gtpm6m0vMain Supervisor Reference

Owning Resources in a Loosely Coupled System

Hardware and software resources in a loosely coupled system are switchable, shared, or unique by processor:

Loosely coupled processors can dynamically acquire and release ownership of switchable hardware and software resources. The processor resource ownership facility (PROF) controls this dynamic ownership and maintains the status of tape drives and system utilities. System utilities are programs that perform repetitive everyday tasks, such as TPF capture.

Data Records Unique to Loosely Coupled Processing

Two tables support loosely coupled processing: the processor resource ownership table and the processor status table.

The processor resource ownership table (PROT) maintains the ownership status of tape drives and system utilities. You can use the ZPROT command to assign, release, and display ownership of resources. Although the PROT maintains tape drive ownership, the tape control program actually assigns and releases ownership. See TPF Operations for information on the ZTVAR command.

The system test compiler creates the PROT offline. You can load the PROT to the online system with the ZSLDR command when the system is in 1052 state.

The PROT consists of fixed file records of record type #PRORI. There is one record for tapes that contains space for a maximum of 257 entries. One or more records can be generated for system utilities; each record can contain as many as 102 entries.

The status of each processor is maintained in the processor status table (PIDT). TPF generates one PIDT for each processor in a loosely coupled complex. The PIDT is a main-storage resident record.