Move LTTng-UST buffer ownership from application to consumer

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

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 84b3f20ed5420b03210e8c80c4f638f4f5072d3b..fc0eb5cb6bbed1ef3b4727eb74a6135b0347fb4c 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -664,14 +664,13 @@ error:
 }
 
 /*
- * For each tracing session, update newly registered apps.
+ * For each tracing session, update newly registered apps. The session list
+ * lock MUST be acquired before calling this.
  */
 static void update_ust_app(int app_sock)
 {
        struct ltt_session *sess, *stmp;
 
-       session_lock_list();
-
        /* For all tracing session(s) */
        cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
                session_lock(sess);
@@ -680,8 +679,6 @@ static void update_ust_app(int app_sock)
                }
                session_unlock(sess);
        }
-
-       session_unlock_list();
 }
 
 /*
@@ -1179,12 +1176,22 @@ static void *thread_manage_apps(void *data)
 
                                        health_code_update();
 
+                                       /*
+                                        * @session_lock
+                                        * Lock the global session list so from the register up to
+                                        * the registration done message, no thread can see the
+                                        * application and change its state.
+                                        */
+                                       session_lock_list();
+
                                        /* Register applicaton to the session daemon */
                                        ret = ust_app_register(&ust_cmd.reg_msg,
                                                        ust_cmd.sock);
                                        if (ret == -ENOMEM) {
+                                               session_unlock_list();
                                                goto error;
                                        } else if (ret < 0) {
+                                               session_unlock_list();
                                                break;
                                        }
 
@@ -1220,6 +1227,7 @@ static void *thread_manage_apps(void *data)
                                                ret = lttng_poll_add(&events, ust_cmd.sock,
                                                                LPOLLERR & LPOLLHUP & LPOLLRDHUP);
                                                if (ret < 0) {
+                                                       session_unlock_list();
                                                        goto error;
                                                }
 
@@ -1232,6 +1240,7 @@ static void *thread_manage_apps(void *data)
                                                DBG("Apps with sock %d added to poll set",
                                                                ust_cmd.sock);
                                        }
+                                       session_unlock_list();
 
                                        health_code_update();
 
@@ -2476,6 +2485,21 @@ skip_domain:
                }
        }
 
+       /*
+        * Send relayd information to consumer as soon as we have a domain and a
+        * session defined.
+        */
+       if (cmd_ctx->session && need_domain) {
+               /*
+                * Setup relayd if not done yet. If the relayd information was already
+                * sent to the consumer, this call will gracefully return.
+                */
+               ret = cmd_setup_relayd(cmd_ctx->session);
+               if (ret != LTTNG_OK) {
+                       goto error;
+               }
+       }
+
        /* Process by command type */
        switch (cmd_ctx->lsm->cmd_type) {
        case LTTNG_ADD_CONTEXT: