Parameters Related to the GET Function

If the DESERV exit gets control for a DESERV GET function invocation, DESX_DESP_PTR points to the DESERV parameter list. If the DESP field DESP_FUNC=X'01' (DESP_FUNC_GET), this indicates a GET function parameter list. See Table 1 for the DESP structure for fields pertaining to a DESERV GET invocation.

DESERV GET will return information on selected members. This information is returned in a DESB structure. The DESB is mapped by the DESB DSECT in the IGWDES macro. If the storage for the DESB is provided by the DESERV GET, the DESP_AREA_PTR field contains the address of this storage. Alternatively the caller may request that DESERV GET not obtain the storage for the DESB. In this case the DESP_AREAPTR_PTR field contains the address of a 4 byte area into which DESERV GET will return the address of a DESB. The DESB will be obtained in the subpool identified by DESP_SUBPOOL (or default to subpool zero). The flag DESP_SUBPOOL_FLG indicates whether the subpool was specified explicitly by the DESERV GET caller.

A DESERV GET invocation identifies the members to be searched for by a name list, a PDS format directory entry, or an SMDE. The DESP field DESP_GETTYPE defines the get type. If the get type is a PDSDE (the member to be searched for is defined by a PDS format directory entry), the DESP_PDSDE_PTR points to a directory entry as returned by the BLDL macro. The PDS2 DSECT in the IHAPDS macro maps this structure. The function of DESERV GET for a PDSDE get type depends on the type of library identified by the concatenation number in the PDS style directory entry. If the concatenation number identifies a PDS, the GET function is simply to convert the PDS style directory entry into a SMDE. If the concatenation number identifies a PDSE, the GET function is to connect to the member identified by the PDS2TTRP field, and to return the appropriate SMDE. In either case the SMDE is retuned (if in the PDSE case the member actually exists) in the data portion of the output buffer (DESB, mapped below).

If the get type is name list, the DESL area points to the names to be searched for. 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 parameter list is shown in Table 2.

If the get type is SMDE, the DESP_SMDE_PTR points to a system-managed directory entry (SMDE) as returned by DESERV GET. DESERV GET will cause a connection to the member identified by the SMDE. DESERV GET will return a copy of the SMDE in the output DESB. The SMDE returned will of course have updated connect token and connect id fields.

There are two input flags which control DESERV GET's view of the PDS or PDSE to be searched. If the DESP_C370LIB flag is on, a PDS may be viewed as a C370LIB. This means that if the PDS has a special member named @@DC370$, this member is treated as the "real" directory for the PDS. If the DESP_SYSTEM_DCB is on, this indicates that the caller (who must be authorized) has indicated that this DCB is "owned by the system" and is not on any DEB chain, therefore DEBCHK should not be done.

The DESERV GET caller will have built the DESL to point to variable length names. The DESN DSECT maps these names in the IGWDES macro. See Table 3 for the DESN parameter list.

The DESP_CONN_INTENT field of the DESP indicates the connection intent requested by the caller. The connection intent only has an effect if the name is found in a PDSE. If the connection intent is DESP_CONN_INTENT_HOLD (X'01'), the effect is similar to a BLDL invocation (because the member is connected for HOLD which is not sufficient to read the member). If the connection intent is DESP_CONN_EXEC (X'02') or DESP_CONN_INTENT_INPUT (X'03'), the effect is similar to a FIND invocation (because the member is connected and sufficient control blocks are built so that the member can be read). The GET function does not currently support a connect intent of NONE.

The output from DESERV GET consists of flags and error codes in the DESL (if the get type is name list) as well as an SMDE (system managed directory entry) pointer. For a gettype of name list, the SMDE is pointed to by the DESL_SMDE_PTR field. For a gettype of PDSDE, the SMDE is in the DESB at the label DESB_DATA. The SMDE is mapped by the SMDE DSECT in the IGWSMDE macro and the PMAR DSECT in the IEWPMAR macro. The SMDE resides in the output buffer as provided by the caller of DESERV GET. The output buffer is mapped by the DESP DSECT of the IGWDES macro. The DESB structure is shown in Table 4.

The basic SMDE format is shown in Table 5.

Table 6 through Table 9 shows the optional SMDE_SECTIONS, or extensions to the SMDE.

If the SMDE represents a directory entry for a program (either a load module or a program object) the program's attributes are defined by the PMAR structure. The PMAR is a subfield of the SMDE and its offset is defined by the field SMDE_PMAR_OFF. Table 10 shows the basic PMAR definition. Table 11 and Table 12 show the PMAR extensions for program objects (PMARL) and load modules (PMARR), respectively.

If the SMDE represents a data member of a PDS or a PDSE, the SMDE_USRD_OFF field indicates the offset into the SMDE for the user data of the directory entry.