Return specifications
On return to component trace, the start/stop routine must place information in the registers. Component trace takes action based on the return codes set by the routine.
Registers on return: On return to component trace, the start/stop routine must place the following information in the registers:
Register | Contents |
---|---|
GPR 0 | Reason code, created by the application program, if the return code is not zero. |
GPR 1 | No requirement. |
GPRs 2 - 14 | You must restore the contents of these registers. |
GPR 15 | Return code. On return from a request
to start tracing, IBM® recommends you set the return codes as follows:
On return from a request to stop tracing, IBM recommends you set the return codes as follows:
|
ARs 0 - 15 | You must restore the contents of these registers. |
Component trace processing after return: If the start/stop routine sets a non-zero return code, the system displays both the return and reason codes through an operator message. For this reason, you should make your return and reason codes as meaningful as possible. The return codes shown in the above table are recommended by IBM.
When issuing CTRACE DEFINE, the application can include the SSRC and SSRSNC parameters to obtain the start/stop routine's return and reason codes.