+void side_event_remove_callbacks(struct side_event_description *desc)
+{
+ struct side_event_state *event_state = side_ptr_get(desc->state);
+ struct side_event_state_0 *es0;
+ struct side_callback *old_cb;
+ uint32_t nr_cb;
+
+ if (side_unlikely(event_state->version != 0))
+ abort();
+ es0 = side_container_of(event_state, struct side_event_state_0, parent);
+ nr_cb = es0->nr_callbacks;
+ if (!nr_cb)
+ return;
+ old_cb = (struct side_callback *) es0->callbacks;
+ (void) __atomic_add_fetch(&es0->enabled, -1, __ATOMIC_RELAXED);
+ /*
+ * Setting the state back to 0 cb and empty callbacks out of
+ * caution. This should not matter because instrumentation is
+ * unreachable.
+ */
+ es0->nr_callbacks = 0;
+ side_rcu_assign_pointer(es0->callbacks, &side_empty_callback);
+ /*
+ * No need to wait for grace period because instrumentation is
+ * unreachable.
+ */
+ free(old_cb);
+}
+
+/*
+ * Unregister event handle. At this point, all side events in that
+ * handle should be unreachable.
+ */
+void side_events_unregister(struct side_events_register_handle *events_handle)
+{
+ struct side_tracer_handle *tracer_handle;
+ uint32_t i;
+
+ if (!events_handle)
+ return;
+ if (finalized)
+ return;
+ if (!initialized)
+ side_init();
+ pthread_mutex_lock(&side_event_lock);
+ side_list_remove_node(&events_handle->node);
+ side_list_for_each_entry(tracer_handle, &side_tracer_list, node) {
+ tracer_handle->cb(SIDE_TRACER_NOTIFICATION_REMOVE_EVENTS,
+ events_handle->events, events_handle->nr_events,
+ tracer_handle->priv);
+ }
+ for (i = 0; i < events_handle->nr_events; i++) {
+ struct side_event_description *event = events_handle->events[i];
+
+ /* Skip NULL pointers */
+ if (!event)
+ continue;
+ side_event_remove_callbacks(event);
+ }
+ pthread_mutex_unlock(&side_event_lock);
+ //TODO: call event batch unregister ioctl
+ free(events_handle);
+}
+
+struct side_tracer_handle *side_tracer_event_notification_register(
+ void (*cb)(enum side_tracer_notification notif,
+ struct side_event_description **events, uint32_t nr_events, void *priv),
+ void *priv)
+{
+ struct side_tracer_handle *tracer_handle;
+ struct side_events_register_handle *events_handle;
+
+ if (finalized)
+ return NULL;
+ if (!initialized)
+ side_init();
+ tracer_handle = (struct side_tracer_handle *)
+ calloc(1, sizeof(struct side_tracer_handle));
+ if (!tracer_handle)
+ return NULL;
+ pthread_mutex_lock(&side_event_lock);
+ tracer_handle->cb = cb;
+ tracer_handle->priv = priv;
+ side_list_insert_node_tail(&side_tracer_list, &tracer_handle->node);
+ side_list_for_each_entry(events_handle, &side_events_list, node) {
+ cb(SIDE_TRACER_NOTIFICATION_INSERT_EVENTS,
+ events_handle->events, events_handle->nr_events, priv);
+ }
+ pthread_mutex_unlock(&side_event_lock);
+ return tracer_handle;
+}
+
+void side_tracer_event_notification_unregister(struct side_tracer_handle *tracer_handle)
+{
+ struct side_events_register_handle *events_handle;
+
+ if (finalized)
+ return;
+ if (!initialized)
+ side_init();
+ pthread_mutex_lock(&side_event_lock);
+ side_list_for_each_entry(events_handle, &side_events_list, node) {
+ tracer_handle->cb(SIDE_TRACER_NOTIFICATION_REMOVE_EVENTS,
+ events_handle->events, events_handle->nr_events,
+ tracer_handle->priv);
+ }
+ side_list_remove_node(&tracer_handle->node);
+ pthread_mutex_unlock(&side_event_lock);
+ free(tracer_handle);
+}
+
+struct side_statedump_request_handle *side_statedump_request_notification_register(void (*statedump_cb)(void))
+{
+ struct side_statedump_request_handle *handle;
+
+ if (finalized)
+ return NULL;
+ if (!initialized)
+ side_init();
+ /*
+ * The statedump request notification should not be registered
+ * from a notification callback.
+ */
+ assert(filter_key == NULL);
+ handle = (struct side_statedump_request_handle *)
+ calloc(1, sizeof(struct side_statedump_request_handle));
+ if (!handle)
+ return NULL;
+ handle->cb = statedump_cb;
+
+ pthread_mutex_lock(&side_statedump_lock);
+ side_list_insert_node_tail_rcu(&side_statedump_list, &handle->node);
+ pthread_mutex_unlock(&side_statedump_lock);
+
+ /* Invoke callback for all tracers. */
+ statedump_cb();
+
+ return handle;
+}
+
+void side_statedump_request_notification_unregister(struct side_statedump_request_handle *handle)
+{
+ if (finalized)
+ return;
+ if (!initialized)
+ side_init();
+ assert(filter_key == NULL);
+
+ pthread_mutex_lock(&side_statedump_lock);
+ side_list_remove_node_rcu(&handle->node);
+ pthread_mutex_unlock(&side_statedump_lock);
+
+ side_rcu_wait_grace_period(&statedump_rcu_gp);
+ free(handle);
+}
+
+void side_tracer_statedump_request(void *key)
+{
+ struct side_statedump_request_handle *handle;
+ struct side_rcu_read_state rcu_read_state;
+
+ /* Invoke the state dump callback specifically for the tracer key. */
+ filter_key = key;
+ side_rcu_read_begin(&statedump_rcu_gp, &rcu_read_state);
+ side_list_for_each_entry_rcu(handle, &side_statedump_list, node)
+ handle->cb();
+ side_rcu_read_end(&statedump_rcu_gp, &rcu_read_state);
+ filter_key = NULL;
+}
+