-struct notification_client_list_element {
- struct notification_client *client;
- struct cds_list_head node;
-};
-
-/*
- * Thread safety of notification_client and notification_client_list.
- *
- * The notification thread (main thread) and the action executor
- * interact through client lists. Hence, when the action executor
- * thread looks-up the list of clients subscribed to a given
- * condition, it will acquire a reference to the list and lock it
- * while attempting to communicate with the various clients.
- *
- * It is not necessary to reference-count clients as they are guaranteed
- * to be 'alive' if they are present in a list and that list is locked. Indeed,
- * removing references to the client from those subscription lists is part of
- * the work performed on destruction of a client.
- *
- * No provision for other access scenarios are taken into account;
- * this is the bare minimum to make these accesses safe and the
- * notification thread's state is _not_ "thread-safe" in any general
- * sense.
- */
-struct notification_client_list {
- pthread_mutex_t lock;
- struct urcu_ref ref;
- const struct lttng_trigger *trigger;
- struct cds_list_head list;
- /* Weak reference to container. */
- struct cds_lfht *notification_trigger_clients_ht;
- struct cds_lfht_node notification_trigger_clients_ht_node;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
-struct notification_client {
- /* Nests within the notification_client_list lock. */
- pthread_mutex_t lock;
- notification_client_id id;
- int socket;
- /* Client protocol version. */
- uint8_t major, minor;
- uid_t uid;
- gid_t gid;
- /*
- * Indicates if the credentials and versions of the client have been
- * checked.
- */
- bool validated;
- /*
- * Conditions to which the client's notification channel is subscribed.
- * List of struct lttng_condition_list_node. The condition member is
- * owned by the client.
- */
- struct cds_list_head condition_list;
- struct cds_lfht_node client_socket_ht_node;
- struct cds_lfht_node client_id_ht_node;
- struct {
- /*
- * If a client's communication is inactive, it means that a
- * fatal error has occurred (could be either a protocol error or
- * the socket API returned a fatal error). No further
- * communication should be attempted; the client is queued for
- * clean-up.
- */
- bool active;
- struct {
- /*
- * During the reception of a message, the reception
- * buffers' "size" is set to contain the current
- * message's complete payload.
- */
- struct lttng_dynamic_buffer buffer;
- /* Bytes left to receive for the current message. */
- size_t bytes_to_receive;
- /* Type of the message being received. */
- enum lttng_notification_channel_message_type msg_type;
- /*
- * Indicates whether or not credentials are expected
- * from the client.
- */
- bool expect_creds;
- /*
- * Indicates whether or not credentials were received
- * from the client.
- */
- bool creds_received;
- /* Only used during credentials reception. */
- lttng_sock_cred creds;
- } inbound;
- struct {
- /*
- * Indicates whether or not a notification addressed to
- * this client was dropped because a command reply was
- * already buffered.
- *
- * A notification is dropped whenever the buffer is not
- * empty.
- */
- bool dropped_notification;
- /*
- * Indicates whether or not a command reply is already
- * buffered. In this case, it means that the client is
- * not consuming command replies before emitting a new
- * one. This could be caused by a protocol error or a
- * misbehaving/malicious client.
- */
- bool queued_command_reply;
- struct lttng_dynamic_buffer buffer;
- } outbound;
- } communication;
- /* call_rcu delayed reclaim. */
- struct rcu_head rcu_node;
-};
-
projects / lttng-tools.git / blobdiff