1# unlocked-io.m4 serial 15
2
3# Copyright (C) 1998-2006, 2009-2020 Free Software Foundation, Inc.
4#
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9dnl From Jim Meyering.
10dnl
11dnl See if the glibc *_unlocked I/O macros or functions are available.
12dnl Use only those *_unlocked macros or functions that are declared
13dnl (because some of them were declared in Solaris 2.5.1 but were removed
14dnl in Solaris 2.6, whereas we want binaries built on Solaris 2.5.1 to run
15dnl on Solaris 2.6).
16
17AC_DEFUN([gl_FUNC_GLIBC_UNLOCKED_IO],
18[
19  AC_DEFINE([USE_UNLOCKED_IO], [1],
20    [Define to 1 if you want getc etc. to use unlocked I/O if available.
21     Unlocked I/O can improve performance in unithreaded apps,
22     but it is not safe for multithreaded apps.])
23
24  dnl Persuade glibc and Solaris <stdio.h> to declare
25  dnl fgets_unlocked(), fputs_unlocked() etc.
26  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
27
28  AC_CHECK_DECLS_ONCE([clearerr_unlocked])
29  AC_CHECK_DECLS_ONCE([feof_unlocked])
30  AC_CHECK_DECLS_ONCE([ferror_unlocked])
31  AC_CHECK_DECLS_ONCE([fflush_unlocked])
32  AC_CHECK_DECLS_ONCE([fgets_unlocked])
33  AC_CHECK_DECLS_ONCE([fputc_unlocked])
34  AC_CHECK_DECLS_ONCE([fputs_unlocked])
35  AC_CHECK_DECLS_ONCE([fread_unlocked])
36  AC_CHECK_DECLS_ONCE([fwrite_unlocked])
37  AC_CHECK_DECLS_ONCE([getc_unlocked])
38  AC_CHECK_DECLS_ONCE([getchar_unlocked])
39  AC_CHECK_DECLS_ONCE([putc_unlocked])
40  AC_CHECK_DECLS_ONCE([putchar_unlocked])
41])
42