[jboss-dev-forums] [JBoss Microcontainer Development] New message: "Circular Dependencies and Semi-Resolve"
JBoss development,
A new message was posted in the thread "Circular Dependencies and
Semi-Resolve":
http://community.jboss.org/message/530202#530202
Author : Adrian Brock
Profile : http://community.jboss.org/people/adrian@jboss.org
Message:
--------------------------------------------------------------
https://jira.jboss.org/jira/browse/JBKERNEL-109
I've committed a prototype for circular dependencies.
This involved three main changes:
1) The ability to "semiResolve" a dependency which means that you know what you
want to depend on,
but it is not in the correct state yet. However, if the only thing that is stopping it
moving to the correct
state is a circular dependency (i.e. other things in the semi-resolved state) then it will
upgraded to fully resolved.
2) Change AbstractDependencyItem to use an enum for the three different types of resolved
states,
resolved, semi-resolved and unresolved and track the different types in
AbstractDependencyInfo for optimized processing of the
different types.
3) A change in AbstractController to introduce an "uninstalling" set like the
"installing" set, to avoid recursive
when uninstalling contexts that have circular dependencies.
Caveats:
* I haven't looked at adding ON_DEMAND processing, although it should be simple to
add?
* The semi-resolved handling only looks at contexts in the previous state to what you
require.
If they are in any earlier state then they are unresovled until they progress to the
previous state.
This avoids having to do a complicated determination on whether there is a path to break
the circular dependency,
rather than just advancing all the related semi-resolved contexts to the next state.
Its usage should be trivial:
public MyDependencyItem extends AbstractDependencyItem
{
public boolean resolve(Controller)
{
// Determine the context we want to be semi-resolved on
ControllerContext ctx = ...;
if (ctx == null)
return false;
// Pass the handling to AbstractDependencyItem
return semiResolve(ctx);
}
}
--------------------------------------------------------------
To reply to this message visit the message page:
http://community.jboss.org/message/530202#530202