On Tue, 28 Jun 2022 22:33:07 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
> This fixes a bug in the debug agent when there is a request to suspend a
> virtual thread that has already terminated. The issue was that unless the
> debug agent was currently under a "suspend all", it would not properly put
> the virtual thread on the `otherThreads` list, and instead added it to
> `runningVThreads`. This meant at the end of `insertThread()` the following
> code tried to do a JVMTI `SetThreadLocalStorage`, which can't be done on a
> terminated thread.
>
>
> if (list != &otherThreads) {
> setThreadLocalStorage(node->thread, (void*)node);
> }
src/jdk.jdwp.agent/share/native/libjdwp/threadControl.c line 418:
> 416: // Thread not alive so put on otherThreads list instead of
> runningVThreads.
> 417: // It might not have started yet or might have terminated.
> Either way,
> 418: // otherThreads is the place for it.
If a terminated thread is added to otherThreads then will be it eventually
removed?
src/jdk.jdwp.agent/share/native/libjdwp/threadControl.c line 419:
> 417: // It might not have started yet or might have terminated.
> Either way,
> 418: // otherThreads is the place for it.
> 419: list = &otherThreads;
Minor nit but the native code here uses 4-space indentation.
test/jdk/com/sun/jdi/SuspendAfterDeath.java line 62:
> 60: public class SuspendAfterDeath extends TestScaffold {
> 61: private volatile ThreadReference thread;
> 62: private volatile boolean breakpointReached = false;
The volatile-write to initialise this to false is not needed here.
test/jdk/com/sun/jdi/SuspendAfterDeath.java line 99:
> 97: List argList = new ArrayList(Arrays.asList(args));
> 98: argList.add("Virtual");
> 99: args = (String[]) argList.toArray(args);
The raw type and casting caught my addition here. Here's something more
succulent if you'd like:
args = Stream.concat(Stream.of(args), Stream.of("Virtual"))
.toArray(String[]::new);
test/jdk/com/sun/jdi/SuspendAfterDeath.java line 135:
> 133: }
> 134: }
> 135: }
I wonder if we need to add `@run main/othervm -Dmain.wrapper=Virtual
SuspendAfterDeath` to the test description so that running the jdk_jdi test
group will exercise the issue. As it stands, I think it would require a test
run with -Dmain.wrapper=Virtual to exercise this code.
-------------
PR: https://git.openjdk.org/jdk19/pull/88
