extern gboolean LockFile (gpointer handle, guint32 offset_low,
guint32 offset_high, guint32 length_low,
guint32 length_high);
extern gboolean UnlockFile (gpointer handle, guint32 offset_low,
guint32 offset_high, guint32 length_low,
guint32 length_high);
extern gboolean LockFile (gpointer handle, guint32 offset_low,
guint32 offset_high, guint32 length_low,
guint32 length_high);
extern gboolean UnlockFile (gpointer handle, guint32 offset_low,
guint32 offset_high, guint32 length_low,
guint32 length_high);