view m4/glob.m4 @ 16869:38e6d30d7e4d

poll/select: prevent busy-waiting 2012-05-21 Paolo Bonzini <bonzini@gnu.org> poll/select: prevent busy-waiting. SwitchToThread() only gives away the rest of the current time slice to another thread in the current process. So if the thread that feeds the file decscriptor we're polling is not in the current process, we get busy-waiting. * lib/poll.c: Use SleepEx(1, TRUE) instead of SwitchToThread(). Patch from Theodore Leblond. * lib/select.c: Split polling out of the loop that sets the output fd_sets. Check for zero result and loop if the wait timeout is infinite.
author Paolo Bonzini <bonzini@gnu.org>
date Mon, 21 May 2012 09:52:42 +0200
parents 8250f2777afc
children e542fd46ad6f
line wrap: on
line source

# glob.m4 serial 14
dnl Copyright (C) 2005-2007, 2009-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

# The glob module assumes you want GNU glob, with glob_pattern_p etc,
# rather than vanilla POSIX glob.  This means your code should
# always include <glob.h> for the glob prototypes.

AC_DEFUN([gl_GLOB],
[ GLOB_H=
  AC_CHECK_HEADERS([glob.h], [], [GLOB_H=glob.h])

  if test -z "$GLOB_H"; then
    AC_CACHE_CHECK([for GNU glob interface version 1],
      [gl_cv_gnu_glob_interface_version_1],
[     AC_COMPILE_IFELSE([AC_LANG_SOURCE(
[[#include <gnu-versions.h>
char a[_GNU_GLOB_INTERFACE_VERSION == 1 ? 1 : -1];]])],
        [gl_cv_gnu_glob_interface_version_1=yes],
        [gl_cv_gnu_glob_interface_version_1=no])])

    if test "$gl_cv_gnu_glob_interface_version_1" = "no"; then
      GLOB_H=glob.h
    fi
  fi

  if test -z "$GLOB_H"; then
    AC_CACHE_CHECK([whether glob lists broken symlinks],
                   [gl_cv_glob_lists_symlinks],
[     if ln -s conf-doesntexist conf$$-globtest 2>/dev/null; then
        gl_cv_glob_lists_symlinks=maybe
      else
        # If we can't make a symlink, then we cannot test this issue.  Be
        # pessimistic about this.
        gl_cv_glob_lists_symlinks=no
      fi

      if test $gl_cv_glob_lists_symlinks = maybe; then
        AC_RUN_IFELSE([
AC_LANG_PROGRAM(
[[#include <stddef.h>
#include <glob.h>]],
[[glob_t found;
if (glob ("conf*-globtest", 0, NULL, &found) == GLOB_NOMATCH) return 1;]])],
          [gl_cv_glob_lists_symlinks=yes],
          [gl_cv_glob_lists_symlinks=no], [gl_cv_glob_lists_symlinks=no])
      fi])

    if test $gl_cv_glob_lists_symlinks = no; then
      GLOB_H=glob.h
    fi
  fi

  rm -f conf$$-globtest

  AC_SUBST([GLOB_H])
  AM_CONDITIONAL([GL_GENERATE_GLOB_H], [test -n "$GLOB_H"])
])

# Prerequisites of lib/glob.*.
AC_DEFUN([gl_PREREQ_GLOB],
[
  AC_REQUIRE([gl_CHECK_TYPE_STRUCT_DIRENT_D_TYPE])dnl
  AC_REQUIRE([AC_C_RESTRICT])dnl
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])dnl
  AC_CHECK_HEADERS_ONCE([sys/cdefs.h unistd.h])dnl
  if test $ac_cv_header_sys_cdefs_h = yes; then
    HAVE_SYS_CDEFS_H=1
  else
    HAVE_SYS_CDEFS_H=0
  fi
  AC_SUBST([HAVE_SYS_CDEFS_H])
  AC_CHECK_FUNCS_ONCE([fstatat getlogin_r getpwnam_r])dnl
])