X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread.h;h=21cc086c6ee8ec9c2db4b7b9c0daceee28ab1b99;hp=e59f74f62c46276d4b5b1f89ea75cef7565315e8;hb=ac1889bfdcb77622bbc818352d65634209d9829f;hpb=2ae99f0b1ce4b1ae352a7bf179b1f040111afd46 diff --git a/src/bin/lttng-sessiond/notification-thread.h b/src/bin/lttng-sessiond/notification-thread.h index e59f74f62..21cc086c6 100644 --- a/src/bin/lttng-sessiond/notification-thread.h +++ b/src/bin/lttng-sessiond/notification-thread.h @@ -1,18 +1,8 @@ /* - * Copyright (C) 2017 - Jérémie Galarneau + * Copyright (C) 2017 Jérémie Galarneau * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License, version 2 only, as - * published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef NOTIFICATION_THREAD_H @@ -26,6 +16,11 @@ #include #include #include +#include +#include "thread.h" + + +typedef uint64_t notification_client_id; struct notification_thread_handle { /* @@ -47,6 +42,8 @@ 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; }; /** @@ -55,19 +52,34 @@ struct notification_thread_handle { * 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 client" - * This hash table owns the "struct client" which must thus be - * disposed-of on removal from the hash table. + * - 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 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 @@ -88,8 +100,14 @@ struct notification_thread_handle { * 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. * @@ -99,25 +117,33 @@ struct notification_thread_handle { * 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", @@ -126,6 +152,7 @@ struct notification_thread_handle { * - 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. @@ -134,6 +161,7 @@ struct notification_thread_handle { * - 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 @@ -143,22 +171,28 @@ struct notification_thread_handle { * "notify", query the notification_trigger_clients_ht and send * a notification to the clients. * - * 6) Connection of a client - * - add client socket to the client_socket_ht. + * 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. * - * 7) Disconnection of a client + * 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. * - * 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. @@ -167,11 +201,15 @@ 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; }; /* notification_thread_data takes ownership of the channel monitor pipes. */ @@ -181,7 +219,7 @@ struct notification_thread_handle *notification_thread_handle_create( struct lttng_pipe *kernel_channel_monitor_pipe); void notification_thread_handle_destroy( struct notification_thread_handle *handle); - -void *thread_notification(void *data); +struct lttng_thread *launch_notification_thread( + struct notification_thread_handle *handle); #endif /* NOTIFICATION_THREAD_H */