On Thu, 25 Jul 2024 01:14:32 GMT, Shaojin Wen <d...@openjdk.org> wrote:
>> @cl4es I would wait, to be honest. I'm currently quite busy, but I hope I
>> can do something here in the next 2-3 weeks.
>
> @eme64 Unsafe.putByte MergeStore of master branch doesn't work
>
>
> import sun.misc.Unsafe;
>
> public class PutBytesTest {
> static final Unsafe UNSAFE = JDKUtils.UNSAFE;
>
> // MergeStore not work
> static void putCharsAt(byte[] val, int index, int c1, int c2, int c3, int
> c4) {
> putByte(val, index , (byte)(c1));
> putByte(val, index + 1, (byte)(c2));
> putByte(val, index + 2, (byte)(c3));
> putByte(val, index + 3, (byte)(c4));
> }
>
> // MergeStore work
> static void putCharsAtArrayStore(byte[] val, int index, int c1, int c2,
> int c3, int c4) {
> val[index] = (byte) c1;
> val[index + 1] = (byte) c2;
> val[index + 2] = (byte) c3;
> val[index + 3] = (byte) c4;
> }
>
> static void putByte(byte[] bytes, int index, byte c) {
> UNSAFE.putByte(bytes, Unsafe.ARRAY_BYTE_BASE_OFFSET + index, c);
> }
>
> static void putNull(byte[] bytes, int index) {
> putCharsAt(bytes, index, 'n', 'u', 'l', 'l');
> }
>
> public static void main(String[] args) {
> for (int i = 0; i < 5; i++) {
> testNull();
> }
> System.out.println("done");
> }
>
> private static void testNull() {
> byte[] bytes = new byte[4096];
> for (int i = 0; i < 1000; i++) {
> int index = 0;
> for (int j = 0; j < 1024; j++) {
> putNull(bytes, index);
> index += 4;
> }
> }
> }
> }
@wenshao Yes, I am aware. I detected a bug with `Unsafe`, and now just disabled
it. I'm trying to make it work again, but it will take some time,
unfortunately. I need to be sure about the VM logic, and also sufficient
testing.
-------------
PR Comment: https://git.openjdk.org/jdk/pull/19626#issuecomment-2252675824
