Multiple fixes when cleaning app and UST sessions

Also adds event's attributes to the ust_app_event data structure.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>

diff --git a/lttng-sessiond/trace-ust.c b/lttng-sessiond/trace-ust.c
index 793ff0f7b8b92580be90a9cf0a5bf443e81e4c6a..bc73b79776780a0d64fe98ceb2e5c93b0bf83a44 100644 (file)
--- a/lttng-sessiond/trace-ust.c
+++ b/lttng-sessiond/trace-ust.c
@@ -70,11 +70,12 @@ struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
        }
        rcu_read_unlock();
 
-       DBG2("Found UST event by name %s", name);
+       DBG2("Trace UST event found by name %s", name);
 
        return caa_container_of(node, struct ltt_ust_event, node);
 
 error:
+       DBG2("Trace UST event NOT found by name %s", name);
        return NULL;
 }
 
@@ -227,6 +228,8 @@ struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
        /* Alloc context hash tables */
        lue->ctx = hashtable_new_str(0);
 
+       DBG2("Trace UST event %s created", lue->attr.name);
+
        return lue;
 
 error_free_event:
@@ -331,20 +334,23 @@ static void destroy_event_rcu(struct rcu_head *head)
        trace_ust_destroy_event(event);
 }
 
-static void destroy_event(struct cds_lfht *ht)
+/*
+ * Cleanup UST events hashtable.
+ */
+static void destroy_event(struct cds_lfht *events)
 {
        int ret;
        struct cds_lfht_node *node;
        struct cds_lfht_iter iter;
 
-       cds_lfht_for_each(ht, &iter, node) {
-               ret = hashtable_del(ht, &iter);
+       cds_lfht_for_each(events, &iter, node) {
+               ret = hashtable_del(events, &iter);
                if (!ret) {
                        call_rcu(&node->head, destroy_event_rcu);
                }
        }
 
-       hashtable_destroy(ht);
+       hashtable_destroy(events);
 }
 
 /*

diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index 8520efb440e71cb84499609c1beb83bcccca8e36..0fc208311931846dcda77e3346c58f712dbb4079 100644 (file)
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -134,73 +134,60 @@ error:
 }
 
 /*
- * Delete a traceable application structure from the global list.
+ * Delete a traceable application structure from the global list. Never call
+ * this function outside of a call_rcu call.
  */
-static void delete_ust_app(struct ust_app *lta)
+static void delete_ust_app(struct ust_app *app)
 {
        int ret;
        struct cds_lfht_node *node;
        struct cds_lfht_iter iter;
-       struct ust_app_session *lts;
+       struct ust_app_session *ua_sess;
 
        rcu_read_lock();
 
-       /* Remove from apps hash table */
-       node = hashtable_lookup(ust_app_ht,
-                       (void *) ((unsigned long) lta->key.pid), sizeof(void *), &iter);
-       if (node == NULL) {
-               ERR("UST app pid %d not found in hash table", lta->key.pid);
-               goto end;
-       } else {
-               ret = hashtable_del(ust_app_ht, &iter);
-               if (ret) {
-                       ERR("UST app unable to delete app %d from hash table",
-                                       lta->key.pid);
-               } else {
-                       DBG2("UST app pid %d deleted", lta->key.pid);
-               }
-       }
-
        /* Remove from key hash table */
        node = hashtable_lookup(ust_app_sock_key_map,
-                       (void *) ((unsigned long) lta->key.sock), sizeof(void *), &iter);
+                       (void *) ((unsigned long) app->key.sock), sizeof(void *), &iter);
        if (node == NULL) {
-               ERR("UST app key %d not found in key hash table", lta->key.sock);
+               /* Not suppose to happen */
+               ERR("UST app key %d not found in key hash table", app->key.sock);
                goto end;
+       }
+
+       ret = hashtable_del(ust_app_sock_key_map, &iter);
+       if (ret) {
+               ERR("UST app unable to delete app sock %d from key hash table",
+                               app->key.sock);
        } else {
-               ret = hashtable_del(ust_app_sock_key_map, &iter);
-               if (ret) {
-                       ERR("UST app unable to delete app sock %d from key hash table",
-                                       lta->key.sock);
-               } else {
-                       DBG2("UST app pair sock %d key %d deleted",
-                                       lta->key.sock, lta->key.pid);
-               }
+               DBG2("UST app pair sock %d key %d deleted",
+                               app->key.sock, app->key.pid);
        }
 
