Add session active test

[lttng-modules.git] / ltt-events.c

diff --git a/ltt-events.c b/ltt-events.c
index b8dbec69a2dfb40cb8d38c73092fbf81389c913c..947d772cf37bec3c1a6b1d2557e2aeb2f19dd904 100644 (file)
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -46,9 +46,14 @@ void ltt_session_destroy(struct ltt_session *session)
 {
        struct ltt_channel *chan, *tmpchan;
        struct ltt_event *event, *tmpevent;
+       int ret;
 
        mutex_lock(&sessions_mutex);
-       session->active = 0;
+       ACCESS_ONCE(session->active) = 0;
+       list_for_each_entry(event, &session->events, list) {
+               ret = _ltt_event_unregister(event);
+               WARN_ON(ret);
+       }
        synchronize_trace();    /* Wait for in-flight events to complete */
        list_for_each_entry_safe(event, tmpevent, &session->events, list)
                _ltt_event_destroy(event);
@@ -68,7 +73,7 @@ int ltt_session_start(struct ltt_session *session)
                ret = -EBUSY;
                goto end;
        }
-       session->active = 1;
+       ACCESS_ONCE(session->active) = 1;
        synchronize_trace();    /* Wait for in-flight events to complete */
 end:
        mutex_unlock(&sessions_mutex);
@@ -84,7 +89,7 @@ int ltt_session_stop(struct ltt_session *session)
                ret = -EBUSY;
                goto end;
        }
-       session->active = 0;
+       ACCESS_ONCE(session->active) = 0;
        synchronize_trace();    /* Wait for in-flight events to complete */
 end:
        mutex_unlock(&sessions_mutex);
@@ -172,8 +177,8 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
        if (chan->free_event_id == -1UL)
                goto full;
        /*
-        * This is O(n^2) (for each event loop called at event creation).
-        * Might require a hash if we have lots of events.
+        * This is O(n^2) (for each event, the loop is called at event
+        * creation). Might require a hash if we have lots of events.
         */
        list_for_each_entry(event, &chan->session->events, list)
                if (!strcmp(event->name, name))
@@ -201,6 +206,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
        default:
                WARN_ON_ONCE(1);
        }
+       list_add(&event->list, &chan->session->events);
        mutex_unlock(&sessions_mutex);
        return event;
 
@@ -218,7 +224,7 @@ full:
 /*
  * Only used internally at session destruction.
  */
-int _ltt_event_destroy(struct ltt_event *event)
+int _ltt_event_unregister(struct ltt_event *event)
 {
        int ret = -EINVAL;
 
@@ -232,9 +238,17 @@ int _ltt_event_destroy(struct ltt_event *event)
        default:
                WARN_ON_ONCE(1);
        }
+       return ret;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+void _ltt_event_destroy(struct ltt_event *event)
+{
        kfree(event->name);
+       list_del(&event->list);
        kmem_cache_free(event_cache, event);
-       return ret;
 }
 
 /**
@@ -284,10 +298,15 @@ static int __init ltt_events_init(void)
        event_cache = KMEM_CACHE(ltt_event, 0);
        if (!event_cache)
                return -ENOMEM;
-       ret = ltt_debugfs_abi_init();
+       ret = ltt_probes_init();
        if (ret)
                goto error;
+       ret = ltt_debugfs_abi_init();
+       if (ret)
+               goto error_abi;
        return 0;
+error_abi:
+       ltt_probes_exit();
 error:
        kmem_cache_destroy(event_cache);
        return ret;
@@ -300,6 +319,7 @@ static void __exit ltt_events_exit(void)
        struct ltt_session *session, *tmpsession;
 
        ltt_debugfs_abi_exit();
+       ltt_probes_exit();
        list_for_each_entry_safe(session, tmpsession, &sessions, list)
                ltt_session_destroy(session);
        kmem_cache_destroy(event_cache);