Parameters Related to the UPDATE Function

If the DESERV exit gets control for a DESERV UPDATE function invocation, DESX_DESP_PTR points to the DESERV parameter list. If the DESP field DESP_FUNC=X'09' (DESP_FUNC_UPDATE), this indicates an UPDATE function parameter list. Table 1 shows the fields of the DESP that pertain to the DESERV UPDATE invocation.

Table 1. DESERV UPDATE DESP Fields
Offset	Length or Bit Pattern	Name	Description
00 (X'00')	104	DESP	DE Services parameter list (structure)
00 (X'00')	16	DESP_HEADER	Standard header (character)
00 (X'00')	8	DESP_ID	Eyecatcher 'IGWDESP' (character)
08 (X'08')	4	DESP_LEN	Length of DESP (signed)
08 (X'08')	X'04'	DESP_LEN_IV	Constant to be used with DESP_LEN
12 (X'0C')	1	DESP_LEV	Control block level (character)
12 (X'0C')	X'04'	DESP_LEV_IV	Constant to be used with DESP_LEV
13 (X'0D')	3	-	Reserved
16 (X'10')	1	DESP_FUNC	Function type (GET=X'01', PUT=X'04', DELETE=X'07', RENAME=X'08', UPDATE=X'09')
	X'09'	DESP_FUNC_UPDATE	Constant to be used with DESP_FUNC
	X'08'	DESP_FUNC_RENAME	Constant to be used with DESP_FUNC
	X'07'	DESP_FUNC_DELETE	Constant to be used with DESP_FUNC
	X'04'	DESP_FUNC_PUT	Constant to be used with DESP_FUNC
	X'01'	DESP_FUNC_GET	Constant to be used with DESP_FUNC
	X'00'	DESP_FUNC_OMITTED	Constant to be used with DESP_FUNC
17 (X'11')	3	-	Reserved
20 (X'14')	4	-	Reserved
24 (X'18')	12	DESP_DATA	Function data (character)
24 (X'18')	2	-	Reserved
26 (X'1A')	1	-	Reserved
27 (X'1B')	1	-	Reserved
28 (X'1C')	1	DESP_LIBTYPE	Function subtype (DCB,DEB) (DCB input X'02', DEB input X'01') (unsigned)
	X'02'	DESP_LIBTYPE_DCB	Constant to be used with DESP_LIBTYPE
	X'01'	DESP_LIBTYPE_DEB	Constant to be used with DESP_LIBTYPE
	X'00'	DESP_LIBTYPE_OMITTED	Constant to be used with DESP_LIBTYPE
29 (X'1D')	1	-	Reserved
30 (X'1E')	1	-	Reserved
31 (X'1F')	1	-	Reserved
32 (X'20')	1	-	Reserved
33 (X'21')	1	-	Reserved
34 (X'22')	1	-	Reserved
35 (X'23')	1	-	Reserved
36 (X'24')	4	DESP_DCB_PTR	DCB address
40 (X'28')	4	DESP_DEB_PTR	DEB address
44 (X'2C')	4	-	Reserved
48 (X'30')	4	-	Reserved
52 (X'34')	4	-	Reserved
56 (X'38')	4	-	Reserved
60 (X'3C')	4	-	Reserved
64 (X'40')	4	-	Reserved
68 (X'44')	4	-	Reserved
72 (X'48')	4	-	Reserved
76 (X'4C')	4	-	Reserved
80 (X'50')	4	DESP_NAME_LIST	List of SMDEs with imbedded PMAR (and PMARL) to update the directory information (DESL) (address)
84 (X'54')	4	DESP_NAME_LIST2	Number of entries in DESL name list (unsigned)
88 (X'58')	4	-	Reserved
92 (X'5C')	4	-	Reserved
96 (X'60')	4	-	Reserved
100 (X'64')	4	-	Reserved

The DESL points to the SMDEs which are to be updated. The DESP_NAME_LIST_PTR points to the DESL and the DESL DSECT in the IGWDES macro maps it. A DESL is an array consisting of the number of entries the DESP field DESP_NAME_LIST2 defines. The DESL structure is shown in Table 2.