X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fnotification-thread-events.c;h=76a7363bf8d03bb907f420abdbd377deff7f8563;hb=428b440c632be8aa4938ae7fcbd5831d492a1d77;hp=2d37af07c6504a1c55eedd2c829418ef16d0a6eb;hpb=2d6bae7ed336ffdda5e9e7f94495f5ef43238847;p=lttng-tools.git diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c index 2d37af07c..76a7363bf 100644 --- a/src/bin/lttng-sessiond/notification-thread-events.c +++ b/src/bin/lttng-sessiond/notification-thread-events.c @@ -48,8 +48,8 @@ #include "lttng-sessiond.h" #include "kernel.h" -#define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) -#define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) +#define CLIENT_POLL_EVENTS_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) +#define CLIENT_POLL_EVENTS_IN_OUT (CLIENT_POLL_EVENTS_IN | LPOLLOUT) /* The tracers currently limit the capture size to PIPE_BUF (4kb on linux). */ #define MAX_CAPTURE_SIZE (PIPE_BUF) @@ -530,7 +530,7 @@ void session_info_destroy(void *_data) if (session_info->channel_infos_ht) { ret = cds_lfht_destroy(session_info->channel_infos_ht, NULL); if (ret) { - ERR("[notification-thread] Failed to destroy channel information hash table"); + ERR("Failed to destroy channel information hash table"); } } lttng_session_trigger_list_destroy(session_info->trigger_list); @@ -870,7 +870,7 @@ int evaluate_channel_condition_for_client( if (!channel_key){ /* No channel found; normal exit. */ - DBG("[notification-thread] No known channel associated with newly subscribed-to condition"); + DBG("No known channel associated with newly subscribed-to condition"); ret = 0; goto end; } @@ -899,7 +899,7 @@ int evaluate_channel_condition_for_client( channel_state_ht_node); } else { /* Nothing to evaluate, no sample was ever taken. Normal exit */ - DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); + DBG("No channel sample associated with newly subscribed-to condition"); ret = 0; goto end; } @@ -909,7 +909,7 @@ int evaluate_channel_condition_for_client( 0, channel_info->session_info->consumed_data_size, channel_info); if (ret) { - WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); + WARN("Fatal error occurred while evaluating a newly subscribed-to condition"); goto end; } @@ -945,7 +945,7 @@ const char *get_condition_session_name(const struct lttng_condition *condition) abort(); } if (status != LTTNG_CONDITION_STATUS_OK) { - ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); + ERR("Failed to retrieve session rotation condition's session name"); goto end; } end: @@ -976,7 +976,7 @@ int evaluate_session_condition_for_client( &iter); node = cds_lfht_iter_get_node(&iter); if (!node) { - DBG("[notification-thread] No known session matching name \"%s\"", + DBG("No known session matching name \"%s\"", session_name); ret = 0; goto end; @@ -1001,7 +1001,7 @@ int evaluate_session_condition_for_client( session_info->rotation.id); if (!*evaluation) { /* Fatal error. */ - ERR("[notification-thread] Failed to create session rotation ongoing evaluation for session \"%s\"", + ERR("Failed to create session rotation ongoing evaluation for session \"%s\"", session_info->name); ret = -1; goto end_session_put; @@ -1053,7 +1053,7 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, &evaluation, &object_uid, &object_gid); break; case LTTNG_OBJECT_TYPE_NONE: - DBG("[notification-thread] Newly subscribed-to condition not bound to object, nothing to evaluate"); + DBG("Newly subscribed-to condition not bound to object, nothing to evaluate"); ret = 0; goto end; case LTTNG_OBJECT_TYPE_UNKNOWN: @@ -1067,7 +1067,7 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, } if (!evaluation) { /* Evaluation yielded nothing. Normal exit. */ - DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); + DBG("Newly subscribed-to condition evaluated to false, nothing to report to client"); ret = 0; goto end; } @@ -1084,7 +1084,7 @@ int evaluate_condition_for_client(const struct lttng_trigger *trigger, cds_list_add(&client_list_element.node, &client_list.clients_list); /* Send evaluation result to the newly-subscribed client. */ - DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); + DBG("Newly subscribed-to condition evaluated to true, notifying client"); ret = send_evaluation_to_clients(trigger, evaluation, &client_list, state, object_uid, object_gid); @@ -1164,7 +1164,7 @@ int notification_thread_client_subscribe(struct notification_client *client, &client_list->triggers_list, client_list_trigger_node) { if (evaluate_condition_for_client(trigger_ht_element->trigger, condition_list_element->condition, client, state)) { - WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); + WARN("Evaluation of a condition on client subscription failed, aborting."); ret = -1; free(client_list_element); pthread_mutex_unlock(&client_list->lock); @@ -1469,7 +1469,7 @@ struct lttng_session_trigger_list *get_session_trigger_list( * Not an error, the list of