EJB and Threads

[rshea]

I have never understood to my satisfaction what the EJB requirement that EJB's cannot create Threads means, and am hoping someone can clarify.

For instance, is it legal to provide a service within JBoss as an MBean that is registers an object with JNDI that an EJB can look up and invoke where the implementation of a method of the JNDI-registered object spawns a Thread?

If this is legal, then what is the demarcation point for where Threads can be created or not within the context of a call into an EJB?

Thanks in advance,
- Rich

[adrian.brock]

There are two points to not creating threads.

1) The server loses control of what threads
are created and how they are synchronized
2) Things like the security and transaction
are attached to the thread.

If you write an MBean you become part of
the server. It is upto you to consider the
above constraints and play fair.

Regards,
Adrian