ike-sa-manager: Improve scalability of IKE_SA count checking

Much like in commit a68454b, we now use a global atomic counter to keep
track of the number of IKE_SAs currently registered. This should improve
scalability for a large number of segments even more.

Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>

diff --git a/src/libcharon/sa/ike_sa_manager.c b/src/libcharon/sa/ike_sa_manager.c
index 6bd49a0865310f3715112bfcf7457261be8962b4..15629fe61b872e857836266c69ae9b8709f44d43 100644 (file)
--- a/src/libcharon/sa/ike_sa_manager.c
+++ b/src/libcharon/sa/ike_sa_manager.c
@@ -276,9 +276,6 @@ typedef struct segment_t segment_t;
 struct segment_t {
        /** mutex to access a segment exclusively */
        mutex_t *mutex;
-
-       /** the number of entries in this segment */
-       u_int count;
 };
 
 typedef struct shareable_segment_t shareable_segment_t;
@@ -370,6 +367,11 @@ struct private_ike_sa_manager_t {
         */
        refcount_t half_open_count_responder;
 
+       /**
+        * Total number of IKE_SAs registered with IKE_SA manager.
+        */
+       refcount_t total_sa_count;
+
        /**
         * Hash table with connected_peers_t objects.
         */
@@ -601,7 +603,7 @@ static u_int put_entry(private_ike_sa_manager_t *this, entry_t *entry)
                item->next = current;
        }
        this->ike_sa_table[row] = item;
-       this->segments[segment].count++;
+       ref_get(&this->total_sa_count);
        return segment;
 }
 
@@ -612,10 +614,9 @@ static u_int put_entry(private_ike_sa_manager_t *this, entry_t *entry)
 static void remove_entry(private_ike_sa_manager_t *this, entry_t *entry)
 {
        table_item_t *item, *prev = NULL;
-       u_int row, segment;
+       u_int row;
 
        row = ike_sa_id_hash(entry->ike_sa_id) & this->table_mask;
-       segment = row & this->segment_mask;
        item = this->ike_sa_table[row];
        while (item)
        {
@@ -629,7 +630,7 @@ static void remove_entry(private_ike_sa_manager_t *this, entry_t *entry)
                        {
                                this->ike_sa_table[row] = item->next;
                        }
-                       this->segments[segment].count--;
+                       ignore_result(ref_put(&this->total_sa_count));
                        free(item);
                        break;
                }
@@ -648,7 +649,7 @@ static void remove_entry_at(private_enumerator_t *this)
        {
                table_item_t *current = this->current;
 
-               this->manager->segments[this->segment].count--;
+               ignore_result(ref_put(&this->manager->total_sa_count));
                this->current = this->prev;
 
                if (this->prev)
@@ -2034,17 +2035,7 @@ METHOD(ike_sa_manager_t, has_contact, bool,
 METHOD(ike_sa_manager_t, get_count, u_int,
        private_ike_sa_manager_t *this)
 {
-       u_int segment, count = 0;
-       mutex_t *mutex;
-
-       for (segment = 0; segment < this->segment_count; segment++)
-       {
-               mutex = this->segments[segment & this->segment_mask].mutex;
-               mutex->lock(mutex);
-               count += this->segments[segment].count;
-               mutex->unlock(mutex);
-       }
-       return count;
+       return (u_int)ref_cur(&this->total_sa_count);
 }
 
 METHOD(ike_sa_manager_t, get_half_open_count, u_int,