Joe R wrote <snip> I would need to set the AR to 1 for home address space and do sac 512 to reference the TCB/rb/cde chain </snip> In the general case this is not correct. The general case is where your PC routine can be invoked from a previous space-switch PC routine, in which case your secondary address space (the one accessed by ALET 1) is not the home address space. ALET 2 is provided for accessing the home address space in AR mode (except for in Disabled Interrupt Exit paths where that is not the case). If you know that your PC routine had to be invoked with primary = home then it is true that ALET 1 works for you (as long as your PC is defined to set the new secondary ASN to the caller's primary ASN; it could choose not to do so, although I'm not sure I've ever seen any do that).
An ARR is not really any different than any other ESTAE-type recovery routine (and in particular no different than an ESTAEX recovery routine). The only difference lies with how you tell the system to locate the parameter data to be placed into register 2 for the recovery routine (and pointed to by SDWAPARM). As Joe R mentioned, for an ARR, it is via MSTA into the linkage stack entry created when the PC is issued. You might find IEAARR an interesting middle-ground choice that can be thought to lie somewhere between ARR and ESTAE/ESTAEX in performance. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
