[glib/wip/hadess/fix-gmemory-monitor-example] docs: Add full code example for GMemoryMonitor

[Bastien Nocera <hadess src gnome org>]

commit cdaf9186c0c78fb6f20edfe0a5b783a849df730b
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Dec 18 12:52:27 2019 +0100

    docs: Add full code example for GMemoryMonitor

 gio/gmemorymonitor.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
---
diff --git a/gio/gmemorymonitor.c b/gio/gmemorymonitor.c
index d0c9cfb0d..4368ee3c5 100644
--- a/gio/gmemorymonitor.c
+++ b/gio/gmemorymonitor.c
@@ -50,6 +50,29 @@
  *
  * See #GMemoryMonitorWarningLevel for details on the various warning levels.
  *
+ * |[<!-- language="C" -->
+ * static void
+ * warning_cb (GMemoryMonitor *m, GMemoryMonitorWarningLevel level)
+ * {
+ *   g_debug ("Warning level: %d", level);
+ *   if (warning_level > G_MEMORY_MONITOR_WARNING_LEVEL_LOW)
+ *     drop_caches ();
+ * }
+ *
+ * static GMemoryMonitor *
+ * monitor_low_memory (void)
+ * {
+ *   GMemoryMonitor *m;
+ *   m = g_memory_monitor_dup_default ();
+ *   g_signal_connect (G_OBJECT (m), "low-memory-warning",
+ *                     G_CALLBACK (warning_cb), NULL);
+ *   return m;
+ * }
+ * ]|
+ *
+ * Don't forget to disconnect the #GMemoryMonitor::low-memory-warning
+ * signal, and unref the #GMemoryMonitor itself when exiting.
+ *
  * Since: 2.64
  */