Trying to create a gsocket server with GUI program - sockets

Question

I am trying to set up server that also has a gui using GTK on a Raspberry Pi. The program is just a proof-of-concept demo.
I create a socket and the client can connect and send data, I see it in wireshark. But the read does not complete until the client disconnects. My code uses g_data_input_stream_read_line_async and g_data_input_stream_read_line_finish. The program displays the data the client sent after the client disconnects.
Here is the output of the program (that is the correct data that was sent by the client).
g_socket_listener_add_inet_port status: 1
g_signal_connect status: 2 (waits here until client connects)
socket connection established!
after g_data_input_stream_new
after g_data_input_stream_set_newline_type
after g_data_input_stream_read_line_async (waits here after client connects, and after client sends data)
before g_data_input_stream_read_line_finish (displays remaining output lines after client disconnects)
after g_data_input_stream_read_line_finish
length: 14
0 5 0 4 0 1 0 1 0 6 0 0 0 7
I suspect I am missing something simple since the data is received, but I've spent quite a few hours unsuccessfully trying to figure out what is missing.
// compiles with:
// gcc `pkg-config --cflags gtk+-3.0` gtk3serv.c -o gtk3serv `pkg-config --libs gtk+-3.0`
#include <gtk/gtk.h>
#include <gio/gio.h>
static void
print_hello (GtkWidget *widget,
gpointer data)
{
g_print ("Hello World\n");
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *button;
GtkWidget *button_box;
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), "Window");
gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);
button_box = gtk_button_box_new (GTK_ORIENTATION_HORIZONTAL);
gtk_container_add (GTK_CONTAINER (window), button_box);
button = gtk_button_new_with_label ("Hello World");
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_widget_destroy), window);
gtk_container_add (GTK_CONTAINER (button_box), button);
gtk_widget_show_all (window);
}
// v<>v<>v<>v<>v<>v<>v<>v<>v<>v<>v
static void on_input_read_finish(GObject *object,
GAsyncResult *result,
gpointer user_data)
{
gchar *clientdata;
gsize length = -1;
gsize i;
g_print("before g_data_input_stream_read_line_finish\n"); // only for debug
clientdata = g_data_input_stream_read_line_finish(G_DATA_INPUT_STREAM(object),
result,
&length,
NULL);
g_print("after g_data_input_stream_read_line_finish\n"); // only for debug
g_print("length: %d\n", length); // only for debug
for(i=0; i<length; i++)
{
g_print("%x ", clientdata[i]);
}
g_print("\n");
}
gboolean sockconnectionestablished(GSocketService *sockservice,
GSocketConnection *connection,
GObject *source_object,
gpointer user_Data)
{
char *clientdata;
gsize length = -1;
gsize i;
g_print("socket connection established!\n"); // only for debug
GDataInputStream *gis = g_data_input_stream_new(g_io_stream_get_input_stream(G_IO_STREAM(connection)));
g_print("after g_data_input_stream_new\n"); // only for debug
g_data_input_stream_set_newline_type(G_DATA_INPUT_STREAM(gis), G_DATA_STREAM_NEWLINE_TYPE_ANY);
g_print("after g_data_input_stream_set_newline_type\n"); // only for debug
g_data_input_stream_read_line_async(G_DATA_INPUT_STREAM(gis),
G_PRIORITY_DEFAULT,
NULL,
on_input_read_finish,
NULL);
g_print("after g_data_input_stream_read_line_async\n"); // only for debug
return 1;
}
// ^<>^<>^<>^<>^<>^<>^<>^<>^<>^<>^
int
main (int argc,
char **argv)
{
GtkApplication *app;
int status;
// v<>v<>v<>v<>v<>v<>v<>v<>v<>v<>v
GError *sockerror = NULL;
GSocketService *sockservice;
gboolean sockstatus;
sockservice = g_socket_service_new();
sockstatus = g_socket_listener_add_inet_port(G_SOCKET_LISTENER(sockservice),
8888,
NULL,
NULL);
g_print("g_socket_listener_add_inet_port status: %d\n", sockstatus); // only for debug
status = g_signal_connect(sockservice,
"incoming",
G_CALLBACK(sockconnectionestablished),
NULL);
g_print("g_signal_connect status: %d\n", status); // only for debug
// ^<>^<>^<>^<>^<>^<>^<>^<>^<>^<>^
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}