On Wed, 2019-10-02 at 10:39 +0200, Severin Gehwolf wrote: > On Tue, 2019-10-01 at 12:51 -0700, Chris Plummer wrote: > > Hi Severin, > > > > Sorry, this is not an area that I have any expertise in. However, I did > > confirm that it fixes the NPE I was seeing with JShellHeapDumpTest.java, > > which brings up a question. You said this happens with -Xcomp, but I was > > never using -Xcomp. Might it also be triggered without -Xcomp? > > Yes, as soon as C1/C2 kick in you might be seeing the issue. In fact, I > had one reproducer which triggered the issue quite reliably which > didn't use -Xcomp explicitly. Nevertheless, certain methods got JIT > compiled soon and the issue surfaced. You should be able to verify by > adding -XX:+PrintCompilation to the host program and/or comparing it to > -Xint runs. > > TLDR; -Xcomp helps reproducing the issue on smaller test cases, but > isn't essential in the general case.
On second thought, I haven't investigated whether running the SA on a heap dump triggers the issue as well. There might be another code path not covered with this patch. If there still is, it might be a similar, but slightly different bug. Thanks, Severin
