projects / deliverable / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| 7a6dbc2f SDJ |
1 | # getdtablesize.m4 serial 7 |
| 2 | dnl Copyright (C) 2008-2018 Free Software Foundation, Inc. | |
| 6ec2e0f5 SDJ |
3 | dnl This file is free software; the Free Software Foundation |
| 4 | dnl gives unlimited permission to copy and/or distribute it, | |
| 5 | dnl with or without modifications, as long as this notice is preserved. | |
| 6 | ||
| 7 | AC_DEFUN([gl_FUNC_GETDTABLESIZE], | |
| 8 | [ | |
| 9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) | |
| 10 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
| 11 | AC_CHECK_FUNCS_ONCE([getdtablesize]) | |
| 12 | AC_CHECK_DECLS_ONCE([getdtablesize]) | |
| 13 | if test $ac_cv_func_getdtablesize = yes && | |
| 14 | test $ac_cv_have_decl_getdtablesize = yes; then | |
| 6ec2e0f5 SDJ |
15 | AC_CACHE_CHECK([whether getdtablesize works], |
| 16 | [gl_cv_func_getdtablesize_works], | |
| 7a6dbc2f SDJ |
17 | [dnl There are two concepts: the "maximum possible file descriptor value + 1" |
| 18 | dnl and the "maximum number of open file descriptors in a process". | |
| 19 | dnl Per SUSv2 and POSIX, getdtablesize() should return the first one. | |
| 20 | dnl On most platforms, the first and the second concept are the same. | |
| 21 | dnl On OpenVMS, however, they are different and getdtablesize() returns | |
| 22 | dnl the second one; thus the test below fails. But we don't care | |
| 23 | dnl because there's no good way to write a replacement getdtablesize(). | |
| 24 | case "$host_os" in | |
| 25 | vms*) gl_cv_func_getdtablesize_works="no (limitation)" ;; | |
| 26 | *) | |
| 27 | dnl Cygwin 1.7.25 automatically increases the RLIMIT_NOFILE soft | |
| 28 | dnl limit up to an unchangeable hard limit; all other platforms | |
| 29 | dnl correctly require setrlimit before getdtablesize() can report | |
| 30 | dnl a larger value. | |
| 31 | AC_RUN_IFELSE([ | |
| 32 | AC_LANG_PROGRAM([[#include <unistd.h>]], | |
| 33 | [int size = getdtablesize(); | |
| 34 | if (dup2 (0, getdtablesize()) != -1) | |
| 35 | return 1; | |
| 36 | if (size != getdtablesize()) | |
| 37 | return 2; | |
| 38 | ])], | |
| 39 | [gl_cv_func_getdtablesize_works=yes], | |
| 40 | [gl_cv_func_getdtablesize_works=no], | |
| 41 | [case "$host_os" in | |
| 42 | cygwin*) # on cygwin 1.5.25, getdtablesize() automatically grows | |
| 43 | gl_cv_func_getdtablesize_works="guessing no" ;; | |
| 44 | *) gl_cv_func_getdtablesize_works="guessing yes" ;; | |
| 45 | esac | |
| 46 | ]) | |
| 47 | ;; | |
| 48 | esac | |
| 6ec2e0f5 SDJ |
49 | ]) |
| 50 | case "$gl_cv_func_getdtablesize_works" in | |
| 7a6dbc2f | 51 | *yes | "no (limitation)") ;; |
| 6ec2e0f5 SDJ |
52 | *) REPLACE_GETDTABLESIZE=1 ;; |
| 53 | esac | |
| 54 | else | |
| 55 | HAVE_GETDTABLESIZE=0 | |
| 56 | fi | |
| 57 | ]) | |
| 58 | ||
| 59 | # Prerequisites of lib/getdtablesize.c. | |
| 60 | AC_DEFUN([gl_PREREQ_GETDTABLESIZE], [:]) |