RFR 8024253: ThreadLocal random can use SecureRandom for the initial seed

[Guy Steele]

On Sep 16, 2013, at 10:50 AM, Doug Lea <dl at cs.oswego.edu> wrote:

>        try {
>            Enumeration<NetworkInterface> ifcs =
>                NetworkInterface.getNetworkInterfaces();
>            boolean retry = false; // retry once if getHardwareAddress is null
>            while (ifcs.hasMoreElements()) {
>                NetworkInterface ifc = ifcs.nextElement();
>                byte[] bs = ifc.getHardwareAddress();
>                if (bs != null) {
>                    for (int i = 0; i < 8 && i < bs.length; ++i)
>                        h = (h << 8) ^ bs[i];
>                    break;
>                }
>                else if (!retry)
>                    retry = true;
>                else
>                    break;
>            }
>        } catch (Exception ignore) {
>        }


This retry logic seems a bit convoluted; how about:

       try {
           Enumeration<NetworkInterface> ifcs =
               NetworkInterface.getNetworkInterfaces();
           if (ifcs.hasMoreElements()) {
               byte[] bs = ifcs.nextElement().getHardwareAddress();
	       if (bs == null && ifcs.hasMoreElements()) {  // try up to two
		   bs = ifcs.nextElement().getHardwareAddress();
	       }
               if (bs != null) {
                   for (int i = 0; i < 8 && i < bs.length; ++i)
                       h = (h << 8) ^ bs[i];
                   break;
               }
           }
       } catch (Exception ignore) {
       }

?