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HP OpenVMS Systemsask the wizard |
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The Question is:
We have a process in RWAST state. Until the system will be booted (it's a
production system), we are only monitoring that process. In the monitor (com
file), we used the f$getjpi lexical function.
And the question is:
Why the resualt of that lexical with this process gives a MWAIT result, while
the process is in RWAST for days?
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Some snapshots:
>sh sys/stat=rwast
OpenVMS V7.1 on node F18WS4 4-FEB-2001 08:54:48.42 Uptime 88 16:06:45
Pid Process Name State Pri I/O CPU Page flts Pages
20E3662F RIA.sc.1.4 RWAST 7 23308 0 00:01:39.80 3999 5549
>state == f$getjpi("20E3662F","state")
>sh sym state
STATE == "MWAIT"
Thx,
Iris
The Answer is :
The state "MWAIT" stands for "Miscellaneous WAIT state". This is a
generic category which includes a number of "sub states", one of which
is RWAST. RWAST stands for "Resource Wait Asynchronous System Trap"
which indicates that the process is waiting for a resource, the
availability of which is expected to be reported by an AST being
delivered to the process. For processes in MWAIT state, the substate is
indicated by the value in the event flag wait mask (JPI code EFWM). The
values of the substates can be found in the macro $RSNDEF from LIB.MLB
Some utilities, like SHOW SYSTEM, decode the MWAIT states into substates.
Others do not. Still others, such as SHOW PROCESS/CONTINUOUS, report an
MWAIT process as "suspended".
The following command procedure will determine the state string for a
process, including substates of MWAIT. Note that since F$GETJPI needs
to be called twice, it is possible for the target process to change
states between the calls. RSN states are derived from an OpenVMS/Alpha
V7.2-1 system. In this example the process state is printed, returning
the string to the caller left as an exercise for the reader.
PSTATE.COM
$ IF p1.EQS."" THEN INQUIRE p1 "PID"
$ state=F$GETJPI(p1,"STATE")
$ efwm=F$GETJPI(p1,"EFWM")
$ IF state.EQS."MWAIT" THEN state=F$ELEMENT(efwm,"/",-
"/RWAST/RWMBX/RWNPG/RWPFF/RWPAG/RWBRK/RWIMG/RWQUO/RWLCK/RWSWP"+-
"/RWMPE/RWMPB/RWSCS/RWCLU/RWCAP/RWCSV/RWSNP/RWXFR/RWINS/RWEXH/")
$ IF state.EQS."".OR.state.EQS."/" THEN state="MWAIT" ! Unrecognised EFWM value
$ SHOW SYM state
$ EXIT
Related topics here in Ask The Wizard include (6), (2347), (5841),
and (7120).
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