Network.erl fix stop returning too early

network:stop through terminate was using nonblocking call to stop network_port- so rapid stop/start would give the second network:start an old whereis(network_port) that was still shutting down, and lead to errors.

Now waits for port DOWN.

Signed-off-by: Peter M <petermm@gmail.com>

Author: petermm

CHANGELOG.md

@@ -38,6 +38,8 @@ certain VM instructions are used.
 shallow comparison was performed, so it was working just for plain values such as atoms and small
 integers
 - Fixed support for setting esp32 boot_path in NVS.
+- Fixed race conditions in network:start/stop.
+- Fixed crash calling network:sta_rssi(), when network not up.
 
 ## [0.6.5] - 2024-10-15
 

libs/eavmlib/src/network.erl

@@ -370,10 +370,25 @@ handle_info(Msg, State) ->
     {noreply, State}.
 
 %% @hidden
-terminate(_Reason, _State) ->
+%% Wait for port to be closed
+terminate(_Reason, State) ->
     Ref = make_ref(),
+    Port = State#state.port,
+    PortMonitor = erlang:monitor(port, Port),
     network_port ! {?SERVER, Ref, stop},
-    ok.
+    wait_for_port_close(PortMonitor, Port).
+
+wait_for_port_close(PortMonitor, Port) ->
+    receive
+        {'DOWN', PortMonitor, port, Port, _DownReason} ->
+            ok;
+        _Other ->
+            % Handle unexpected messages if necessary
+            wait_for_port_close(PortMonitor, Port)
+        % Timeout after 1 second just in case.
+    after 1000 ->
+        {error, timeout}
+    end.
 
 %%
 %% Internal operations