RFR 8066397 Remove network-related seed initialization code in ThreadLocal/SplittableRandom

[Paul Sandoz]

On Dec 2, 2014, at 5:42 PM, Peter Levart <peter.levart at gmail.com> wrote:

> On 12/02/2014 11:02 AM, Paul Sandoz wrote:
>> Hi,
>> 
>> Please find below a patch to remove the networking code computing a seed in ThreadLocal/SplittableRandom.
>> 
>> We thought it a good idea at the time :-) but subsequently on certain platforms this results in very high initalization costs that can propagate to other classes such as ConcurrentSkipList*.
>> 
>> The short-term solution is to remove this code and fallback just using current system time. This needs to be back-ported to 8u40.
>> 
>> A longer term solution is to provide a simple public API to get access to some seed bytes that is optimal for the underlying platform, for example, based on Peter's investigations. For linux /dev/urandom is sufficient as a source of bytes. The main problem seems to be Windows. It would also be nice to back-port to say 8u60 using a private API and update TLR/SR.
> 
> Hi,
> 
> Here's a proof of concept for an API that just delegates to system-provided "cryptographically secure" (as declared by the system(s)) pseudo random number generator:
> 
> http://cr.openjdk.java.net/~plevart/jdk9-dev/SystemRandom/webrev.01/
> 

That's rather good. I updated the bug with a link to your email.

Paul.