loglevels: deal with fixup upon library load

[lttng-ust.git] / liblttng-ust / ltt-probes.c

diff --git a/liblttng-ust/ltt-probes.c b/liblttng-ust/ltt-probes.c
index d2623947aece9e34c7ebdcec89bfb0c6b68e13ab..2994512825660596060f8875915c026d3f01dc71 100644 (file)
--- a/liblttng-ust/ltt-probes.c
+++ b/liblttng-ust/ltt-probes.c
@@ -235,7 +235,8 @@ struct loglevel_entry *get_loglevel(const char *name)
  * loglevel. Add them to the events list as created.
  */
 static
-void _probes_create_loglevel_events(struct loglevel_entry *loglevel)
+void _probes_create_loglevel_events(struct loglevel_entry *entry,
+                               struct session_loglevel *loglevel)
 {
        struct lttng_probe_desc *probe_desc;
        int i;
@@ -247,7 +248,7 @@ void _probes_create_loglevel_events(struct loglevel_entry *loglevel)
                        if (!(probe_desc->event_desc[i]->loglevel))
                                continue;
                        ev_ll = *probe_desc->event_desc[i]->loglevel;
-                       if (!strcmp(ev_ll->identifier, loglevel->name)) {
+                       if (!strcmp(ev_ll->identifier, entry->name)) {
                                struct ltt_event *ev;
                                int ret;
 
@@ -263,7 +264,6 @@ void _probes_create_loglevel_events(struct loglevel_entry *loglevel)
                                cds_list_add(&ev->loglevel_list,
                                        &loglevel->events);
                        }
-                               
                }
        }
 }
@@ -272,46 +272,64 @@ void _probes_create_loglevel_events(struct loglevel_entry *loglevel)
  * Add the loglevel to the loglevel hash table. Must be called with
  * ust lock held.
  */
-struct loglevel_entry *add_loglevel(const char *name,
+struct session_loglevel *add_loglevel(const char *name,
        struct ltt_channel *chan,
        struct lttng_ust_event *event_param)
 {
        struct cds_hlist_head *head;
        struct cds_hlist_node *node;
        struct loglevel_entry *e;
+       struct session_loglevel *sl;
        size_t name_len = strlen(name) + 1;
        uint32_t hash = jhash(name, name_len-1, 0);
+       int found = 0;
 
+       /* loglevel entry */
        head = &loglevel_table[hash & (LOGLEVEL_TABLE_SIZE - 1)];
        cds_hlist_for_each_entry(e, node, head, hlist) {
                if (!strcmp(name, e->name)) {
-                       DBG("loglevel %s busy", name);
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (!found) {
+               /*
+                * Using zmalloc here to allocate a variable length element. Could
+                * cause some memory fragmentation if overused.
+                */
+               e = zmalloc(sizeof(struct loglevel_entry) + name_len);
+               if (!e)
+                       return ERR_PTR(-ENOMEM);
+               memcpy(&e->name[0], name, name_len);
+               cds_hlist_add_head(&e->hlist, head);
+       }
+
+       /* session loglevel */
+       cds_list_for_each_entry(sl, &e->session_list, session_list) {
+               if (chan == sl->chan) {
+                       DBG("loglevel %s busy for this channel", name);
                        return ERR_PTR(-EEXIST);        /* Already there */
                }
        }
-       /*
-        * Using zmalloc here to allocate a variable length element. Could
-        * cause some memory fragmentation if overused.
-        */
-       e = zmalloc(sizeof(struct loglevel_entry) + name_len);
-       if (!e)
+       sl = zmalloc(sizeof(struct session_loglevel));
+       if (!sl)
                return ERR_PTR(-ENOMEM);
-       memcpy(&e->name[0], name, name_len);
-       e->chan = chan;
-       e->enabled = 1;
-       memcpy(&e->event_param, event_param, sizeof(e->event_param));
-       cds_hlist_add_head(&e->hlist, head);
-       CDS_INIT_LIST_HEAD(&e->events);
-       _probes_create_loglevel_events(e);
-       cds_list_add(&e->list, &chan->session->loglevels);
-       return e;
+       sl->chan = chan;
+       sl->enabled = 1;
+       memcpy(&sl->event_param, event_param, sizeof(sl->event_param));
+       CDS_INIT_LIST_HEAD(&sl->events);
+       cds_list_add(&sl->list, &chan->session->loglevels);
+       cds_list_add(&sl->session_list, &e->session_list);
+       _probes_create_loglevel_events(e, sl);
+       return sl;
 }
 
 /*
  * Remove the loglevel from the loglevel hash table. Must be called with
  * ust_lock held. Only called at session teardown.
  */
-void _remove_loglevel(struct loglevel_entry *loglevel)
+void _remove_loglevel(struct session_loglevel *loglevel)
 {
        struct ltt_event *ev, *tmp;
 
@@ -323,12 +341,16 @@ void _remove_loglevel(struct loglevel_entry *loglevel)
        cds_list_for_each_entry_safe(ev, tmp, &loglevel->events, list) {
                cds_list_del(&ev->list);
        }
-       cds_hlist_del(&loglevel->hlist);
+       cds_list_del(&loglevel->session_list);
        cds_list_del(&loglevel->list);
+       if (cds_list_empty(&loglevel->entry->session_list)) {
+               cds_hlist_del(&loglevel->entry->hlist);
+               free(loglevel->entry);
+       }
        free(loglevel);
 }
 
-int ltt_loglevel_enable(struct loglevel_entry *loglevel)
+int ltt_loglevel_enable(struct session_loglevel *loglevel)
 {
        struct ltt_event *ev;
        int ret;
@@ -346,7 +368,7 @@ int ltt_loglevel_enable(struct loglevel_entry *loglevel)
        return 0;
 }
 
-int ltt_loglevel_disable(struct loglevel_entry *loglevel)
+int ltt_loglevel_disable(struct session_loglevel *loglevel)
 {
        struct ltt_event *ev;
        int ret;