erts: Allow one dangling fd if there is a gethost port

1 files changed, 24 insertions, 2 deletions

diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl
index b72d6cbe52..e17d0ff96c 100644
--- a/erts/emulator/test/driver_SUITE.erl
+++ b/erts/emulator/test/driver_SUITE.erl
@@ -2395,13 +2395,35 @@ z_test(Config) when is_list(Config) ->
 
 check_io_debug() ->
     get_stable_check_io_info(),
-    {NoErrorFds, NoUsedFds, NoDrvSelStructs, NoDrvEvStructs}
+    {NoErrorFds, NoUsedFds, NoDrvSelStructs, NoDrvEvStructs} = CheckIoDebug
 	= erts_debug:get_internal_state(check_io_debug),
+    HasGetHost = has_gethost(),
+    ct:log("check_io_debug: ~p~n"
+           "HasGetHost: ~p",[CheckIoDebug, HasGetHost]),
     0 = NoErrorFds,
-    NoUsedFds = NoDrvSelStructs,
+    if
+        NoUsedFds == NoDrvSelStructs ->
+            ok;
+        HasGetHost andalso (NoUsedFds == (NoDrvSelStructs - 1)) ->
+            %% If the inet_gethost port is alive, we may have
+            %% one extra used fd that is not selected on
+            ok
+    end,
     0 = NoDrvEvStructs,
     ok.
 
+has_gethost() ->
+    has_gethost(erlang:ports()).
+has_gethost([P|T]) ->
+    case erlang:port_info(P, name) of
+        {name,"inet_gethost"++_} ->
+            true;
+        _ ->
+            has_gethost(T)
+    end;
+has_gethost([]) ->
+    false.
+
 %flush_msgs() ->
 %    receive
 %	M ->