RFC类别的实现方式

The following additions to the statement CALL-FUNCTION-RFC effect a Remote Function Call:

· CALL FUNCTION - DESTINATION (synchronous RFC)

同步调用，一般用在同步实现的情况，比如过账，或者涉及资金往来的情况。
If the addition DESTINATION is specified without one of the following two additions, the calling program waits until the remotely-called function has finished.

· CALL FUNCTION - STARTING NEW TASK (asynchronous RFC, aRFC)

异步调用，一般用在实时性要求不高的情况。
With the addition STARTING NEW TASK, the processing of the calling program is continued as soon as the remotely-called function is started, without waiting for it to end. The results can be obtained from callback routines.

· CALL FUNCTION - IN BACKGROUND TASK (transactional RFC, tRFC)
With the addition IN BACKGROUND TASK, the remotely-called function is marked for execution and is started using the statement COMMIT WORK.

事务调用,保证事务的一致性。