OS.c revision 5ec34c4c 
1/* Some OS-dependent utility code */
2
3#ifdef HAVE_CONFIG_H
4#include <config.h>
5#endif
6#include <X11/Xosdefs.h>
7#include <X11/IntrinsicP.h>
8#include "Private.h"
9
10#ifdef HAVE_UNISTD_H
11#include <unistd.h>	/* for sysconf(), and getpagesize() */
12#endif
13
14#if defined(_WIN32) && !defined(__CYGWIN__)
15/* AC_CHECK_FUNCS([getpagesize]) may report a false positive for
16   getpagesize() when using MinGW gcc, since it's present in libgcc.a */
17#undef HAVE_GETPAGESIZE
18#endif
19
20#if defined(linux)
21/* kernel header doesn't work with -ansi */
22/* #include <asm/page.h> *//* for PAGE_SIZE */
23#define HAS_SC_PAGESIZE	/* _SC_PAGESIZE may be an enum for Linux */
24#endif
25
26int
27_XawGetPageSize(void)
28{
29    static int pagesize = -1;
30
31    if (pagesize != -1)
32	return pagesize;
33
34    /* Try each supported method in the preferred order */
35
36#if defined(_SC_PAGESIZE) || defined(HAS_SC_PAGESIZE)
37    pagesize = (int) sysconf(_SC_PAGESIZE);
38#endif
39
40#ifdef _SC_PAGE_SIZE
41    if (pagesize == -1)
42	pagesize = (int) sysconf(_SC_PAGE_SIZE);
43#endif
44
45#ifdef HAVE_GETPAGESIZE
46    if (pagesize == -1)
47	pagesize = getpagesize();
48#endif
49
50#ifdef PAGE_SIZE
51    if (pagesize == -1)
52	pagesize = PAGE_SIZE;
53#endif
54
55    if (pagesize == -1)
56	pagesize = 0;
57
58    return pagesize;
59}
60