triggers applying to that session * will be initialized when the session is created. */ - DBG("[notification-thread] No trigger list found for session \"%s\" as it is not yet known to the notification system", + DBG("No trigger list found for session \"%s\" as it is not yet known to the notification system", session_name); goto end; } @@ -1578,7 +1578,7 @@ bool trigger_applies_to_session(const struct lttng_trigger *trigger, condition_status = lttng_condition_session_rotation_get_session_name( condition, &condition_session_name); if (condition_status != LTTNG_CONDITION_STATUS_OK) { - ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); + ERR("Failed to retrieve session rotation condition's session name"); goto end; } @@ -1633,7 +1633,7 @@ struct lttng_session_trigger_list *lttng_session_trigger_list_build( trigger_count++; } - DBG("[notification-thread] Found %i triggers that apply to newly created session", + DBG("Found %i triggers that apply to newly created session", trigger_count); return session_trigger_list; error: @@ -1659,7 +1659,7 @@ struct session_info *find_or_create_session_info( &iter); node = cds_lfht_iter_get_node(&iter); if (node) { - DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)", + DBG("Found session info of session \"%s\" (uid = %i, gid = %i)", name, uid, gid); session = caa_container_of(node, struct session_info, sessions_ht_node); @@ -1677,7 +1677,7 @@ struct session_info *find_or_create_session_info( session = session_info_create(name, uid, gid, trigger_list, state->sessions_ht); if (!session) { - ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", + ERR("Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", name, uid, gid); lttng_session_trigger_list_destroy(trigger_list); goto error; @@ -1715,7 +1715,7 @@ int handle_notification_thread_command_add_channel( struct cds_lfht_iter iter; struct session_info *session_info = NULL; - DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", + DBG("Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", channel_name, session_name, channel_key_int, lttng_domain_type_str(channel_domain)); @@ -1757,7 +1757,7 @@ int handle_notification_thread_command_add_channel( } rcu_read_unlock(); - DBG("[notification-thread] Found %i triggers that apply to newly added channel", + DBG("Found %i triggers that apply to newly added channel", trigger_count); channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); if (!channel_trigger_list) { @@ -1817,7 +1817,7 @@ int handle_notification_thread_command_remove_channel( struct channel_key key = { .key = channel_key, .domain = domain }; struct channel_info *channel_info; - DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", + DBG("Removing channel key = %" PRIu64 " in %s domain", channel_key, lttng_domain_type_str(domain)); rcu_read_lock(); @@ -1833,7 +1833,7 @@ int handle_notification_thread_command_remove_channel( * channel that doesn't exist. */ if (!node) { - ERR("[notification-thread] Channel being removed is unknown to the notification thread"); + ERR("Channel being removed is unknown to the notification thread"); goto end; } @@ -1921,7 +1921,7 @@ int handle_notification_thread_command_session_rotation( session_info->rotation.id = trace_archive_chunk_id; trigger_list = get_session_trigger_list(state, session_name); if (!trigger_list) { - DBG("[notification-thread] No triggers applying to session \"%s\" found", + DBG("No triggers applying to session \"%s\" found", session_name); goto end; } @@ -2034,14 +2034,14 @@ int handle_notification_thread_command_add_tracer_event_source( cds_list_add(&element->node, &state->tracer_event_sources_list); - DBG3("[notification-thread] Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'", + DBG3("Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'", tracer_event_source_fd, lttng_domain_type_str(domain_type)); /* Adding the read side pipe to the event poll. */ - ret = lttng_poll_add(&state->events, tracer_event_source_fd, LPOLLIN | LPOLLERR); + ret = lttng_poll_add(&state->events, tracer_event_source_fd, LPOLLPRI | LPOLLIN | LPOLLERR); if (ret < 0) { - ERR("[notification-thread] Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'", + ERR("Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'", tracer_event_source_fd, lttng_domain_type_str(element->domain)); cds_list_del(&element->node); @@ -2066,13 +2066,13 @@ int drain_event_notifier_notification_pipe( ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); if (ret < 0) { - ERR("[notification-thread] Error creating lttng_poll_event"); + ERR("Error creating lttng_poll_event"); goto end; } ret = lttng_poll_add(&events, pipe, LPOLLIN); if (ret < 0) { - ERR("[notification-thread] Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d", + ERR("Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d", pipe); goto end; } @@ -2100,7 +2100,7 @@ int drain_event_notifier_notification_pipe( ret = handle_one_event_notifier_notification(state, pipe, domain); if (ret) { - ERR("[notification-thread] Error consuming an event notifier notification from pipe: fd = %d", + ERR("Error consuming an event notifier notification from pipe: fd = %d", pipe); } } @@ -2110,95 +2110,121 @@ end: } static -int handle_notification_thread_command_remove_tracer_event_source( - struct notification_thread_state *state, - int tracer_event_source_fd, - enum lttng_error_code *_cmd_result) +struct notification_event_tracer_event_source_element * +find_tracer_event_source_element(struct notification_thread_state *state, + int tracer_event_source_fd) { - int ret = 0; - bool found = false; - enum lttng_error_code cmd_result = LTTNG_OK; - struct notification_event_tracer_event_source_element *source_element = NULL, *tmp; + struct notification_event_tracer_event_source_element *source_element; - cds_list_for_each_entry_safe(source_element, tmp, + cds_list_for_each_entry(source_element, &state->tracer_event_sources_list, node) { - if (source_element->fd != tracer_event_source_fd) { - continue; + if (source_element->fd == tracer_event_source_fd) { + goto end; } - - DBG("[notification-thread] Removed tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", - tracer_event_source_fd, - lttng_domain_type_str(source_element->domain)); - cds_list_del(&source_element->node); - found = true; - break; } - if (!found) { - /* - * This is temporarily allowed since the poll activity set is - * not properly cleaned-up for the moment. This is adressed in - * an upcoming fix. - */ - source_element = NULL; - goto end; - } + source_element = NULL; +end: + return source_element; +} - if (!source_element->is_fd_in_poll_set) { - /* Skip the poll set removal. */ - goto end; - } +static +int remove_tracer_event_source_from_pollset( + struct notification_thread_state *state, + struct notification_event_tracer_event_source_element *source_element) +{ + int ret = 0; - DBG3("[notification-thread] Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", - tracer_event_source_fd, + assert(source_element->is_fd_in_poll_set); + + DBG3("Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + source_element->fd, lttng_domain_type_str(source_element->domain)); /* Removing the fd from the event poll set. */ - ret = lttng_poll_del(&state->events, tracer_event_source_fd); + ret = lttng_poll_del(&state->events, source_element->fd); if (ret < 0) { - ERR("[notification-thread] Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", - tracer_event_source_fd, + ERR("Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'", + source_element->fd, lttng_domain_type_str(source_element->domain)); - cmd_result = LTTNG_ERR_FATAL; + ret = -1; goto end; } source_element->is_fd_in_poll_set = false; - ret = drain_event_notifier_notification_pipe(state, tracer_event_source_fd, + /* + * Force the notification thread to restart the poll() loop to ensure + * that any events from the removed fd are removed. + */ + state->restart_poll = true; + + ret = drain_event_notifier_notification_pipe(state, source_element->fd, source_element->domain); if (ret) { - ERR("[notification-thread] Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s", - tracer_event_source_fd, + ERR("Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s", + source_element->fd, lttng_domain_type_str(source_element->domain)); - cmd_result = LTTNG_ERR_FATAL; + ret = -1; goto end; } - /* - * The drain_event_notifier_notification_pipe() call might have read - * data from an fd that we received in event in the latest _poll_wait() - * call. Make sure the thread call poll_wait() again to ensure we have - * a clean state. - */ - state->restart_poll = true; - end: - free(source_element); - *_cmd_result = cmd_result; return ret; } -int handle_notification_thread_remove_tracer_event_source_no_result( +int handle_notification_thread_tracer_event_source_died( struct notification_thread_state *state, int tracer_event_source_fd) { - int ret; - enum lttng_error_code cmd_result; + int ret = 0; + struct notification_event_tracer_event_source_element *source_element; + + source_element = find_tracer_event_source_element(state, + tracer_event_source_fd); + + assert(source_element); + + ret = remove_tracer_event_source_from_pollset(state, source_element); + if (ret) { + ERR("Failed to remove dead tracer event source from poll set"); + } + + return ret; +} + +static +int handle_notification_thread_command_remove_tracer_event_source( + struct notification_thread_state *state, + int tracer_event_source_fd, + enum lttng_error_code *_cmd_result) +{ + int ret = 0; + enum lttng_error_code cmd_result = LTTNG_OK; + struct notification_event_tracer_event_source_element *source_element = NULL; - ret = handle_notification_thread_command_remove_tracer_event_source( - state, tracer_event_source_fd, &cmd_result); - (void) cmd_result; + source_element = find_tracer_event_source_element(state, + tracer_event_source_fd); + + assert(source_element); + + /* Remove