struct channel_key channel_key;
struct cds_list_head list;
struct cds_lfht_node channel_triggers_ht_node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct lttng_trigger_ht_element {
struct lttng_trigger *trigger;
struct cds_lfht_node node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct lttng_condition_list_element {
struct lttng_trigger *trigger;
struct cds_list_head list;
struct cds_lfht_node notification_trigger_ht_node;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct notification_client {
uid_t uid;
gid_t gid;
/*
- * Indicates if the credentials and versions of the client has been
+ * Indicates if the credentials and versions of the client have been
* checked.
*/
bool validated;
struct lttng_dynamic_buffer buffer;
} outbound;
} communication;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
struct channel_state_sample {
struct cds_lfht_node channel_state_ht_node;
uint64_t highest_usage;
uint64_t lowest_usage;
+ /* call_rcu delayed reclaim. */
+ struct rcu_head rcu_node;
};
+static unsigned long hash_channel_key(struct channel_key *key);
+static int evaluate_condition(struct lttng_condition *condition,
+ struct lttng_evaluation **evaluation,
+ struct notification_thread_state *state,
+ struct channel_state_sample *previous_sample,
+ struct channel_state_sample *latest_sample,
+ uint64_t buffer_capacity);
+static
+int send_evaluation_to_clients(struct lttng_trigger *trigger,
+ struct lttng_evaluation *evaluation,
+ struct notification_client_list *client_list,
+ struct notification_thread_state *state,
+ uid_t channel_uid, gid_t channel_gid);
+
static
int match_client(struct cds_lfht_node *node, const void *key)
{
val = condition->threshold_ratio.value * (double) UINT32_MAX;
hash ^= hash_key_u64(&val, lttng_ht_seed);
- } else if (condition->threshold_ratio.set) {
+ } else if (condition->threshold_bytes.set) {
uint64_t val;
val = condition->threshold_bytes.value;
}
}
+static
+unsigned long hash_channel_key(struct channel_key *key)
+{
+ unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed);
+ unsigned long domain_hash = hash_key_ulong(
+ (void *) (unsigned long) key->domain, lttng_ht_seed);
+
+ return key_hash ^ domain_hash;
+}
+
+static
+void free_channel_info_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct channel_info, rcu_node));
+}
+
static
void channel_info_destroy(struct channel_info *channel_info)
{
if (channel_info->channel_name) {
free(channel_info->channel_name);
}
- free(channel_info);
+ call_rcu(&channel_info->rcu_node, free_channel_info_rcu);
}
static
return NULL;
}
+/* This function must be called with the RCU read lock held. */
+static
+int evaluate_condition_for_client(struct lttng_trigger *trigger,
+ struct lttng_condition *condition,
+ struct notification_client *client,
+ struct notification_thread_state *state)
+{
+ int ret;
+ struct cds_lfht_iter iter;
+ struct cds_lfht_node *node;
+ struct channel_info *channel_info = NULL;
+ struct channel_key *channel_key = NULL;
+ struct channel_state_sample *last_sample = NULL;
+ struct lttng_channel_trigger_list *channel_trigger_list = NULL;
+ struct lttng_evaluation *evaluation = NULL;
+ struct notification_client_list client_list = { 0 };
+ struct notification_client_list_element client_list_element = { 0 };
+
+ assert(trigger);
+ assert(condition);
+ assert(client);
+ assert(state);
+
+ /* Find the channel associated with the trigger. */
+ cds_lfht_for_each_entry(state->channel_triggers_ht, &iter,
+ channel_trigger_list , channel_triggers_ht_node) {
+ struct lttng_trigger_list_element *element;
+
+ cds_list_for_each_entry(element, &channel_trigger_list->list, node) {
+ struct lttng_condition *current_condition =
+ lttng_trigger_get_condition(
+ element->trigger);
+
+ assert(current_condition);
+ if (!lttng_condition_is_equal(condition,
+ current_condition)) {
+ continue;
+ }
+
+ /* Found the trigger, save the channel key. */
+ channel_key = &channel_trigger_list->channel_key;
+ break;
+ }
+ if (channel_key) {
+ /* The channel key was found stop iteration. */