        /* Socket is already closed at this point */
 
        /* Delete ust app sessions info */
-       if (lta->sock_closed) {
-               lta->key.sock = -1;
+       if (app->sock_closed) {
+               app->key.sock = -1;
        }
 
-       cds_lfht_for_each_entry(lta->sessions, &iter, lts, node) {
-               hashtable_del(lta->sessions, &iter);
-               delete_ust_app_session(lta->key.sock, lts);
+       cds_lfht_for_each_entry(app->sessions, &iter, ua_sess, node) {
+               hashtable_del(app->sessions, &iter);
+               delete_ust_app_session(app->key.sock, ua_sess);
        }
 
-       ret = hashtable_destroy(lta->sessions);
+       ret = hashtable_destroy(app->sessions);
        if (ret < 0) {
                ERR("UST app destroy session hashtable failed");
                goto end;
        }
 
-       if (lta->key.sock >= 0) {
-               close(lta->key.sock);
+       if (!app->sock_closed) {
+               close(app->key.sock);
        }
 
-       free(lta);
+       DBG2("UST app pid %d deleted", app->key.pid);
+       free(app);
 end:
        rcu_read_unlock();
 }
@@ -299,28 +286,26 @@ int ust_app_register(struct ust_register_msg *msg, int sock)
                return -ENOMEM;
        }
 
+       lta->ppid = msg->ppid;
        lta->uid = msg->uid;
        lta->gid = msg->gid;
-       lta->key.pid = msg->pid;
-       lta->ppid = msg->ppid;
        lta->v_major = msg->major;
        lta->v_minor = msg->minor;
-       lta->key.sock = sock;
        strncpy(lta->name, msg->name, sizeof(lta->name));
        lta->name[16] = '\0';
-       hashtable_node_init(&lta->node, (void *)((unsigned long)lta->key.pid),
-                       sizeof(void *));
-
-       /* Session hashtable */
        lta->sessions = hashtable_new(0);
 
-       /* Set sock key map */
+       /* Set key map */
+       lta->key.pid = msg->pid;
+       hashtable_node_init(&lta->node, (void *)((unsigned long)lta->key.pid),
+                       sizeof(void *));
+       lta->key.sock = sock;
        hashtable_node_init(&lta->key.node, (void *)((unsigned long)lta->key.sock),
                        sizeof(void *));
 
        rcu_read_lock();
-       hashtable_add_unique(ust_app_ht, &lta->node);
        hashtable_add_unique(ust_app_sock_key_map, &lta->key.node);
+       hashtable_add_unique(ust_app_ht, &lta->node);
        rcu_read_unlock();
 
        DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s"
@@ -363,6 +348,7 @@ void ust_app_unregister(int sock)
        close(sock);
        /* Using a flag because we still need "sock" as a key. */
        lta->sock_closed = 1;
+       hashtable_del(ust_app_ht, &iter);
        call_rcu(&node->head, delete_ust_app_rcu);
 error:
        rcu_read_unlock();
@@ -451,20 +437,26 @@ void ust_app_clean_list(void)
        int ret;
        struct cds_lfht_node *node;
        struct cds_lfht_iter iter;
+       struct ust_app *app;
 
-       DBG2("UST app clean hash table");
+       DBG2("UST app cleaning registered apps hash table");
 
        rcu_read_lock();
 
