sessiond: introduce ltt_session::locked_ref look-up functions

[lttng-tools.git] / src / bin / lttng-sessiond / rotation-thread.cpp

diff --git a/src/bin/lttng-sessiond/rotation-thread.cpp b/src/bin/lttng-sessiond/rotation-thread.cpp
index 418a2d62bcf032ec54db286ddf92815180968633..ca7237802e61096846d9fca358a7d3cd39767842 100644 (file)
--- a/src/bin/lttng-sessiond/rotation-thread.cpp
+++ b/src/bin/lttng-sessiond/rotation-thread.cpp
@@ -315,7 +315,7 @@ int launch_session_rotation(ltt_session& session)
        DBG("Launching scheduled time-based rotation on session \"%s\"", session.name);
 
        ASSERT_SESSION_LIST_LOCKED();
-       ASSERT_LOCKED(session.lock);
+       ASSERT_LOCKED(session._lock);
 
        ret = cmd_rotate_session(&session,
                                 &rotation_return,
@@ -539,9 +539,7 @@ void ls::rotation_thread::_handle_job_queue()
                        cds_list_del(&job->head);
                }
 
-               session_lock_list();
-               const auto unlock_list =
-                       lttng::make_scope_exit([]() noexcept { session_unlock_list(); });
+               const auto list_lock = lttng::sessiond::lock_session_list();
 
                /* locked_ref will unlock the session and release the ref held by the job. */
                session_lock(job->session);
@@ -585,19 +583,18 @@ void ls::rotation_thread::_handle_notification(const lttng_notification& notific
                condition_session_name,
                consumed);
 
-       session_lock_list();
-       const auto unlock_list = lttng::make_scope_exit([]() noexcept { session_unlock_list(); });
-
-       ltt_session::locked_ref session{ [&condition_session_name]() {
-               auto raw_session_ptr = session_find_by_name(condition_session_name);
-
-               if (raw_session_ptr) {
-                       session_lock(raw_session_ptr);
-               }
-
-               return raw_session_ptr;
-       }() };
-       if (!session) {
+       /*
+        * Mind the order of the declaration of list_lock vs session:
+        * the session list lock must always be released _after_ the release of
+        * a session's reference (the destruction of a ref/locked_ref) to ensure
+        * since the reference's release may unpublish the session from the list of
+        * sessions.
+        */
+       const auto list_lock = lttng::sessiond::lock_session_list();
+       ltt_session::locked_ref session;
+       try {
+               session = ltt_session::find_locked_session(condition_session_name);
+       } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) {
                DBG_FMT("Failed to find session while handling notification: notification_type={}, session name=`{}`",
                        lttng_condition_type_str(condition_type),
                        condition_session_name);
@@ -839,7 +836,7 @@ void ls::rotation_thread::subscribe_session_consumed_size_rotation(ltt_session&
                .gid = LTTNG_OPTIONAL_INIT_VALUE(session.gid),
        };
 
-       ASSERT_LOCKED(session.lock);
+       ASSERT_LOCKED(session._lock);
 
        auto rotate_condition = lttng::make_unique_wrapper<lttng_condition, lttng_condition_put>(
                lttng_condition_session_consumed_size_create());