+ break;
+ }
+ }
+
+ if (!channel_key){
+ /* No channel found; normal exit. */
+ DBG("[notification-thread] No channel associated with newly subscribed-to condition");
+ ret = 0;
+ goto end;
+ }
+
+ /* Fetch channel info for the matching channel. */
+ cds_lfht_lookup(state->channels_ht,
+ hash_channel_key(channel_key),
+ match_channel_info,
+ channel_key,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ assert(node);
+ channel_info = caa_container_of(node, struct channel_info,
+ channels_ht_node);
+
+ /* Retrieve the channel's last sample, if it exists. */
+ cds_lfht_lookup(state->channel_state_ht,
+ hash_channel_key(channel_key),
+ match_channel_state_sample,
+ channel_key,
+ &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (node) {
+ last_sample = caa_container_of(node,
+ struct channel_state_sample,
+ 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");
+ ret = 0;
+ goto end;
+ }
+
+ ret = evaluate_condition(condition, &evaluation, state, NULL,
+ last_sample, channel_info->capacity);
+ if (ret) {
+ WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition");
+ goto end;
+ }
+
+ if (!evaluation) {
+ /* Evaluation yielded nothing. Normal exit. */
+ DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client");
+ ret = 0;
+ goto end;
+ }
+
+ /*
+ * Create a temporary client list with the client currently
+ * subscribing.
+ */
+ cds_lfht_node_init(&client_list.notification_trigger_ht_node);
+ CDS_INIT_LIST_HEAD(&client_list.list);
+ client_list.trigger = trigger;
+
+ CDS_INIT_LIST_HEAD(&client_list_element.node);
+ client_list_element.client = client;
+ cds_list_add(&client_list_element.node, &client_list.list);
+
+ /* Send evaluation result to the newly-subscribed client. */
+ DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client");
+ ret = send_evaluation_to_clients(trigger, evaluation, &client_list,
+ state, channel_info->uid, channel_info->gid);
+
+end:
+ return ret;
+}
+
static
int notification_thread_client_subscribe(struct notification_client *client,
struct lttng_condition *condition,
condition_list_element->condition = condition;
cds_list_add(&condition_list_element->node, &client->condition_list);
- /*
- * Add the client to the list of clients interested in a given trigger
- * if a "notification" trigger with a corresponding condition was
- * added prior.
- */
cds_lfht_lookup(state->notification_trigger_clients_ht,
lttng_condition_hash(condition),
match_client_list_condition,
client_list = caa_container_of(node, struct notification_client_list,
notification_trigger_ht_node);
+ if (evaluate_condition_for_client(client_list->trigger, condition,
+ client, state)) {
+ WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting.");
+ ret = -1;
+ free(client_list_element);
+ goto end_unlock;
+ }
+
+ /*
+ * Add the client to the list of clients interested in a given trigger
+ * if a "notification" trigger with a corresponding condition was
+ * added prior.
+ */
client_list_element->client = client;
CDS_INIT_LIST_HEAD(&client_list_element->node);
cds_list_add(&client_list_element->node, &client_list->list);
return 0;
}
+static
+void free_notification_client_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct notification_client, rcu_node));
+}
+
static
void notification_client_destroy(struct notification_client *client,
struct notification_thread_state *state)
}
lttng_dynamic_buffer_reset(&client->communication.inbound.buffer);
lttng_dynamic_buffer_reset(&client->communication.outbound.buffer);
- free(client);
+ call_rcu(&client->rcu_node, free_notification_client_rcu);
}
/*
return applies;
}
-static
-unsigned long hash_channel_key(struct channel_key *key)
-{
- return hash_key_u64(&key->key, lttng_ht_seed) ^ hash_key_ulong(
- (void *) (unsigned long) key->domain, lttng_ht_seed);
-}
-
static
int handle_notification_thread_command_add_channel(
struct notification_thread_state *state,
channel_key = &new_channel_info->key;
+ rcu_read_lock();
/* Build a list of all triggers applying to the new channel. */
cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element,
node) {
new_element = zmalloc(sizeof(*new_element));
if (!new_element) {
- goto error;
+ goto error_unlock;
}
CDS_INIT_LIST_HEAD(&new_element->node);
new_element->trigger = trigger_ht_element->trigger;
trigger_count);
channel_trigger_list = zmalloc(sizeof(*channel_trigger_list));
if (!channel_trigger_list) {
- goto error;
+ goto error_unlock;
}
channel_trigger_list->channel_key = *channel_key;
CDS_INIT_LIST_HEAD(&channel_trigger_list->list);
cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node);
cds_list_splice(&trigger_list, &channel_trigger_list->list);
- rcu_read_lock();
/* Add channel to the channel_ht which owns the channel_infos. */
cds_lfht_add(state->channels_ht,
hash_channel_key(channel_key),
rcu_read_unlock();
*cmd_result = LTTNG_OK;
return 0;
+error_unlock:
+ rcu_read_unlock();
error:
/* Empty trigger list */
channel_info_destroy(new_channel_info);
return 1;
}
+static
+void free_channel_trigger_list_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct lttng_channel_trigger_list,
+ rcu_node));
+}
+
+static
+void free_channel_state_sample_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct channel_state_sample,
+ rcu_node));
+}
+
static
int handle_notification_thread_command_remove_channel(
struct notification_thread_state *state,
free(trigger_list_element);
}
cds_lfht_del(state->channel_triggers_ht, node);
- free(trigger_list);
+ call_rcu(&trigger_list->rcu_node, free_channel_trigger_list_rcu);
/* Free sampled channel state. */
cds_lfht_lookup(state->channel_state_ht,
channel_state_ht_node);
cds_lfht_del(state->channel_state_ht, node);
- free(sample);
+ call_rcu(&sample->rcu_node, free_channel_state_sample_rcu);
}
/* Remove the channel from the channels_ht and free it. */
channels_ht_node) {
struct lttng_trigger_list_element *trigger_list_element;
struct lttng_channel_trigger_list *trigger_list;
+ struct cds_lfht_iter lookup_iter;
if (!trigger_applies_to_channel(trigger, channel)) {
continue;
hash_channel_key(&channel->key),
match_channel_trigger_list,
&channel->key,
- &iter);
- node = cds_lfht_iter_get_node(&iter);
+ &lookup_iter);
+ node = cds_lfht_iter_get_node(&lookup_iter);
assert(node);
- /* Free the list of triggers associated with this channel. */
trigger_list = caa_container_of(node,
struct lttng_channel_trigger_list,
channel_triggers_ht_node);
CDS_INIT_LIST_HEAD(&trigger_list_element->node);
trigger_list_element->trigger = trigger;
cds_list_add(&trigger_list_element->node, &trigger_list->list);
+
/* A trigger can only apply to one channel. */
break;
}
return ret;
}
+static
+void free_notification_client_list_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct notification_client_list,
+ rcu_node));
+}
+
+static
+void free_lttng_trigger_ht_element_rcu(struct rcu_head *node)
+{
+ free(caa_container_of(node, struct lttng_trigger_ht_element,
+ rcu_node));
+}
+
static
int handle_notification_thread_command_unregister_trigger(
struct notification_thread_state *state,
DBG("[notification-thread] Removed trigger from channel_triggers_ht");
cds_list_del(&trigger_element->node);
+ /* A trigger can only appear once per channel */
+ break;
}
}
free(client_list_element);
}
cds_lfht_del(state->notification_trigger_clients_ht, node);
- free(client_list);
+ call_rcu(&client_list->rcu_node, free_notification_client_list_rcu);
/* Remove trigger from triggers_ht. */
trigger_ht_element = caa_container_of(triggers_ht_node,
action = lttng_trigger_get_action(trigger_ht_element->trigger);
lttng_action_destroy(action);
lttng_trigger_destroy(trigger_ht_element->trigger);
- free(trigger_ht_element);
+ call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu);
end:
rcu_read_unlock();
if (_cmd_reply) {
struct notification_thread_command *cmd;
/* Read event_fd to put it back into a quiescent state. */
- ret = read(handle->cmd_queue.event_fd, &counter, sizeof(counter));
+ ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, sizeof(counter));
if (ret == -1) {
goto error;
}
projects / lttng-tools.git / blobdiff