TCTL — Transfer control from an SRB routine

Description

The TCTL (transfer control) macro allows an SRB routine to exit from its processing and to pass control directly to a task.

Requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Supervisor state and any PSW key
Dispatchable unit mode:	SRB
Cross memory mode:	PASN=HASN=SASN
AMODE:	24- or 31-bit
ASC mode:	Primary
Interrupt status:	Enabled for I/O or external interrupts
Locks:	None held
Control parameters:	Must be in the caller's primary address space

The caller must include the following mapping macros:

None.

If you are using the default for the TCB parameter, on input to the TCTL macro, general purpose register (GPR) 4 must contain the address of the TCB.

The system does not return to the caller after invoking this macro, so register contents on exit from the macro are not applicable.

None.

The TCTL macro is coded as follows:

Syntax	Description

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

␢	One or more blanks must precede TCTL.

TCTL

␢	One or more blanks must follow TCTL.

TCB=(4)	Default: Register 4 contains TCB address.
TCB=`tcbaddr`	`tcbaddr`: A-type address or registers (2) - (12).

The parameters are explained as follows:

TCB=(4)
TCB=tcbaddr: Specifies the task designated for dispatching. Register 4 is the default; if you use the default, you must ensure that register 4 contains the appropriate TCB address.
Note: The TCB resides in storage below 16 megabytes.

070

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

The system does not return to the caller after this macro has been invoked, so return codes from the macro are not applicable.

From SRB mode processing, terminate the SRB and give control to the task specified in register 4.

TCTL TCB=(4)