Use this system macro to unlock a virtual file access (VFA) or a record
hold table (RHT) lock.
Format
- label
- A symbolic name can be assigned to the macro statement.
- LOCK
- Specifies the type of lock, where:
- VFA
- Specifies a VFA lock.
- RHT
- Specifies an RHT lock.
- TYPE
- Specifies whether the lock is immediate or delayed, where:
- I
- Specifies immediate.
- D
- Specifies delayed. A delayed unlock is cached whenever possible,
which means the lock is saved in the module file status table (MFST) and
processed as part of the next channel program that communicates with the
device.
Entry Requirements
Register 5 (R5) must contain the address of the VFA buffer control area
(BCA) only.
Return Conditions
- Control is returned to the next sequential instruction (NSI).
- Register 14 (R14) and register 15 (R15) are used to branch and link to the
macro service routine so the contents of both registers are corrupted.
All other registers are preserved.
Programming Considerations
- You can run this macro from any I-stream.
- This macro is for use in the control program (CP) only.
- System errors can occur while processing the $ULKRC macro.
See Messages (System Error and Offline) for more
information about these system errors.
Examples
The following example shows you how to unlock a VFA lock using this
macro.
$ULKRC LOCK=VFA