77 lines
2.5 KiB
Plaintext
77 lines
2.5 KiB
Plaintext
# pselect.m4
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# serial 11
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dnl Copyright (C) 2011-2024 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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AC_DEFUN([gl_FUNC_PSELECT],
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[
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AC_REQUIRE([gl_SYS_SELECT_H])
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AC_REQUIRE([AC_C_RESTRICT])
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AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
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AC_CHECK_FUNCS_ONCE([pselect])
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if test $ac_cv_func_pselect = yes; then
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AC_CACHE_CHECK([whether signature of pselect conforms to POSIX],
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[gl_cv_sig_pselect],
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[AC_LINK_IFELSE(
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[AC_LANG_PROGRAM(
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[[#include <sys/select.h>
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]],
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[[int (*p) (int, fd_set *, fd_set *, fd_set *restrict,
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struct timespec const *restrict,
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sigset_t const *restrict) = pselect;
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return !p;]])],
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[gl_cv_sig_pselect=yes],
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[gl_cv_sig_pselect=no])])
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dnl On FreeBSD 8.2, pselect() doesn't always reject bad fds.
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AC_CACHE_CHECK([whether pselect detects invalid fds],
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[gl_cv_func_pselect_detects_ebadf],
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[
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AC_RUN_IFELSE([AC_LANG_PROGRAM([[
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#include <sys/types.h>
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#include <sys/time.h>
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#if HAVE_SYS_SELECT_H
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# include <sys/select.h>
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#endif
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#include <unistd.h>
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#include <errno.h>
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]GL_MDA_DEFINES],
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[[
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fd_set set;
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dup2(0, 16);
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FD_ZERO(&set);
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FD_SET(16, &set);
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close(16);
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struct timespec timeout;
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timeout.tv_sec = 0;
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timeout.tv_nsec = 5000;
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return pselect (17, &set, NULL, NULL, &timeout, NULL) != -1 || errno != EBADF;
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]])], [gl_cv_func_pselect_detects_ebadf=yes],
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[gl_cv_func_pselect_detects_ebadf=no],
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[
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case "$host_os" in
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# Guess yes on Linux systems.
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linux-* | linux) gl_cv_func_pselect_detects_ebadf="guessing yes" ;;
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# Guess yes on systems that emulate the Linux system calls.
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midipix*) gl_cv_func_pselect_detects_ebadf="guessing yes" ;;
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# Guess yes on glibc systems.
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*-gnu* | gnu*) gl_cv_func_pselect_detects_ebadf="guessing yes" ;;
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# If we don't know, obey --enable-cross-guesses.
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*) gl_cv_func_pselect_detects_ebadf="$gl_cross_guess_normal" ;;
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esac
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])
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])
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case $gl_cv_func_pselect_detects_ebadf in
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*yes) ;;
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*) REPLACE_PSELECT=1 ;;
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esac
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fi
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if test $ac_cv_func_pselect = no || test $gl_cv_sig_pselect = no; then
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REPLACE_PSELECT=1
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fi
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])
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