+static
+const char *get_base_path(struct ltt_session *session,
+ struct consumer_output *consumer)
+{
+ if (session->net_handle > 0) {
+ return consumer->dst.net.base_dir;
+ } else {
+ return consumer->dst.session_root_path;
+ }
+}
+
+/*
+ * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
+ *
+ * Ask the consumer to rotate the session output directory.
+ * The session lock must be held.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_rotate_session(struct ltt_session *session,
+ struct lttng_rotate_session_return **rotate_return)
+{
+ int ret;
+ struct tm *timeinfo;
+ char datetime[16];
+ time_t now;
+
+ assert(session);
+
+ if (rotate_return) {
+ *rotate_return = zmalloc(sizeof(struct lttng_rotate_session_return));
+ if (!*rotate_return) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ }
+
+ if (session->live_timer || session->snapshot_mode ||
+ !session->output_traces) {
+ ret = -LTTNG_ERR_ROTATE_NOT_AVAILABLE;
+ goto error;
+ }
+
+ if (session->rotate_pending || session->rotate_pending_relay) {
+ ret = -LTTNG_ERR_ROTATE_PENDING;
+ goto error;
+ }
+
+ /* Special case for the first rotation. */
+ if (session->rotate_count == 0) {
+ const char *base_path = NULL;
+
+ /* Either one of the two sessions is enough to get the root path. */
+ if (session->kernel_session) {
+ base_path = get_base_path(session, session->kernel_session->consumer);
+ } else if (session->ust_session) {
+ base_path = get_base_path(session, session->ust_session->consumer);
+ } else {
+ assert(0);
+ }
+ assert(base_path);
+ snprintf(session->rotation_chunk.current_rotate_path,
+ PATH_MAX, "%s",
+ base_path);
+ } else {
+ /*
+ * The currently active tracing path is now the folder we
+ * want to rotate.
+ */
+ snprintf(session->rotation_chunk.current_rotate_path,
+ PATH_MAX, "%s",
+ session->rotation_chunk.active_tracing_path);
+ }
+
+ session->rotate_count++;
+ session->rotate_pending = true;
+ session->rotate_pending_relay_check_in_progress = false;
+ session->rotate_status = LTTNG_ROTATE_STARTED;
+
+ /*
+ * Create the path name for the next chunk.
+ */
+ now = time(NULL);
+ if (now == (time_t) -1) {
+ ret = -LTTNG_ERR_ROTATE_NOT_AVAILABLE;
+ goto error;
+ }
+ session->last_chunk_start_ts = session->current_chunk_start_ts;
+ session->current_chunk_start_ts = now;
+
+ timeinfo = localtime(&now);
+ strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
+ if (session->kernel_session) {
+ /*
+ * The active path for the next rotation/destroy.
+ * Ex: ~/lttng-traces/auto-20170922-111748/20170922-111754-42
+ */
+ snprintf(session->rotation_chunk.active_tracing_path,
+ PATH_MAX, "%s/%s-%" PRIu64,
+ get_base_path(session, session->kernel_session->consumer),
+ datetime, session->rotate_count + 1);
+ /*
+ * The sub-directory for the consumer
+ * Ex: /20170922-111754-42/kernel
+ */
+ snprintf(session->kernel_session->consumer->chunk_path,
+ PATH_MAX, "/%s-%" PRIu64 "%s", datetime,
+ session->rotate_count + 1,
+ session->kernel_session->consumer->subdir);
+ ret = kernel_rotate_session(session);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+ if (session->ust_session) {
+ snprintf(session->rotation_chunk.active_tracing_path,
+ PATH_MAX, "%s/%s-%" PRIu64,
+ get_base_path(session, session->ust_session->consumer),
+ datetime, session->rotate_count + 1);
+ snprintf(session->ust_session->consumer->chunk_path,
+ PATH_MAX, "/%s-%" PRIu64, datetime,
+ session->rotate_count + 1);
+ ret = ust_app_rotate_session(session);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+
+ if (rotate_return) {
+ (*rotate_return)->rotate_id = session->rotate_count;
+ (*rotate_return)->status = LTTNG_ROTATE_STARTED;
+ }
+
+ DBG("Cmd rotate session %s, rotate_id %" PRIu64, session->name,
+ session->rotate_count);
+ ret = LTTNG_OK;
+
+ goto end;
+
+error:
+ if (rotate_return) {
+ (*rotate_return)->status = LTTNG_ROTATE_ERROR;
+ }
+end:
+ return ret;
+}
+
+/*
+ * Command LTTNG_ROTATE_PENDING from the lttng-ctl library.
