The Symbiont/Job Controller Interface (SMB) routines provide the
interface between the job controller and symbiont processes. A
user-written symbiont must use these routines to communicate with
the job controller.
1 – SMB$CHECK_FOR_MESSAGE
The SMB$CHECK_FOR_MESSAGE routine determines whether a message
sent from the job controller to the symbiont is waiting to be
read.
Format
SMB$CHECK_FOR_MESSAGE
1.1 – Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
1.2 – Arguments
None.
1.3 – Description
When your symbiont calls the SMB$INITIALIZE routine to initialize
the interface between the symbiont and the job controller, you
can choose to have requests from the job controller delivered
by means of an AST. If you choose not to use ASTs, your symbiont
must call SMB$CHECK_FOR_MESSAGE during the processing of tasks in
order to see if a message from the job controller is waiting to
be read. If a message is waiting, SMB$CHECK_FOR_MESSAGE returns a
success code; if not, it returns a zero.
If a message is waiting, the symbiont should call SMB$READ_
MESSAGE to read it to determine if immediate action should be
taken (as in the case of STOP_TASK, RESET_STREAM or PAUSE_TASK).
If a message is not waiting, SMB$CHECK_MESSAGE returns a zero.
If this condition is detected, the symbiont should continue
processing the request at hand.
1.4 – Condition Values Returned
SS$_NORMAL One or more messages waiting.
0 No messages waiting.
2 – SMB$INITIALIZE
The SMB$INITIALIZE routine initializes the user-written symbiont
and the interface between the symbiont and the job controller. It
allocates and initializes the internal databases of the interface
and sets up the mechanism that is to wake up the symbiont when a
message is received.
Format
SMB$INITIALIZE structure_level [,ast_routine] [,streams]
2.1 – Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
2.2 – Arguments
structure_level
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
Version of the symbiont/job controller interface. The structure_
level argument is the address of a longword containing the
version of the symbiont/job controller interface used when the
symbiont was compiled. Always place the value of the symbol
SMBMSG$K_STRUCTURE_LEVEL in the longword addressed by this
argument. Each programming language provides an appropriate
mechanism for defining symbols.
ast_routine
OpenVMS usage:ast_procedure
type: procedure value
access: read only
mechanism: by reference
Message-handling routine called at AST level. The ast_routine
argument is the address of the entry point of the message-
handling routine to be called at AST level when the symbiont
receives a message from the job controller. The AST routine is
called with no parameters and returns no value. If an AST routine
is specified, the routine is called once each time the symbiont
receives a message from the job controller.
The AST routine typically reads the message and determines if
immediate action must be taken. Be aware that an AST can be
delivered only while the symbiont is operating at non-AST level.
Thus, to ensure delivery of messages from the job controller, the
symbiont should not perform lengthy operations at AST level.
If you do not specify the ast_routine argument, the symbiont
must call the SMB$CHECK_FOR_MESSAGE routine to check for waiting
messages.
streams
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
Maximum number of streams the symbiont is to support. The streams
argument is the address of a longword containing the number of
streams that the symbiont is to support. The number must be in
the range of 1 to 32.
If you do not specify this argument, a default value of 1 is
used. Thus, by default, a symbiont supports one stream. Such a
symbiont is called a single-threaded symbiont.
A stream (or thread) is a logical link between a queue and a
symbiont. When a symbiont is linked to more than one queue, and
serves those queues simultaneously, it is called a multithreaded
symbiont.
2.3 – Description
Your symbiont must call SMB$INITIALIZE before calling any
other SMB routines. It calls SMB$INITIALIZE in order to do the
following:
o Allocate and initialize the SMB facility's internal database.
o Establish the interface between the job controller and the
symbiont.
o Determine the threading scheme of the symbiont.
o Set up the mechanism to wake your symbiont when a message is
received.
After the symbiont calls SMB$INITIALIZE, it can communicate with
the job controller using the other SMB routines.
2.4 – Condition Values Returned
SS$_NORMAL Normal successful completion.
SMB$_INVSTRLEV Invalid structure level.
This routine also returns any codes returned by $ASSIGN and
LIB$GET_VM.
3 – SMB$READ_MESSAGE
The SMB$READ_MESSAGE routine copies a message that the job
controller has sent into the caller's specified buffer.
Format
SMB$READ_MESSAGE stream ,buffer ,request
3.1 – Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
3.2 – Arguments
stream
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: write only
mechanism: by reference
Stream number specifying the stream to which the message refers.
