loglevels: deal with fixup upon library load

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 5867b124878c6993291591094d049634c5c699f1..bcc432e74a62a64df0b1ebf00388f4c0230de32b 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -189,19 +189,30 @@ struct tracepoint_loglevel_entry  {
        long value;
 };
 
+struct loglevel_entry;
+
 /*
- * Entry describing an active loglevel, along with the event attribute
- * and channel information configuring the events that need to be
- * enabled.
+ * Entry describing a per-session active loglevel, along with the event
+ * attribute and channel information configuring the events that need to
+ * be enabled.
  */
-struct loglevel_entry {
-       struct cds_hlist_node hlist;
+struct session_loglevel {
        struct ltt_channel *chan;
        struct lttng_ctx *ctx;  /* TODO */
        struct lttng_ust_event event_param;
        struct cds_list_head events;    /* list of events enabled */
        struct cds_list_head list;      /* per-session list of loglevels */
+       struct cds_list_head session_list;
+       struct loglevel_entry *entry;
        unsigned int enabled:1;
+};
+
+/*
+ * Entry describing an active loglevel (per name) for all sessions.
+ */
+struct loglevel_entry {
+       struct cds_hlist_node hlist;
+       struct cds_list_head session_list;
        char name[0];
 };
 
@@ -411,14 +422,14 @@ struct lttng_ust_tracepoint_iter *
        lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
 
 struct loglevel_entry *get_loglevel(const char *name);
-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);
-void _remove_loglevel(struct loglevel_entry *e);
-int ltt_loglevel_enable(struct loglevel_entry *loglevel);
-int ltt_loglevel_disable(struct loglevel_entry *loglevel);
+void _remove_loglevel(struct session_loglevel *loglevel);
+int ltt_loglevel_enable(struct session_loglevel *loglevel);
+int ltt_loglevel_disable(struct session_loglevel *loglevel);
 int ltt_loglevel_create(struct ltt_channel *chan,
        struct lttng_ust_event *event_param,
-       struct loglevel_entry **_entry);
+       struct session_loglevel **sl);
 
 #endif /* _LTTNG_UST_EVENTS_H */

diff --git a/liblttng-ust/ltt-events.c b/liblttng-ust/ltt-events.c
index c754d6ff5348e3346fc2765bbaad478a6d834bfc..e3fd3f79fdd9bb913a3f01987866a4c08e57ee7d 100644 (file)
--- a/liblttng-ust/ltt-events.c
+++ b/liblttng-ust/ltt-events.c
@@ -74,7 +74,7 @@ struct ust_pending_probe {
 };
 
 static void _ltt_event_destroy(struct ltt_event *event);
-static void _ltt_loglevel_destroy(struct loglevel_entry *entry);
+static void _ltt_loglevel_destroy(struct session_loglevel *sl);
 static void _ltt_channel_destroy(struct ltt_channel *chan);
 static int _ltt_event_unregister(struct ltt_event *event);
 static
@@ -136,10 +136,38 @@ int pending_probe_fix_events(const struct lttng_event_desc *desc)
        uint32_t hash = jhash(name, name_len - 1, 0);
        int ret = 0;
 
-       /* TODO:
+       /*
         * For this event, we need to lookup the loglevel. If active (in
         * the active loglevels hash table), we must create the event.
         */
+       if (desc->loglevel) {
+               const struct tracepoint_loglevel_entry *ev_ll;
+               struct loglevel_entry *loglevel;
+
+               ev_ll = *desc->loglevel;
+               loglevel = get_loglevel(ev_ll->identifier);
+               if (loglevel) {
+                       struct session_loglevel *sl;
+
+                       cds_list_for_each_entry(sl, &loglevel->session_list,
+                                       session_list) {
+                               struct ltt_event *ev;
+                               int ret;
+
+                               /* create event */
+                               ret = ltt_event_create(sl->chan,
+                                       &sl->event_param, NULL,
+                                       &ev);
+                               /*
+                                * TODO: report error.
+                                */
+                               if (ret)
+                                       continue;
+                               cds_list_add(&ev->loglevel_list,
+                                       &sl->events);
+                       }
+               }
+       }
 
        head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
        cds_hlist_for_each_entry_safe(e, node, p, head, node) {
@@ -190,7 +218,7 @@ void ltt_session_destroy(struct ltt_session *session)
 {
        struct ltt_channel *chan, *tmpchan;
        struct ltt_event *event, *tmpevent;
-       struct loglevel_entry *loglevel, *tmploglevel;
+       struct session_loglevel *loglevel, *tmploglevel;
        int ret;
 
        CMM_ACCESS_ONCE(session->active) = 0;
@@ -360,22 +388,22 @@ void _ltt_channel_destroy(struct ltt_channel *chan)
 
 int ltt_loglevel_create(struct ltt_channel *chan,
        struct lttng_ust_event *event_param,
-       struct loglevel_entry **_entry)
+       struct session_loglevel **_sl)
 {
-       struct loglevel_entry *entry;
+       struct session_loglevel *sl;
 
-       entry = add_loglevel(event_param->name, chan, event_param);
-       if (!entry || IS_ERR(entry)) {
-               return PTR_ERR(entry);
+       sl = add_loglevel(event_param->name, chan, event_param);
+       if (!sl || IS_ERR(sl)) {
+               return PTR_ERR(sl);
        }
-       *_entry = entry;
+       *_sl = sl;
        return 0;
 }
 
 static
-void _ltt_loglevel_destroy(struct loglevel_entry *entry)
+void _ltt_loglevel_destroy(struct session_loglevel *sl)
 {
-       _remove_loglevel(entry);
+       _remove_loglevel(sl);
 }
 
 /*

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;

diff --git a/liblttng-ust/lttng-ust-abi.c b/liblttng-ust/lttng-ust-abi.c
index 548b3a5298ebdd8c1e86e4099abf2b39c5c07191..25f213bbc1ce1bf72fd09194459177f9bfce5064 100644 (file)
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -664,7 +664,7 @@ int lttng_abi_create_loglevel(int channel_objd,
                              struct lttng_ust_event *event_param)
 {
        struct ltt_channel *channel = objd_private(channel_objd);
-       struct loglevel_entry *loglevel;
+       struct session_loglevel *loglevel;
        int loglevel_objd, ret;
 
        event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
@@ -968,7 +968,7 @@ static const struct lttng_ust_objd_ops lttng_event_ops = {
 static
 long lttng_loglevel_cmd(int objd, unsigned int cmd, unsigned long arg)
 {
-       struct loglevel_entry *loglevel = objd_private(objd);
+       struct session_loglevel *loglevel = objd_private(objd);
 
        switch (cmd) {
        case LTTNG_UST_CONTEXT:
@@ -990,7 +990,7 @@ long lttng_loglevel_cmd(int objd, unsigned int cmd, unsigned long arg)
 static
 int lttng_loglevel_release(int objd)
 {
-       struct loglevel_entry *loglevel = objd_private(objd);
+       struct session_loglevel *loglevel = objd_private(objd);
 
        if (loglevel)
                return lttng_ust_objd_unref(loglevel->chan->objd);