Thank you Severin! On Mon, Jun 19, 2017 at 11:10 AM, Severin Gehwolf <sgehw...@redhat.com> wrote:
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> Hi Thomas, > > On Tue, 2017-06-13 at 15:55 +0200, Thomas Stüfe wrote: > > Ping... Anyone? > > > > On Thu, Jun 1, 2017 at 2:18 PM, Thomas Stüfe <thomas.stu...@gmail.com > > > wrote: > > > Hi all, > > > > > > please take a look at this proposed fix for a theoretical race in > > > the jdwp library. > > > > > > Issue: https://bugs.openjdk.java.net/browse/JDK-8181419 > > > webrev: http://cr.openjdk.java.net/~stuefe/webrevs/ > 8181419-Race-in-jdwp-invoker-handling-may-lead-to-crashes- > or-invalid-results/webrev.00/webrev/ > > > > > > In short, this is an addition to Severin's fix to the jdwp invoke > > > handling (https://bugs.openjdk.java.net/browse/JDK-8153711). > > > > > > We have a potential race condition where the delayed cleanup of the > > > saved returnvalue object reference and the exception reference > > > (released in deletePotentiallySavedGlobalRefs() ) may be overtaken > > > by a new request which populates the thread request structure anew. > > > If this happens, deletePotentiallySavedGlobalRefs() may actually > > > release the return value / exception references of the follow up > > > request, if that one was already processed. > > > > > > The solution I choose is safe and conservative. We still release > > > both references, but use the locally saved JNI references. We just > > > avoid accessing the thread local request structure after it has > > > been cleared for reuse. This keeps timing and locking behaviour > > > unchanged. > > > > > > I am currently running jtreg tests for com/sun/jdi on AIX and > > > Linux. > > The fix makes sense to me. Looks good! I'm not an OpenJDK Reviewer. > > Cheers, > Severin >
