RFR (XS): 8078399: Deprecate -Xoss, -Xsqnopause, -Xoptimize and -Xboundthreads options in JDK 9 (original) (raw)

David Holmes david.holmes at oracle.com
Wed Jun 24 04:25:20 UTC 2015

Hi Dmitry,

On 23/06/2015 11:02 PM, Dmitry Dmitriev wrote:

Hello David,

Please, see my comments inline. On 23.06.2015 15:49, David Holmes wrote: Hi Dmitry,

On 23/06/2015 8:35 PM, Dmitry Dmitriev wrote: Hello,

Please review this small fix which deprecate -Xoss, -Xsqnopause, -Xoptimize and -Xboundthreads options in JDK 9. Also, I need a sponsor for this fix, who can push it. I can sponsor this for you. But first ... Thank you! Currently HotSpot silently ignore these 4 options. Here are description of these options: "-Xoss", "-Xsqnopause", "-Xoptimize" - EVM option leaved for compatibility. From Java 2 SDK for Solaris Developer's Guide: "Prior to version 1.3.0, the production releases of the Java 2 SDK for the Solaris Operating Environment shipped with a virtual-machine implementation known as the Exact VM (EVM). Beginning with version 1.3.0, the Exact VM is replaced by the Java HotSpot VM.". So, from Java 1.4 EVM is not used as VM for JDK on Solaris and these very old flags just silently ignored by HotSpot. "-Xboundthreads" - was used to bind user level threads to kernel threads on Solaris in case when new thread library is not available. But old T1 libthread has been removed from Solaris in release 10. JDK9 requires Solaris 10u9 or higher. So, this flag become useless. All these options are deprecated, i.e. following warning is printed when option is specified: "Java HotSpot(TM) 64-Bit Server VM warning: Option -Xoss was deprecated in version 9.0 and will likely be removed in a future release.". In next major release all these options can be removed. Webrev: http://cr.openjdk.java.net/~ddmitriev/8078399/webrev.00/ <http://cr.openjdk.java.net/%7Eddmitriev/8078399/webrev.00/> JBS: https://bugs.openjdk.java.net/browse/JDK-8078399 Tested: JPRT Can you not add these options to the set of obsoleteflags ? (and delete the code that references them of course) Unfortunately, I not understand what set of obsolete flags you mean. Do you mean os::obsoleteoption method or obsoletejvmflags table? Since obsoletejvmflags is developed for "XX:" options I not see how it easily can be done. In case of os::obsoleteoption methods then I will need to add these options to all implementations. Probably, I not understand you correctly.

It was the obsolete_jvm_flags table I meant - sorry about the typo. Pity it doesn't support -X options. :(

My only suggestion here is to at least use the same warning message as would be seen for obsolete -XX flags (something I should have suggested when reviewing the CCC request):

warning("ignoring option %s; support was removed in %s", stripped_argname, version);

ref:

java -XX:+UseOldInlining -version Java HotSpot(TM) Server VM warning: ignoring option UseOldInlining; support was removed in 9.0

vs

java -Xoss -version Java HotSpot(TM) Server VM warning: Option -Xoss was deprecated in version 9.0 and will likely be removed in a future release.

and if you use an actual JVM_Version then this won't need to be updated when the new version string comes in. :)

Thanks, David

Thanks, Dmitry

Thanks, David Thanks, Dmitry

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