/*
- * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
*
- * 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
#include <common/utils.h>
#include <common/align.h>
#include <common/time.h>
-#include <sys/eventfd.h>
#include <sys/stat.h>
#include <time.h>
#include <signal.h>
#include "notification-thread-commands.h"
#include "lttng-sessiond.h"
#include "health-sessiond.h"
+#include "thread.h"
#include <urcu.h>
#include <urcu/list.h>
#include <urcu/rculfhash.h>
-/**
- * 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_ht_node) 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.
*/
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) {
{
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) {
} else {
handle->channel_monitoring_pipes.kernel_consumer = -1;
}
+
end:
return handle;
error:
+ lttng_pipe_destroy(event_pipe);
notification_thread_handle_destroy(handle);
return NULL;
}
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");
}
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;
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");
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);
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);
+ }
+ if (state->triggers_by_name_uid_ht) {
+ ret = cds_lfht_destroy(state->triggers_by_name_uid_ht, NULL);
+ assert(!ret);
+ }
+ if (state->trigger_tokens_ht) {
+ ret = cds_lfht_destroy(state->trigger_tokens_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);
}
+
+ assert(cds_list_empty(&state->tracer_event_sources_list));
+
+ if (state->executor) {
+ action_executor_destroy(state->executor);
+ }
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)
memset(state, 0, sizeof(*state));
state->notification_channel_socket = -1;
+ state->trigger_id.next_tracer_token = 1;
lttng_poll_init(&state->events);
ret = notification_channel_socket_create();
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) {
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;
}
+ state->triggers_by_name_uid_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+ 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+ if (!state->triggers_by_name_uid_ht) {
+ goto error;
+ }
+
+ state->trigger_tokens_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+ 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+ if (!state->trigger_tokens_ht) {
+ goto error;
+ }
+
+ CDS_INIT_LIST_HEAD(&state->tracer_event_sources_list);
+
+ state->executor = action_executor_create(handle);
+ if (!state->executor) {
+ goto error;
+ }
+ mark_thread_as_ready(handle);
end:
return 0;
error:
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;
}
* 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;
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);
goto end;
}
- /* Ready to handle client connections. */
- sessiond_notify_ready();
-
while (true) {
int fd_count, i;
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) {
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) {
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;
}
projects / lttng-tools.git / blobdiff