com.kabira.platform.annotation

Annotation Type Asynchronous

@Documented
 @Inherited
 @Retention(value=RUNTIME)
 @Target(value=METHOD)
public @interface Asynchronous

Annotation to indicate whether a method should be executed asynchronously.

The default behavior is to execute a Managed object method synchronously within the calling transaction. When annotated as @Asynchronous, a method runs asynchronously in a separate transaction. A new transaction is transparently started for the method, and deadlocks are automatically retried.

If the work done in an asynchronous method is supposed to be rolled back, the method should throw a Transaction.Rollback exception.

A method annotated as @Asynchronous must have a void return and parameters are restricted to those types supported for Managed objects.

The Transaction.Result of an asynchronous method is not available to an application. Applications that need to keep track of this need to implement a separate non-transactional mechanism to track this.

Execution of asynchronous methods have the following behavior:

• The method is executed and the enclosed transaction started after the calling transaction commits.
• If the calling transaction is rolled back, the method is not executed.
• The runtime guarantees that the method executes to completion once and only once.
• Multiple calls to an asynchronous method on a same Managed object instance are guaranteed to execute in the same order. Given:

  @Managed
  class MyClass
  {
      @Asynchronous
      void asyncOp(int val);
  }
  new Transaction()
  {
      @Override
      public void run()
      {
          ...
          myObj.asyncOp(1);
          myObj.asyncOp(2);
      }
  }.execute();

  The runtime insures that asyncOp() is called with val==1 first. Execution of asynchronous methods on different instances have no order guarantees.

It is important to note that execution of an asynchronous method and its associated transaction only happen after the calling transaction commits, it is not executed if the calling transaction is rolled back for any reason.

If the @Asynchronous annotation is used on a method for a class that isn't @Managed, the annotation is ignored.

See Also:

Managed, Transaction, Transaction.Rollback

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
Transaction.IsolationLevel	isolationLevel Define the transaction isolation level used when running this transaction.

Element Detail

isolationLevel

public abstract Transaction.IsolationLevel isolationLevel

Define the transaction isolation level used when running this transaction.

Returns:

IsolationLevel

Default:

com.kabira.platform.Transaction.IsolationLevel.SERIALIZABLE