X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread.h;h=8b4c7af2b0326dec1126ea2767cc1ffcf0e9761c;hp=134804f9d0718a76415e898f556e612921c95f9f;hb=HEAD;hpb=f2b3ef9f7d7adf6cc0678cd5933b638f5a9e75a6 diff --git a/src/bin/lttng-sessiond/notification-thread.h b/src/bin/lttng-sessiond/notification-thread.h deleted file mode 100644 index 134804f9d..000000000 --- a/src/bin/lttng-sessiond/notification-thread.h +++ /dev/null @@ -1,227 +0,0 @@ -/* - * Copyright (C) 2017 Jérémie Galarneau - * - * SPDX-License-Identifier: GPL-2.0-only - * - */ - -#ifndef NOTIFICATION_THREAD_H -#define NOTIFICATION_THREAD_H - -#include "action-executor.h" -#include "thread.h" -#include -#include -#include -#include -#include -#include -#include -#include -#include - - -typedef uint64_t notification_client_id; - -struct notification_thread_handle { - /* - * Queue of struct notification command. - * event_pipe must be WRITE(2) to signal that a new command - * has been enqueued. - */ - struct { - struct lttng_pipe *event_pipe; - struct cds_list_head list; - pthread_mutex_t lock; - } cmd_queue; - /* - * Read side of pipes used to receive channel status info collected - * by the various consumer daemons. - */ - struct { - int ust32_consumer; - int ust64_consumer; - int kernel_consumer; - } channel_monitoring_pipes; - /* Used to wait for the launch of the notification thread. */ - sem_t ready; -}; - -/** - * This thread maintains an internal state associating clients and triggers. - * - * In order to speed-up and simplify queries, hash tables providing the - * following associations are maintained: - * - * - client_socket_ht: associate a client's socket (fd) to its - * "struct notification_client". - * This hash table owns the "struct notification_client" which must - * thus be disposed-of on removal from the hash table. - * - * - client_id_ht: associate a client's id to its "struct notification_client" - * This hash table holds a _weak_ reference to the - * "struct notification_client". - * - * - 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 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 - * (struct channel_state). - * This previous sample is kept to implement edge-triggered - * conditions as we need to detect the state transitions. - * This hash table owns the channel state. - * - * - notification_trigger_clients_ht: - * associates notification-emitting triggers to clients - * (struct notification_client_list) subscribed to those - * conditions. - * The condition's hash and match functions are used directly since - * all triggers in this hash table have the "notify" action. - * This hash table holds no ownership. - * - * - channels_ht: - * 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: - * 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. - * - * The thread reacts to the following internal events: - * 1) creation of a tracing channel, - * 2) destruction of a tracing channel, - * 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: - * 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. - * - 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", - * - traverse the list of conditions of every client to build a list of - * clients which have to be notified when this trigger's condition is met, - * - 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. - * - * 4) Unregistration of a trigger - * - 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 - * - evaluate the conditions associated with the triggers found in - * the channel_triggers_ht, - * - if a condition evaluates to "true" and the condition is of type - * "notify", query the notification_trigger_clients_ht and send - * a notification to the clients. - * - * 6) Session rotation ongoing - * - * 7) Session rotation completed - * - * 8) Connection of a client - * - add client socket to the client_socket_ht, - * - add client socket to the client_id_ht. - * - * 9) Disconnection of a client - * - remove client socket from the client_id_ht, - * - 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. - * - * 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. - * - * 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 notification_thread_state { - int notification_channel_socket; - struct lttng_poll_event events; - struct cds_lfht *client_socket_ht; - struct cds_lfht *client_id_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; - notification_client_id next_notification_client_id; - struct action_executor *executor; -}; - -/* notification_thread_data takes ownership of the channel monitor pipes. */ -struct notification_thread_handle *notification_thread_handle_create( - struct lttng_pipe *ust32_channel_monitor_pipe, - struct lttng_pipe *ust64_channel_monitor_pipe, - struct lttng_pipe *kernel_channel_monitor_pipe); -void notification_thread_handle_destroy( - struct notification_thread_handle *handle); -struct lttng_thread *launch_notification_thread( - struct notification_thread_handle *handle); - -#endif /* NOTIFICATION_THREAD_H */