SUSPEND — Suspend execution of an RB

Description

Note: To suspend an SRB, use the variation of the SUSPEND macro described under SUSPEND — Suspend execution of an SRB.

To suspend execution of a request block (RB), use this variation of the SUSPEND macro. The RB remains suspended until a subsequent RESUME macro causes the RB to resume execution.

Environment

The requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Supervisor state with PSW key 0
Dispatchable unit mode:	Task
Cross memory mode:	Any
AMODE:	24- or 31-bit
ASC mode:	Primary or secondary
Interrupt status:	Can be either enabled or disabled
Locks:	Can hold the CPU or local lock
Control parameters:	Must be in the caller's primary address space

Programming requirements

The caller must include the IHAPSA mapping macro and the CVT mapping macro specifying DSECT=YES.

Restrictions

The list and execute forms of the SUSPEND macro are not valid for suspending execution of an RB.

Input register information

Before issuing the SUSPEND macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter or using it as a base register.

Output register information

After the caller issues the macro, the system might use some registers as work registers or might change the contents of some registers. When the system returns control to the caller, the contents of these registers are not the same as they were before the macro was issued. Therefore, if the caller depends on these registers containing the same value before and after issuing the macro, the caller must save these registers before issuing the macro and restore them after the system returns control.

When control returns to the caller, the general purpose registers (GPRs) contain:

Register: Contents
0: Address of the suspended TCB
1: Address of the suspended RB
2-10: Unchanged
11-15: Used as work registers by the system

Performance implications

None.

Syntax

The SUSPEND macro is written as follows:

Syntax	Description

`name`	`name`: Symbol. Begin `name` in column 1.

␢	One or more blanks must precede SUSPEND.

SUSPEND

␢	One or more blanks must follow SUSPEND.

RB=PREVIOUS	Default: RB=PREVIOUS
RB=CURRENT

Parameters

The parameters are explained as follows:

RB=PREVIOUS
RB=CURRENT: Specifies which RB on the TCB to suspend. The current RB is the one that is executing; it is the first RB on the RB chain. The previous RB is the one that follows the current RB on the RB chain.

ABEND codes

070

See z/OS MVS System Codes for an explanation and programmer responses for this code.

Return and reason codes

None.

Example

Suspend the execution of the most recently chained request block of the current task.

SUSPEND  RB=CURRENT