Revise programming model with use of virtual threads

[edbratt]

Is your feature request related to a problem? Please describe.
Simplify the programming model with Virtual Threads

Describe the solution you'd like
Jakarta EE 12 is proposed with a base Java version of 21. We should actively consider including more features that can simplify the programming model due to the fact that virtual thread will be available. We should consider areas in the platform where there are restrictions in programming model intended to steer developers away from blocking style code and platform management of threads. For example, some messaging patterns require the use of MDBs. In a virtual thread environment, code can be written to just call the messaging provider and the virtual thread can just wait (block) for the next message to become available. When it is available, continue with its work. Previously, this would be managed by an MDB or maybe with Inversion of Control. This requirement may be relaxed.

We can consider additional virtual thread enhancements however with the base JDK at 21, some of the more recent virtual thread enhancements may not be available.

[jhanders34]

Virual threads aren't a magic bullet so I am happy that you are limiting it to particular scenarios. You can read more of what I am talking about in this article. It will be interesting as the technology improves how it can be used, but we may want to have options for users as well who do not want to use virtual threads to opt out of the use of virtual threads. Some of that can be making use of concurrency managed pools that may or may not be configured with virtual threads.