gtpd2m1r | Data Communications Services Reference |
This package is a tool which the user (application) can use to supplement existing system message recovery capability an/or to combine message recovery function with data base recovery function. This type of implementation can lead to shortened transaction path length and/or improved data integrity. The application can choose the point of recovery, the location and contents of log records, if any, and the tracking (timeout) period. This function is independent of line disciplines, and, thus, can be used with BSC or SNA devices. The user determines the extent of and provides for this recovery capability. The application recovery (AR) package provides the interface to a system maintained data area.
When system generated, this package enables an application (user) to assume responsibility for all non-SNA input and output message recovery. If system SNA input recovery is not system generated, then the package enables the application to assume responsibility for SNA input message recovery as well. If system SNA input recovery is system generated, then the TPF system will be responsible for SNA input recovery. SNA output recovery is the responsibility of the the TPF system. Any data base recovery function is the responsibility of the application.
The application recovery table (ART) resides in the protected global area and is loaded by GOGO (INSL-GLBL, Application Global Area PLM). The Core Allocator Record (INSL-GLBL) will have been updated to reserve the required amount of core for the ART table. The GOA is used by GOGO to load the global area.
APPLICATION RECOVERY PROGRAM (03-ARP)
This program, activated by user request and the Restart function, controls access to and maintenance of the application recovery table (ART).
This program is used to load the core application recovery table (AR0RT) to the global area.
This program activates the application recovery initialization program during restart.
This program supports the Random Number Table (CVNH) and the hashing algorithm used by the AR Package to access a unique slot in the ART. This interface is through the HASHC macro.
Items within this record define the amount of core necessary to reserve for the ART and the location within the global area. This and other information is used by GOGO to load the ART.
Core record maintained by the application recovery Program and used by an application to preserve information about a particular input/output message/function.
Block associated with each TPF input/output message to provide information about the origin, destination, and characteristics.
The timer value used to activate the timeout program (ARPT) is stored in this record. This program record is retrieved and the timer value (CK1ART) is used for the CRETC to activate ARPT. This value is SIP (System Installation Package) input via RCYTO in macro MSGRT.
When timeout occurs, the application name in the RCPL is used to find the associated RCAT entry so the appropriate application can be reactivated.