RFR (S) 8182554: Code for os::random() assumes long is 32 bits

[Thomas Stüfe]

Hi Coleen,

long->int: this makes sense.
thread safety: So, if I understand this correctly, before it could happen
that two threads calling at the same time would return the same value from
the random sequence? Your patch seems fine and solves this.

Kind Regards, Thomas


On Wed, Jun 28, 2017 at 5:46 PM, <coleen.phillimore at oracle.com> wrote:

> Summary: And make updating the _rand_seed thread safe.
>
> See bug for more details.
>
> open webrev at http://cr.openjdk.java.net/~coleenp/8182554.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8182554
>
> Tested with JPRT and performance tested addition of cas in os::random call
> (no regressions).   The only thing that uses os::random more than like once
> is Symbol creation.
>
> Thanks,
> Coleen
>