sessiond: introduce ltt_session::locked_ref look-up functions

[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.cpp

diff --git a/src/bin/lttng-sessiond/ust-app.cpp b/src/bin/lttng-sessiond/ust-app.cpp
index 2788ddbe07d489d7436af922b380743539c9f5a3..2439d1e99c4572a2d10284aec9553637907a9cd9 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.cpp
+++ b/src/bin/lttng-sessiond/ust-app.cpp
@@ -497,7 +497,6 @@ static void delete_ust_app_channel_rcu(struct rcu_head *head)
 static void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
 {
        uint64_t discarded = 0, lost = 0;
-       struct ltt_session *session;
        struct ltt_ust_channel *uchan;
 
        if (ua_chan->attr.type != LTTNG_UST_ABI_CHAN_PER_CPU) {
@@ -505,7 +504,16 @@ static void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan
        }
 
        lttng::urcu::read_lock_guard read_lock;
-       session = session_find_by_id(ua_chan->session->tracing_id);
+
+       ltt_session::ref session;
+       try {
+               session = ltt_session::find_session(ua_chan->session->tracing_id);
+       } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) {
+               DBG_FMT("Failed to save per-pid lost/discarded counters: {}, location='{}'",
+                       ex.what(),
+                       ex.source_location);
+       }
+
        if (!session || !session->ust_session) {
                /*
                 * Not finding the session is not an error because there are
@@ -522,7 +530,7 @@ static void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan
                 * events is done exactly once. The session is then unpublished
                 * from the session list, resulting in this condition.
                 */
-               goto end;
+               return;
        }
 
        if (ua_chan->attr.overwrite) {
@@ -540,16 +548,11 @@ static void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan
                                               ua_chan->name);
        if (!uchan) {
                ERR("Missing UST channel to store discarded counters");
-               goto end;
+               return;
        }
 
        uchan->per_pid_closed_app_discarded += discarded;
        uchan->per_pid_closed_app_lost += lost;
-
-end:
-       if (session) {
-               session_put(session);
-       }
 }
 
 /*
@@ -1024,7 +1027,7 @@ static void delete_ust_app(struct ust_app *app)
         * The session list lock must be held during this function to guarantee
         * the existence of ua_sess.
         */
-       session_lock_list();
+       const auto list_lock = lttng::sessiond::lock_session_list();
        /* Delete ust app sessions info */
        sock = app->sock;
        app->sock = -1;
@@ -1114,7 +1117,6 @@ static void delete_ust_app(struct ust_app *app)
 
        DBG2("UST app pid %d deleted", app->pid);
        free(app);
-       session_unlock_list();
 }
 
 /*
@@ -3444,7 +3446,7 @@ static int create_channel_per_uid(struct ust_app *app,
        int ret;
        struct buffer_reg_uid *reg_uid;
        struct buffer_reg_channel *buf_reg_chan;
-       struct ltt_session *session = nullptr;
+       ltt_session::ref session;
        enum lttng_error_code notification_ret;
 
        LTTNG_ASSERT(app);
@@ -3475,9 +3477,9 @@ static int create_channel_per_uid(struct ust_app *app,
                goto error;
        }
 
-       session = session_find_by_id(ua_sess->tracing_id);
-       LTTNG_ASSERT(session);
-       ASSERT_LOCKED(session->lock);
+       /* Guaranteed to exist; will not throw. */
+       session = ltt_session::find_session(ua_sess->tracing_id);
+       ASSERT_LOCKED(session->_lock);
        ASSERT_SESSION_LIST_LOCKED();
 
        /*
@@ -3545,9 +3547,6 @@ send_channel:
        }
 
 error:
-       if (session) {
-               session_put(session);
-       }
        return ret;
 }
 
@@ -3567,7 +3566,7 @@ static int create_channel_per_pid(struct ust_app *app,
        int ret;
        lsu::registry_session *registry;
        enum lttng_error_code cmd_ret;
-       struct ltt_session *session = nullptr;
+       ltt_session::ref session;
        uint64_t chan_reg_key;
 
        LTTNG_ASSERT(app);
@@ -3594,9 +3593,9 @@ static int create_channel_per_pid(struct ust_app *app,
                goto error;
        }
 
-       session = session_find_by_id(ua_sess->tracing_id);
-       LTTNG_ASSERT(session);
-       ASSERT_LOCKED(session->lock);
+       /* Guaranteed to exist; will not throw. */
+       session = ltt_session::find_session(ua_sess->tracing_id);
+       ASSERT_LOCKED(session->_lock);
        ASSERT_SESSION_LIST_LOCKED();
 
        /* Create and get channel on the consumer side. */
@@ -3645,9 +3644,6 @@ error_remove_from_registry:
                }
        }
 error:
-       if (session) {
-               session_put(session);
-       }
        return ret;
 }
 
@@ -3894,7 +3890,7 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
        int ret = 0;
        struct ust_app_channel *metadata;
        struct consumer_socket *socket;
-       struct ltt_session *session = nullptr;
+       ltt_session::ref session;
 
        LTTNG_ASSERT(ua_sess);
        LTTNG_ASSERT(app);
@@ -3943,9 +3939,9 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
         */
        locked_registry->_metadata_key = metadata->key;
 
-       session = session_find_by_id(ua_sess->tracing_id);
-       LTTNG_ASSERT(session);
-       ASSERT_LOCKED(session->lock);
+       /* Guaranteed to exist; will not throw. */
+       session = ltt_session::find_session(ua_sess->tracing_id);
+       ASSERT_LOCKED(session->_lock);
        ASSERT_SESSION_LIST_LOCKED();
 
        /*
@@ -3985,9 +3981,6 @@ error_consumer:
        lttng_fd_put(LTTNG_FD_APPS, 1);
        delete_ust_app_channel(-1, metadata, app, locked_registry);
 error:
-       if (session) {
-               session_put(session);
-       }
        return ret;
 }