VX/JSP – OpenVMS Print & Batch

Request flow

A DCL command enters through VX/DCL, which calls SYS$SNDJBC. The service builds a job stream and writes it into the jobs file, then signals the controller through a shared request record. The controller routes the request to the right queue slot and feeds the queue's qmgr over a FIFO; the queue worker then starts a pjob symbiont to run the job.

Process lifecycle

The three daemons share one fixed startup pattern. Each of jspctl, qmgr and pjob runs the same six phases in order: initialise, open the log, attach the spool area, start, enter the main loop, and finalise on shutdown.

Records

The three core record classes preserve the OpenVMS field semantics so that queue, job and form attributes survive migration byte for byte:

• Queue record. Carries the queue name, node name and server address, the process id, manager and queue status flags, default and mounted form numbers, job count and job limit, base, standard and active priorities, owner, device, processor and library names, a generic-queue routing list, and a description.
• Job record. Carries the entry number (which replaces the VMS job id), job status and flags, the VMS exit status, submitting user uid and gid, form number, copy count, page ranges, up to eight DCL parameters, submit, after and until times, the log file and working directory, and a per-file array (up to 16 files per job) with each file's name, status, page range and copy counts.
• Form record. Carries the form number, length and width, top, bottom, left and right margins, flags, description, page-setup and setup names, and stock.

Job record state byte

The state byte on each job record tracks where the entry is in its lifecycle.

SYS$SNDJBC and SYS$SNDJBCW

SYS$SNDJBC sends a request to the job controller: it submits and controls jobs, and creates, alters and controls queues. Requests carry a function code plus an item list. The service supports the full VMS function range; the operation codes below are a representative subset of those implemented.

Input item codes cover the job and queue attributes an application sets when submitting or altering work, such as after-time, base priority, batch flag, characteristic name, checkpoint data and command-language interpreter. Return status uses the standard VMS JBC$ status codes, for example normal completion, invalid function code, invalid item code and empty job.

SYS$GETQUI and SYS$GETQUIW

SYS$GETQUI queries queue, job, file and form information. It supports ten function codes over a large item-code space, and this is the service behind SHOW QUEUE and the qmon monitor.

Qualifiers

The queue and job commands carry the OpenVMS qualifier sets, covering print, batch and queue/form definition. The source-visible qualifiers include:

• INITIALIZE/QUEUE: /BASE_PRIORITY, /BATCH, /BURST, /DEFAULT, /FEED, /FORM, /FORM_MOUNTED, /JOB_LIMIT, /ON, /PRIORITY, /START, /STOCK, /TRAILER.
• PRINT: /AFTER, /COPIES, /DELETE, /FEED, /FORM, /HEADER, /HOLD, /NOTIFY, /PRIORITY, /QUEUE, /SETUP, /STOCK, /TRAILER.
• SUBMIT: /AFTER=time, /DELETE, /HOLD, /[NO]KEEP, /NOTIFY, /PARAMETERS=(p1..p8), /PRINTER[=queue], /QUEUE=queue (default SYS$BATCH).

Worked example: submit a batch job

Submitting a DCL command file and checking its status, using the site's demo batch queue:

$ submit/notify/queue=sys$batch/print/nokeep FUNDS_TRANSFER.COM
  Job FUNDS_TRANSFER.COM pending on SYS$BATCH, entry 2
$
$ show queue/full/all sys$batch
Batch queue SYS$BATCH, running
    /PRIORITY=0  /NOENABLE_GENERIC
    /JOB_LIMIT=1
Jobname               Username   Entry   Status
-------               --------   -----   ------
FUNDS_TRANSFER.COM    batchop        2   executing

Job FUNDS_TRANSFER.COM (queue SYS$BATCH, entry 2) completed.
$

Sample queue display output

VX/JSP retains the VMS queue listing format, so operators see familiar output. The qmon monitor prints queues (Q:) and jobs (J:) with their record numbers, process ids, owners and status:

                                           --- locks ---
    rec#  job# name                    pid    own    upd status
Q:     0     0 JSPCTL                18053  18053      0 running - available jobs 0 max 0
Q:     1     1 SYS$BATCH             18056  18056      0 running - idle,available jobs 5 max 5
J:     6     6 EVENT_6               18283  18277      0 Executing    18277 00040001
J:    11    11 EVENT_11                  0      0      0 Pending          0 00040001
                                                          5 of 7 jobs executing
Q:     2     2 SYS$PRINT             18059  18059      0 running - idle,available jobs 1 max 1
   4 queue records, 14 job records, 6 executing

Batch path

A batch job runs its command file exactly as it did on OpenVMS. The original DCL syntax is retained, so existing .COM procedures migrate without modification. Submitting users' uid and gid are honoured, queue priorities and scheduling intervals control execution, and a single queue can run multiple jobs at once up to its job limit.

Print path

The print path reproduces the VMS symbiont behaviour: form setup and load, page geometry (headers, trailers, feeds, page ranges), burst and flag pages, and carriage-control fixup that converts VMS record formatting to the target stream. Setup modules and text libraries are supported through the /SETUP and /LIBRARY qualifiers. Print jobs can restart on a specific page, and queues support reordering and job prioritization.

Networked printing

Printing to physical devices maps VMS devices to their Linux equivalents. Jobs can print to locally connected devices or spoolers, to direct printer connections, or to mapped network printers. A print-device layer handles host and port connections with PCL and PJL detection, and dedicated symbionts cover terminal-server (telnet) and Xerox devices.

Forms

Forms are first-class: DEFINE/FORM records margins, length, width, stock and page-setup names, and the form_read tool dumps form records for inspection. Queues carry a default and a mounted form, so form-based print layouts migrate with the queue definitions that reference them.

Divergences from OpenVMS

VX/JSP preserves external behaviour while substituting Linux facilities for VMS internals where there is no direct equivalent.

Processes and tools

Queue files (spool directory)

System services

• SYS$SNDJBC / SYS$SNDJBCW - submit and control jobs; create and control queues.
• SYS$GETQUI / SYS$GETQUIW - query queue, job, file and form information (10 function codes).

Key DCL verbs

Limits

Build and install

VX/JSP builds with the standard Linux toolchain: g++ and gcc, POSIX threads, fcntl record locks and BSD sockets, with an optional X11/Xt (or Qt) build for the qmon GUI. Install places the controller and workers setuid root, or grants the equivalent Linux capabilities.