Build config UAVCAN_MAX_NETWORK_SIZE_HINT (#33)

libuavcan/include/uavcan/build_config.hpp

@@ -228,6 +228,21 @@ static const unsigned FloatComparisonEpsilonMult = UAVCAN_FLOAT_COMPARISON_EPSIL
 static const unsigned FloatComparisonEpsilonMult = 10;
 #endif
 
+/**
+ * This constant defines how many receiver objects will be statically pre-allocated by classes that listen to messages
+ * of type uavcan.protocol.NodeStatus from other nodes. If the number of publishers exceeds this value, extra
+ * listeners will be allocated in the dynamic memory (one block per listener).
+ *
+ * The default value is safe to use in any application (since extra memory can always be retrieved from the pool).
+ * Applications that are extremely memory sensitive and are not expected to operate in large networks can override
+ * the default with a lower value.
+ */
+#ifdef UAVCAN_MAX_NETWORK_SIZE_HINT
+static const unsigned MaxNetworkSizeHint = UAVCAN_MAX_NETWORK_SIZE_HINT;
+#else
+static const unsigned MaxNetworkSizeHint = 64;  ///< Rest will go into the dynamic memory
+#endif
+
 }
 
 #endif // UAVCAN_BUILD_CONFIG_HPP_INCLUDED

libuavcan/include/uavcan/protocol/dynamic_node_id_server/node_discoverer.hpp

@@ -94,8 +94,6 @@ class NodeDiscoverer : TimerBase
 
     enum { TimerPollIntervalMs = 170 }; // ~ ceil(500 ms service timeout / 3)
 
-    enum { NumNodeStatusStaticReceivers = 64 };
-
     /*
      * States
      */
@@ -106,7 +104,7 @@ class NodeDiscoverer : TimerBase
     NodeMap node_map_;                                  ///< Will not work in UAVCAN_TINY
 
     ServiceClient<protocol::GetNodeInfo, GetNodeInfoResponseCallback> get_node_info_client_;
-    Subscriber<protocol::NodeStatus, NodeStatusCallback, NumNodeStatusStaticReceivers, 0> node_status_sub_;
+    Subscriber<protocol::NodeStatus, NodeStatusCallback, MaxNetworkSizeHint, 0> node_status_sub_;
 
     /*
      * Methods

libuavcan/include/uavcan/protocol/node_status_monitor.hpp

@@ -51,12 +51,7 @@ private:
 
     typedef MethodBinder<NodeStatusMonitor*, void (NodeStatusMonitor::*)(const TimerEvent&)> TimerCallback;
 
-    /*
-     * We'll be able to handle this many nodes in the network without any dynamic memory.
-     */
-    enum { NumStaticReceivers = 64 };
-
-    Subscriber<protocol::NodeStatus, NodeStatusCallback, NumStaticReceivers, 0> sub_;
+    Subscriber<protocol::NodeStatus, NodeStatusCallback, MaxNetworkSizeHint, 0> sub_;
 
     TimerEventForwarder<TimerCallback> timer_;