Use this system macro to enable:
- An E-type program to request that the control program (CP)
establish a uniprocessor (UP) environment or reestablish the multiple
processor (MP) environment in a TPF system running on a multiple I-stream
central processing complex (CPC). This macro can only be run from a
program that operates on the main I-stream. This macro enables a
program that is not capable of processing in an MP environment to complete its
processing in a UP environment.
- The time-of-day (TOD) clock synchronization services to be
invoked when a TPF system has been paused.
Required Authorizations
|
Key0
| Restricted
| System
| Common Storage
|
| X
| X
|
|
Format
- label
- A symbolic name can be assigned to the macro statement.
- FUNC
- Specify one of the following:
- BEGIN
- Establish a UP environment.
- END
- Reestablish the MP environment.
- SYNC
- Invoke the TOD synchronization services. The TPF system must be in
a UP environment at this time.
- RQST
- The RQST parameter is required when the FUNC=SYNC is specified.
- VAL
- Determine and save status of all TOD clocks in the CPC. Restart any
stopped clocks.
- SET
- Synchronize the main I-stream TOD clock to a requested time.
Synchronize all other I-stream TOD clocks to the main I-stream clock
value.
Notes:
- If the TPF system is in a loosely coupled environment, the main I-stream
is synchronized to the external source of clock pulses. This
synchronization is via the TOD RPQ or the sysplex timer (STR). All
other I-streams are synchronized to the main I-stream. If the TPF
system is not in a loosely coupled environment, then the main I-stream is
either synchronized to a sysplex timer or it remains in local mode. All
other I-streams are synchronized to the main I-stream.
- The IBM 9037 Sysplex Timer is part of IBM Enterprise Systems Connection
(ESCON).
- SSYN
- Disable sync checks on all I-streams and for the TOD RPQ sets the sync
selection register on the main I-stream.
- Note:
- If the TPF system is in a loosely coupled environment with the High
Performance Option (HPO) feature installed, all I-streams are synchronized to
the external source of clock pulses (TOD RPQ or STR). If the TPF system
is not in a loosely coupled environment with the HPO feature installed, then
the main I-stream remains in local mode, providing clock synchronization
pulses for the other I-streams.
Entry Requirements
- This macro can be run on the main I-stream only.
- R9 must contain the address of the entry control block (ECB) being
processed.
Return Conditions
- Control is returned to the next sequential instruction (NSI).
- The contents of all user registers are preserved across this macro call
(R0 through R7, R14 through R15).
- The condition code upon return from this macro is unknown.
Programming Considerations
- This macro can be run on the main I-stream only.
- Use this macro with discretion. Processing in a UP environment can
seriously impact performance on an MP CPC. The time spent in the UP
environment must be kept to a minimum.
- The same ECB must stop and restart the MP environment.
- No memory locks or record holds are permitted while the system is in a UP
environment (paused).
- The TPF system must be paused by requesting FUNC=BEGIN before any other
function request. If the TPF system is not paused, the entry is exited
and a system error dump is issued. If another request is active, the
entry is exited and a system error dump is taken.
- When requesting a system UP pause, this ECB must not have previously
paused the TPF system. If it has, a system error dump is taken and
control is returned to the program.
- When requesting a system MP restart, this ECB must have previously paused
the TPF system. If not, the entry is exited and a system error dump is
issued.
Examples
None.