On 20/04/16 12:40, Alan Bateman wrote: > > On 19/04/2016 18:00, Andrew Dinn wrote: >> : >> I have been building and testing on JDK9 Byteman using the EA program >> releases and have not seen anything break so far. However, that may just >> be because i) Byteman and the Byteman tests are only using runtime >> classes from the java base module and ii) app code used in tests is not >> modularized -- well, at least not using Jigsaw (see below). > It's good to hear that you are testing with the EA builds. > > I think the main thing for Byteman, and this will be true at least some > other agents too, is that there will likely need to be updated to > support instrumentation with modules. We have a reasonable compatibility > story for existing JVM TI and java agents but as soon as you get into > instrumenting code to statically or reflectively access code in other > modules then it may require the agent to arrange for this access to be > allowed.
Having to explicitly manage module dependencies to retain compatibiity with previous behaviour is at the very least a /nuisance/ because it now means I -- and, no doubt, others in the agent business -- will have to implement a dual-source agent, one for JDK9(+) and another to continue to operate in JDK8/7/6 (yes, people can and do still use the latest Byteman release in all those JDK releases). A solution internal to the JVM which preserved existing behaviour and so did not require the insertion of JDK-specific jumps through JDK-specific hoops would be much preferred. Still, I suppose the releavant implementors are a relatively small crowd and ought to know what we are doing and how to fix it. That minor rant aside (sorry, I feel better for that but I don't suppose anyone else on this list does :-) I will happily investigate the available dynamic module-management APIs and see what options exist to remedy the changes to the status quo and retain as much backwards compatibility as I can. At that point I will come back and comment on the very useful advice you have provided below. Thanks very much for your help so far. regards, Andrew Dinn ----------- Senior Principal Software Engineer Red Hat UK Ltd Registered in UK and Wales under Company Registration No. 3798903 Directors: Michael Cunningham (US), Michael O'Neill (Ireland), Paul Argiry (US)