the tracer source from the list. */ + cds_list_del(&source_element->node); + + if (!source_element->is_fd_in_poll_set) { + /* Skip the poll set removal. */ + goto end; + } + + ret = remove_tracer_event_source_from_pollset(state, source_element); + if (ret) { + ERR("Failed to remove tracer event source from poll set"); + cmd_result = LTTNG_ERR_FATAL; + } + +end: + free(source_element); + *_cmd_result = cmd_result; return ret; } @@ -2404,7 +2430,7 @@ int bind_trigger_to_matching_session(struct lttng_trigger *trigger, status = lttng_condition_session_rotation_get_session_name( condition, &session_name); if (status != LTTNG_CONDITION_STATUS_OK) { - ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); + ERR("Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); ret = -1; goto end; } @@ -2417,13 +2443,13 @@ int bind_trigger_to_matching_session(struct lttng_trigger *trigger, trigger_list = get_session_trigger_list(state, session_name); if (!trigger_list) { - DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", + DBG("Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", session_name); goto end; } - DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", + DBG("Newly registered trigger bound to session \"%s\"", session_name); ret = lttng_session_trigger_list_add(trigger_list, trigger); end: @@ -2469,7 +2495,7 @@ int bind_trigger_to_matching_channels(struct lttng_trigger *trigger, CDS_INIT_LIST_HEAD(&trigger_list_element->node); trigger_list_element->trigger = trigger; cds_list_add(&trigger_list_element->node, &trigger_list->list); - DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"", + DBG("Newly registered trigger bound to channel \"%s\"", channel->name); } end: @@ -2985,7 +3011,7 @@ void teardown_tracer_notifier(struct notification_thread_state *state, trigger_tokens_ht_element->trigger); /* TODO talk to all app and remove it */ - DBG("[notification-thread] Removed trigger from tokens_ht"); + DBG("Removed trigger from tokens_ht"); cds_lfht_del(state->trigger_tokens_ht, &trigger_tokens_ht_element->node); @@ -3040,7 +3066,7 @@ int handle_notification_thread_command_unregister_trigger( continue; } - DBG("[notification-thread] Removed trigger from channel_triggers_ht"); + DBG("Removed trigger from channel_triggers_ht"); cds_list_del(&trigger_element->node); /* A trigger can only appear once per channel */ break; @@ -3083,29 +3109,56 @@ end: return 0; } +static +int pop_cmd_queue(struct notification_thread_handle *handle, + struct notification_thread_command **cmd) +{ + int ret; + uint64_t counter; + + pthread_mutex_lock(&handle->cmd_queue.lock); + ret = lttng_read(handle->cmd_queue.event_fd, &counter, sizeof(counter)); + if (ret != sizeof(counter)) { + ret = -1; + goto error_unlock; + } + + /* Simulate behaviour of EFD_SEMAPHORE for older kernels. */ + counter -= 1; + if (counter != 0) { + ret = lttng_write(handle->cmd_queue.event_fd, &counter, + sizeof(counter)); + if (ret != sizeof(counter)) { + PERROR("Failed to write back to event_fd for EFD_SEMAPHORE emulation"); + ret = -1; + goto error_unlock; + } + } + + *cmd = cds_list_first_entry(&handle->cmd_queue.list, + struct notification_thread_command, cmd_list_node); + cds_list_del(&((*cmd)->cmd_list_node)); + ret = 0; + +error_unlock: + pthread_mutex_unlock(&handle->cmd_queue.lock); + return ret; +} + /* Returns 0 on success, 1 on exit requested, negative value on error. */ int handle_notification_thread_command( struct notification_thread_handle *handle, struct notification_thread_state *state) { int ret; - uint64_t counter; struct notification_thread_command *cmd; - /* Read the event pipe to put it back into a quiescent state. */ - ret = lttng_read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, - sizeof(counter)); - if (ret != sizeof(counter)) { + ret = pop_cmd_queue(handle, &cmd); + if (ret) { goto error; } - pthread_mutex_lock(&handle->cmd_queue.lock); - cmd = cds_list_first_entry(&handle->cmd_queue.list, - struct notification_thread_command, cmd_list_node); - cds_list_del(&cmd->cmd_list_node); - pthread_mutex_unlock(&handle->cmd_queue.lock); - - DBG("[notification-thread] Received `%s` command", + DBG("Received `%s` command", notification_command_type_str(cmd->type)); switch (cmd->type) { case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: @@ -3220,7 +3273,7 @@ int handle_notification_thread_command( break; } default: - ERR("[notification-thread] Unknown internal command received"); + ERR("Unknown internal command received"); goto error_unlock; } @@ -3294,7 +3347,7 @@ int handle_notification_thread_client_connect( int ret; struct notification_client *client; - DBG("[notification-thread] Handling new notification channel client connection"); + DBG("Handling new notification channel client connection"); client = zmalloc(sizeof(*client)); if (!client) { @@ -3312,14 +3365,14 @@ int handle_notification_thread_client_connect( ret = client_reset_inbound_state(client); if (ret) { - ERR("[notification-thread] Failed to reset client communication's inbound state"); + ERR("Failed to reset client communication's inbound state"); ret = 0; goto error; } ret = lttcomm_accept_unix_sock(state->notification_channel_socket); if (ret < 0) { - ERR("[notification-thread] Failed to accept new notification channel client connection"); + ERR("Failed to accept new notification channel client connection"); ret = 0; goto error; } @@ -3328,26 +3381,26 @@ int handle_notification_thread_client_connect( ret = socket_set_non_blocking(client->socket); if (ret) { - ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); + ERR("Failed to set new notification channel client connection socket as non-blocking"); goto error; } ret = lttcomm_setsockopt_creds_unix_sock(client->socket); if (ret < 0) { - ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); + ERR("Failed to set socket options on new notification channel client socket"); ret = 0; goto error; } + client->communication.current_poll_events = CLIENT_POLL_EVENTS_IN; ret = lttng_poll_add(&state->events, client->socket, - LPOLLIN | LPOLLERR | - LPOLLHUP | LPOLLRDHUP); + client->communication.current_poll_events); if (ret < 0) { - ERR("[notification-thread] Failed to add notification channel client socket to poll set"); + ERR("Failed to add notification channel client socket to poll set"); ret = 0; goto error; } - DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", + DBG("Added new notification channel client socket (%i) to poll set", client->socket); rcu_read_lock(); @@ -3387,7 +3440,7 @@ int notification_thread_client_disconnect( ret = lttng_poll_del(&state->events, client->socket); if (ret) { - ERR("[notification-thread] Failed to remove client socket %d from poll set", + ERR("Failed to remove client socket %d from poll set", client->socket); } @@ -3413,12 +3466,12 @@ int handle_notification_thread_client_disconnect( struct notification_client *client; rcu_read_lock(); - DBG("[notification-thread] Closing client connection (socket fd = %i)", + DBG("Closing client connection (socket fd = %i)", client_socket); client = get_client_from_socket(client_socket, state); if (!client) { /* Internal state corruption, fatal error. */ - ERR("[notification-thread] Unable to find client (socket fd = %i)", + ERR("Unable to find client (socket fd = %i)", client_socket); ret = -1; goto end; @@ -3438,7 +3491,7 @@ int handle_notification_thread_client_disconnect_all( bool error_encoutered = false; rcu_read_lock(); - DBG("[notification-thread] Closing all client connections"); + DBG("Closing all client connections"); cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, client_socket_ht_node) { int ret; @@ -3473,6 +3526,18 @@ int handle_notification_thread_trigger_unregister_all( return error_occurred ? -1 : 0; } +static +bool client_has_outbound_data_left( + const struct notification_client *client) +{ + const struct lttng_payload_view pv = lttng_payload_view_from_payload( + &client->communication.outbound.payload, 0, -1); + const bool has_data = pv.buffer.size != 0; + const bool has_fds = lttng_payload_view_get_fd_handle_count(&pv); + + return has_data || has_fds; +} + static int client_handle_transmission_status( struct notification_client *client, @@ -3483,24 +3548,51 @@ int client_handle_transmission_status( switch (transmission_status) { case CLIENT_TRANSMISSION_STATUS_COMPLETE: - ret = lttng_poll_mod(&state->events, client->socket, - CLIENT_POLL_MASK_IN); - if (ret) { - goto end; - } - - break; case CLIENT_TRANSMISSION_STATUS_QUEUED: + { + int current_poll_events; + int new_poll_events; /* * We want to be notified whenever there is buffer space - * available to send the rest of the payload. + * available to send the rest of the payload if we are + * waiting to send data to the client. + * + * The state of the outbound queue being sampled here is + * fine since: + * - it is okay to wake-up "for nothing" in case we see + * that data is left, but another thread succeeds in + * flushing it before us when handling the client "out" + * event. We will simply stop monitoring that event the next + * time it wakes us up and we see no data left to be sent, + * - if another thread fails to flush the entire client + * outgoing queue, it will issue a "communication update" + * command and cause the client's (e)poll mask to be + * re-evaluated. + * + * The situation we seek to avoid would be to disable the + * monitoring of "out" client events indefinitely when there is + * data to be sent, which can't happen because of the + * aforementioned "communication update" mechanism. */ - ret = lttng_poll_mod(&state->events, client->socket, - CLIENT_POLL_MASK_IN_OUT); - if (ret) { - goto end; + pthread_mutex_lock(&client->lock); + current_poll_events = client->communication.current_poll_events; + new_poll_events = client_has_outbound_data_left(client) ? + CLIENT_POLL_EVENTS_IN_OUT : + CLIENT_POLL_EVENTS_IN; + client->communication.current_poll_events = new_poll_events; + pthread_mutex_unlock(&client->lock); + + /* Update the monitored event set only if it changed. */ + if (current_poll_events != new_poll_events) { + ret = lttng_poll_mod(&state->events, client->socket, + new_poll_events); + if (ret) { + goto end; + } } + break; + } case CLIENT_TRANSMISSION_STATUS_FAIL: ret = notification_thread_client_disconnect(client, state); if (ret) { @@ -3548,14 +3640,14 @@ enum client_transmission_status client_flush_outgoing_queue( /* Send data. */ to_send_count = pv.buffer.size; - DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", + DBG("Flushing client (socket fd = %i) outgoing queue", client->socket); ret = lttcomm_send_unix_sock_non_block(client->socket, pv.buffer.data, to_send_count); if ((ret >= 0 && ret < to_send_count)) { - DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", + DBG("Client (socket fd = %i) outgoing queue could not be completely flushed", client->socket); to_send_count -= max(ret, 0); @@ -3574,7 +3666,7 @@ enum client_transmission_status client_flush_outgoing_queue( goto end; } else if (ret < 0) { /* Generic error, disable the client's communication. */ - ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)", + ERR("Failed to flush outgoing queue, disconnecting client (socket fd = %i)", client->socket); client->communication.active = false; status = CLIENT_TRANSMISSION_STATUS_FAIL; @@ -3606,7 +3698,7 @@ send_fds: client->socket, &pv); if (ret < 0) { /* Generic error, disable the client's communication. */ - ERR("[notification-thread] Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)", + ERR("Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)", client->socket); client->communication.active = false; status = CLIENT_TRANSMISSION_STATUS_FAIL; @@ -3640,18 +3732,6 @@ error: return CLIENT_TRANSMISSION_STATUS_ERROR; } -static -bool client_has_outbound_data_left( - const struct notification_client *client) -{ - const struct lttng_payload_view pv = lttng_payload_view_from_payload( - &client->communication.outbound.payload, 0, -1); - const bool has_data = pv.buffer.size != 0; - const bool has_fds = lttng_payload_view_get_fd_handle_count(&pv); - - return has_data || has_fds; -} - /* Client lock must _not_ be held by the caller. */ static int client_send_command_reply(struct notification_client *client, @@ -3671,7 +3751,7 @@ int client_send_command_reply(struct notification_client *client, memcpy(buffer, &msg, sizeof(msg)); memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); - DBG("[notification-thread] Send command reply (%i)", (int) status); + DBG("Send command reply (%i)", (int) status); pthread_mutex_lock(&client->lock); if (client->communication.outbound.queued_command_reply) { @@ -3726,7 +3806,7 @@ int client_handle_message_unknown(struct notification_client *client, if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { - ERR("[notification-thread] Invalid notification channel message: length = %u", + ERR("Invalid notification channel message: length = %u", msg->size); ret = -1; goto end; @@ -3739,7 +3819,7 @@ int client_handle_message_unknown(struct notification_client *client, break; default: ret = -1; - ERR("[notification-thread] Invalid notification channel message: unexpected message type"); + ERR("Invalid notification channel message: unexpected message type"); goto end; } @@ -3785,7 +3865,7 @@ int client_handle_message_handshake(struct notification_client *client, client->major = handshake_client->major; client->minor = handshake_client->minor; if (!client->communication.inbound.creds_received) { - ERR("[notification-thread] No credentials received from client"); + ERR("No credentials received from client"); ret = -1; goto end; } @@ -3794,9 +3874,11 @@ int client_handle_message_handshake(struct notification_client *client, &client->communication.inbound.creds); client->gid = LTTNG_SOCK_GET_GID_CRED( &client->communication.inbound.creds); - DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", + client->is_sessiond = LTTNG_SOCK_GET_PID_CRED(&client->communication.inbound.creds) == getpid(); + DBG("Received handshake from client: uid = %u, gid = %u, protocol version = %i.