--- libaitio/configure.in	2014/01/21 15:59:44	1.51.2.2
+++ libaitio/configure.in	2016/08/18 09:08:23	1.56.2.1
@@ -1,8 +1,8 @@
 #
 # $Author: misho $
-# $Id: configure.in,v 1.51.2.2 2014/01/21 15:59:44 misho Exp $
+# $Id: configure.in,v 1.56.2.1 2016/08/18 09:08:23 misho Exp $
 #
-AC_INIT(libaitio, 6.9, misho@elwix.org)
+AC_INIT(libaitio, 7.4, misho@elwix.org)
 AC_CONFIG_SRCDIR([src/aitio.c])
 AC_CONFIG_HEADERS([inc/config.h])
 
@@ -12,11 +12,12 @@ ac_cv_func_realloc_0_nonnull="yes"
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_INSTALL
+AC_PROG_RANLIB
 
 AC_CANONICAL_HOST
 AC_CANONICAL_TARGET
 
-AC_CHECK_TOOL(MKDEP, mkdep, no)
+AC_CHECK_TOOL(MKDEP, mkdep, ../mkdep)
 AC_SUBST(MKDEP)
 
 CFLAGS="-Wall -O2 -fPIC ${CFLAGS}"
@@ -37,7 +38,7 @@ AC_C_INLINE
 
 # Checks for library functions.
 AC_FUNC_MMAP
-AC_CHECK_FUNCS([bzero memset munmap])
+AC_CHECK_FUNCS([bzero memset munmap fpurge])
 AC_CHECK_FUNCS([pthread_create pthread_exit])
 AC_CHECK_FUNCS([shm_open shm_unlink])
 
@@ -83,6 +84,20 @@ AC_ARG_ENABLE(aio,
 				;;
 		esac ],)
 AC_MSG_RESULT($AIO)
+
+ZCBUF=no
+AC_MSG_CHECKING(Zero-copy buffer Build)
+AC_ARG_ENABLE(zcpy-buffer,
+	[  --enable-zcpy-buffer    Build library with zero-copy buffer ], 
+	[ ZCBUF=$enableval
+		case "$enableval" in
+			yes)
+				AC_DEFINE(ZCBUF_ENABLE,, [Build library with zero-copy buffer])
+				;;
+			*)
+				;;
+		esac ],)
+AC_MSG_RESULT($ZCBUF)
 
 AC_CONFIG_FILES([Makefile
                  inc/Makefile