On Tue, 20 Oct 2026 09:17:55 GMT, Koichi Sakata <[email protected]> wrote:
> This change fixes an infinite loop in the clhsdb dumpcodecache command. > > [JDK-8166317](https://bugs.openjdk.org/browse/JDK-8166317) introduced > trimming of the unused tail of the interpreter’s stub buffer, allowing > `_queue_end` to `equal _buffer_limit`. The native `StubQueue::next()` was > updated to handle this case, but the corresponding change was not made to > SA’s `StubQueue.getNext()`. > > The native `StubQueue::next()` already handles this case: > https://github.com/openjdk/jdk/blob/a5d5806cb48100eff225898129bb357778d7cfa0/src/hotspot/share/code/stubs.hpp#L211-L213 > This change adds the missing wrap-around condition to SA’s > `StubQueue.getNext()`. > > ### Testing > - jtreg:hotspot/jtreg/serviceability/sa/ > > > TEST TOTAL PASS FAIL ERROR > SKIP > jtreg:test/hotspot/jtreg/serviceability/sa 80 75 0 0 > 5 > > > - Manual verification: dumpcodecache returns to the clhsdb prompt, and a > subsequent command can be executed. > > $ jhsdb clhsdb --pid 13353 > Attaching to process 133539, please wait... > hsdb> dumpcodecache > Disassembly for compiled method [public static int toUnsignedInt(byte) > @0x0000ffff50175988 ] @0x0000ffff74ac8008 > > Method > public static int toUnsignedInt(byte) @0x0000ffff50175988 of public final > class java.lang.Byte [signature > Ljava/lang/Number;Ljava/lang/Comparable<Ljava/lang/Byte;>;Ljava/lang/constant/Constable;] > @0x0000001c0005f000 > <snip> > 0x0000ffff746a495c: br x8 > > java.lang.NullPointerException > java.lang.NullPointerException > hsdb> > > > During verification, I also observed NullPointerExceptions during CodeHeap > iteration. Source history indicates that these are caused by a separate > null-handling regression introduced by > [JDK-8349088](https://bugs.openjdk.org/browse/JDK-8349088). I will file a > separate JBS issue and address that problem independently. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). Thank you for reviewing, Chris and Yasumasa! ------------- PR Comment: https://git.openjdk.org/jdk/pull/33463#issuecomment-6356256386
