RFR (S): 7117303: VM uses non-monotonic time source and complains that it is non-monotonic

Charles K Pepperdine kirk at kodewerk.com
Sat Dec 10 07:59:15 UTC 2011

Hi John,

The link http://monaco.sfbay.sun.com/detail.jsp?cr=7117303 is unreachable.


On Dec 9, 2011, at 8:30 PM, John Cuthbertson wrote:

> Hi Everyone,
> I have updated the comments based upon feedback from David Holmes. A new webrev can be found at: http://cr.openjdk.java.net/~johnc/7117303/webrev.1/
> Thanks,
> JohnC
> On 12/7/2011 9:59 AM, John Cuthbertson wrote:
>> Hi Everyone,
>> Can I have a couple of volunteers review the changes for this CR? The webrev can be found at: http://cr.openjdk.java.net/~johnc/7117303/webrev.0/.
>> Summary:
>> I replaced the calls to os::javaTimeMillis() in the GC where we expect monotonicity with calls os::javaTimeNanos(), converting the result to milliseconds. os::javaTimeNanos(), at least on some configurations, does guarantee monotonicity and so is a better alternative. The changes in the os_<*> files are to make use of the named conversion constants I added/moved to globalDefinitions.hpp - we seemed to have multiple names for the same two constants.
>> Testing: GC test suite on solaris and Linux, NSK tests on solaris, and jprt.
>> Thanks,
>> JohnC

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