+@deftypefn Extension void unlock_stream (FILE * @var{stream})
+
+If the OS supports it, ensure that the supplied stream is setup to
+avoid any multi-threaded locking. Otherwise leave the @code{FILE}
+pointer unchanged. If the @var{stream} is @code{NULL} do nothing.
+
+@end deftypefn
+
+@deftypefn Extension void unlock_std_streams (void)
+
+If the OS supports it, ensure that the standard I/O streams,
+@code{stdin}, @code{stdout} and @code{stderr} are setup to avoid any
+multi-threaded locking. Otherwise do nothing.
+
+@end deftypefn
+
+@deftypefn Extension {FILE *} fopen_unlocked (const char *@var{path}, @
+ const char * @var{mode})