--- a/src/core/ngx_os_init.h
+++ b/src/core/ngx_os_init.h
@@ -4,23 +4,40 @@
 
 #include <ngx_config.h>
 #include <ngx_core.h>
-#if 0
-#include <ngx_connection.h>
+
+
+#define NGX_IO_SENDFILE    1
+#define NGX_IO_ZEROCOPY    2
+
+#if (HAVE_SENDFILE)
+#define NGX_HAVE_SENDFILE  NGX_IO_SENDFILE
+#else
+#define NGX_HAVE_SENDFILE  0
 #endif
 
+#if (HAVE_ZEROCOPY)
+#define NGX_HAVE_ZEROCOPY  NGX_IO_ZEROCOPY
+#else
+#define NGX_HAVE_ZEROCOPY  0
+#endif
+
+
 
 typedef struct {
     ssize_t       (*recv)(ngx_connection_t *c, char *buf, size_t size);
     void           *dummy_recv_chain;
     void           *dummy_send;
     ngx_chain_t  *(*send_chain)(ngx_connection_t *c, ngx_chain_t *in);
+    int             flags;
 } ngx_os_io_t;
 
 
 int ngx_os_init(ngx_log_t *log);
 
+
 extern ngx_os_io_t  ngx_os_io;
 extern int          ngx_max_sockets;
+extern int          ngx_inherited_nonblocking;
 
 
 #endif /* _NGX_OS_INIT_H_INCLUDED_ */