Retrieve_Context_Interest_Data (CTXRCID, CTX4RCID)

CTXRCID is for AMODE(31) callers.
CTX4RCID is for AMODE(64) callers and allows parameters in 64 bit addressable storage.

A resource manager calls the Retrieve_Context_Interest_Data service to retrieve the context interest data supplied by the resource manager in:

A call to the Express_Context_Interest service
A call to the Set_Context_Interest_Data service

In response to the call, context services also returns a return code.

A resource manager can express interest in a context multiple times. The particular interest for this call is identified by the context interest token your resource manager received from the Express_Context_Interest service.

Environment

The requirements for the resource manager are:

Minimum authorization:

PKM allowing key 0-7, or supervisor state

Dispatchable unit mode:

Task or SRB

Cross memory mode:

Any PASN, any HASN, any SASN

AMODE:

31 bit (CTXRCID)
64 bit (CTX4RCID)

ASC mode:

Primary or AR

Interrupt status:

Enabled for I/O and external interrupts

Locks:

No locks held

Control parameters:

Control parameters must be in the primary address space and addressable by the resource manager.

Programming requirements

Either link edit the resource manager's object code with the linkable stub routine CTXCSS (31 bit) or CTX4CSS (64 bit) from SYS1.CSSLIB, or LOAD and CALL the service. The high level language (HLL) definitions for the callable service are:

HLL definition	Description
CTXASM	390 Assembler declarations
CTXC	C/390 declarations

Restrictions

To call the service, the resource manager associated with the context interest token specified in the call must be in set state, which means it has registered and called the Set_Exit_Information service, specifying context services as the exit manager.

Input register information

Before issuing the call, the resource manager does not have to place any information into any register unless using it in register notation for the parameters, or using it as a base register.

Output register information

When control returns to the resource manager, the GPRs contain:.

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

When control returns to the resource manager, the 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 resource managers depend on register contents remaining the same before and after issuing a call. If the system changes the contents of registers on which the resource manager depends, the resource manager must save them before calling the service, and restore them after the system returns control.

Performance implications

None.

Syntax

Write the call as shown in the syntax diagram. You must code the parameters in the CALL statement as shown.

CALL CTXRCID

(return_code
,context_interest_token
,context_interest_data)

CALL CTX4RCID

(return_code
,context_interest_token
,context_interest_data)

Parameters

The parameters are explained as follows:

return_code

Returned parameter

Type: Integer
Character Set: N/A
Length: 4 bytes

Contains the return code from the Retrieve_Context_Interest_Data service.

,context_interest_token

Supplied parameter

Type: Character string
Character Set: No restriction
Length: 16 bytes

Specifies the context interest token that identifies your resource manager's interest in the context. Your resource manager received the token from the Express_Context_Interest service.

,context_interest_data

Returned parameter

Type: Character string
Character Set: No restriction
Length: 16 bytes

Receives the context interest data associated with this context interest. The resource manager supplied the data on the most recent call to the Express_Context_Interest or Set_Context_Interest_Data service. If no earlier call has supplied context interest data, the field contains hexadecimal zeros.

ABEND codes

The call might result in an abend X'AC7' with a reason code of either X'00160000' or X'00160001'. See z/OS MVS System Codes for the explanations and actions.

Return codes

When the service returns control to the resource manager, GPR 15 and return_code contain a hexadecimal return code.

Return Code in: Hexadecimal Equate Symbol	Meaning and action
0 CTX_OK	Meaning: Successful completion. Action: None.
103 CTX_INTERRUPT_STATUS_INV	Meaning: Program error. The resource manager is disabled; the interrupt status must be enabled for I/O and external interrupts. The system rejects the service call. Action: Check the resource manager for a probable coding error. Correct the resource manager and rerun it.
105 CTX_LOCKS_HELD	Meaning: Program error. The resource manager is holding one or more locks; no locks must be held. The system rejects the service call. Action: Check the resource manager for a probable coding error. Correct the resource manager and rerun it.
107 CTX_UNSUPPORTED_RELEASE	Meaning: Environmental error. The system release does not support this service. The system rejects the service call. Action: Remove the resource manager from the system, and install it on a system that supports registration services. Then rerun the resource manager.
365 CTX_CI_TOKEN_INV	Meaning: Program error. The context interest token specified in the call is not valid. The system rejects the service call. Action: Check the resource manager for a probable coding error. Correct the resource manager and rerun it.
FFF CTX_UNEXPECTED_ERROR	Meaning: System error. The service that was called encountered an unexpected error. The system rejects the service call. Action: Search problem reporting databases for a fix for the problem. If no fix exists, contact the IBM® Support Center.

Example

In the pseudocode example, the resource manager issues a call to retrieve context interest data. Storage for the call parameters has been allocated.

⋮
CI_TOKEN = CONTEXT_INTEREST_TOKEN
CALL CTXRCID(RC,CI_TOKEN,CI_DATA)
IF RC = CTX_OK THEN
  CONTEXT_I_DATA = CI_DATA
⋮