sessiond: notification: maintain an id to notification_client ht

[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread-events.c

diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c
index 6f0ee7d7942cf762b38c6c7edc37ab97caa8972b..51b95ee6da2e85b2501eda2b839cd39629ff760c 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -131,6 +131,7 @@ struct notification_client_list {
 };
 
 struct notification_client {
+       notification_client_id id;
        int socket;
        /* Client protocol version. */
        uint8_t major, minor;
@@ -148,6 +149,7 @@ struct notification_client {
         */
        struct cds_list_head condition_list;
        struct cds_lfht_node client_socket_ht_node;
+       struct cds_lfht_node client_id_ht_node;
        struct {
                struct {
                        /*
@@ -262,16 +264,25 @@ int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list,
 
 
 static
-int match_client(struct cds_lfht_node *node, const void *key)
+int match_client_socket(struct cds_lfht_node *node, const void *key)
 {
        /* This double-cast is intended to supress pointer-to-cast warning. */
-       int socket = (int) (intptr_t) key;
-       struct notification_client *client;
+       const int socket = (int) (intptr_t) key;
+       const struct notification_client *client = caa_container_of(node,
+                       struct notification_client, client_socket_ht_node);
 
-       client = caa_container_of(node, struct notification_client,
-                       client_socket_ht_node);
+       return client->socket == socket;
+}
+
+static
+int match_client_id(struct cds_lfht_node *node, const void *key)
+{
+       /* This double-cast is intended to supress pointer-to-cast warning. */
+       const notification_client_id id = *((notification_client_id *) key);
+       const struct notification_client *client = caa_container_of(
+                       node, struct notification_client, client_id_ht_node);
 
-       return !!(client->socket == socket);
+       return client->id == id;
 }
 
 static
@@ -475,6 +486,18 @@ unsigned long hash_channel_key(struct channel_key *key)
        return key_hash ^ domain_hash;
 }
 
+static
+unsigned long hash_client_socket(int socket)
+{
+       return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed);
+}
+
+static
+unsigned long hash_client_id(notification_client_id id)
+{
+       return hash_key_u64(&id, lttng_ht_seed);
+}
+
 /*
  * Get the type of object to which a given condition applies. Bindings let
  * the notification system evaluate a trigger's condition when a given
@@ -1138,6 +1161,7 @@ void notification_client_destroy(struct notification_client *client,
 
        if (client->socket >= 0) {
                (void) lttcomm_close_unix_sock(client->socket);
+               client->socket = -1;
        }
        lttng_dynamic_buffer_reset(&client->communication.inbound.buffer);
        lttng_dynamic_buffer_reset(&client->communication.outbound.buffer);
@@ -1157,8 +1181,8 @@ struct notification_client *get_client_from_socket(int socket,
        struct notification_client *client = NULL;
 
        cds_lfht_lookup(state->client_socket_ht,
-                       hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed),
-                       match_client,
+                       hash_client_socket(socket),
+                       match_client_socket,
                        (void *) (unsigned long) socket,
                        &iter);
        node = cds_lfht_iter_get_node(&iter);
@@ -1172,6 +1196,34 @@ end:
        return client;
 }
 
+/*
+ * Call with rcu_read_lock held (and hold for the lifetime of the returned
+ * client pointer).
+ */
+static
+struct notification_client *get_client_from_id(notification_client_id id,
+               struct notification_thread_state *state)
+{
+       struct cds_lfht_iter iter;
+       struct cds_lfht_node *node;
+       struct notification_client *client = NULL;
+
+       cds_lfht_lookup(state->client_id_ht,
+                       hash_client_id(id),
+                       match_client_id,
+                       &id,
+                       &iter);
+       node = cds_lfht_iter_get_node(&iter);
+       if (!node) {
+               goto end;
+       }
+
+       client = caa_container_of(node, struct notification_client,
+                       client_id_ht_node);
+end:
+       return client;
+}
+
 static
 bool buffer_usage_condition_applies_to_channel(
                const struct lttng_condition *condition,
@@ -2347,12 +2399,6 @@ error:
        return -1;
 }
 
-static
-unsigned long hash_client_socket(int socket)
-{
-       return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed);
-}
-
 static
 int socket_set_non_blocking(int socket)
 {
@@ -2411,6 +2457,7 @@ int handle_notification_thread_client_connect(
                ret = -1;
                goto error;
        }
+       client->id = state->next_notification_client_id++;
        CDS_INIT_LIST_HEAD(&client->condition_list);
        lttng_dynamic_buffer_init(&client->communication.inbound.buffer);
        lttng_dynamic_buffer_init(&client->communication.outbound.buffer);
@@ -2459,6 +2506,9 @@ int handle_notification_thread_client_connect(
        cds_lfht_add(state->client_socket_ht,
                        hash_client_socket(client->socket),
                        &client->client_socket_ht_node);
+       cds_lfht_add(state->client_id_ht,
+                       hash_client_id(client->id),
+                       &client->client_id_ht_node);
        rcu_read_unlock();
 
        return ret;
@@ -2492,6 +2542,8 @@ int handle_notification_thread_client_disconnect(
        }
        cds_lfht_del(state->client_socket_ht,
                        &client->client_socket_ht_node);
+        cds_lfht_del(state->client_id_ht,
+                       &client->client_id_ht_node);
        notification_client_destroy(client, state);
 end:
        rcu_read_unlock();