concurrency of conversation-scoped components
Hi,
I have two questions.
1. JBoss Seam 2.0.0.BETA1 Reference Guide - 3.1.10. Concurrency model:
Seam enforces a single thread per conversation per process model for the conversation context by serializing concurrent requests in the same long-running conversation context.
What is "per process" here?
JVM? JSF event-handler? request process? business process? others?
2. I have the following Seam SFSB.
@Stateful
@Name("concurrencyTesting")
public class ConcurrencyTestingAction
implements ConcurrencyTesting, Serializable {
private int count;
@In
private FacesMessages facesMessages;
@Logger
private Log log;
@Begin
public void start() {}
public void doLongWork() {
log.debug("doLongWork start:count[#0]", count);
try {
Thread.sleep(60 * 1000);
} catch (InterruptedException e) {
log.debug("InterruptedException occured.", e);
}
count++;
facesMessages.add("doLongWork: count[#0]", count);
log.debug("doLongWork end:count[#0]", count);
}
public void doShortWork() {
log.debug("doShortWork start:count[#0]", count);
count++;
facesMessages.add("doShortWork: count[#0]", count);
log.debug("doShortWork end:count[#0]", count);
}
public int getCount() {
return count;
}
@End
public void end() {}
@Destroy @Remove
public void destroy() {}
}
I also have next xhml file.
... ...
<h:messages globalOnly="true" styleClass="message"/>
<ul>
<li><s:link value="conversation start" action="#{concurrencyTesting.start}" /></li>
<li><s:link value="conversation end" action="#{concurrencyTesting.end}" /></li>
<li><s:link value="short work" action="#{concurrencyTesting.doShortWork}" /></li>
<li><s:link value="long work" action="#{concurrencyTesting.doLongWork}" /></li>
</ul>
... ...
(1)Start the conversation by clicking "conversation start" link in browser tab #1.
(2)Open a new tab #2 with right clicking on the "short work" link.
(3)Invoke #{concurrencyTesting.doLongWork} event-handler, which sleeps in 60 secs, in tab #1.
If I invoke #{concurrencyTesting.doLongWork} event-handler quickly in tab#2(concurrent request for same conversation),
the method invocation is blocked.
And when the processing in tab #1 is over, the method invocation in tab #2 starts.
This is OK!
But if I invoke #{concurrencyTesting.doShortWork} instead of #{concurrencyTesting.doLongWork} in tab #2,
this method is invoked immediately with a new temporary conversation.
I expected that the method invocation was also blocked...
Is this Seam spec?
JBoss AS 4.2.0.GA
JBoss Seam CVS(before about 12 hours)
Thanks.