-       hashtable_get_first(ust_app_ht, &iter);
-       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+       cds_lfht_for_each(ust_app_ht, &iter, node) {
+               app = caa_container_of(node, struct ust_app, node);
+               close(app->key.sock);
+               app->sock_closed = 1;
+
                ret = hashtable_del(ust_app_ht, &iter);
                if (!ret) {
                        call_rcu(&node->head, delete_ust_app_rcu);
                }
-               hashtable_get_next(ust_app_ht, &iter);
        }
 
+       hashtable_destroy(ust_app_ht);
+       hashtable_destroy(ust_app_sock_key_map);
+
        rcu_read_unlock();
 }
 
@@ -503,7 +495,8 @@ error:
 /*
  * Alloc new UST app channel.
  */
-static struct ust_app_channel *alloc_ust_app_channel(char *name)
+static struct ust_app_channel *alloc_ust_app_channel(char *name,
+               struct lttng_ust_channel *attr)
 {
        struct ust_app_channel *ua_chan;
 
@@ -514,15 +507,23 @@ static struct ust_app_channel *alloc_ust_app_channel(char *name)
                goto error;
        }
 
+       /* Setup channel name */
        strncpy(ua_chan->name, name, sizeof(ua_chan->name));
        ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
+
        ua_chan->handle = -1;
        ua_chan->ctx = hashtable_new(0);
-       CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
        ua_chan->events = hashtable_new_str(0);
        hashtable_node_init(&ua_chan->node, (void *) ua_chan->name,
                        strlen(ua_chan->name));
 
+       CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
+
+       /* Copy attributes */
+       if (attr) {
+               memcpy(&ua_chan->attr, attr, sizeof(ua_chan->attr));
+       }
+
        DBG3("UST app channel %s allocated", ua_chan->name);
 
        return ua_chan;
@@ -534,7 +535,8 @@ error:
 /*
  * Alloc new UST app event.
  */
-static struct ust_app_event *alloc_ust_app_event(char *name)
+static struct ust_app_event *alloc_ust_app_event(char *name,
+               struct lttng_ust_event *attr)
 {
        struct ust_app_event *ua_event;
 
@@ -551,6 +553,11 @@ static struct ust_app_event *alloc_ust_app_event(char *name)
        hashtable_node_init(&ua_event->node, (void *) ua_event->name,
                        strlen(ua_event->name));
 
+       /* Copy attributes */
+       if (attr) {
+               memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
+       }
+
        DBG3("UST app event %s allocated", ua_event->name);
 
        return ua_event;
@@ -593,7 +600,7 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan,
                if (ua_event_node == NULL) {
                        DBG2("UST event %s not found on shadow copy channel",
                                        uevent->attr.name);
-                       ua_event = alloc_ust_app_event(uevent->attr.name);
+                       ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
                        if (ua_event == NULL) {
                                goto next;
                        }
@@ -633,7 +640,7 @@ static void shadow_copy_session(struct ust_app_session *ua_sess,
                if (ua_chan_node == NULL) {
                        DBG2("Channel %s not found on shadow session copy, creating it",
                                        uchan->name);
-                       ua_chan = alloc_ust_app_channel(uchan->name);
+                       ua_chan = alloc_ust_app_channel(uchan->name, &uchan->attr);
                        if (ua_chan == NULL) {
                                /* malloc failed... continuing */
                                goto next;
@@ -722,6 +729,65 @@ error:
        return NULL;
 }
 
