--- a/hotspot/src/share/vm/runtime/os.hpp	Tue Nov 18 15:25:14 2014 -0800
+++ b/hotspot/src/share/vm/runtime/os.hpp	Wed Dec 03 14:21:14 2014 +0000
@@ -500,6 +500,7 @@
   //File i/o operations
 
   static size_t read(int fd, void *buf, unsigned int nBytes);
+  static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
   static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
   static size_t write(int fd, const void *buf, unsigned int nBytes);