes are not freed immediately anymore.

lib/route.h

@@ -253,8 +253,10 @@ enum ea_stored {
 
 struct ea_storage {
   struct ea_storage *next_hash;		/* Next in hash chain */
-  _Atomic u32 uc;			/* Use count */
+  struct lfuc uc;			/* Use count */
   u32 hash_key;				/* List hash */
+  /* 32 bits unused but we don't wanna squeeze the use count
+   * into 32 bits to pack with the list hash, sorry */
   ea_list l[0];				/* The list itself */
 };
 
@@ -543,7 +545,7 @@ static inline struct ea_storage *ea_get_storage(ea_list *r)
 
 static inline ea_list *ea_ref(ea_list *r)
 {
-  ASSERT_DIE(0 < atomic_fetch_add_explicit(&ea_get_storage(r)->uc, 1, memory_order_acq_rel));
+  lfuc_lock(&ea_get_storage(r)->uc);
   return r;
 }
 
@@ -556,33 +558,25 @@ static inline ea_list *ea_lookup(ea_list *r, u32 squash_upto, enum ea_stored oid
     return ea_lookup_slow(r, squash_upto, oid);
 }
 
-struct ea_free_deferred {
-  struct deferred_call dc;
-  ea_list *attrs;
-};
-
-void ea_free_deferred(struct deferred_call *dc);
-
-static inline ea_list *ea_free_later(ea_list *r)
+#define ea_free_later ea_free
+extern event ea_cleanup_event;
+static inline void ea_free(ea_list *l)
 {
-  struct ea_free_deferred efd = {
-    .dc.hook = ea_free_deferred,
-    .attrs = r,
-  };
-
-  defer_call(&efd.dc, sizeof efd);
-  return r;
+  if (l)
+    lfuc_unlock(&ea_get_storage(l)->uc, &global_work_list, &ea_cleanup_event);
 }
 
 static inline ea_list *ea_lookup_tmp(ea_list *r, u32 squash_upto, enum ea_stored oid)
 {
-  return ea_free_later(ea_lookup(r, squash_upto, oid));
+  ea_free_later(r = ea_lookup(r, squash_upto, oid));
+  return r;
 }
 
 static inline ea_list *ea_ref_tmp(ea_list *r)
 {
   ASSERT_DIE(r->stored);
-  return ea_free_later(ea_ref(r));
+  ea_free_later(ea_ref(r));
+  return r;
 }
 
 static inline ea_list *ea_strip_to(ea_list *r, u32 strip_to)
@@ -594,13 +588,6 @@ static inline ea_list *ea_strip_to(ea_list *r, u32 strip_to)
   return r;
 }
 
-void ea__free(struct ea_storage *r);
-static inline void ea_free(ea_list *l) {
-  if (!l) return;
-  struct ea_storage *r = ea_get_storage(l);
-  if (1 == atomic_fetch_sub_explicit(&r->uc, 1, memory_order_acq_rel)) ea__free(r);
-}
-
 void ea_dump(ea_list *);
 void ea_dump_all(void);
 void ea_show_list(struct cli *, ea_list *);

nest/rt-attr.c

@@ -1227,8 +1227,6 @@ ea_list_ref(ea_list *l)
     ea_ref(l->next);
 }
 
-static void ea_free_nested(ea_list *l);
-
 static void
 ea_list_unref(ea_list *l)
 {
@@ -1249,7 +1247,7 @@ ea_list_unref(ea_list *l)
     }
 
   if (l->next)
-    ea_free_nested(l->next);
+    lfuc_unlock(&ea_get_storage(l->next)->uc, &global_work_list, &ea_cleanup_event);
 }
 
 void
@@ -1523,7 +1521,7 @@ ea_dump(ea_list *e)
 	    (e->flags & EALF_SORTED) ? 'S' : 's',
 	    (e->flags & EALF_BISECT) ? 'B' : 'b',
 	    e->stored,
-	    s ? atomic_load_explicit(&s->uc, memory_order_relaxed) : 0,
+	    s ? atomic_load_explicit(&s->uc.uc, memory_order_relaxed) : 0,
 	    s ? s->hash_key : 0);
       for(i=0; i<e->count; i++)
 	{
@@ -1623,6 +1621,8 @@ ea_append(ea_list *to, ea_list *what)
  *	rta's
  */
 
+event ea_cleanup_event;
+
 static HASH(struct ea_storage) rta_hash_table;
 
 #define RTAH_KEY(a)		a->l, a->hash_key
@@ -1675,7 +1675,7 @@ ea_lookup_slow(ea_list *o, u32 squash_upto, enum ea_stored oid)
 
   if (r)
   {
-    atomic_fetch_add_explicit(&r->uc, 1, memory_order_acq_rel);
+    lfuc_lock_revive(&r->uc);
     RTA_UNLOCK;
     return r->l;
   }
@@ -1699,7 +1699,9 @@ ea_lookup_slow(ea_list *o, u32 squash_upto, enum ea_stored oid)
   r->l->flags |= huge;
   r->l->stored = oid;
   r->hash_key = h;
-  atomic_store_explicit(&r->uc, 1, memory_order_release);
+
+  memset(&r->uc, 0, sizeof r->uc);
+  lfuc_lock_revive(&r->uc);
 
   HASH_INSERT2(rta_hash_table, RTAH, rta_pool, r);
 
@@ -1708,41 +1710,26 @@ ea_lookup_slow(ea_list *o, u32 squash_upto, enum ea_stored oid)
 }
 
 static void
-ea_free_locked(struct ea_storage *a)
-{
-  /* Somebody has cloned this rta inbetween. This sometimes happens. */
-  if (atomic_load_explicit(&a->uc, memory_order_acquire))
-    return;
-
-  HASH_REMOVE2(rta_hash_table, RTAH, rta_pool, a);
-
-  ea_list_unref(a->l);
-  if (a->l->flags & EALF_HUGE)
-    mb_free(a);
-  else
-    sl_free(a);
-}
-
-static void
-ea_free_nested(struct ea_list *l)
-{
-  struct ea_storage *r = ea_get_storage(l);
-  if (1 == atomic_fetch_sub_explicit(&r->uc, 1, memory_order_acq_rel))
-    ea_free_locked(r);
-}
-
-void
-ea__free(struct ea_storage *a)
+ea_cleanup(void *_ UNUSED)
 {
   RTA_LOCK;
-  ea_free_locked(a);
-  RTA_UNLOCK;
-}
 
-void
-ea_free_deferred(struct deferred_call *dc)
+  HASH_WALK_FILTER(rta_hash_table, next_hash, r, rp)
   {
-  ea_free(SKIP_BACK(struct ea_free_deferred, dc, dc)->attrs);
+    if (lfuc_finished(&r->uc))
+    {
+      HASH_DO_REMOVE(rta_hash_table, RTAH, rp);
+
+      ea_list_unref(r->l);
+      if (r->l->flags & EALF_HUGE)
+	mb_free(r);
+      else
+	sl_free(r);
+    }
+  }
+  HASH_WALK_FILTER_END;
+
+  RTA_UNLOCK;
 }
 
 /**
@@ -1800,6 +1787,10 @@ rta_init(void)
   rte_src_init();
   ea_class_init();
 
+  ea_cleanup_event = (event) {
+    .hook = ea_cleanup,
+  };
+
   RTA_UNLOCK;
 
   /* These attributes are required to be first for nice "show route" output */