+ *
+ * Check if the session has finished its rotation.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_rotate_pending(struct ltt_session *session,
+ struct lttng_rotate_pending_return **pending_return,
+ uint64_t rotate_id)
+{
+ int ret;
+
+ assert(session);
+
+ DBG("Cmd rotate pending session %s, rotate_id %" PRIu64, session->name,
+ session->rotate_count);
+
+ *pending_return = zmalloc(sizeof(struct lttng_rotate_pending_return));
+ if (!*pending_return) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ if (session->rotate_count != rotate_id) {
+ (*pending_return)->status = LTTNG_ROTATE_EXPIRED;
+ ret = LTTNG_OK;
+ goto end;
+ }
+
+ if (session->rotate_status == LTTNG_ROTATE_ERROR) {
+ DBG("An error occurred during rotation");
+ (*pending_return)->status = LTTNG_ROTATE_ERROR;
+ } else if (session->rotate_status == LTTNG_ROTATE_EMPTY) {
+ DBG("Nothing to rotate");
+ (*pending_return)->status = LTTNG_ROTATE_EMPTY;
+ /* Rotate with a relay */
+ } else if (session->rotate_pending_relay) {
+ DBG("Session %s, rotate_id %" PRIu64 " still pending",
+ session->name, session->rotate_count);
+ (*pending_return)->status = LTTNG_ROTATE_STARTED;
+ } else if (session->rotate_pending) {
+ DBG("Session %s, rotate_id %" PRIu64 " still pending",
+ session->name, session->rotate_count);
+ (*pending_return)->status = LTTNG_ROTATE_STARTED;
+ } else {
+ DBG("Session %s, rotate_id %" PRIu64 " finished",
+ session->name, session->rotate_count);
+ (*pending_return)->status = LTTNG_ROTATE_COMPLETED;
+ snprintf((*pending_return)->output_path, PATH_MAX, "%s",
+ session->rotation_chunk.current_rotate_path);
+ }
+
+ ret = LTTNG_OK;
+
+ goto end;
+
+end:
+ return ret;
+}
+
+/*
+ * Command LTTNG_ROTATE_SETUP from the lttng-ctl library.
+ *
+ * Configure the automatic rotation parameters.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_rotate_setup(struct ltt_session *session,
+ uint64_t timer_us, uint64_t size)
+{
+ int ret;
+
+ assert(session);
+
+ DBG("Cmd rotate setup session %s", session->name);
+
+ if (timer_us && session->rotate_timer_period) {
+ ret = LTTNG_ERR_ROTATE_TIMER_EXISTS;
+ goto end;
+ }
+
+ if (size && session->rotate_size) {
+ ret = LTTNG_ERR_ROTATE_SIZE_EXISTS;
+ goto end;
+ }
+
+ if (timer_us && !session->rotate_timer_period) {
+ session->rotate_timer_period = timer_us;
+ /*
+ * Only start the timer if the session is active, otherwise
+ * it will be started when the session starts.
+ */
+ if (session->active) {
+ ret = sessiond_rotate_timer_start(session, timer_us);
+ if (ret) {
+ ERR("Failed to enable rotate timer");
+ ret = LTTNG_ERR_UNK;
+ goto end;
+ }
+ }
+ } else if (timer_us == -1ULL && session->rotate_timer_period > 0) {
+ sessiond_rotate_timer_stop(session);
+ }
+ session->rotate_size = size;
+
+ ret = LTTNG_OK;
+
+ goto end;
+
+end:
+ return ret;
+}
+