+
+/*
+ * Enable UST channel for session and domain.
+ */
+int channel_ust_enable(struct ltt_ust_session *usess, int domain,
+ struct ltt_ust_channel *uchan)
+{
+ int ret = LTTCOMM_OK;
+
+ /* If already enabled, everything is OK */
+ if (uchan->enabled) {
+ DBG3("Channel %s already enabled. Skipping", uchan->name);
+ goto end;
+ }
+
+ switch (domain) {
+ case LTTNG_DOMAIN_UST:
+ DBG2("Channel %s being enabled in UST global domain", uchan->name);
+ /* Enable channel for global domain */
+ ret = ust_app_enable_channel_glb(usess, uchan);
+ break;
+ case LTTNG_DOMAIN_UST_PID:
+ case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+ case LTTNG_DOMAIN_UST_EXEC_NAME:
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ if (ret < 0) {
+ if (ret != -EEXIST) {
+ ret = LTTCOMM_UST_CHAN_ENABLE_FAIL;
+ goto error;
+ } else {
+ ret = LTTCOMM_OK;
+ }
+ }
+
+ uchan->enabled = 1;
+ DBG2("Channel %s enabled successfully", uchan->name);
+
+end:
+error:
+ return ret;
+}
+
+/*
+ * Create UST channel for session and domain.
+ */
+int channel_ust_create(struct ltt_ust_session *usess, int domain,
+ struct lttng_channel *attr)
+{
+ int ret = LTTCOMM_OK;
+ struct ltt_ust_channel *uchan = NULL;
+ struct lttng_channel *defattr = NULL;
+
+ /* Creating channel attributes if needed */
+ if (attr == NULL) {
+ defattr = channel_new_default_attr(domain);
+ if (defattr == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+ attr = defattr;
+ }
+
+ /* Create UST channel */
+ uchan = trace_ust_create_channel(attr, usess->pathname);
+ if (uchan == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+ uchan->enabled = 1;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_UST:
+ DBG2("Channel %s being created in UST global domain", uchan->name);
+
+ /* Enable channel for global domain */
+ ret = ust_app_create_channel_glb(usess, uchan);
+ break;
+ case LTTNG_DOMAIN_UST_PID:
+ case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+ case LTTNG_DOMAIN_UST_EXEC_NAME:
+ default:
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error_free_chan;
+ }
+
+ if (ret < 0 && ret != -EEXIST) {
+ ret = LTTCOMM_UST_CHAN_ENABLE_FAIL;
+ goto error_free_chan;
+ }
+
+ /* Adding the channel to the channel hash table. */
+ rcu_read_lock();
+ lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
+ rcu_read_unlock();
+
+ DBG2("Channel %s created successfully", uchan->name);
+
+ free(defattr);
+ return LTTCOMM_OK;
+
+error_free_chan:
+ /*
+ * No need to remove the channel from the hash table because at this point
+ * it was not added hence the direct call and no call_rcu().
+ */
+ trace_ust_destroy_channel(uchan);
+error:
+ free(defattr);
+ return ret;
+}
+
+/*
+ * Disable UST channel for session and domain.
+ */
+int channel_ust_disable(struct ltt_ust_session *usess, int domain,
+ struct ltt_ust_channel *uchan)
+{
+ int ret = LTTCOMM_OK;
+
+ /* Already disabled */
+ if (uchan->enabled == 0) {
+ DBG2("Channel UST %s already disabled", uchan->name);
+ goto end;
+ }
+
+ /* Get the right channel's hashtable */
+ switch (domain) {
+ case LTTNG_DOMAIN_UST:
+ DBG2("Channel %s being disabled in UST global domain", uchan->name);
+ /* Disable channel for global domain */
+ ret = ust_app_disable_channel_glb(usess, uchan);
+ break;
+ case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+ case LTTNG_DOMAIN_UST_EXEC_NAME:
+ case LTTNG_DOMAIN_UST_PID:
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ if (ret < 0 && ret != -EEXIST) {
+ ret = LTTCOMM_UST_DISABLE_FAIL;
+ goto error;
+ }
+
+ uchan->enabled = 0;
+
+ DBG2("Channel %s disabled successfully", uchan->name);
+
+ return LTTCOMM_OK;
+
+end:
+error:
+ return ret;
+}