2424. [port] configure now probes for a working epoll

implementation. Allow the use of kqueue, epoll and /dev/poll to be selected at compile time. [RT #18277]
2008-08-22 13:17:56 +00:00
parent a7485cd61d
commit 3dfa202e4f
3 changed files with 165 additions and 113 deletions
--- a/5
+++ b/5
@@ -1,3 +1,8 @@
+2424.	[port]		configure now probes for a working epoll
+			implementation.  Allow the use of kqueue,
+			epoll and /dev/poll to be selected at compile
+			time. [RT #18277]
+			
 2423.   [security]      Randomize server selection on queries, so as to
                        make forgery a little more difficult.  Instead of
                        always preferring the server with the lowest RTT,
--- a/212
+++ b/212
@@ -14,7 +14,7 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 #
-# $Id: configure,v 1.432 2008/08/05 07:05:47 marka Exp $
+# $Id: configure,v 1.433 2008/08/22 13:17:56 marka Exp $
 #
 # Portions Copyright (C) 1996-2001  Nominum, Inc.
 #
@@ -29,7 +29,7 @@
 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-# From configure.in Revision: 1.446 .
+# From configure.in Revision: 1.447 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61.
 #
@@ -1625,6 +1625,9 @@ if test -n "$ac_init_help"; then
 Optional Features:
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
+  --enable-kqueue         use BSD kqueue when available [default=yes]
+  --enable-epoll          use Linux epoll when available [default=yes]
+  --enable-devpoll        use /dev/poll when available [default=yes]
  --enable-openssl-version-check
                          Check OpenSSL Version [default=yes]
  --enable-threads	enable multithreading
@@ -5290,7 +5293,16 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 #
 # check if we have kqueue
 #
-{ echo "$as_me:$LINENO: checking for kqueue" >&5
+# Check whether --enable-kqueue was given.
+if test "${enable_kqueue+set}" = set; then
+  enableval=$enable_kqueue; want_kqueue="$enableval"
+else
+  want_kqueue="yes"
+fi
+
+case $want_kqueue in
+yes)
+	{ echo "$as_me:$LINENO: checking for kqueue" >&5
 echo $ECHO_N "checking for kqueue... $ECHO_C" >&6; }
 if test "${ac_cv_func_kqueue+set}" = set; then
  echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -5377,9 +5389,14 @@ else
  ac_cv_have_kqueue=no
 fi

-case $ac_cv_have_kqueue in
-yes)
-	ISC_PLATFORM_HAVEKQUEUE="#define ISC_PLATFORM_HAVEKQUEUE 1"
+	case $ac_cv_have_kqueue in
+	yes)
+		ISC_PLATFORM_HAVEKQUEUE="#define ISC_PLATFORM_HAVEKQUEUE 1"
+		;;
+	*)
+		ISC_PLATFORM_HAVEKQUEUE="#undef ISC_PLATFORM_HAVEKQUEUE"
+		;;
+	esac
 	;;
 *)
 	ISC_PLATFORM_HAVEKQUEUE="#undef ISC_PLATFORM_HAVEKQUEUE"
@@ -5388,12 +5405,26 @@ esac


 #
-# check if we have epoll
+# check if we have epoll.  Linux kernel 2.4 has epoll_create() which fails,
+# so we need to try running the code, not just test its existence.
 #
-{ echo "$as_me:$LINENO: checking for epoll_create" >&5
-echo $ECHO_N "checking for epoll_create... $ECHO_C" >&6; }
-if test "${ac_cv_func_epoll_create+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
+# Check whether --enable-epoll was given.
+if test "${enable_epoll+set}" = set; then
+  enableval=$enable_epoll; want_epoll="$enableval"
+else
+  want_epoll="yes"
+fi
+
+case $want_epoll in
+yes)
+	{ echo "$as_me:$LINENO: checking epoll support" >&5
+echo $ECHO_N "checking epoll support... $ECHO_C" >&6; }
+	if test "$cross_compiling" = yes; then
+  { { echo "$as_me:$LINENO: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
 else
  cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
@@ -5401,85 +5432,52 @@ _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
-/* Define epoll_create to an innocuous variant, in case <limits.h> declares epoll_create.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define epoll_create innocuous_epoll_create

