src.ctf.lttng-live: make `lttng_live_attach_session()` return status

[babeltrace.git] / src / plugins / ctf / lttng-live / lttng-live.c

diff --git a/src/plugins/ctf/lttng-live/lttng-live.c b/src/plugins/ctf/lttng-live/lttng-live.c
index 7da40dc26c94847c32eea839af94163f4faa3ec4..fa493cbb3853fc7960764ecaf34ee00f1b33a9ee 100644 (file)
--- a/src/plugins/ctf/lttng-live/lttng-live.c
+++ b/src/plugins/ctf/lttng-live/lttng-live.c
@@ -35,6 +35,7 @@
 
 #include <glib.h>
 #include <inttypes.h>
+#include <stdbool.h>
 #include <unistd.h>
 
 #include "common/assert.h"
@@ -274,9 +275,8 @@ void lttng_live_destroy_session(struct lttng_live_session *session)
        BT_COMP_LOGD("Destroy lttng live session");
        if (session->id != -1ULL) {
                if (lttng_live_detach_session(session)) {
-                       if (session->lttng_live_msg_iter &&
-                                       !lttng_live_graph_is_canceled(
-                                               session->lttng_live_msg_iter)) {
+                       if (!lttng_live_graph_is_canceled(
+                                       session->lttng_live_msg_iter)) {
                                /* Old relayd cannot detach sessions. */
                                BT_COMP_LOGD("Unable to detach lttng live session %" PRIu64,
                                        session->id);
@@ -437,13 +437,12 @@ enum lttng_live_iterator_status lttng_live_get_session(
 {
        enum lttng_live_iterator_status status;
        uint64_t trace_idx;
-       int ret = 0;
 
        if (!session->attached) {
-               ret = lttng_live_attach_session(session);
-               if (ret) {
-                       if (lttng_live_msg_iter && lttng_live_graph_is_canceled(
-                                       lttng_live_msg_iter)) {
+               enum lttng_live_attach_session_status attach_status =
+                       lttng_live_attach_session(session);
+               if (attach_status != LTTNG_LIVE_ATTACH_SESSION_STATUS_OK) {
+                       if (lttng_live_graph_is_canceled(lttng_live_msg_iter)) {
                                status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
                        } else {
                                status = LTTNG_LIVE_ITERATOR_STATUS_ERROR;
@@ -457,13 +456,30 @@ enum lttng_live_iterator_status lttng_live_get_session(
                        status != LTTNG_LIVE_ITERATOR_STATUS_END) {
                goto end;
        }
-       for (trace_idx = 0; trace_idx < session->traces->len; trace_idx++) {
+       trace_idx = 0;
+       while (trace_idx < session->traces->len) {
                struct lttng_live_trace *trace =
                        g_ptr_array_index(session->traces, trace_idx);
 
                status = lttng_live_metadata_update(trace);
-               if (status != LTTNG_LIVE_ITERATOR_STATUS_OK &&
-                               status != LTTNG_LIVE_ITERATOR_STATUS_END) {
+               switch (status) {
+               case LTTNG_LIVE_ITERATOR_STATUS_OK:
+                       trace_idx++;
+                       break;
+               case LTTNG_LIVE_ITERATOR_STATUS_END:
+                       /*
+                        * The trace has ended. Remove it of the array an
+                        * continue the iteration.
+                        * We can remove the trace safely when using the
+                        * g_ptr_array_remove_index_fast because it replaces
+                        * the element at trace_idx with the array's last
+                        * element. trace_idx is not incremented because of
+                        * that.
+                        */
+                       (void) g_ptr_array_remove_index_fast(session->traces,
+                               trace_idx);
+                       break;
+               default:
                        goto end;
                }
        }
@@ -1281,16 +1297,6 @@ bt_component_class_message_iterator_next_method_status lttng_live_msg_iter_next(
 
                BT_ASSERT_DBG(lttng_live_msg_iter->sessions);
                session_idx = 0;
-               /*
-                * Use a while loop instead of a for loop so we can restart the
-                * iteration if we remove an element. We can safely call
-                * next_stream_iterator_for_session() multiple times on the
-                * same session as we only fetch a new message if there is no
-                * current next message for each live stream iterator.
-                * If all live stream iterator of that session already have a
-                * current next message, the function will simply exit return
-                * the same candidate live stream iterator every time.
-                */
                while (session_idx < lttng_live_msg_iter->sessions->len) {
                        struct lttng_live_session *session =
                                g_ptr_array_index(lttng_live_msg_iter->sessions,
@@ -1308,14 +1314,15 @@ bt_component_class_message_iterator_next_method_status lttng_live_msg_iter_next(
                        if (stream_iter_status == LTTNG_LIVE_ITERATOR_STATUS_END) {
                                if (session->closed && session->traces->len == 0) {
                                        /*
-                                        * Remove the session from the list and restart the
-                                        * iteration at the beginning of the array since the
-                                        * removal shuffle the elements of the array.
+                                        * Remove the session from the list.
+                                        * session_idx is not modified since
+                                        * g_ptr_array_remove_index_fast
+                                        * replaces the the removed element with
+                                        * the array's last element.
                                         */
                                        g_ptr_array_remove_index_fast(
                                                lttng_live_msg_iter->sessions,
                                                session_idx);
-                                       session_idx = 0;
                                } else {
                                        session_idx++;
                                }