Fix: sessiond: size-based notification occasionally not triggered

[lttng-tools.git] / src / bin / lttng-sessiond / rotate.c

diff --git a/src/bin/lttng-sessiond/rotate.c b/src/bin/lttng-sessiond/rotate.c
index 9e1126bdf03e6b86b523f659af3ef1359ba847b4..1cbff999a283b14ea1b8dd06c1448a3ad58c47c2 100644 (file)
--- a/src/bin/lttng-sessiond/rotate.c
+++ b/src/bin/lttng-sessiond/rotate.c
@@ -47,12 +47,13 @@ int subscribe_session_consumed_size_rotation(struct ltt_session *session, uint64
        int ret;
        enum lttng_condition_status condition_status;
        enum lttng_notification_channel_status nc_status;
-       struct lttng_condition *rotate_condition = NULL;
-       struct lttng_action *notify_action = NULL;
+       const uint64_t eventfd_increment_value = 1;
        const struct lttng_credentials session_creds = {
                .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
                .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
        };
+       struct lttng_condition *rotate_condition;
+       struct lttng_action *notify_action = NULL;
 
        rotate_condition = lttng_condition_session_consumed_size_create();
        if (!rotate_condition) {
@@ -109,6 +110,15 @@ int subscribe_session_consumed_size_rotation(struct ltt_session *session, uint64
                goto end;
        }
 
+       ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
+                         &eventfd_increment_value,
+                         sizeof(eventfd_increment_value));
+       if (ret != sizeof(eventfd_increment_value)) {
+               PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
+               ret = -1;
+               goto end;
+       }
+
        ret = notification_thread_command_register_trigger(
                        notification_thread_handle, session->rotate_trigger,
                        true);
@@ -134,6 +144,7 @@ int unsubscribe_session_consumed_size_rotation(struct ltt_session *session,
 {
        int ret = 0;
        enum lttng_notification_channel_status status;
+       const uint64_t eventfd_increment_value = 1;
 
        assert(session->rotate_trigger);
        status = lttng_notification_channel_unsubscribe(
@@ -145,8 +156,17 @@ int unsubscribe_session_consumed_size_rotation(struct ltt_session *session,
                goto end;
        }
 
-       ret = notification_thread_command_unregister_trigger(
-                       notification_thread_handle, session->rotate_trigger);
+       ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
+                         &eventfd_increment_value,
+                         sizeof(eventfd_increment_value));
+       if (ret != sizeof(eventfd_increment_value)) {
+               PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
+               ret = -1;
+               goto end;
+       }
+
+       ret = notification_thread_command_unregister_trigger(notification_thread_handle,
+                                                            session->rotate_trigger);
        if (ret != LTTNG_OK) {
                ERR("Session unregister trigger error: %d", ret);
                goto end;