On 26/02/2026 02:49, Mengyang Li wrote:
Hello everyone, With “Custom Scheduler Prototype v2”, the JDK loads
the class specified by jdk. virtualThreadScheduler. implClass via the
internal AppClassLoader. This works for typical apps, but fails for
Spring Boot fat JARs where the application
:
Would it be feasible to switch to an SPI (similar to JDBC) so custom
schedulers are pluggable under non-standard class loaders? Potentially
the same approach could apply to a pluggable Poller API.
In this prototype, the scheduler is configured system-wide and cannot be
changed mid-flight. It has to be visible to the application class
loader, otherwise there would be no way to schedule virtual threads
before the custom class loader is created. It can be re-visited if
efforts in this area go further than the prototype. For now, the custom
scheduler has to deployed on the class path or module path.
There is no Poller API. The class that I think you have found the JDK
internal class that supports blocking operations when using the Socket
and other networking APIs. It's not something that we want to expose in
any way. If the context for your comment is a library that does syscalls
directly (FFM or JNI) then the "primitive" that it can use to
park/unpark virtual threads is LockSupport.park/unpark, it does not need
Poller.
-Alan