+/*
+ * Create the specified channel onto the UST tracer for a UST session.
+ */
+static int create_ust_channel(struct ust_app *app,
+               struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
+{
+       int ret;
+
+       /* TODO: remove cast and use lttng-ust-abi.h */
+       ret = ustctl_create_channel(app->key.sock, ua_sess->handle,
+                       (struct lttng_ust_channel_attr *)&ua_chan->attr, &ua_chan->obj);
+       if (ret < 0) {
+               DBG("Error creating channel %s for app (pid: %d, sock: %d) "
+                               "and session handle %d with ret %d",
+                               ua_chan->name, app->key.pid, app->key.sock,
+                               ua_sess->handle, ret);
+               goto error;
+       }
+
+       ua_chan->handle = ua_chan->obj->handle;
+       ua_chan->attr.shm_fd = ua_chan->obj->shm_fd;
+       ua_chan->attr.wait_fd = ua_chan->obj->wait_fd;
+       ua_chan->attr.memory_map_size = ua_chan->obj->memory_map_size;
+
+       DBG2("UST app channel %s created successfully for pid:%d and sock:%d",
+                       ua_chan->name, app->key.pid, app->key.sock);
+
+error:
+       return ret;
+}
+
+/*
+ * Create the specified event onto the UST tracer for a UST session.
+ */
+static int create_ust_event(struct ust_app *app,
+               struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
+               struct ust_app_event *ua_event)
+{
+       int ret = 0;
+
+       /* Create UST event on tracer */
+       ret = ustctl_create_event(app->key.sock, &ua_event->attr, ua_chan->obj,
+                       &ua_event->obj);
+       if (ret < 0) {
+               ERR("Error ustctl create event %s for app pid: %d with ret %d",
+                               ua_event->attr.name, app->key.pid, ret);
+               goto error;
+       }
+
+       ua_event->handle = ua_event->obj->handle;
+       ua_event->enabled = 1;
+
+       DBG2("UST app event %s created successfully for pid:%d",
+                       ua_event->attr.name, app->key.pid);
+
+error:
+       return ret;
+}
+
 static struct ust_app_channel *create_ust_app_channel(
                struct ust_app_session *ua_sess, struct ltt_ust_channel *uchan,
                struct ust_app *app)
@@ -737,35 +803,22 @@ static struct ust_app_channel *create_ust_app_channel(
        if (ua_chan_node == NULL) {
                DBG2("Unable to find channel %s in ust session uid %u",
                                uchan->name, ua_sess->uid);
-               ua_chan = alloc_ust_app_channel(uchan->name);
+               ua_chan = alloc_ust_app_channel(uchan->name, &uchan->attr);
                if (ua_chan == NULL) {
                        goto error;
                }
                shadow_copy_channel(ua_chan, uchan);
+
                hashtable_add_unique(ua_sess->channels, &ua_chan->node);
        } else {
                ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
        }
 
-       /* TODO: remove cast and use lttng-ust-abi.h */
-       ret = ustctl_create_channel(app->key.sock, ua_sess->handle,
-                       (struct lttng_ust_channel_attr *)&uchan->attr, &ua_chan->obj);
+       ret = create_ust_channel(app, ua_sess, ua_chan);
        if (ret < 0) {
-               DBG("Error creating channel %s for app (pid: %d, sock: %d) "
-                               "and session handle %d with ret %d",
-                               ua_chan->name, app->key.pid, app->key.sock,
-                               ua_sess->handle, ret);
                goto error;
        }
 
-       ua_chan->handle = ua_chan->obj->handle;
-       ua_chan->attr.shm_fd = ua_chan->obj->shm_fd;
-       ua_chan->attr.wait_fd = ua_chan->obj->wait_fd;
-       ua_chan->attr.memory_map_size = ua_chan->obj->memory_map_size;
-
-       DBG2("Channel %s UST create successfully for pid:%d and sock:%d",
-                       ua_chan->name, app->key.pid, app->key.sock);
-
        return ua_chan;
 
 error:
@@ -787,7 +840,7 @@ static struct ust_app_event *create_ust_app_event(
        if (ua_event_node == NULL) {
                DBG2("UST app event %s not found, creating it", uevent->attr.name);
                /* Does not exist so create one */
-               ua_event = alloc_ust_app_event(uevent->attr.name);
+               ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
                if (ua_event == NULL) {
                        /* Only malloc can failed so something is really wrong */
                        goto error;
@@ -799,21 +852,10 @@ static struct ust_app_event *create_ust_app_event(
                ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
        }
 
