gtpa2m1p | Application Programming |
Because the starting of a commit scope is under ECB control, you can implement TPF transaction services support without affecting the way existing applications run. However, existing applications may be impacted by applications using this support.
Normal find processing is not affected by TPF transaction services support.
Find-with-hold processing may be affected; see Holding Records for more information.
Normal file processing is not affected by TPF transaction services support.
File-with-unhold processing may be affected, however; see Holding Records for more information.
Although there are no API changes for processes that are outside of the commit scope, you need to understand what effect the commit scope has on them. For requests outside of the commit scope, a commit-level hold is viewed the same as an ECB-level hold. This means that if the requested record is held at the ECB level or the commit level, the request will be queued. This processing could result in an increase in record hold duration and an increase in record hold deadlock conditions.
For example, look at the scenario in Figure 15. Program A, which is using TPF transaction services support, causes a deadlock to occur.
Figure 15. Example of a Deadlock Condition