gistfile1.txt

# Force not to use eventfd
AC_ARG_ENABLE([eventfd], [AS_HELP_STRING([--disable-eventfd], [disable eventfd [default=no]])],
    [zmq_disable_eventfd=yes], [zmq_disable_eventfd=no])

if test "x$zmq_disable_eventfd" != "xyes"; then
    # Check if we have eventfd.h header file.
    AC_CHECK_HEADERS(sys/eventfd.h, 
                     [AC_DEFINE(ZMQ_HAVE_EVENTFD, 1, [Have eventfd extension.])])
fi