Providing an EXTRACT answer area

The EXTRACT macro provides TCB information for either the active task or one of its subtasks. Figure 1 shows the order in which the information from the requested fields is returned. If the information from a field is not requested, the associated fullword is omitted. See z/OS MVS Programming: Authorized Assembler Services Reference EDT-IXG for a description of the EXTRACT answer area fields.

Figure 1. EXTRACT Answer Area Fields

You must provide an answer area consisting of contiguous fullwords, one for each of the codes specified in the FIELDS parameter, with the exception of ALL. If ALL is specified, you must provide a 7-word area to accommodate the GRS, FRS, reserved, AETX, PRI, CMC, and TIOT fields. The ALL code does not include the COMM, TSO, PSB, TJID, and ASID fields.

Most of the addresses are returned in the low-order three bytes of the fullword, and the high-order byte is set to zero; the fields for AETX, TIOT, and PSB could have a nonzero first byte. Fields for which no addresses or values are specified in the task control block are set to zero.

For example, if you code FIELDS=(TIOT,GRS,PRI,TSO,PSB,TJID) you must provide a 6-fullword answer area, and the extracted information appears in the same relative order as shown in Figure 1. (That is, GRS is returned in the first word, PRI in the second word, TIOT in the third word, and so forth.)

If FIELDS=(ALL,TSO,PSB,COMM,ASID) is coded, you need an 11-fullword answer area, and the extracted information appears in the answer area in the relative order shown above.