Reclaim outbound slots on peer disconnect:
- TcpClient_ThreadProc fired on_disconnect but never cleared the outbound
slot, closed the fd, joined the io thread, or freed the connection, so a
dead peer permanently held its outboundClients[] slot. After MAX_CONS (32)
churned connections the node could make no new outbound connections, and
leaked fds/threads/memory. (The inbound side already self-reclaimed.)
- Add a reaper (Node_ReapDeadOutbound) on the maintenance thread: under
outboundLock it detaches dead (disconnect-notified) slots, then joins the
io thread and destroys/frees each connection outside the lock.
- Guard against use-after-free with a pin count on tcp_connection_t
(TcpConnection_Pin/Unpin). The only cross-thread consumer holding a raw
connection pointer across a blocking op is the `sync` command (via
Node_GetBestOutboundPeer); it now pins the peer and unpins when done, and
the reaper skips pinned connections. Discovery's snapshots run on the
reaper's own thread, so they need no pin.
- Node_GetBestOutboundPeer/GetClientList/GetPeerEndpoints skip
disconnect-notified connections so a dead peer is never handed out.
- Node_Destroy stops+joins the maintenance thread before tearing down
outbound clients, so the reaper can't race shutdown.
Strike disconnected peers from the discovery peer list:
- Add NodeDiscovery_RemovePeer + Node_HandlePeerDisconnect: on disconnect,
remove the peer from the known-peer table once no live connection (inbound
or outbound) to its listen endpoint remains (Node_HasLiveConnectionTo;
disconnect-notified conns don't count, so both directions dropping at once
is handled). Wired into Node_Server_OnDisconnect and Node_Client_OnDisconnect.
dcrubro
88a9caa46c