Hi, Please pre-emptively review a fix to update the buffer implementations to leverage the Unsafe unaligned accessors:
http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8151163-buffer-unsafe-unaligned-access/webrev/ http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8151163-buffer-unsafe-unaligned-access-hotspot/webrev/ The JDK changes depend on those for the following which is in CCC review: https://bugs.openjdk.java.net/browse/JDK-8149469 ByteBuffer API and implementation enhancements for VarHandles http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8149469-byte-buffer-align-and-unifying-enhancements/webrev/ The changes in this webrev take advantage of those for JDK-8149469 and apply the unsafe double addressing scheme so certain byte buffer view implementations can work across heap and direct buffers. This should improve the performance on x86 for: 1) direct ByteBuffers using the wider unit size method accessors; and 2) wider unit size views over heap ByteBuffers. As a consequence Bits.java has greatly reduced in size :-) The HotSpot changes update the test that was originally added when the heap ByteBuffer method accessors were updated to utilise unsafe unaligned access. I split the test out so as to reduce the execution time, since I doubled the amount of tests. These tests could be improved for views at various unaligned/unaligned positions in the byte buffer, but i left that for now. I plan to push through hs-comp since JDK-8149469 will go through hs-comp. Later on today i will kick of a JPRT hotspot test run. — This is a small step towards unifying the buffer implementations using the unsafe double addressing scheme: https://bugs.openjdk.java.net/browse/JDK-6509032 Thanks, Paul.
