+AC_CHECK_FUNCS_ONCE(accept4)
+AC_CHECK_TYPES([struct timespec, clockid_t], [], [], [[#include <time.h>]])
+AC_SEARCH_LIBS([clock_gettime], [rt posix4])
+AC_CHECK_FUNCS([clock_gettime])
+
+# Check system type
+case "$host_os" in
+freebsd*)
+ build_target=freebsd
+ ;;
+darwin*)
+ build_target=macos
+ LDFLAGS="${LDFLAGS} -framework CoreFoundation -framework IOKit"
+ ;;
+*)
+ ;;
+esac
+
+AM_CONDITIONAL([FREEBSD], [test x$build_target = xfreebsd])
+AM_CONDITIONAL([MACOS], [test x$build_target = xmacos])