Use this system macro to obtain an available system work block (SWB)
storage address.
Required Authorizations
|
Key0
| Restricted
| System
| Common Storage
|
| X
|
|
|
Format
- label
- A symbolic name can be assigned to the macro statement.
- BLOCK=reg
- Specifies where the SWB address will be placed after the macro completes
processing, where reg is a register from R0 - R7.
Entry Requirements
This macro is restricted to ECB-controlled programs.
Return Conditions
None.
Programming Considerations
- An SWB is not released when the entry control block (ECB) exits. To
prevent the TPF system from running out of SWBs, the application program that
issues the GSWBC macro must also release the SWB by issuing the RSWBC
macro. See RSWBC-Release a System Work Block (SWB) for more information about the RSWBC macro.
- The address returned is a 31-bit address and may point to an SWB allocated
above the 16-MB boundary. The application program must be running in
31-bit mode to access data above the 16-MB boundary.
Examples
The following example gets an SWB and places the address in register 5
(R5).
GSWBC BLOCK=R5