-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char epoll_create (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef epoll_create
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char epoll_create ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined __stub_epoll_create || defined __stub___epoll_create
-choke me
-#endif
-
-int
-main ()
-{
-return epoll_create ();
-  ;
-  return 0;
+#include <sys/epoll.h>
+int main() {
+	if (epoll_create(1) < 0)
+		return (1);
+	return (0);
 }
+
 _ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
+rm -f conftest$ac_exeext
 if { (ac_try="$ac_link"
 case "(($ac_try" in
  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
  *) ac_try_echo=$ac_try;;
 esac
 eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_link") 2>conftest.er1
+  (eval "$ac_link") 2>&5
  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && {
-	 test -z "$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       } && test -s conftest$ac_exeext &&
-       $as_test_x conftest$ac_exeext; then
-  ac_cv_func_epoll_create=yes
+  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  { echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+	ISC_PLATFORM_HAVEEPOLL="#define ISC_PLATFORM_HAVEEPOLL 1"
 else
-  echo "$as_me: failed program was:" >&5
+  echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5

-	ac_cv_func_epoll_create=no
+( exit $ac_status )
+{ echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
 fi

-rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-{ echo "$as_me:$LINENO: result: $ac_cv_func_epoll_create" >&5
-echo "${ECHO_T}$ac_cv_func_epoll_create" >&6; }
-if test $ac_cv_func_epoll_create = yes; then
-  ac_cv_have_epoll=yes
-else
-  ac_cv_have_epoll=no
-fi

-case $ac_cv_have_epoll in
-yes)
-	ISC_PLATFORM_HAVEEPOLL="#define ISC_PLATFORM_HAVEEPOLL 1"
 	;;
 *)
 	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"
@@ -5490,6 +5488,15 @@ esac
 #
 # check if we support /dev/poll
 #
+# Check whether --enable-devpoll was given.
+if test "${enable_devpoll+set}" = set; then
+  enableval=$enable_devpoll; want_devpoll="$enableval"
+else
+  want_devpoll="yes"
+fi
+
+case $want_devpoll in
+yes)

 for ac_header in sys/devpoll.h
 do
@@ -5634,6 +5641,11 @@ fi

 done

+	;;
+*)
+	ISC_PLATFORM_HAVEDEVPOLL="#undef ISC_PLATFORM_HAVEDEVPOLL"
+	;;
+esac


 #
@@ -9975,7 +9987,7 @@ ia64-*-hpux*)
  ;;
 *-*-irix6*)
  # Find out which ABI we are using.
-  echo '#line 9978 "configure"' > conftest.$ac_ext
+  echo '#line 9990 "configure"' > conftest.$ac_ext
  if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
@@ -12097,11 +12109,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:12100: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:12112: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:12104: \$? = $ac_status" >&5
+   echo "$as_me:12116: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -12340,11 +12352,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:12343: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:12355: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:12347: \$? = $ac_status" >&5
+   echo "$as_me:12359: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -12400,11 +12412,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:12403: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:12415: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:12407: \$? = $ac_status" >&5
+   echo "$as_me:12419: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -14548,7 +14560,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 14551 "configure"
+#line 14563 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -14646,7 +14658,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 14649 "configure"
+#line 14661 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -16839,11 +16851,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:16842: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:16854: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:16846: \$? = $ac_status" >&5
+   echo "$as_me:16858: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -16899,11 +16911,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:16902: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:16914: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:16906: \$? = $ac_status" >&5
+   echo "$as_me:16918: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -18227,7 +18239,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 18230 "configure"
+#line 18242 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -18325,7 +18337,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 18328 "configure"
+#line 18340 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -19162,11 +19174,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:19165: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:19177: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:19169: \$? = $ac_status" >&5
+   echo "$as_me:19181: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -19222,11 +19234,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:19225: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:19237: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:19229: \$? = $ac_status" >&5
+   echo "$as_me:19241: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -21256,11 +21268,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:21259: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:21271: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:21263: \$? = $ac_status" >&5
+   echo "$as_me:21275: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -21499,11 +21511,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:21502: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:21514: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:21506: \$? = $ac_status" >&5
+   echo "$as_me:21518: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
@@ -21559,11 +21571,11 @@ else
   -e 's:.*FLAGS}? :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:21562: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:21574: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:21566: \$? = $ac_status" >&5
+   echo "$as_me:21578: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -23707,7 +23719,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 23710 "configure"
+#line 23722 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -23805,7 +23817,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<EOF
-#line 23808 "configure"
+#line 23820 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
--- a/configure.in
+++ b/configure.in
@@ -18,7 +18,7 @@ AC_DIVERT_PUSH(1)dnl
 esyscmd([sed "s/^/# /" COPYRIGHT])dnl
 AC_DIVERT_POP()dnl

