add g-main-loop app

gnome/glib/CMakeLists.txt

@@ -7,3 +7,6 @@ add_test(
     NAME hello-glib
     COMMAND hello-glib
 )
+
+add_executable(g-mainloop-app g-mainloop-app.c)
+target_link_libraries(g-mainloop-app PRIVATE PkgConfig::GLIB)

gnome/glib/g-mainloop-app.c

@@ -0,0 +1,41 @@
+/**
+ * Copyright © 2026 Chee Bin HOH. All rights reserved.
+ *
+ * @file g-mainloop-app.c
+ * @brief glib mainloop app with timer.
+ */
+
+#include <glib.h>
+
+static gboolean on_timeout(gpointer user_data) {
+  GMainLoop *mainloop = (GMainLoop *)user_data;
+
+  static int count = 5;
+
+  if (count < 1) {
+    g_print("quitting...\n");
+    g_main_loop_quit(mainloop);
+
+    return G_SOURCE_REMOVE;
+  } else {
+    g_print("timer is fired, count down %d to zero...\n", count);
+  }
+
+  count--;
+
+  return G_SOURCE_CONTINUE;
+}
+
+int main(int argc, char *argv[]) {
+  GMainLoop *mainloop = NULL;
+
+  mainloop = g_main_loop_new(NULL, FALSE);
+
+  g_timeout_add(1000, on_timeout, mainloop);
+
+  g_main_loop_run(mainloop);
+
+  g_main_loop_unref(mainloop);
+
+  return 0;
+}