The `GetThreadListStackTraces` returns `JVMTI_THREAD_STATE_RUNNABLE` for a VirtualThread blocked on a monitor when called for more than one thread. When called for a single VirtualThread it correctly returns a state that includes the `JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER` flag. The `VM_GetThreadListStackTraces::doit` should call the `get_threadOop_and_JavaThread` instead of `cv_external_thread_to_JavaThread`. But the `get_threadOop_and_JavaThread` has a check for the current thread by comparing with the JavaThread::current() which does not work for a `VM_op`. Some refactoring of the `GetSingleStackTraceClosure` and `get_threadOop_and_JavaThread` was made to make it working for a `VM_op`.
Also, a minor bug in the `GetSingleStackTraceClosure::do_thread()` was discovered during testing. A minor refactoring of the `GetSingleStackTraceClosure` was made to fix the issue. Also, a new test was added to provide coverage: - `test/hotspot/jtreg/serviceability/jvmti/vthread/ThreadListStackTracesTest` Testing: - ran new test: `test/hotspot/jtreg/serviceability/jvmti/vthread/ThreadListStackTracesTest` - TBD: tiers 1-6 ------------- Commit messages: - remove a trailing space in new ThreadListStackTracesTest.java - 8295976: GetThreadListStackTraces returns wrong state for blocked VirtualThread Changes: https://git.openjdk.org/jdk/pull/14326/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14326&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8295976 Stats: 241 lines in 5 files changed: 224 ins; 10 del; 7 mod Patch: https://git.openjdk.org/jdk/pull/14326.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/14326/head:pull/14326 PR: https://git.openjdk.org/jdk/pull/14326
