If you are using local or global shared resources, use the MRKBFR macro to mark a buffer.

The format of the MRKBFR macro is:

label

specifies 1 to 8 characters that provide a symbolic address for the MRKBFR macro.

MARK={DINVALID|XINVALID|OUT|RLS}

specifies the buffer identified in the RPL is either marked for output, or is to be released from either exclusive control or shared status. To do both, issue MRKBFR twice: once with MARK=OUT, once with MARK=RLS.

DINVALID|XINVALID

specifies that either the data component or the index component buffers are to be marked invalid. The buffers being invalidated are those that contain records with RBA values within the RBA range pointed to by the RPL ARG address. DINVALID specifies that the data component buffers be marked invalid. XINVALID specifies that the index component buffers be marked invalid.

OUT

specifies that the buffer be marked for output. The buffer is kept either under exclusive control or in shared status.

RLS

specifies that the buffer be released either from exclusive control or shared status.

RPL=address

specifies the address of the request parameter list defining the MRKBFR request. Use the SCHBFR or GET RPL to locate the buffer being marked or released. These RPL parameters have meaning for MRKBFR:

ACB=address

 

ARG=address

The address of the 8-byte field that contains the beginning and ending RBAs of the range being searched on.

For compressed data sets, the RBA of another record or the address of the next record in a buffer cannot be determined using the length of the current record or the length of the record provided to VSAM.

For extended addressing, the addressof a 16-byte field containing the beginning and ending 8-byte RBAs of the range.

ECB=address

 

TRANSID=number

All other RPL parameters are ignored. RPLs are assumed not to be chained. OPTCD=LOC is assumed.

If the ACB related to the RPL has MACRF=GSR, the program issuing MRKBFR must be in supervisor state with protection key 0 to 7.