RFR 8160885 Unsafe.compareAndExchangeDouble/FloatAcquire should defer to compareAndExchangeLong/IntAcquire

[Michael Haupt]

Hi Paul,

thumbs up.

Best,

Michael

> Am 07.07.2016 um 12:06 schrieb Paul Sandoz <paul.sandoz at oracle.com>:
> 
> Hi,
> 
> Please review the simple patch below.
> 
> As spotted by Andrew Haley the Unsafe.compareAndExchangeDouble/FloatAcquire methods were incorrectly deferring to compareAndExchangeLong/IntVolatile rather than compareAndExchangeLong/IntAcquire. Other, related, double/float Unsafe methods defer correctly to the long/int variants.
> 
> Thanks,
> Paul.
> 
> diff -r 7ca81adc8bad src/java.base/share/classes/jdk/internal/misc/Unsafe.java
> --- a/src/java.base/share/classes/jdk/internal/misc/Unsafe.java	Wed Jul 06 17:38:29 2016 +0200
> +++ b/src/java.base/share/classes/jdk/internal/misc/Unsafe.java	Wed Jul 06 19:08:55 2016 +0200
> @@ -1709,9 +1709,9 @@
>     public final float compareAndExchangeFloatAcquire(Object o, long offset,
>                                                   float expected,
>                                                   float x) {
> -        int w = compareAndExchangeIntVolatile(o, offset,
> -                                              Float.floatToRawIntBits(expected),
> -                                              Float.floatToRawIntBits(x));
> +        int w = compareAndExchangeIntAcquire(o, offset,
> +                                             Float.floatToRawIntBits(expected),
> +                                             Float.floatToRawIntBits(x));
>         return Float.intBitsToFloat(w);
>     }
> 
> @@ -1793,9 +1793,9 @@
>     public final double compareAndExchangeDoubleAcquire(Object o, long offset,
>                                                         double expected,
>                                                         double x) {
> -        long w = compareAndExchangeLongVolatile(o, offset,
> -                                                Double.doubleToRawLongBits(expected),
> -                                                Double.doubleToRawLongBits(x));
> +        long w = compareAndExchangeLongAcquire(o, offset,
> +                                               Double.doubleToRawLongBits(expected),
> +                                               Double.doubleToRawLongBits(x));
>         return Double.longBitsToDouble(w);
>     }
> 

-- 

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