%i, client is sessiond = %s", client->uid, client->gid, (int) client->major, - (int) client->minor); + (int) client->minor, + client->is_sessiond ? "true" : "false"); if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { @@ -3809,7 +3891,7 @@ int client_handle_message_handshake(struct notification_client *client, &client->communication.outbound.payload.buffer, send_buffer, sizeof(send_buffer)); if (ret) { - ERR("[notification-thread] Failed to send protocol version to notification channel client"); + ERR("Failed to send protocol version to notification channel client"); goto end_unlock; } @@ -3820,14 +3902,14 @@ int client_handle_message_handshake(struct notification_client *client, /* Set reception state to receive the next message header. */ ret = client_reset_inbound_state(client); if (ret) { - ERR("[notification-thread] Failed to reset client communication's inbound state"); + ERR("Failed to reset client communication's inbound state"); goto end; } /* Flushes the outgoing queue. */ ret = client_send_command_reply(client, state, status); if (ret) { - ERR("[notification-thread] Failed to send reply to notification channel client"); + ERR("Failed to send reply to notification channel client"); goto end; } @@ -3862,7 +3944,7 @@ int client_handle_message_subscription( expected_condition_size = client->communication.inbound.payload.buffer.size; ret = lttng_condition_create_from_payload(&condition_view, &condition); if (ret != expected_condition_size) { - ERR("[notification-thread] Malformed condition received from client"); + ERR("Malformed condition received from client"); goto end; } @@ -3882,13 +3964,13 @@ int client_handle_message_subscription( /* Set reception state to receive the next message header. */ ret = client_reset_inbound_state(client); if (ret) { - ERR("[notification-thread] Failed to reset client communication's inbound state"); + ERR("Failed to reset client communication's inbound state"); goto end; } ret = client_send_command_reply(client, state, status); if (ret) { - ERR("[notification-thread] Failed to send reply to notification channel client"); + ERR("Failed to send reply to notification channel client"); goto end; } @@ -3907,7 +3989,7 @@ int client_dispatch_message(struct notification_client *client, client->communication.inbound.msg_type != LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && !client->validated) { - WARN("[notification-thread] client attempted a command before handshake"); + WARN("client attempted a command before handshake"); ret = -1; goto end; } @@ -4056,7 +4138,47 @@ int handle_notification_thread_client_out( } pthread_mutex_lock(&client->lock); - transmission_status = client_flush_outgoing_queue(client); + if (!client_has_outbound_data_left(client)) { + /* + * A client "out" event can be received when no payload is left + * to send under some circumstances. + * + * Many threads can flush a client's outgoing queue and, if they + * had to queue their message (socket was full), will use the + * "communication update" command to signal the (e)poll thread + * to monitor for space being made available in the socket. + * + * Commands are sent over an internal pipe serviced by the same + * thread as the client sockets. + * + * When space is made available in the socket, there is a race + * between the (e)poll thread and the other threads that may + * wish to use the client's socket to flush its outgoing queue. + * + * A non-(e)poll thread may attempt (and succeed) in flushing + * the queue before the (e)poll thread gets a chance to service + * the client's "out" event. + * + * In this situation, the (e)poll thread processing the client + * out event will see an empty payload: there is nothing to do + * except unsubscribing (e)poll "out" events. + * + * Note that this thread is the (e)poll thread so it can modify + * the (e)poll mask directly without using a communication + * update command. Other threads that flush the outgoing queue + * will use the "communication update" command to wake up this + * thread and force it to monitor "out" events. + * + * When other threads succeed in emptying the outgoing queue, + * they don't need to update the (e)poll mask: if the "out" + * event is monitored, it will fire once and the (e)poll + * thread will reach this condition, causing the event to + * stop being monitored. + */ + transmission_status = CLIENT_TRANSMISSION_STATUS_COMPLETE; + } else { + transmission_status = client_flush_outgoing_queue(client); + } pthread_mutex_unlock(&client->lock); ret = client_handle_transmission_status( @@ -4102,7 +4224,7 @@ bool evaluate_buffer_usage_condition(const struct lttng_condition *condition, condition_type = lttng_condition_get_type(condition); if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { - DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, + DBG("Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, threshold, sample->highest_usage); /* @@ -4113,7 +4235,7 @@ bool evaluate_buffer_usage_condition(const struct lttng_condition *condition, result = true; } } else { - DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, + DBG("High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, threshold, sample->highest_usage); /* @@ -4140,7 +4262,7 @@ bool evaluate_session_consumed_size_condition( parent); threshold = size_condition->consumed_threshold_bytes.value; - DBG("[notification-thread] Session consumed size condition being evaluated: threshold = %" PRIu64 ", current size = %" PRIu64, + DBG("Session consumed size condition being evaluated: threshold = %" PRIu64 ", current size = %" PRIu64, threshold, session_consumed_size); return session_consumed_size >= threshold; } @@ -4356,7 +4478,7 @@ int notification_client_list_send_evaluation( ret = lttng_notification_serialize(¬ification, &msg_payload); if (ret) { - ERR("[notification-thread] Failed to serialize notification"); + ERR("Failed to serialize notification"); ret = -1; goto end; } @@ -4394,6 +4516,15 @@ int notification_client_list_send_evaluation( goto skip_client; } + if (lttng_trigger_is_hidden(trigger) && !client->is_sessiond) { + /* + * Notifications resulting from an hidden trigger are + * only sent to the session daemon. + */ + DBG("Skipping client as the trigger is hidden and the client is not the session daemon"); + goto skip_client; + } + if (source_object_creds) { if (client->uid != lttng_credentials_get_uid(source_object_creds) && client->gid != lttng_credentials_get_gid(source_object_creds) && @@ -4402,17 +4533,17 @@ int notification_client_list_send_evaluation( * Client is not allowed to monitor this * object. */ - DBG("[notification-thread] Skipping client at it does not have the object permission to receive notification for this trigger"); + DBG("Skipping client at it does not have the object permission to receive notification for this trigger"); goto skip_client; } } if (client->uid != lttng_credentials_get_uid(trigger_creds)) { - DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); + DBG("Skipping client at it does not have the permission to receive notification for this trigger"); goto skip_client; } - DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", + DBG("Sending notification to client (fd = %i, %zu bytes)", client->socket, msg_payload.buffer.size); if (client_has_outbound_data_left(client)) { @@ -4523,21 +4654,21 @@ struct lttng_event_notifier_notification *recv_one_event_notifier_notification( } if (capture_buffer_size > MAX_CAPTURE_SIZE) { - ERR("[notification-thread] Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes", + ERR("Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes", capture_buffer_size, MAX_CAPTURE_SIZE); goto end; } capture_buffer = zmalloc(capture_buffer_size); if (!capture_buffer) { - ERR("[notification-thread] Failed to allocate capture buffer"); + ERR("Failed to allocate capture buffer"); goto end; } /* Fetch additional payload (capture). */ ret = lttng_read(notification_pipe_read_fd, capture_buffer, capture_buffer_size); if (ret != capture_buffer_size) { - ERR("[notification-thread] Failed to read from event source pipe (fd = %i)", + ERR("Failed to read from event source pipe (fd = %i)", notification_pipe_read_fd); goto end; } @@ -4616,10 +4747,11 @@ int dispatch_one_event_notifier_notification(struct notification_thread_state *s notification->capture_buf_size, false); if (evaluation == NULL) { - ERR("[notification-thread] Failed to create event rule hit evaluation while creating and enqueuing action executor job"); + ERR("Failed to create event rule matches evaluation while creating and enqueuing action executor job"); ret = -1; goto end_unlock; } + client_list = get_client_list_from_condition(state, lttng_trigger_get_const_condition(element->trigger)); executor_status = action_executor_enqueue_trigger(state->executor, @@ -4706,14 +4838,14 @@ int handle_one_event_notifier_notification( notification = recv_one_event_notifier_notification(pipe, domain); if (notification == NULL) { /* Reception failed, don't consider it fatal. */ - ERR("[notification-thread] Error receiving an event notifier notification from tracer: fd = %i, domain = %s", + ERR("Error receiving an event notifier notification from tracer: fd = %i, domain = %s", pipe, lttng_domain_type_str(domain)); goto end; } ret = dispatch_one_event_notifier_notification(state, notification); if (ret) { - ERR("[notification-thread] Error dispatching an event notifier notification from tracer: fd = %i, domain = %s", + ERR("Error dispatching an event notifier notification from tracer: fd = %i, domain = %s", pipe, lttng_domain_type_str(domain)); goto end; } @@ -4751,7 +4883,7 @@ int handle_notification_thread_channel_sample( */ ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); if (ret != sizeof(sample_msg)) { - ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", + ERR("Failed to read from monitoring pipe (fd = %i)", pipe); ret = -1; goto end; @@ -4780,14 +4912,14 @@ int handle_notification_thread_channel_sample( * channel's destruction before we get a chance to process that * sample. */ - DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", + DBG("Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", latest_sample.key.key, lttng_domain_type_str(domain)); goto end_unlock; } channel_info = caa_container_of(node, struct channel_info, channels_ht_node); - DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64", total consumed = %" PRIu64")", + DBG("Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64", total consumed = %" PRIu64")", channel_info->name, latest_sample.key.key, channel_info->session_info->name,