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## commonj.work
Interface WorkManager

    public interface WorkManager

The WorkManager is the abstraction for dispatching and monitoring asynchronous work and is a factory for creating application short or long lived Works.

WorkManagers are created by the server administrator. The vendor specific systems management console allows the administrator to create one or more WorkManagers and associate a JNDI name with each one. The administrator may specify implementation specific information such as min/max Works for each WorkManager. An application that requires a WorkManager should declare a resource-ref in the EJB or webapp that needs the WorkManager. The vendor descriptor editor or J2EE IDE can be used to bind this resource-ref to a physical WorkManager at deploy or development time. An EJB or servlet can then get a reference to a WorkManager by looking up the resource-ref name in JNDI and then casting it. For example, if the resource-ref was called wm/WorkManager:

     <resource-ref>
       <res-ref-name>wm/WorkManager</res-ref-name>
       <res-type>commonj.work.WorkManager</res-type>
       <res-auth>Container</res-auth>
       <res-sharing-scope>Shareable</res-sharing-scope>
     </resource-ref>

The Java code to look this up would look like:

       InitialContext ic = new InitialContext();
       WorkManager wm = (WorkManager)ic.lookup("java:comp/env/wm/WorkManager");

The res-auth and res-sharing scopes are ignored in this version of the specification. The EJB or servlet can then use the WorkManager as it needs to.

When a Work is scheduled, the declared context that is present on the thread (the J2EE context) will be saved and propagated to the asynchronous methods that are executed. This J2EE context at minimum will contain the java:comp namespace and ClassLoader of the scheduler unless specified otherwise. Other J2EE contexts such as security or a transactional context may be optionally added by the application server vendor. Global transactions are always available using the java:comp/UserTransaction JNDI name and are used in the same fashion as they are used in servlets and bean-managed transaction Enterprise Java Beans.

A WorkManager can also be a pinned WorkManager. This is a WorkManager obtained using the RemoteWorkItem.getWorkManager method. This allows subsequent scheduleWorks to be send to the same remote WorkManager as the one that is associated with the RemoteWorkItem. Pinned WorkManagers are only supported on vendor implementations that support remote Works. However, applications that follow the programming model will work on all implementations however serializable Works will be executed within the local JVM only on those implementations.

If the scheduled `Work` is a daemon Work, then the life-cycle of that Work is tied to the application that scheduled it. If the application is stopped, the `Work.release()` method will be called.

Since:
  1.0
See Also:
  `Work`, `RemoteWorkItem`

Field Summary
`static long` | `IMMEDIATE` This constant can be used as a timeout for the waitForXXX methods.
`static long` | `INDEFINITE` This constant can be used as a timeout for either the waitForXXX methods.

Method Summary
`WorkItem` | `schedule(Work work)` Dispatches a Work asynchronously.
`WorkItem` | `schedule(Work work, WorkListener wl)` Dispatches a Work asynchronously.
`boolean` | `waitForAll(Collection workItems, long timeout_ms)` Wait for all WorkItems in the collection to finish successfully or otherwise.
`Collection` | `waitForAny(Collection workItems, long timeout_ms)` Wait for any of the WorkItems in the collection to finish.

Field Detail

### IMMEDIATE

    static final long IMMEDIATE

  This constant can be used as a timeout for the waitForXXX methods. It will check the current state of the supplied Work objects and return immediately with the result.

  Since:
    1.0
  See Also:
    Constant Field Values

### INDEFINITE

    static final long INDEFINITE

  This constant can be used as a timeout for either the waitForXXX methods. It will cause the waitForXXX to block indefinitely until the the wait is satisfied.

  Since:
    1.0
  See Also:
    Constant Field Values

Method Detail

### schedule

    WorkItem schedule(Work work)
                      throws WorkException,
                             IllegalArgumentException

  Dispatches a Work asynchronously. The work is dispatched and the method returns immediately. The J2EE context of the caller is used to execute the Work.

  At-most-once semantics are provided. If the server fails then the Work will not be executed on restart.

  If this WorkManager is a pinned one, i.e. one obtained using `RemoteWorkItem.getPinnedWorkManager()` and that JVM that it represents has failed then a `WorkRejectedException` will be thrown even if the remote JVM restarts. The pinned WorkManager must be refreshed by using a normal WorkManager and then acquiring a new pinned WorkManager.

  Parameters:
    `work` - the Work to execute.
  Returns:
    the workitem representing the asynchronous work. If the Work is serializable then a RemoteWorkItem is always returned.
  Throws:
    `If` - queuing this up results in an exception then a WorkException is thrown.
    `IllegalArgumentException` - thrown if work is a javax.ejb.EnterpriseBean.
    `WorkException`
  Since:
    1.0

### schedule

    WorkItem schedule(Work work,
                      WorkListener wl)
                      throws WorkException,
                             IllegalArgumentException

  Dispatches a Work asynchronously. The work is dispatched and the method returns immediately. The J2EE context of the caller is used to execute the Work.

  At-most-once semantics are provided. If the server fails then the Work will not be executed on restart.

  The WorkListener methods are called using the J2EE context of the caller as the Work progresses through processing.

  If this WorkManager is a pinned one, i.e. one obtained using `RemoteWorkItem.getPinnedWorkManager()` and that JVM that it represents has failed then a `WorkRejectedException` will be thrown even if the remote JVM restarts. The pinned WorkManager must be refreshed by using a normal WorkManager and then acquiring a new pinned WorkManager.

  Parameters:
    `work` - the Work to execute.
    `wl` - can be null or a WorkListener which is used to inform the application of the progress of a Work.
  Returns:
    The workitem representing the asynchronous work. If the Work is serializable then a RemoteWorkItem is always returned.
  Throws:
    `WorkException` - If queuing this up results in an exception then a WorkException is thrown.
    `IllegalArgumentException` - thrown if work is a javax.ejb.EnterpriseBean.
  Since:
    1.0

### waitForAll

    boolean waitForAll(Collection workItems,
                       long timeout_ms)
                       throws InterruptedException,
                              IllegalArgumentException

  Wait for all WorkItems in the collection to finish successfully or otherwise. WorkItems from different WorkManagers can be placed in a single collection and waited on together.

  The WorkItems collection should not be altered once submitted until the method returns.

  Parameters:
    `workItems` - the Collection of WorkItem objects to wait for.
    `timeout_ms` - the timout in milliseconds. If this is 0 then this method returns immediately.
  Returns:
    true if all WorkItems have completed, false if the timeout has expired.
  Throws:
    `InterruptedException` - thrown if the wait is interrupted.
    `IllegalArgumentException` - thrown if workItems is null, any of the objects in the collection are not WorkItems or the timeout_ms is negative.
  Since:
    1.0

### waitForAny

    Collection waitForAny(Collection workItems,
                          long timeout_ms)
                          throws InterruptedException,
                                 IllegalArgumentException

  Wait for any of the WorkItems in the collection to finish. If there are no WorkItems in the list then it returns immediately indicating a timeout. WorkItems from different WorkManagers can be placed in a single collection and waited on together.

  The WorkItems collection should not be altered once submitted until the method returns.

  Parameters:
    `workItems` - the Collection of WorkItem objects to wait for.
    `timeout_ms` - the timeout in ms. If this is 0 then the method returns immediately, i.e. does not block.
  Returns:
    the WorkItems that have completed or an empty Collection if it time out expires before any finished.
  Throws:
    `InterruptedException` - thrown if the wait is interrupted.
    `IllegalArgumentException` - thrown if workItems is null, any of the objects in the collection are not WorkItems or the timeout_ms is negative.
  Since:
    1.0

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