Implement snapshot commands in lttng-sessiond

[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 0f553a671603845a6bdd40b9819505963d27c45b..dd0f6f8db96c81fcf1e2cf643c951c725857c272 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -4845,3 +4845,66 @@ void ust_app_destroy(struct ust_app *app)
 
        call_rcu(&app->pid_n.head, delete_ust_app_rcu);
 }
+
+/*
+ * Take a snapshot for a given UST session. The snapshot is sent to the given
+ * output.
+ *
+ * Return 0 on success or else a negative value.
+ */
+int ust_app_snapshot_record(struct ltt_ust_session *usess,
+               struct snapshot_output *output, int wait)
+{
+       int ret = 0;
+       struct lttng_ht_iter iter;
+       struct ust_app *app;
+
+       assert(usess);
+       assert(output);
+
+       rcu_read_lock();
+
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+               struct consumer_socket *socket;
+               struct lttng_ht_iter chan_iter;
+               struct ust_app_channel *ua_chan;
+               struct ust_app_session *ua_sess;
+               struct ust_registry_session *registry;
+
+               ua_sess = lookup_session_by_app(usess, app);
+               if (!ua_sess) {
+                       /* Session not associated with this app. */
+                       continue;
+               }
+
+               /* Get the right consumer socket for the application. */
+               socket = consumer_find_socket_by_bitness(app->bits_per_long,
+                               output->consumer);
+               if (!socket) {
+                       ret = -EINVAL;
+                       goto error;
+               }
+
+               cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
+                               ua_chan, node.node) {
+                       ret = consumer_snapshot_channel(socket, ua_chan->key, output, 0,
+                                       ua_sess->euid, ua_sess->egid, wait);
+                       if (ret < 0) {
+                               goto error;
+                       }
+               }
+
+               registry = get_session_registry(ua_sess);
+               assert(registry);
+               ret = consumer_snapshot_channel(socket, registry->metadata_key, output,
+                               1, ua_sess->euid, ua_sess->egid, wait);
+               if (ret < 0) {
+                       goto error;
+               }
+
+       }
+
+error:
+       rcu_read_unlock();
+       return ret;
+}