+ /*
+ * Add session to list for teardown. This is safe since at this point we
+ * are the only one using this list.
+ */
+ pthread_mutex_lock(&ua_sess->lock);
+
+ /*
+ * Normally, this is done in the delete session process which is
+ * executed in the call rcu below. However, upon registration we can't
+ * afford to wait for the grace period before pushing data or else the
+ * data pending feature can race between the unregistration and stop
+ * command where the data pending command is sent *before* the grace
+ * period ended.
+ *
+ * The close metadata below nullifies the metadata pointer in the
+ * session so the delete session will NOT push/close a second time.
+ */
+ registry = get_session_registry(ua_sess);
+ if (registry && !registry->metadata_closed) {
+ /* Push metadata for application before freeing the application. */
+ (void) push_metadata(registry, ua_sess->consumer);
+
+ /*
+ * Don't ask to close metadata for global per UID buffers. Close
+ * metadata only on destroy trace session in this case. Also, the
+ * previous push metadata could have flag the metadata registry to
+ * close so don't send a close command if closed.
+ */
+ if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID &&
+ !registry->metadata_closed) {
+ /* And ask to close it for this session registry. */
+ (void) close_metadata(registry, ua_sess->consumer);
+ }
+ }
+
+ cds_list_add(&ua_sess->teardown_node, <a->teardown_head);
+ pthread_mutex_unlock(&ua_sess->lock);
+ }
+
+ /* Free memory */
+ call_rcu(<a->pid_n.head, delete_ust_app_rcu);
+
+ rcu_read_unlock();
+ return;
+}
+
+/*
+ * Return traceable_app_count
+ */
+unsigned long ust_app_list_count(void)
+{
+ unsigned long count;
+
+ rcu_read_lock();
+ count = lttng_ht_get_count(ust_app_ht);
+ rcu_read_unlock();
+
+ return count;
+}
+
+/*
+ * Fill events array with all events name of all registered apps.
+ */
+int ust_app_list_events(struct lttng_event **events)
+{
+ int ret, handle;
+ size_t nbmem, count = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct lttng_event *tmp_event;
+
+ nbmem = UST_APP_EVENT_LIST_SIZE;
+ tmp_event = zmalloc(nbmem * sizeof(struct lttng_event));
+ if (tmp_event == NULL) {
+ PERROR("zmalloc ust app events");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct lttng_ust_tracepoint_iter uiter;
+
+ health_code_update();
+
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ handle = ustctl_tracepoint_list(app->sock);
+ if (handle < 0) {
+ if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app list events getting handle failed for app pid %d",
+ app->pid);
+ }
+ continue;
+ }
+
+ while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
+ &uiter)) != -LTTNG_UST_ERR_NOENT) {
+ /* Handle ustctl error. */
+ if (ret < 0) {
+ free(tmp_event);
+ if (ret != -LTTNG_UST_ERR_EXITING || ret != -EPIPE) {
+ ERR("UST app tp list get failed for app %d with ret %d",
+ app->sock, ret);
+ } else {
+ DBG3("UST app tp list get failed. Application is dead");
+ /*
+ * This is normal behavior, an application can die during the
+ * creation process. Don't report an error so the execution can
+ * continue normally. Continue normal execution.
+ */
+ break;
+ }
+ goto rcu_error;
+ }
+
+ health_code_update();
+ if (count >= nbmem) {
+ /* In case the realloc fails, we free the memory */
+ void *ptr;
+
+ DBG2("Reallocating event list from %zu to %zu entries", nbmem,
+ 2 * nbmem);
+ nbmem *= 2;
+ ptr = realloc(tmp_event, nbmem * sizeof(struct lttng_event));
+ if (ptr == NULL) {
+ PERROR("realloc ust app events");
+ free(tmp_event);
+ ret = -ENOMEM;
+ goto rcu_error;
+ }
+ tmp_event = ptr;
+ }
+ memcpy(tmp_event[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
+ tmp_event[count].loglevel = uiter.loglevel;
+ tmp_event[count].type = (enum lttng_event_type) LTTNG_UST_TRACEPOINT;
+ tmp_event[count].pid = app->pid;
+ tmp_event[count].enabled = -1;
+ count++;
+ }
+ }
+
+ ret = count;
+ *events = tmp_event;
+
+ DBG2("UST app list events done (%zu events)", count);
+
+rcu_error:
+ rcu_read_unlock();
+error:
+ health_code_update();
+ return ret;
+}
+
+/*
+ * Fill events array with all events name of all registered apps.
+ */
+int ust_app_list_event_fields(struct lttng_event_field **fields)
+{
+ int ret, handle;
+ size_t nbmem, count = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct lttng_event_field *tmp_event;
+
+ nbmem = UST_APP_EVENT_LIST_SIZE;
+ tmp_event = zmalloc(nbmem * sizeof(struct lttng_event_field));
+ if (tmp_event == NULL) {
+ PERROR("zmalloc ust app event fields");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct lttng_ust_field_iter uiter;
+
+ health_code_update();
+
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ handle = ustctl_tracepoint_field_list(app->sock);
+ if (handle < 0) {
+ if (handle != -EPIPE && handle != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app list field getting handle failed for app pid %d",
+ app->pid);
+ }
+ continue;
+ }
+
+ while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
+ &uiter)) != -LTTNG_UST_ERR_NOENT) {
+ /* Handle ustctl error. */
+ if (ret < 0) {
+ free(tmp_event);
+ if (ret != -LTTNG_UST_ERR_EXITING || ret != -EPIPE) {
+ ERR("UST app tp list field failed for app %d with ret %d",
+ app->sock, ret);
+ } else {
+ DBG3("UST app tp list field failed. Application is dead");
+ /*
+ * This is normal behavior, an application can die during the
+ * creation process. Don't report an error so the execution can
+ * continue normally.
