+/*
+ * Fill events array with all events name of all registered apps.
+ */
+int ust_app_list_event_fields(struct lttng_event_field **fields)
+{
+ int ret, handle;
+ size_t nbmem, count = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct lttng_event_field *tmp;
+
+ nbmem = UST_APP_EVENT_LIST_SIZE;
+ tmp = zmalloc(nbmem * sizeof(struct lttng_event_field));
+ if (tmp == NULL) {
+ PERROR("zmalloc ust app event fields");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct lttng_ust_field_iter uiter;
+
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ handle = ustctl_tracepoint_field_list(app->sock);
+ if (handle < 0) {
+ ERR("UST app list event fields getting handle failed for app pid %d",
+ app->pid);
+ continue;
+ }
+
+ while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
+ &uiter)) != -ENOENT) {
+ if (count >= nbmem) {
+ DBG2("Reallocating event field list from %zu to %zu entries", nbmem,
+ 2 * nbmem);
+ nbmem *= 2;
+ tmp = realloc(tmp, nbmem * sizeof(struct lttng_event_field));
+ if (tmp == NULL) {
+ PERROR("realloc ust app event fields");
+ ret = -ENOMEM;
+ goto rcu_error;
+ }
+ }
+
+ memcpy(tmp[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
+ tmp[count].type = uiter.type;
+
+ memcpy(tmp[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
+ tmp[count].event.loglevel = uiter.loglevel;
+ tmp[count].event.type = LTTNG_UST_TRACEPOINT;
+ tmp[count].event.pid = app->pid;
+ tmp[count].event.enabled = -1;
+ count++;
+ }
+ }
+
+ ret = count;
+ *fields = tmp;
+
+ DBG2("UST app list event fields done (%zu events)", count);
+
+rcu_error:
+ rcu_read_unlock();
+error:
+ return ret;
+}
+