JdbMethodExitTest.java tries to determine the jdb threadID for the "main"
thread, and then later use it in jdb commands that require a threadID. It does
this by first having the debuggee execute the following:
System.out.println("threadid="+Thread.currentThread().getId());
And then later on the test parses the threadID from this output. The problem is
that the id returned by getId() has no relation to threadIDs used by jdb, which
are actually JDWP ObjectIDs. In the past this has worked due to some dumb luck.
getID() always returns 1 for the main thread, which is always the thread we are
executing in. Coincidentally the JDWP ObjectID for the main Thread object is
also always 1 because this is the first ObjectID that the debug agent ever
needs to create. However, when the debuggee main thread is a virtual thread,
neither getId() nor JDWP assign 1 to the threadID, and in fact both will end up
with very different values for the threadID. The end result is errors from jdb
for using an invalid threadID.
The correct threadID can be obtained by executing the jdb "threads" command and
parsing it from a line that looks like the following:
(java.lang.VirtualThread)694 main running (at breakpoint)
Note this test will also fail due to
[JDK-8309334](https://bugs.openjdk.org/browse/JDK-8309334) and
[JDK-8309397](https://bugs.openjdk.org/browse/JDK-8309397), which should be
fixed first.
I've tested with mach5 tier5 in a workspace that has integrated the various CRs
mentioned. Once JDK-8309334 and JDK-8309397 are fixed, before integrating this
PR I'll first merge and verify that the test being removed from the problem
list by this PR also passes.
-------------
Commit messages:
- remove test from problem list
- properly determine the main threadId
Changes: https://git.openjdk.org/jdk/pull/14294/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14294&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8309396
Stats: 11 lines in 2 files changed: 5 ins; 2 del; 4 mod
Patch: https://git.openjdk.org/jdk/pull/14294.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/14294/head:pull/14294
PR: https://git.openjdk.org/jdk/pull/14294
