X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread.c;h=c964e7c910b062a82753c50c58b78d728a9454c1;hp=7bd65361a25a7b97063305ca8eec2e0b6551abbf;hb=ac1889bfdcb77622bbc818352d65634209d9829f;hpb=d0119529da31f9968b6ef59e38cfa54aca1a2013 diff --git a/src/bin/lttng-sessiond/notification-thread.c b/src/bin/lttng-sessiond/notification-thread.c index 7bd65361a..c964e7c91 100644 --- a/src/bin/lttng-sessiond/notification-thread.c +++ b/src/bin/lttng-sessiond/notification-thread.c @@ -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. */ #define _LGPL_SOURCE @@ -37,119 +27,12 @@ #include "notification-thread-commands.h" #include "lttng-sessiond.h" #include "health-sessiond.h" +#include "thread.h" #include #include #include -/** - * 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 client" - * This hash table owns the "struct client" which must thus be - * disposed-of on removal from the hash table. - * - * - 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. - * This hash table owns the list, but not the triggers themselves. - * - * - 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. - * - * - triggers_ht: - * associated 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. - * - * 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, - * - * - * 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 - * - * 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 - * - * 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 triggers_ht - * - * 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 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) Connection of a client - * - add client socket to the client_socket_ht. - * - * 7) 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 - * - 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. - * - * 9) 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. - */ - /* * Destroy the thread data previously created by the init function. */ @@ -162,17 +45,13 @@ void notification_thread_handle_destroy( goto end; } - if (handle->cmd_queue.event_fd < 0) { - goto end; - } - ret = close(handle->cmd_queue.event_fd); - if (ret < 0) { - PERROR("close notification command queue event_fd"); - } - assert(cds_list_empty(&handle->cmd_queue.list)); pthread_mutex_destroy(&handle->cmd_queue.lock); + sem_destroy(&handle->ready); + if (handle->cmd_queue.event_pipe) { + lttng_pipe_destroy(handle->cmd_queue.event_pipe); + } if (handle->channel_monitoring_pipes.ust32_consumer >= 0) { ret = close(handle->channel_monitoring_pipes.ust32_consumer); if (ret) { @@ -202,18 +81,24 @@ struct notification_thread_handle *notification_thread_handle_create( { int ret; struct notification_thread_handle *handle; + struct lttng_pipe *event_pipe = NULL; handle = zmalloc(sizeof(*handle)); if (!handle) { goto end; } - /* FIXME Replace eventfd by a pipe to support older kernels. */ - handle->cmd_queue.event_fd = eventfd(0, EFD_CLOEXEC | EFD_SEMAPHORE); - if (handle->cmd_queue.event_fd < 0) { - PERROR("eventfd notification command queue"); + sem_init(&handle->ready, 0, 0); + + event_pipe = lttng_pipe_open(FD_CLOEXEC); + if (!event_pipe) { + ERR("event_pipe creation"); goto error; } + + handle->cmd_queue.event_pipe = event_pipe; + event_pipe = NULL; + CDS_INIT_LIST_HEAD(&handle->cmd_queue.list); ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL); if (ret) { @@ -253,6 +138,7 @@ struct notification_thread_handle *notification_thread_handle_create( end: return handle; error: + lttng_pipe_destroy(event_pipe); notification_thread_handle_destroy(handle); return NULL; } @@ -276,7 +162,7 @@ char *get_notification_channel_sock_path(void) goto error; } } else { - char *home_path = utils_get_home_dir(); + const char *home_path = utils_get_home_dir(); if (!home_path) { ERR("Can't get HOME directory for socket creation"); @@ -343,8 +229,16 @@ int notification_channel_socket_create(void) } if (getuid() == 0) { - ret = chown(sock_path, 0, - utils_get_group_id(tracing_group_name)); + gid_t gid; + + ret = utils_get_group_id(config.tracing_group_name.value, true, + &gid); + if (ret) { + /* Default to root group. */ + gid = 0; + } + + ret = chown(sock_path, 0, gid); if (ret) { ERR("Failed to set the notification channel socket's group"); ret = -1; @@ -390,7 +284,7 @@ int init_poll_set(struct lttng_poll_event *poll_set, ERR("[notification-thread] Failed to add notification channel socket to pollset"); goto error; } - ret = lttng_poll_add(poll_set, handle->cmd_queue.event_fd, + ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), LPOLLIN | LPOLLERR); if (ret < 0) { ERR("[notification-thread] Failed to add notification command queue event fd to pollset"); @@ -438,6 +332,10 @@ void fini_thread_state(struct notification_thread_state *state) ret = cds_lfht_destroy(state->client_socket_ht, NULL); assert(!ret); } + if (state->client_id_ht) { + ret = cds_lfht_destroy(state->client_id_ht, NULL); + assert(!ret); + } if (state->triggers_ht) { ret = handle_notification_thread_trigger_unregister_all(state); assert(!ret); @@ -458,11 +356,21 @@ void fini_thread_state(struct notification_thread_state *state) assert(!ret); } if (state->channels_ht) { - ret = cds_lfht_destroy(state->channels_ht, - NULL); + ret = cds_lfht_destroy(state->channels_ht, NULL); + assert(!ret); + } + if (state->sessions_ht) { + ret = cds_lfht_destroy(state->sessions_ht, NULL); + assert(!ret); + } + /* + * Must be destroyed after all channels have been destroyed. + * See comment in struct lttng_session_trigger_list. + */ + if (state->session_triggers_ht) { + ret = cds_lfht_destroy(state->session_triggers_ht, NULL); assert(!ret); } - if (state->notification_channel_socket >= 0) { notification_channel_socket_destroy( state->notification_channel_socket); @@ -470,6 +378,21 @@ void fini_thread_state(struct notification_thread_state *state) lttng_poll_clean(&state->events); } +static +void mark_thread_as_ready(struct notification_thread_handle *handle) +{ + DBG("Marking notification thread as ready"); + sem_post(&handle->ready); +} + +static +void wait_until_thread_is_ready(struct notification_thread_handle *handle) +{ + DBG("Waiting for notification thread to be ready"); + sem_wait(&handle->ready); + DBG("Notification thread is ready"); +} + static int init_thread_state(struct notification_thread_handle *handle, struct notification_thread_state *state) @@ -505,12 +428,24 @@ int init_thread_state(struct notification_thread_handle *handle, goto error; } + state->client_id_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, + CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); + if (!state->client_id_ht) { + goto error; + } + state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); if (!state->channel_triggers_ht) { goto error; } + state->session_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, + CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); + if (!state->session_triggers_ht) { + goto error; + } + state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); if (!state->channel_state_ht) { @@ -528,12 +463,17 @@ int init_thread_state(struct notification_thread_handle *handle, if (!state->channels_ht) { goto error; } - + state->sessions_ht = cds_lfht_new(DEFAULT_HT_SIZE, + 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); + if (!state->sessions_ht) { + goto error; + } state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); if (!state->triggers_ht) { goto error; } + mark_thread_as_ready(handle); end: return 0; error: @@ -569,7 +509,7 @@ int handle_channel_monitoring_pipe(int fd, uint32_t revents, ret = handle_notification_thread_channel_sample( state, fd, domain); if (ret) { - ERR("[notification-thread] Consumer sample handling error occured"); + ERR("[notification-thread] Consumer sample handling error occurred"); ret = -1; goto end; } @@ -581,6 +521,7 @@ end: * This thread services notification channel clients and commands received * from various lttng-sessiond components over a command queue. */ +static void *thread_notification(void *data) { int ret; @@ -589,15 +530,15 @@ void *thread_notification(void *data) DBG("[notification-thread] Started notification thread"); + health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION); + rcu_register_thread(); + rcu_thread_online(); + if (!handle) { ERR("[notification-thread] Invalid thread context provided"); goto end; } - rcu_register_thread(); - rcu_thread_online(); - - health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION); health_code_update(); ret = init_thread_state(handle, &state); @@ -605,9 +546,6 @@ void *thread_notification(void *data) goto end; } - /* Ready to handle client connections. */ - sessiond_notify_ready(); - while (true) { int fd_count, i; @@ -632,9 +570,6 @@ void *thread_notification(void *data) int fd = LTTNG_POLL_GETFD(&state.events, i); uint32_t revents = LTTNG_POLL_GETEV(&state.events, i); - if (!revents) { - continue; - } DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents); if (fd == state.notification_channel_socket) { @@ -652,7 +587,7 @@ void *thread_notification(void *data) ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd); goto error; } - } else if (fd == handle->cmd_queue.event_fd) { + } else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) { ret = handle_notification_thread_command(handle, &state); if (ret < 0) { @@ -707,9 +642,43 @@ void *thread_notification(void *data) exit: error: fini_thread_state(&state); - health_unregister(health_sessiond); +end: rcu_thread_offline(); rcu_unregister_thread(); -end: + health_unregister(health_sessiond); + return NULL; +} + +static +bool shutdown_notification_thread(void *thread_data) +{ + struct notification_thread_handle *handle = thread_data; + + notification_thread_command_quit(handle); + return true; +} + +struct lttng_thread *launch_notification_thread( + struct notification_thread_handle *handle) +{ + struct lttng_thread *thread; + + thread = lttng_thread_create("Notification", + thread_notification, + shutdown_notification_thread, + NULL, + handle); + if (!thread) { + goto error; + } + + /* + * Wait for the thread to be marked as "ready" before returning + * as other subsystems depend on the notification subsystem + * (e.g. rotation thread). + */ + wait_until_thread_is_ready(handle); + return thread; +error: return NULL; }