1 files changed, 87 insertions, 2 deletions

diff --git a/src/net.h b/src/net.h
index 182847067a..bb024f35f0 100644
--- a/src/net.h
+++ b/src/net.h
@@ -983,9 +983,57 @@ private:
     void NotifyNumConnectionsChanged();
     /** Return true if the peer is inactive and should be disconnected. */
     bool InactivityCheck(const CNode& node) const;
-    bool GenerateSelectSet(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set, std::set<SOCKET> &error_set);
-    void SocketEvents(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set, std::set<SOCKET> &error_set);
+
+    /**
+     * Generate a collection of sockets to check for IO readiness.
+     * @param[in] nodes Select from these nodes' sockets.
+     * @param[out] recv_set Sockets to check for read readiness.
+     * @param[out] send_set Sockets to check for write readiness.
+     * @param[out] error_set Sockets to check for errors.
+     * @return true if at least one socket is to be checked (the returned set is not empty)
+     */
+    bool GenerateSelectSet(const std::vector<CNode*>& nodes,
+                           std::set<SOCKET>& recv_set,
+                           std::set<SOCKET>& send_set,
+                           std::set<SOCKET>& error_set);
+
+    /**
+     * Check which sockets are ready for IO.
+     * @param[in] nodes Select from these nodes' sockets.
+     * @param[out] recv_set Sockets which are ready for read.
+     * @param[out] send_set Sockets which are ready for write.
+     * @param[out] error_set Sockets which have errors.
+     * This calls `GenerateSelectSet()` to gather a list of sockets to check.
+     */
+    void SocketEvents(const std::vector<CNode*>& nodes,
+                      std::set<SOCKET>& recv_set,
+                      std::set<SOCKET>& send_set,
+                      std::set<SOCKET>& error_set);
+
+    /**
+     * Check connected and listening sockets for IO readiness and process them accordingly.
+     */
     void SocketHandler();
+
+    /**
+     * Do the read/write for connected sockets that are ready for IO.
+     * @param[in] nodes Nodes to process. The socket of each node is checked against
+     * `recv_set`, `send_set` and `error_set`.
+     * @param[in] recv_set Sockets that are ready for read.
+     * @param[in] send_set Sockets that are ready for send.
+     * @param[in] error_set Sockets that have an exceptional condition (error).
+     */
+    void SocketHandlerConnected(const std::vector<CNode*>& nodes,
+                                const std::set<SOCKET>& recv_set,
+                                const std::set<SOCKET>& send_set,
+                                const std::set<SOCKET>& error_set);
+
+    /**
+     * Accept incoming connections, one from each read-ready listening socket.
+     * @param[in] recv_set Sockets that are ready for read.
+     */
+    void SocketHandlerListening(const std::set<SOCKET>& recv_set);
+
     void ThreadSocketHandler();
     void ThreadDNSAddressSeed();
 
@@ -1177,6 +1225,43 @@ private:
      */
     std::vector<CService> m_onion_binds;
 
+    /**
+     * RAII helper to atomically create a copy of `vNodes` and add a reference
+     * to each of the nodes. The nodes are released when this object is destroyed.
+     */
+    class NodesSnapshot
+    {
+    public:
+        explicit NodesSnapshot(const CConnman& connman, bool shuffle)
+        {
+            {
+                LOCK(connman.cs_vNodes);
+                m_nodes_copy = connman.vNodes;
+                for (auto& node : m_nodes_copy) {
+                    node->AddRef();
+                }
+            }
+            if (shuffle) {
+                Shuffle(m_nodes_copy.begin(), m_nodes_copy.end(), FastRandomContext{});
+            }
+        }
+
+        ~NodesSnapshot()
+        {
+            for (auto& node : m_nodes_copy) {
+                node->Release();
+            }
+        }
+
+        const std::vector<CNode*>& Nodes() const
+        {
+            return m_nodes_copy;
+        }
+
+    private:
+        std::vector<CNode*> m_nodes_copy;
+    };
+
     friend struct CConnmanTest;
     friend struct ConnmanTestMsg;
 };