-       /* Create UST event on tracer */
-       ret = ustctl_create_event(app->key.sock, &uevent->attr, ua_chan->obj,
-                       &ua_event->obj);
+       ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
        if (ret < 0) {
-               ERR("Error ustctl create event %s for app pid: %d with ret %d",
-                               uevent->attr.name, app->key.pid, ret);
-               /* TODO: free() ua_event */
                goto error;
        }
-       ua_event->handle = ua_event->obj->handle;
-       ua_event->enabled = 1;
-
-
-       DBG2("Event %s UST create successfully for pid:%d", uevent->attr.name,
-                       app->key.pid);
 
        return ua_event;
 
@@ -958,7 +1000,7 @@ int ust_app_add_event_all(struct ltt_ust_session *usess,
        struct ust_app_channel *ua_chan;
        struct ust_app_event *ua_event;
 
-       DBG2("UST app adding event %s to global domain for session uid %d",
+       DBG("UST app creating event %s for all apps for session uid %d",
                        uevent->attr.name, usess->uid);
 
        rcu_read_lock();
@@ -1117,15 +1159,10 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 {
        int ret = 0;
        struct cds_lfht_iter iter;
-       struct cds_lfht_node *node;
        struct ust_app *app;
        struct ust_app_session *ua_sess;
        struct ust_app_channel *ua_chan;
        struct ust_app_event *ua_event;
-       struct ltt_ust_channel *uchan;
-       struct ltt_ust_event *uevent;
-
-       rcu_read_lock();
 
        if (usess == NULL) {
                DBG2("No UST session on global update. Returning");
@@ -1135,6 +1172,8 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
        DBG2("UST app global update for app sock %d for session uid %d", sock,
                        usess->uid);
 
+       rcu_read_lock();
+
        app = find_app_by_sock(sock);
        if (app == NULL) {
                ERR("Failed to update app sock %d", sock);
@@ -1146,31 +1185,26 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
                goto error;
        }
 
-       hashtable_get_first(usess->domain_global.channels, &iter);
-       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
-               uchan = caa_container_of(node, struct ltt_ust_channel, node);
-
-               ua_chan = create_ust_app_channel(ua_sess, uchan, app);
-               if (ua_chan == NULL) {
-                       goto next_chan;
+       /*
+        * We can iterate safely here over all UST app session sicne the create ust
+        * app session above made a shadow copy of the UST global domain from the
+        * ltt ust session.
+        */
+       cds_lfht_for_each_entry(ua_sess->channels, &iter, ua_chan, node) {
+               ret = create_ust_channel(app, ua_sess, ua_chan);
+               if (ret < 0) {
+                       /* FIXME: Should we quit here or continue... */
+                       continue;
                }
 
-               hashtable_get_first(uchan->events, &iter);
-               while ((node = hashtable_iter_get_node(&iter)) != NULL) {
-                       uevent = caa_container_of(node, struct ltt_ust_event, node);
-
-                       ua_event = create_ust_app_event(ua_sess, ua_chan, uevent, app);
-                       if (ua_event == NULL) {
-                               goto next_event;
+               /* For each events */
+               cds_lfht_for_each_entry(ua_chan->events, &iter, ua_event, node) {
+                       ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
+                       if (ret < 0) {
+                               /* FIXME: Should we quit here or continue... */
+                               continue;
                        }
-
-next_event:
-                       hashtable_get_next(uchan->events, &iter);
                }
-
-next_chan:
-               /* Next item in hash table */
-               hashtable_get_next(usess->domain_global.channels, &iter);
        }
 
        if (usess->start_trace) {

diff --git a/lttng-sessiond/ust-app.h b/lttng-sessiond/ust-app.h
index a69ed845162ac71adb7ca88f1aee70e9a9b1f35b..3fa4d423ccbf69c2dabd499f2cb843275074f2c7 100644 (file)
--- a/lttng-sessiond/ust-app.h
+++ b/lttng-sessiond/ust-app.h
@@ -56,6 +56,7 @@ struct ust_app_event {
        int enabled;
        int handle;
        struct lttng_ust_object_data *obj;
+       struct lttng_ust_event attr;
        char name[LTTNG_UST_SYM_NAME_LEN];
        struct cds_lfht *ctx;
        struct cds_lfht_node node;