CSRREFR — Refresh an object

Description

To refresh changed data that is in a window, a scroll area, or a temporary object, call the CSRREFR window service. CSRREFR refreshes changed data within specified blocks as follows:

If the object is permanent, CSRREFR replaces specified changed blocks in windows or the scroll area with corresponding blocks from the object on DASD.
For a temporary object, CSRREFR refreshes specified changed blocks in windows and the object by setting the blocks to binary zeros.

Environment

The requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Problem state with PSW key 8-15
Dispatchable unit mode:	Task
Cross memory mode:	PASN=HASN=SASN
AMODE:	24- or 31-bit, but all addresses must be 31-bit addresses
ASC mode:	Primary
Interrupt status:	Enabled for I/O and external interrupts
Locks:	No locks held
Control parameters:	Must be in the primary address space

Programming requirements

None.

Restrictions

The caller must follow all the restrictions imposed by the DIV macro.

Input register information

Before calling the CSRREFR service, the caller must ensure that the following general purpose registers (GPRs) contain the specified information:

Register: Contents
13: The address of a standard 18-word save area

Output register information

When control returns to the caller, the GPRs contain:

Register: Contents
0: Contains the reason code.
1: Used as a work register by the system
2-13: Unchanged
14: Used as a work register by the system
15: Return code

When control returns to the caller, the access registers (ARs) contain:

Register: Contents
0-1: Used as work registers by the system
2-13: Unchanged
14-15: Used as work registers by the system

Some callers depend on register contents remaining the same before and after issuing a service. If the system changes the contents of registers on which the caller depends, the caller must save them before issuing the service, and restore them after the system returns control.

Performance implications

None.

Syntax

Write the CALL as shown on the syntax diagram. You must code all parameters on the CALL statement in the order shown.

Syntax	Description
CALL CSRREFR	,(object_id ,offset ,span ,return_code ,reason_code)

Parameters

All input to callable services is in the form of RX-type addresses.

The parameters are explained as follows:

,(object_id

Specifies the object identifier. Supply the same object identifier that CSRIDAC returned when you obtained access to the object.

Define object_id as character data of length 8.

,offset

Specifies the offset into the object in blocks of 4096 bytes. A value of 0 specifies the first block of 4096 bytes or bytes 0 to 4095 of the object; a value of 1 specifies the second block of 4096 bytes, or bytes 4096 to 8191 of the object, and so forth.

Define offset as integer data of length 4.

offset and span, together, determine what part of the object window services refreshes. To refresh the entire object, specify 0 for offset and 0 for span.

,span

Specifies how many 4096-byte blocks CSRREFR is to refresh.

Define span as integer data of length 4.

,return_code

When CSRREFR completes, return_code contains the return code. Define return_code as integer data of length 4.

,reason_code)

When CSRREFR completes, reason_code contains the reason code. Define reason_code as integer data of length 4.

ABEND codes

CSRREFR might abnormally terminate with abend code X'019D'. See z/OS MVS System Codes for an explanation and programmer responses.

Return and reason codes

When the CSRREFR service returns control to your program, GPR 15 (and return_code) contains a return code and GPR 0 (and reason_code) contains a reason code. The following table identifies return code and reason code combinations and explains their meanings.

The data-in-virtual reason code, which is returned with CSRREFR return code X'C', is two bytes long and right justified. It is explained in the description of the DIV macro (DIV — Data-in-virtual).

Hexadecimal Return Code	Hexadecimal Reason Code	Meaning and Action
00000000	00000000	Meaning: The operation was successful. Action: None.
00000008	00000152	Meaning: Program error. The system could not refresh all the temporary objects within the specified span. Action: Investigate the following possible causes: The window to be refreshed contains an I/O DEFINEd block The data space in which the window is located is deleted.
0000000C	xxxxnnnn	Meaning: The value `nnnn` is a data-in-virtual reason code. The value `xxxx` is not part of the intended programming interface. Action: See the DIV macro description for an explanation of `nnnn`.
0000002C	00000004	Meaning: Program error. Window services have not been defined to your system, or the link to the service failed. Action: If window services are available on your system, rerun the program one or more times. If the problem persists, record the return and reason code, and contact the appropriate IBM® support personnel.