diff --git a/lib/cpp/aclocal/ax_event_base.m4 b/lib/cpp/aclocal/ax_event_base.m4
new file mode 100644
index 0000000..4418350
--- /dev/null
+++ b/lib/cpp/aclocal/ax_event_base.m4
@@ -0,0 +1,84 @@
+dnl @synopsis AX_EVENT([MINIMUM-VERSION])
+dnl
+dnl Test for the libevent libraries of a particular version (or newer)
+dnl
+dnl If no path to the installed event library is given the macro
+dnl searchs under /usr, /usr/local, and /opt, and evaluates the
+dnl $EVENT_ROOT environment variable.
+dnl
+dnl This macro calls:
+dnl
+dnl   AC_SUBST(EVENT_CPPFLAGS) / AC_SUBST(EVENT_LDFLAGS)
+dnl
+dnl And sets:
+dnl
+dnl   HAVE_EVENT
+dnl
+dnl @category InstalledPackages
+dnl @category Cxx
+dnl @author Marc Kwiatkowski <marc@facebook.com>
+dnl @version 2006-06-15
+dnl @license AllPermissive
+
+AC_DEFUN([AX_EVENT_BASE],
+[
+AC_ARG_WITH([event],
+	AS_HELP_STRING([--with-event@<:@=DIR@:>@], [use event (default is yes) - it is possible to specify an alternate root directory for event]),
+	[
+    if test "$withval" = "no"; then
+    		want_event="no"
+    elif test "$withval" = "yes"; then
+        want_event="yes"
+        ac_event_path=""
+    else
+        want_event="yes"
+        ac_event_path="$withval"
+    fi
+    ],
+    [want_event="yes"])
+
+if test "x$want_event" = "xyes"; then
+	event_lib_version_req=ifelse([$1], ,1.2.0,$1)
+	event_lib_version_req_shorten=`expr $event_lib_version_req : '\([[0-9]]*\.[[0-9]]*\)'`
+	event_lib_version_req_major=`expr $event_lib_version_req : '\([[0-9]]*\)'`
+	event_lib_version_req_minor=`expr $event_lib_version_req : '[[0-9]]*\.\([[0-9]]*\)'`
+	event_lib_version_req_sub_minor=`expr $event_lib_version_req : '[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
+	if test "x$event_lib_version_req_sub_minor" = "x" ; then
+	    event_lib_version_req_sub_minor="0"
+    	fi
+	WANT_EVENT_VERSION=`expr $event_lib_version_req_major \* 10000 \+  $event_lib_version_req_minor \* 100 \+ $event_lib_version_req_sub_minor`
+	WANT_EVENT_MAJOR_VERSION=$event_lib_version_req_major
+	WANT_EVENT_MINOR_VERSION=$event_lib_version_req_minor
+	AC_MSG_CHECKING(for eventlib >= $event_lib_version_req)
+	succeeded=no
+        
+	if test "$ac_event_path" != "" && test -f "$ac_event_path/include/event.h"; then
+	    ac_event_include_path=$ac_event_path/include
+	    EVENT_CPPFLAGS="-I$ac_event_include_path"
+	    EVENT_LDFLAGS="-L$ac_event_path/lib -levent"
+            succeeded=yes
+	else
+	    for ac_event_path_tmp in /usr /usr/local /opt ; do
+		if test -f "$ac_event_path_tmp/include/event.h"; then
+		    ac_event_include_path=$ac_event_path_tmp/include
+		    EVENT_CPPFLAGS="-I$ac_event_include_path"
+		    EVENT_LDFLAGS="-L$ac_event_path_tmp/lib -levent"
+                    succeeded=yes
+		    break;
+		fi
+	    done
+	fi
+
+	if test "$succeeded" != "yes" ; then
+            AC_MSG_ERROR([[We could not detect the event libraries (version $event_lib_version_req_shorten or higher). If you have a staged event library (still not installed) please specify \$EVENT_ROOT in your environment and do not give a PATH to --with-event option.  If you are sure you have event installed, then check your version number looking in <event/version.hpp>. See http://randspringer.de/event for more documentation.]])
+	else
+            AC_SUBST(EVENT_CPPFLAGS)
+	    AC_SUBST(EVENT_LDFLAGS)
+	    AC_DEFINE(HAVE_EVENT,,[define if the EVENT library is available])
+	fi
+
+        CPPFLAGS="$CPPFLAGS_SAVED"
+       	LDFLAGS="$LDFLAGS_SAVED"
+fi
+
+])