-AC_REVISION($Revision: 1.446 $)
+AC_REVISION($Revision: 1.447 $)

 AC_INIT(lib/dns/name.c)
 AC_PREREQ(2.59)
@@ -320,10 +320,20 @@ AC_SUBST(ISC_PLATFORM_HAVELIFCONF)
 #
 # check if we have kqueue
 #
-AC_CHECK_FUNC(kqueue, ac_cv_have_kqueue=yes, ac_cv_have_kqueue=no)
-case $ac_cv_have_kqueue in
+AC_ARG_ENABLE(kqueue,
+	[  --enable-kqueue         use BSD kqueue when available [[default=yes]]],
+	      want_kqueue="$enableval",  want_kqueue="yes")
+case $want_kqueue in
 yes)
-	ISC_PLATFORM_HAVEKQUEUE="#define ISC_PLATFORM_HAVEKQUEUE 1"
+	AC_CHECK_FUNC(kqueue, ac_cv_have_kqueue=yes, ac_cv_have_kqueue=no)
+	case $ac_cv_have_kqueue in
+	yes)
+		ISC_PLATFORM_HAVEKQUEUE="#define ISC_PLATFORM_HAVEKQUEUE 1"
+		;;
+	*)
+		ISC_PLATFORM_HAVEKQUEUE="#undef ISC_PLATFORM_HAVEKQUEUE"
+		;;
+	esac
 	;;
 *)
 	ISC_PLATFORM_HAVEKQUEUE="#undef ISC_PLATFORM_HAVEKQUEUE"
@@ -332,12 +342,27 @@ esac
 AC_SUBST(ISC_PLATFORM_HAVEKQUEUE)

 #
-# check if we have epoll
+# check if we have epoll.  Linux kernel 2.4 has epoll_create() which fails,
+# so we need to try running the code, not just test its existence.
 #
-AC_CHECK_FUNC(epoll_create, ac_cv_have_epoll=yes, ac_cv_have_epoll=no)
-case $ac_cv_have_epoll in
+AC_ARG_ENABLE(epoll,
+	[  --enable-epoll          use Linux epoll when available [[default=yes]]],
+	      want_epoll="$enableval",  want_epoll="yes")
+case $want_epoll in
 yes)
-	ISC_PLATFORM_HAVEEPOLL="#define ISC_PLATFORM_HAVEEPOLL 1"
+	AC_MSG_CHECKING(epoll support)
+	AC_TRY_RUN([
+#include <sys/epoll.h>
+int main() {
+	if (epoll_create(1) < 0)
+		return (1);
+	return (0);
+}
+],
+	[AC_MSG_RESULT(yes)
+	ISC_PLATFORM_HAVEEPOLL="#define ISC_PLATFORM_HAVEEPOLL 1"],
+	[AC_MSG_RESULT(no)
+	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"])
 	;;
 *)
 	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"
@@ -348,11 +373,21 @@ AC_SUBST(ISC_PLATFORM_HAVEEPOLL)
 #
 # check if we support /dev/poll
 #
-AC_CHECK_HEADERS(sys/devpoll.h,
-ISC_PLATFORM_HAVEDEVPOLL="#define ISC_PLATFORM_HAVEDEVPOLL 1"
-,
-ISC_PLATFORM_HAVEDEVPOLL="#undef ISC_PLATFORM_HAVEDEVPOLL"
-)
+AC_ARG_ENABLE(devpoll,
+	[  --enable-devpoll        use /dev/poll when available [[default=yes]]],
+	      want_devpoll="$enableval",  want_devpoll="yes")
+case $want_devpoll in
+yes)
+	AC_CHECK_HEADERS(sys/devpoll.h,
+	ISC_PLATFORM_HAVEDEVPOLL="#define ISC_PLATFORM_HAVEDEVPOLL 1"
+	,
+	ISC_PLATFORM_HAVEDEVPOLL="#undef ISC_PLATFORM_HAVEDEVPOLL"
+	)
+	;;
+*)
+	ISC_PLATFORM_HAVEDEVPOLL="#undef ISC_PLATFORM_HAVEDEVPOLL"
+	;;
+esac
 AC_SUBST(ISC_PLATFORM_HAVEDEVPOLL)

 #