[9] RFR (M) 8054386: Allow Java debugging when CDS is enabled

Chris Plummer chris.plummer at oracle.com
Thu Jun 4 23:32:26 UTC 2015

Hi David,

Here's an updated webrev:




On 6/3/15 11:29 PM, David Holmes wrote:
> Hi Chris,
> Hotspot change is good.
> Only a couple of style nits with the tests (where are our Java style 
> guidelines ???). Taking CDSJDITest.java as an example:
> If you are okay with this line length:
>  115     public static OutputAnalyzer executeAndLog(ProcessBuilder pb, 
> String logName) throws Exception {
> then you can remove a number of line breaks in the headers of other 
> functions. (I don't follow the 70-80 char line length  dogma ;) )
> If you do break a header of a function the { still stays on the same 
> line as the last header component ie:
>      private static void addToClassList(PrintStream ps, String classes[])
>          throws IOException {
> not:
>  139     private static void addToClassList(PrintStream ps, String 
> classes[])
>  140         throws IOException
>  141     {
> Cheers,
> David
> On 2/06/2015 5:36 PM, Chris Plummer wrote:
>> [Adding core-libs-dev at openjdk.java.net since this update includes
>> changes to jdk/test library code]
>> Please review the updated webrev:
>> Webrev: http://cr.openjdk.java.net/~cjplummer/8054386/webrev.02/
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8054386
>> There were concerns about the new hotspot tests referencing jdk tests.
>> One concern was that if the jdk tests change, they could break the
>> hotspot tests, and this might initially go undetected. The other concern
>> is that if the jdk and hotspot tests are placed in separate test
>> bundles, then it would not be possible to run the hotspot tests.
>> Because of these concerns, I moved the tests that were in
>> hotspot/test/runtime/CDSJDITests to instead be in
>> jdk/test/com/sun/jdi/CDSJDITests. There was a slight renaming of the
>> tests in the process. Also, I had to update the jdk version of
>> ProcessTool.java to include the createJavaProcessBuilder() variant that
>> is in the hotspot version of ProcessTool.java.
>> Lastly, in CDSJITTest.java I changed:
>>      OutputAnalyzer output = new OutputAnalyzer(pb.start());
>> to instead be:
>>      OutputAnalyzer output = ProcessTools.executeProcess(pb);
>> I had to do this since the jdk version of the OutputAnalyzer constructor
>> is not public. The 1st version is what is commonly used in hostspot
>> tests, and the 2nd version is what is commonly used in jdk tests. I
>> decided to adopt the jdk way rather than make the OutputAnalyzer
>> constructors public, although this will probably happen eventually when
>> the two versions are unified.
>> thanks,
>> Chris
>> On 5/19/15 7:25 AM, Chris Plummer wrote:
>>> Hi,
>>> Please review the following changes for allowing java debugging when
>>> CDS is enabled.
>>> Webrev:http://cr.openjdk.java.net/~cjplummer/8054386/webrev.01/
>>> Bug:https://bugs.openjdk.java.net/browse/JDK-8054386
>>> The VM changes are simple. I removed the check that prevents debugging
>>> with CDS enabled, and added logic that will map the CDS archive RW
>>> when debugging is enabled.
>>> The tests are a bit more complex. There are a bunch of existing JDI
>>> tests for testing debugging support. Rather than start from scratch or
>>> clone them, I instead just wrote wrapper tests that put the relevant
>>> JDI test classes in the archive, and then invoke the JDI test. I did
>>> this for 3 of the JDI tests. If you feel there are others that would
>>> be good candidates, I'd be happy to add them. I'm looking for ones
>>> that would result in modification of the RO class metadata, such as
>>> setting a breakpoint (for which I already added two tests).
>>> Testing done:
>>> -Using JPRT to run the new jtreg tests on all platforms.
>>> -Using JPRT to run all jtreg runtime tests on linux x86 and x_64.
>>> -Regular JPRT "-testset hotspot" run
>>> -Putting the JCK JVMTI tests in the archive and then running them.
>>> -Putting the nsk jdb, jdwp, jvmti, and jdi tests in the archive and
>>> then running them.
>>> -Putting a simple test class in the archive and then setting a
>>> breakpoint on it using jdb
>>> Some of the above testing resulted in the discovery of bugs that still
>>> need to be addressed: JDK-8078644, JDK-8078730, and JDK-8079181.
>>> I also verified that without the change to map the archive RW, the
>>> above testing resulted in a SEGV, which is what you would expect (and
>>> actually want to see to prove that the testing is effective).
>>> thanks,
>>> Chris

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