How to increase the number of threads for the JMS/JCA-Inflow based jBPM services in SOA-P

Issue

• We have configured jBPM inside the SOA platform to use the JMS/JCA-Inflow based scheduler and message service implementations in deploy/jbpm.esb/jbpm-service.xml:

   <!-- JMS message service -->
   <mbean code="org.jboss.internal.soa.esb.dependencies.JCAInflowAdapter"
      name="jboss.esb:service=JBPMJobExecutor">
      <attribute name="BeanType">org.jboss.soa.esb.services.jbpm.integration.command.JobListener</attribute>
      <attribute name="Adapter">jms-ra.rar</attribute>
      <attribute name="ActivationSpec">
      destination=queue/JbpmJobQueue
      destinationType=javax.xml.Queue
      </attribute>
      <!-- optional attributes -->
      <attribute name="MessagingInterface">javax.jms.MessageListener</attribute>
      <attribute name="IsTransacted">true</attribute>
      <attribute name="ActivationBridge">org.jboss.soa.esb.listeners.jca.JBoss42ActivationBridge</attribute>
      <attribute name="Description">jBPM Job Listener inflow</attribute>
      <depends>jboss.esb.destination:service=Queue,name=JbpmJobQueue</depends>
   </mbean>

   [.. snip - other jBPM services ..]

• We want to know how to increase number of threads for this configuration?