Steps for comparing global ENQ response time to RESERVE

About this task

Follow these steps to compare global ENQ response time to RESERVE:

Procedure

Copy out SYS1.SAMPLIB(ISGNQRSP).

Modify the following section of the program by appending ,RNL=NO as shown:

LOOP     EQU   *                                                   
*                                                                  
         STCK  TSTART                  SAVE TOD AT START OF REQUEST
         ENQ   (QNAME,RNAME,S,8,SYSTEMS),RNL=NO 
         STCK  TSTOP                   SAVE TOD AT END OF REQUEST  
         DEQ   (QNAME,RNAME,8,SYSTEMS),RNL=NO

To test RESERVE, modify the following section:

LOOP     EQU   *                                                   
*                                                                  
         STCK  TSTART                  SAVE TOD AT START OF REQUEST
         RESERVE (QNAME,RNAME,E,8,SYSTEMS),UCB=UCBADDR 
         STCK  TSTOP                   SAVE TOD AT END OF REQUEST  
         DEQ   (QNAME,RNAME,8,SYSTEMS)

Change the following assignments at the bottom of the program:

QNAME    DC    CL8'QNAMEABC'           FICTITIOUS ENQ RESOURCE NAME
RNAME    DC    CL8'ENQTIMER'                                       
*

Change QNAMEABC to a resource that is in your exclusion list (EXCL) and not in your conversion list (CONV).

After the RNAME line, add:

UCBADDR  DC    XL4'nnnnnnnn'           Address of UCB to RESERVE

Locate a UCB for a device that can be RESERVED by this system without causing an impact to other systems. Ensure that SYNCHRES=YES while the job is running, so that the RESERVE actually occurs under the ENQ process. The following system commands can help you determine the reserve status:

Table 1. System commands for reserve status
Command	Function
D, U,DASD,ONLINE	Displays the unit device numbers of online DASD with VOLSER and status
DS QP,(DEVICE NUMBER),UCB	Displays the UCB information, given the device number
D GRS	Displays global resource serialization information for a given system — including SYNCHRES indication.
SETGRS SYNCHRES=YES	Sets the SYNCHRES indication for a given system to YES