MONITOR MPLOCK command
Summary
- Privileges
- System administrator
- Function
- You can display information about Model 204 multiprocessor lock contention. The command output is mainly intended for Rocket Software Technical Support.
Syntax
MONITOR MPLOCK
Example
Your output might look similar to the following:
MONITOR MPLOCK Name Usage Spins Waits Posts ---- ----- ----- ----- ----- NONE no contention SIR1 no contention SIR2 no contention ITS1 no contention ITS2 no contention USR1 no contention USR2 no contention TST1 no contention TST2 no contention ECTM no contention ECMM no contention MQCH no contention MQST no contention MQTA no contention HASH DKDP 6 1 DKFB 79 78 93 DKFR 32 25 DKSW 91 45 56 LRUQ DKUC 90 1 DFB1 3 1 DFB2 67 2 2 DFR2 1 RCLK no contention FORT no contention V7IB no contention V7OB no contention QMAN no contention QUEU no contention DBCD DKUC 1 DU2L 4 2 1 DKRR 2 1 DKFB 2 FILD no contention TWND no contention CMLW CDEQ 1 PAGE no contention CNST no contention SMFS no contention JRNL BUFF 3
Usage
For each lock, separate counts are maintained for each use of the lock-meaning, for each purpose for which the lock can be requested).
| Output column | Indicates... |
|---|---|
Name |
Lock name |
Usage |
Usage names per lock name |
Spins |
Number of times that there was contention for the lock, and the requesting task was able to obtain the lock within MAXSPINS spins. |
Waits |
Number of times that there was contention, and the requesting task had to enter a WAIT for the lock. |
Posts |
Number of times that a task released a lock, and there was a waiting task to be posted. |
(unlabeled) |
If there is no contention for the lock |
All numbers are cumulative since the beginning of the run. The lock names and usage names relate to Model 204 internals only.
When you run Model 204 with the MP/204 (multiprocessor) option, the Model 204 nucleus uses a number of locks to control access to shared memory resources. For each lock, the output indicates the number of times since Model 204 started that contention for the lock occurred. Contention means that one task attempted to acquire the lock, but could not because another task was holding the lock at the time.
If you issue a MONITOR MPLOCK command, but are not running MP/204, the following message is displayed:
M204.1925: MPLOCK OPTION REQUIRES NMPSUBS>0