+ */
+ break;
+ }
+ goto rcu_error;
+ }
+
+ health_code_update();
+ if (count >= nbmem) {
+ /* In case the realloc fails, we free the memory */
+ void *ptr;
+
+ DBG2("Reallocating event field list from %zu to %zu entries", nbmem,
+ 2 * nbmem);
+ nbmem *= 2;
+ ptr = realloc(tmp_event, nbmem * sizeof(struct lttng_event_field));
+ if (ptr == NULL) {
+ PERROR("realloc ust app event fields");
+ free(tmp_event);
+ ret = -ENOMEM;
+ goto rcu_error;
+ }
+ tmp_event = ptr;
+ }
+
+ memcpy(tmp_event[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
+ tmp_event[count].type = uiter.type;
+ tmp_event[count].nowrite = uiter.nowrite;
+
+ memcpy(tmp_event[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
+ tmp_event[count].event.loglevel = uiter.loglevel;
+ tmp_event[count].event.type = LTTNG_UST_TRACEPOINT;
+ tmp_event[count].event.pid = app->pid;
+ tmp_event[count].event.enabled = -1;
+ count++;
+ }
+ }
+
+ ret = count;
+ *fields = tmp_event;
+
+ DBG2("UST app list event fields done (%zu events)", count);
+
+rcu_error:
+ rcu_read_unlock();
+error:
+ health_code_update();
+ return ret;
+}
+
+/*
+ * Free and clean all traceable apps of the global list.
+ *
+ * Should _NOT_ be called with RCU read-side lock held.
+ */
+void ust_app_clean_list(void)
+{
+ int ret;
+ struct ust_app *app;
+ struct lttng_ht_iter iter;
+
+ DBG2("UST app cleaning registered apps hash table");
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ret = lttng_ht_del(ust_app_ht, &iter);
+ assert(!ret);
+ call_rcu(&app->pid_n.head, delete_ust_app_rcu);
+ }
+
+ /* Cleanup socket hash table */
+ cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
+ sock_n.node) {
+ ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
+ assert(!ret);
+ }
+
+ /* Cleanup notify socket hash table */
+ cds_lfht_for_each_entry(ust_app_ht_by_notify_sock->ht, &iter.iter, app,
+ notify_sock_n.node) {
+ ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter);
+ assert(!ret);
+ }
+ rcu_read_unlock();
+
+ /* Destroy is done only when the ht is empty */
+ ht_cleanup_push(ust_app_ht);
+ ht_cleanup_push(ust_app_ht_by_sock);
+ ht_cleanup_push(ust_app_ht_by_notify_sock);
+}
+
+/*
+ * Init UST app hash table.
+ */
+void ust_app_ht_alloc(void)
+{
+ ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ ust_app_ht_by_notify_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+}
+
+/*
+ * For a specific UST session, disable the channel for all registered apps.
+ */
+int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
+ struct ltt_ust_channel *uchan)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_str *ua_chan_node;
+ struct ust_app *app;
+ struct ust_app_session *ua_sess;
+ struct ust_app_channel *ua_chan;
+
+ if (usess == NULL || uchan == NULL) {
+ ERR("Disabling UST global channel with NULL values");
+ ret = -1;
+ goto error;
+ }
+
+ DBG2("UST app disabling channel %s from global domain for session id %" PRIu64,
+ uchan->name, usess->id);
+
+ rcu_read_lock();
+
+ /* For every registered applications */
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct lttng_ht_iter uiter;
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+
+ /* Get channel */
+ lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
+ ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
+ /* If the session if found for the app, the channel must be there */
+ assert(ua_chan_node);
+
+ ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
+ /* The channel must not be already disabled */
+ assert(ua_chan->enabled == 1);
+
+ /* Disable channel onto application */
+ ret = disable_ust_app_channel(ua_sess, ua_chan, app);
+ if (ret < 0) {
+ /* XXX: We might want to report this error at some point... */
+ continue;
+ }
+ }
+
+ rcu_read_unlock();
+
+error:
+ return ret;
+}
+
+/*
+ * For a specific UST session, enable the channel for all registered apps.
+ */
+int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
+ struct ltt_ust_channel *uchan)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct ust_app_session *ua_sess;
+
+ if (usess == NULL || uchan == NULL) {
+ ERR("Adding UST global channel to NULL values");
+ ret = -1;
+ goto error;
+ }
+
+ DBG2("UST app enabling channel %s to global domain for session id %" PRIu64,
+ uchan->name, usess->id);
+
+ rcu_read_lock();
+
+ /* For every registered applications */
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+
+ /* Enable channel onto application */
+ ret = enable_ust_app_channel(ua_sess, uchan, app);
+ if (ret < 0) {
+ /* XXX: We might want to report this error at some point... */
+ continue;
+ }