#include <common/compat/poll.h>
#include <common/hashtable/hashtable.h>
#include <pthread.h>
+#include <semaphore.h>
struct notification_thread_handle {
/*
int ust64_consumer;
int kernel_consumer;
} channel_monitoring_pipes;
+ /* Used to wait for the launch of the notification thread. */
+ sem_t ready;
};
/**
* - channel_triggers_ht:
* associates a channel key to a list of
* struct lttng_trigger_list_nodes. The triggers in this list are
- * those that have conditions that apply to this channel.
+ * those that have conditions that apply to a particular channel.
* A channel entry is only created when a channel is added; the
* list of triggers applying to such a channel is built at that
* moment.
* This hash table owns the list, but not the triggers themselves.
*
+ * - session_triggers_ht:
+ * associates a session name to a list of
+ * struct lttng_trigger_list_nodes. The triggers in this list are
+ * those that have conditions that apply to a particular session.
+ * A session entry is only created when a session is created; the
+ * list of triggers applying to this new session is built at that
+ * moment. This happens at the time of creation of a session_info.
+ * Likewise, the list is destroyed at the time of the session_info's
+ * destruction.
+ *
* - channel_state_ht:
* associates a pair (channel key, channel domain) to its last
* sampled state received from the consumer daemon
* associates a channel_key to a struct channel_info. The hash table
* holds the ownership of the struct channel_info.
*
+ * - sessions_ht:
+ * associates a session_name (hash) to a struct session_info. The
+ * hash table holds no ownership of the struct session_info;
+ * the session_info structure is owned by the session's various
+ * channels through their struct channel_info (ref-counting is used).
+ *
* - triggers_ht:
- * associated a condition to a struct lttng_trigger_ht_element.
+ * associates a condition to a struct lttng_trigger_ht_element.
* The hash table holds the ownership of the
* lttng_trigger_ht_elements along with the triggers themselves.
*
* 3) registration of a trigger,
* 4) unregistration of a trigger,
* 5) reception of a channel monitor sample from the consumer daemon.
+ * 6) Session rotation ongoing
+ * 7) Session rotation completed
*
* Events specific to notification-emitting triggers:
- * 6) connection of a notification client,
- * 7) disconnection of a notification client,
- * 8) subscription of a client to a conditions' notifications,
- * 9) unsubscription of a client from a conditions' notifications,
+ * 8) connection of a notification client,
+ * 9) disconnection of a notification client,
+ * 10) subscription of a client to a conditions' notifications,
+ * 11) unsubscription of a client from a conditions' notifications,
*
*
* 1) Creation of a tracing channel
* - notification_trigger_clients_ht is traversed to identify
* triggers which apply to this new channel,
- * - triggers identified are added to the channel_triggers_ht.
+ * - triggers identified are added to the channel_triggers_ht.
* - add channel to channels_ht
+ * - if it is the first channel of a session, a session_info is created and
+ * added to the sessions_ht. A list of the triggers associated with that
+ * session is built, and it is added to session_triggers_ht.
*
* 2) Destruction of a tracing channel
* - remove entry from channel_triggers_ht, releasing the list wrapper and
* elements,
* - remove entry from the channel_state_ht.
* - remove channel from channels_ht
+ * - if it was the last known channel of a session, the session_info
+ * structure is torndown, which in return destroys the list of triggers
+ * applying to that session.
*
* 3) Registration of a trigger
* - if the trigger's action is of type "notify",
* - add list of clients (even if it is empty) to the
* notification_trigger_clients_ht,
* - add trigger to channel_triggers_ht (if applicable),
+ * - add trigger to session_triggers_ht (if applicable),
* - add trigger to triggers_ht
* - evaluate the trigger's condition right away to react if that condition
* is true from the beginning.
* - if the trigger's action is of type "notify",
* - remove the trigger from the notification_trigger_clients_ht,
* - remove trigger from channel_triggers_ht (if applicable),
+ * - remove trigger from session_triggers_ht (if applicable),
* - remove trigger from triggers_ht
*
* 5) Reception of a channel monitor sample from the consumer daemon
* "notify", query the notification_trigger_clients_ht and send
* a notification to the clients.
*
- * 6) Connection of a client
+ * 6) Session rotation ongoing
+ *
+ * 7) Session rotation completed
+ *
+ * 8) Connection of a client
* - add client socket to the client_socket_ht.
*
- * 7) Disconnection of a client
+ * 9) Disconnection of a client
* - remove client socket from the client_socket_ht,
* - traverse all conditions to which the client is subscribed and remove
* the client from the notification_trigger_clients_ht.
*
- * 8) Subscription of a client to a condition's notifications
+ * 10) Subscription of a client to a condition's notifications
* - Add the condition to the client's list of subscribed conditions,
* - Look-up notification_trigger_clients_ht and add the client to
* list of clients.
* - Evaluate the condition for the client that subscribed if the trigger
* was already registered.
*
- * 9) Unsubscription of a client to a condition's notifications
+ * 11) Unsubscription of a client to a condition's notifications
* - Remove the condition from the client's list of subscribed conditions,
* - Look-up notification_trigger_clients_ht and remove the client
* from the list of clients.
struct lttng_poll_event events;
struct cds_lfht *client_socket_ht;
struct cds_lfht *channel_triggers_ht;
+ struct cds_lfht *session_triggers_ht;
struct cds_lfht *channel_state_ht;
struct cds_lfht *notification_trigger_clients_ht;
struct cds_lfht *channels_ht;
+ struct cds_lfht *sessions_ht;
struct cds_lfht *triggers_ht;
};
struct lttng_pipe *kernel_channel_monitor_pipe);
void notification_thread_handle_destroy(
struct notification_thread_handle *handle);
-
-void *thread_notification(void *data);
+bool launch_notification_thread(struct notification_thread_handle *handle);
#endif /* NOTIFICATION_THREAD_H */
projects / lttng-tools.git / blobdiff