On Thu, 20 Jul 2023 06:53:26 GMT, Serguei Spitsyn <sspit...@openjdk.org> wrote:
> This problem is encountered when a JVMTI agent is loaded into running VM. The > JvmtiExport::get_jvmti_interface() is called from the agent's Agent_OnAttach > entrypoint. To support virtual threads it enables JVMTI notifications from > the VirtualThread class with a call to: > `JvmtiEnvBase::enable_virtual_threads_notify_jvmti()`. > The problem is that there is no JVMTI environments at this point yet. This > assert is hit when a virtual thread is created concurrently after the JVMTI > notifications have been enabled but the requested JVMTI environment has not > been created yet. > The fix is to create a JVMTI env first and only then to enable the JVMTI > notifications. > > This issue is very hard to reproduce. I had to use some tricks with adding > `os::naked_short_nanosleep()` and also by refactoring the test > `VThreadTLSTest.java`. At least, I was able to verify this test does not fail > with my fix anymore. > > Testing: > - submitted hundreds of `VThreadTLSTest.java` mach5 runs on several > platforms in the `fastdebug` mode > - in progress: mach5 tiers 1-6 This pull request has now been integrated. Changeset: 783de32b Author: Serguei Spitsyn <sspit...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/783de32b6af4383b5ba71b91c307a5dddd0dae13 Stats: 26 lines in 2 files changed: 14 ins; 12 del; 0 mod 8300051: assert(JvmtiEnvBase::environments_might_exist()) failed: to enter event controller, JVM TI environments must exist Reviewed-by: dholmes, pchilanomate ------------- PR: https://git.openjdk.org/jdk/pull/14945
