Using transfer priorities in protocol:: classes

libuavcan/include/uavcan/node/node.hpp

@@ -145,8 +145,10 @@ public:
      * Once started, the node can't stop.
      * If the node failed to start up, it's recommended to destroy the current node instance and start over.
      * Returns negative error code.
+     * @param node_status_transfer_priority Transfer priority that will be used for outgoing NodeStatus messages.
+     *                                      Normal priority is used by default.
      */
-    int start();
+    int start(const TransferPriority node_status_transfer_priority = TransferPriorityNormal);
 
 #if !UAVCAN_TINY
     /**
@@ -260,7 +262,8 @@ public:
 
 template <std::size_t MemPoolSize_, unsigned OutgoingTransferRegistryStaticEntries,
           unsigned OutgoingTransferMaxPayloadLen>
-int Node<MemPoolSize_, OutgoingTransferRegistryStaticEntries, OutgoingTransferMaxPayloadLen>::start()
+int Node<MemPoolSize_, OutgoingTransferRegistryStaticEntries, OutgoingTransferMaxPayloadLen>::start(
+    const TransferPriority priority)
 {
     if (started_)
     {
@@ -274,7 +277,7 @@ int Node<MemPoolSize_, OutgoingTransferRegistryStaticEntries, OutgoingTransferMa
     {
         goto fail;
     }
-    res = proto_nsp_.startAndPublish();
+    res = proto_nsp_.startAndPublish(priority);
     if (res < 0)
     {
         goto fail;
@@ -322,7 +325,7 @@ checkNetworkCompatibility(NetworkCompatibilityCheckResult& result)
     }
 
     NetworkCompatibilityChecker checker(*this);
-    StaticAssert<(sizeof(checker) < 2048)>::check();
+    StaticAssert<(sizeof(checker) < 2048)>::check();  // Making sure that the code footprint doesn't explode
     res = checker.execute();
     result = checker.getResult();
     return res;

libuavcan/include/uavcan/node/publisher.hpp

@@ -100,22 +100,26 @@ public:
     /**
      * Allows to change the priority of outgoing transfers.
      * Note that only High, Normal and Low priorities can be used; Service priority is not available for messages.
-     * Attempt to use Service priority will result in assertion failure in debug builds, and it will have no
-     * effect in release builds.
+     * Returns negative error code if priority cannot be set, non-negative on success.
      */
-    void setPriority(const TransferPriority prio)
+    int setPriority(const TransferPriority prio)
     {
         if (prio < NumTransferPriorities && prio != TransferPriorityService)
         {
-            TransferSender* const ts = getTransferSender();
+            TransferSender* const ts = getTransferSender();  // TODO: Static TransferSender?
             if (ts != NULL)
             {
                 ts->setPriority(prio);
+                return 0;
+            }
+            else
+            {
+                return -ErrLogic;
             }
         }
         else
         {
-            UAVCAN_ASSERT(0);
+            return -ErrInvalidParam;
         }
     }
 

libuavcan/include/uavcan/protocol/dynamic_node_id_allocation_client.hpp

@@ -58,11 +58,14 @@ public:
      * @param hardware_version  Hardware version information, where unique_id must be set correctly.
      * @param preferred_node_id Node ID that the application would like to take; set to broadcast (zero) if
      *                          the application doesn't have any preference (this is default).
+     * @param transfer_priority Transfer priority, Normal by default.
      * @return                  Zero on success
      *                          Negative error code on failure
      *                          -ErrLogic if 1. the node is not in passive mode or 2. the client is already started
      */
-    int start(const protocol::HardwareVersion& hardware_version, const NodeID preferred_node_id = NodeID::Broadcast);
+    int start(const protocol::HardwareVersion& hardware_version,
+              const NodeID preferred_node_id = NodeID::Broadcast,
+              const TransferPriority transfer_priority = TransferPriorityNormal);
 
     /**
      * Use this method to determine when allocation is complete.

libuavcan/include/uavcan/protocol/node_status_provider.hpp

@@ -68,7 +68,7 @@ public:
      * Starts the provider and immediately broadcasts uavcan.protocol.NodeStatus.
      * Returns negative error code.
      */
-    int startAndPublish();
+    int startAndPublish(TransferPriority priority = TransferPriorityNormal);
 
     /**
      * Publish the message uavcan.protocol.NodeStatus right now, out of schedule.