On Jun 28, 2008, at 2:10 PM, David Blevins wrote:
When we add that functionality we'll want to make an option on the
container to control how long a calling thread should wait till
timeout occurs and a ConcurrentAccessTimeoutException is thrown.
Any thoughts on what the default timeout should be? Couple seconds,
couple minutes, infinite?
Went with 30 seconds. Added some functionality so that people can
specify this as "30s" "30 seconds" "1000ms" "1000 milliseconds". Even
supports singular "1 second".
The spec group hasn't determined what the related xml is for
declaring bean vs container concurrency management, so we'll have to
make something up. Same goes for how to specify the "concurrency
attribute" of a bean's methods. Any ideas on what the xml should
look like?
Ended up modeling it completely after the transaction related
annotations. So that gives us:
<concurrency-type>Bean</concurrency-type>
<concurrency-type>Container</concurrency-type>
<assembly-descriptor>
<container-concurrency>
<method>
<ejb-name>SomeEJB</ejb-name>
<method-name>*</method-name>
</method>
<concurrency-attribute>ReadOnly</concurrency-attribute>
</container-concurrency>
</assembly-descriptor>
One thing to note is that the annotations we now support:
@ConcurrencyManagement(BEAN)
@ConcurrencyManagement(CONTAINER)
@Lock(READ)
@Lock(WRITE)
...are different than the ones in the draft spec:
@BeanManagedConcurrency
@ContainerManagedConcurrency
@ReadOnly
@ReadWrite
I don't particularly care for these and am trying to get them
changed. 1) They don't match any of the existing javax.ejb.
annotations like @TransactionManagement or @TransactionAttribute. 2)
Nothing stops you from mistakenly using both @ReadOnly and @ReadWrite
on the same class or method. 3) Requires the user to learn via docs
and remember that @ReadOnly and @ReadWrite apply to the same "logical
group" and are mutually exclusive and that the default is @ReadWrite
-- all of this can be communicated with the @Option(Enum) style
annotation.
Side benefit is that it's way easier to process as we only have to
look for two annotations (@ConcurrencyManagement and @Lock) vs four
(@BeanManagedConcurrency/@ContainerManagedConcurrency and @ReadOnly/
@ReadWrite).
-David
