{
struct lttng_live_session *session = trace->session;
struct lttng_live_metadata *metadata = trace->metadata;
- ssize_t ret = 0;
size_t size, len_read = 0;
char *metadata_buf = NULL;
+ bool keep_receiving;
FILE *fp = NULL;
enum ctf_metadata_decoder_status decoder_status;
enum lttng_live_iterator_status status =
LTTNG_LIVE_ITERATOR_STATUS_OK;
bt_logging_level log_level = trace->log_level;
bt_self_component *self_comp = trace->self_comp;
+ enum lttng_live_get_one_metadata_status metadata_status;
/* No metadata stream yet. */
if (!metadata) {
goto error;
}
+ keep_receiving = true;
/* Grab all available metadata. */
- do {
+ while (keep_receiving) {
+ size_t reply_len = 0;
/*
- * get_one_metadata_packet returns the number of bytes
- * received, 0 when we have received everything, a
- * negative value on error.
+ * lttng_live_get_one_metadata_packet() asks the Relay Daemon
+ * for new metadata. If new metadata is received, the function
+ * writes it to the provided file handle and updates the
+ * reply_len output parameter. We call this function in loop
+ * until it returns _END meaning that no new metadata is
+ * available.
+ * We may receive a _CLOSED status if the metadata stream we
+ * are requesting is no longer available on the relay.
+ * If we receive an _ERROR status, it means there was a
+ * networking, allocating, or some other unrecoverable error.
*/
- ret = lttng_live_get_one_metadata_packet(trace, fp);
- if (ret > 0) {
- len_read += ret;
+ metadata_status = lttng_live_get_one_metadata_packet(trace, fp,
+ &reply_len);
+
+ switch (metadata_status) {
+ case LTTNG_LIVE_GET_ONE_METADATA_STATUS_OK:
+ len_read += reply_len;
+ break;
+ case LTTNG_LIVE_GET_ONE_METADATA_STATUS_END:
+ keep_receiving = false;
+ break;
+ case LTTNG_LIVE_GET_ONE_METADATA_STATUS_CLOSED:
+ keep_receiving = false;
+ break;
+ case LTTNG_LIVE_GET_ONE_METADATA_STATUS_ERROR:
+ goto error;
+ default:
+ abort();
}
- } while (ret > 0);
+ }
/*
- * Consider metadata closed as soon as we get an error reading
- * it (e.g. cannot be found).
+ * A closed metadata stream means the trace is no longer active. Return
+ * _END so that the caller can remove the trace from its list.
*/
- if (ret < 0) {
- if (!metadata->closed) {
- metadata->closed = true;
- /*
- * Release our reference on the trace as soon as
- * we know the metadata stream is not available
- * anymore. This won't necessarily teardown the
- * metadata objects immediately, but only when
- * the data streams are done.
- */
- metadata->trace = NULL;
- }
- if (errno == EINTR) {
- if (lttng_live_graph_is_canceled(
- session->lttng_live_msg_iter)) {
- status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
- goto end;
- }
- }
+ if (metadata_status == LTTNG_LIVE_GET_ONE_METADATA_STATUS_CLOSED) {
+ status = LTTNG_LIVE_ITERATOR_STATUS_END;
+ goto end;
}
if (bt_close_memstream(&metadata_buf, &size, fp)) {
}
goto end;
+
error:
- status = LTTNG_LIVE_ITERATOR_STATUS_ERROR;
+ if (errno == EINTR) {
+ if (lttng_live_graph_is_canceled(session->lttng_live_msg_iter)) {
+ status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
+ }
+ } else {
+ status = LTTNG_LIVE_ITERATOR_STATUS_ERROR;
+ }
end:
if (fp) {
int closeret;