Registers and return codes

Db2 uses registers to store important information and return codes to help you determine the status of stand-alone log activity.

Begin program-specific programming interface information. The request macro invoking these services can be used by reentrant programs. The macro requires that register 13 point to an 18-word save area at invocation. In addition, registers 0, 1, 14, and 15 are used as work and linkage registers. A return code is passed back in register 15 at the completion of each request. When the return code is nonzero, a reason code is placed in register 0. Return codes identify a class of errors, while the reason code identifies a specific error condition of that class. The stand-alone log return codes are shown in the following table.

Table 1. Stand-alone log return codes
Return code	Explanation
0	Successful completion.
4	Exception condition (for example, end of file), not an error. This return code is not applicable for OPEN and CLOSE requests.
8	Unsuccessful completion due to improper user protocol.
12	Unsuccessful completion. Error encountered during processing of a valid request.

The stand-alone log services invoke executable macros that can execute only in 24-bit addressing mode and reference data below the 16-MB line. User-written applications should be link-edited as AMODE(24), RMODE(24). End program-specific programming interface information.