--- libev/libev.m4	2008/04/06 09:53:19	1.10
+++ libev/libev.m4	2013/10/28 12:36:44	1.16
@@ -1,28 +1,42 @@
 dnl this file is part of libev, do not make local modifications
 dnl http://software.schmorp.de/pkg/libev
 
-dnl libev support 
-AC_CHECK_HEADERS(sys/inotify.h sys/epoll.h sys/event.h sys/queue.h port.h poll.h sys/select.h sys/eventfd.h) 
+dnl libev support
+AC_CHECK_HEADERS(sys/inotify.h sys/epoll.h sys/event.h port.h poll.h sys/select.h sys/eventfd.h sys/signalfd.h)
  
-AC_CHECK_FUNCS(inotify_init epoll_ctl kqueue port_create poll select eventfd)
+AC_CHECK_FUNCS(inotify_init epoll_ctl kqueue port_create poll select eventfd signalfd)
  
-AC_CHECK_FUNC(clock_gettime, [], [ 
-   if test -z "$LIBEV_M4_AVOID_LIBRT"; then
-      AC_CHECK_LIB(rt, clock_gettime) 
+AC_CHECK_FUNCS(clock_gettime, [], [
+   dnl on linux, try syscall wrapper first
+   if test $(uname) = Linux; then
+      AC_MSG_CHECKING(for clock_gettime syscall)
+      AC_LINK_IFELSE([AC_LANG_PROGRAM(
+                      [#include <unistd.h>
+                       #include <sys/syscall.h>
+                       #include <time.h>],
+                      [struct timespec ts; int status = syscall (SYS_clock_gettime, CLOCK_REALTIME, &ts)])],
+                     [ac_have_clock_syscall=1
+                      AC_DEFINE(HAVE_CLOCK_SYSCALL, 1, Define to 1 to use the syscall interface for clock_gettime)
+                      AC_MSG_RESULT(yes)],
+                     [AC_MSG_RESULT(no)])
+   fi
+   if test -z "$LIBEV_M4_AVOID_LIBRT" && test -z "$ac_have_clock_syscall"; then
+      AC_CHECK_LIB(rt, clock_gettime)
       unset ac_cv_func_clock_gettime
       AC_CHECK_FUNCS(clock_gettime)
    fi
 ])
 
-AC_CHECK_FUNC(nanosleep, [], [ 
+AC_CHECK_FUNCS(nanosleep, [], [
    if test -z "$LIBEV_M4_AVOID_LIBRT"; then
-      AC_CHECK_LIB(rt, nanosleep) 
+      AC_CHECK_LIB(rt, nanosleep)
       unset ac_cv_func_nanosleep
       AC_CHECK_FUNCS(nanosleep)
    fi
 ])
 
-AC_CHECK_LIB(m, ceil)
-
-
+if test -z "$LIBEV_M4_AVOID_LIBM"; then
+   LIBM=m
+fi
+AC_SEARCH_LIBS(floor, $LIBM, [AC_DEFINE(HAVE_FLOOR, 1, Define to 1 if the floor function is available)])