--- a/src/java.base/share/classes/sun/nio/ch/IOUtil.java	Fri Mar 23 09:51:02 2018 +0100
+++ b/src/java.base/share/classes/sun/nio/ch/IOUtil.java	Fri Mar 23 14:18:18 2018 +0000
@@ -397,7 +397,9 @@
      * The read end of the pipe is returned in the high 32 bits,
      * while the write end is returned in the low 32 bits.
      */
-    static native long makePipe(boolean blocking);
+    static native long makePipe(boolean blocking) throws IOException;
+
+    static native int write1(int fd, byte b) throws IOException;
 
     static native boolean drain(int fd) throws IOException;