+2013-09-26 Eric Blake <eblake@redhat.com>
+
+ getdtablesize: work around cygwin issue
+ * m4/getdtablesize.m4 (gl_FUNC_GETDTABLESIZE): Detect problem.
+ * modules/getdtablesize (configure.ac): Build replacement.
+ * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Set up a witness.
+ * modules/unistd (Makefile.am): Expose the witness.
+ * lib/unistd.in.h (getdtablesize): Declare replacement.
+ * lib/getdtablesize.c (rpl_getdtablesize): Work around it.
+ * tests/test-getdtablesize.c (main): Test it.
+ * doc/glibc-functions/getdtablesize.texi (getdtablesize): Document it.
+
2013-09-25 Mats Erik Andersson <gnu@gisladisker.se>
pmccabe2html: escaping of special characters
@item
This function is missing on some platforms:
mingw, MSVC 9.
+
+@item
+This function does not represent the true @code{RLIMIT_NOFILE} soft
+limit on some platforms:
+Cygwin 1.7.25.
@end itemize
Portability problems not fixed by Gnulib:
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-#include <stdio.h>
+# include <stdio.h>
-#include "msvc-inval.h"
+# include "msvc-inval.h"
-#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
static int
_setmaxstdio_nothrow (int newmax)
{
return result;
}
-# define _setmaxstdio _setmaxstdio_nothrow
-#endif
+# define _setmaxstdio _setmaxstdio_nothrow
+# endif
-/* Cache for the previous getdtablesize () result. */
+/* Cache for the previous getdtablesize () result. Safe to cache because
+ Windows also lacks setrlimit. */
static int dtablesize;
int
return dtablesize;
}
+#elif HAVE_GETDTABLESIZE
+
+# include <sys/resource.h>
+# undef getdtablesize
+
+int
+rpl_getdtablesize(void)
+{
+ /* To date, this replacement is only compiled for Cygwin 1.7.25,
+ which auto-increased the RLIMIT_NOFILE soft limit until it
+ hits the compile-time constant hard limit of 3200. Although
+ that version of cygwin supported a child process inheriting
+ a smaller soft limit, the smaller limit is not enforced, so
+ we might as well just report the hard limit. */
+ struct rlimit lim;
+ if (!getrlimit (RLIMIT_NOFILE, &lim) && lim.rlim_max != RLIM_INFINITY)
+ return lim.rlim_max;
+ return getdtablesize ();
+}
+
#endif
#if @GNULIB_GETDTABLESIZE@
/* Return the maximum number of file descriptors in the current process.
In POSIX, this is same as sysconf (_SC_OPEN_MAX). */
-# if !@HAVE_GETDTABLESIZE@
+# if @REPLACE_GETDTABLESIZE@
+# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+# undef getdtablesize
+# define getdtablesize rpl_getdtablesize
+# endif
+_GL_FUNCDECL_RPL (getdtablesize, int, (void));
+_GL_CXXALIAS_RPL (getdtablesize, int, (void));
+# else
+# if !@HAVE_GETDTABLESIZE@
_GL_FUNCDECL_SYS (getdtablesize, int, (void));
-# endif
+# endif
_GL_CXXALIAS_SYS (getdtablesize, int, (void));
+# endif
_GL_CXXALIASWARN (getdtablesize);
#elif defined GNULIB_POSIXCHECK
# undef getdtablesize
-# getdtablesize.m4 serial 4
+# getdtablesize.m4 serial 5
dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
AC_DEFUN([gl_FUNC_GETDTABLESIZE],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([AC_CANONICAL_HOST])
AC_CHECK_FUNCS_ONCE([getdtablesize])
- if test $ac_cv_func_getdtablesize != yes; then
+ if test $ac_cv_func_getdtablesize = yes; then
+ # Cygwin 1.7.25 automatically increases the RLIMIT_NOFILE soft limit
+ # up to an unchangeable hard limit; all other platforms correctly
+ # require setrlimit before getdtablesize() can report a larger value.
+ AC_CACHE_CHECK([whether getdtablesize works],
+ [gl_cv_func_getdtablesize_works],
+ [AC_RUN_IFELSE([
+ AC_LANG_PROGRAM([[#include <unistd.h>]],
+ [int size = getdtablesize();
+ if (dup2 (0, getdtablesize()) != -1)
+ return 1;
+ if (size != getdtablesize())
+ return 2;
+ ])],
+ [gl_cv_func_getdtablesize_works=yes],
+ [gl_cv_func_getdtablesize_works=no],
+ [case "$host_os" in
+ cygwin*) # on cygwin 1.5.25, getdtablesize() automatically grows
+ gl_cv_func_getdtablesize_works="guessing no" ;;
+ *) gl_cv_func_getdtablesize_works="guessing yes" ;;
+ esac])
+ ])
+ case "$gl_cv_func_getdtablesize_works" in
+ *yes) ;;
+ *) REPLACE_GETDTABLESIZE=1 ;;
+ esac
+ else
HAVE_GETDTABLESIZE=0
fi
])
-# unistd_h.m4 serial 66
+# unistd_h.m4 serial 67
dnl Copyright (C) 2006-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
REPLACE_FTRUNCATE=0; AC_SUBST([REPLACE_FTRUNCATE])
REPLACE_GETCWD=0; AC_SUBST([REPLACE_GETCWD])
REPLACE_GETDOMAINNAME=0; AC_SUBST([REPLACE_GETDOMAINNAME])
+ REPLACE_GETDTABLESIZE=0; AC_SUBST([REPLACE_GETDTABLESIZE])
REPLACE_GETLOGIN_R=0; AC_SUBST([REPLACE_GETLOGIN_R])
REPLACE_GETGROUPS=0; AC_SUBST([REPLACE_GETGROUPS])
REPLACE_GETPAGESIZE=0; AC_SUBST([REPLACE_GETPAGESIZE])
Depends-on:
unistd
+extensions
msvc-inval [test $HAVE_GETDTABLESIZE = 0]
configure.ac:
gl_FUNC_GETDTABLESIZE
-if test $HAVE_GETDTABLESIZE = 0; then
+if test $HAVE_GETDTABLESIZE = 0 || test $REPLACE_GETDTABLESIZE = 1; then
AC_LIBOBJ([getdtablesize])
gl_PREREQ_GETDTABLESIZE
fi
LGPLv2+
Maintainer:
-Bruno Haible
+Bruno Haible, Eric Blake
-e 's|@''REPLACE_FTRUNCATE''@|$(REPLACE_FTRUNCATE)|g' \
-e 's|@''REPLACE_GETCWD''@|$(REPLACE_GETCWD)|g' \
-e 's|@''REPLACE_GETDOMAINNAME''@|$(REPLACE_GETDOMAINNAME)|g' \
+ -e 's|@''REPLACE_GETDTABLESIZE''@|$(REPLACE_GETDTABLESIZE)|g' \
-e 's|@''REPLACE_GETLOGIN_R''@|$(REPLACE_GETLOGIN_R)|g' \
-e 's|@''REPLACE_GETGROUPS''@|$(REPLACE_GETGROUPS)|g' \
-e 's|@''REPLACE_GETPAGESIZE''@|$(REPLACE_GETPAGESIZE)|g' \
main (int argc, char *argv[])
{
ASSERT (getdtablesize () >= 3);
+ ASSERT (dup2 (0, getdtablesize() - 1) == getdtablesize () - 1);
+ ASSERT (dup2 (0, getdtablesize()) == -1);
return 0;
}