The stream argument is the address of a longword into which the
job controller writes the number of the stream referred to by
the message. In single-threaded symbionts, the stream number is
always 0.
buffer
OpenVMS usage:char_string
type: character string
access: write only
mechanism: by descriptor
Address of the descriptor that points to the buffer into which
the job controller writes the message. SMB$READ_MESSAGE uses
the Run-Time Library string-handling (STR$) routines to copy
the message into the buffer you supply. The buffer should be
specified by a dynamic string descriptor.
request
OpenVMS usage:identifier
type: longword (unsigned)
access: write only
mechanism: by reference
Code that identifies the request. The request argument is the
address of a longword into which SMB$READ_MESSAGE writes the code
that identifies the request.
There are seven request codes. Each code is interpreted as a
message by the symbiont. The codes and their descriptions follow:
SMBMSG$K_START_ Initiates processing on an inactive
STREAM symbiont stream. The job controller sends
this message when a START/QUEUE or an
INITIALIZE/QUEUE/START command is issued
on a stopped queue.
SMBMSG$K_STOP_ Stops processing on a started queue. The
STREAM job controller sends this message when a
STOP/QUEUE/NEXT command is issued, after
the symbiont completes any currently active
task.
SMBMSG$K_RESET_ Aborts all processing on a started stream
STREAM and requeues the current job. The job
controller sends this message when a
STOP/QUEUE/RESET command is issued.
SMBMSG$K_START_TASK Requests that the symbiont begin processing
a task. The job controller sends this
message when a file is pending on an idle,
started queue.
SMBMSG$K_STOP_TASK Requests that the symbiont abort the
processing of a task. The job controller
sends this message when a STOP/QUEUE/ABORT
or STOP/QUEUE/REQUEUE command is issued.
The item SMBMSG$K_STOP_CONDITION identifies
whether this is an abort or a requeue
request.
SMBMSG$K_PAUSE_TASK Requests that the symbiont pause in the
processing of a task but retain the
resources necessary to continue. The
job controller sends this message when
a STOP/QUEUE command is issued without
the /ABORT, /ENTRY, /REQUEUE, or /NEXT
qualifier for a queue that is currently
printing a job.
SMBMSG$K_RESUME_ Requests that the symbiont continue
TASK processing a task that has been stopped
with a PAUSE_TASK request. This message is
sent when a START/QUEUE command is issued
for a queue served by a symbiont that has
paused in processing the current task.
3.3 – Description
Your symbiont calls SMB$READ_MESSAGE to read a message that the
job controller has sent to the symbiont.
Each message from the job controller consists of a code
identifying the function the symbiont is to perform and a number
of message items. There are seven codes. Message items are pieces
of information that the symbiont needs to carry out the requested
function.
For example, when you enter the DCL command PRINT, the job
controller sends a message containing a START_TASK code and
a message item containing the specification of the file to be
printed.
SMB$READ_MESSAGE writes the code into a longword (specified by
the request argument) and writes the accompanying message items,
if any, into a buffer (specified by the buffer argument).
See the description of the SMB$READ_MESSAGE_ITEM routine for
information about processing the individual message items.
3.4 – Condition Values Returned
SS$_NORMAL Normal successful completion.
LIB$_INVARG Routine completed unsuccessfully because of an
invalid argument.
This routine also returns any of the condition codes returned by
the Run-Time Library string-handling (STR$) routines.
4 – SMB$READ_MESSAGE_ITEM
The SMB$READ_MESSAGE_ITEM routine reads a buffer that was filled
in by the SMB$READ_MESSAGE routine, parses one message item from
the buffer, writes the item's code into a longword, and writes
the item into a buffer.
Format
SMB$READ_MESSAGE_ITEM message ,context ,item_code ,buffer
[,size]
4.1 – Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
4.2 – Arguments
message
OpenVMS usage:char_string
type: character string
access: read only
mechanism: by descriptor
Message items that SMB$READ_MESSAGE_ITEM is to read. The message
argument is the address of a descriptor of a buffer. The buffer
is the one that contains the message items that SMB$READ_MESSAGE_
ITEM is to read. The buffer specified here must be the same as
that specified with the call to the SMB$READ_MESSAGE routine,
which fills the buffer with the contents of the message.
context
OpenVMS usage:context
type: longword (unsigned)
access: modify
mechanism: by reference
Value initialized to 0 specifying the first message item in
the buffer to be read. The context argument is the address of a
longword that the SMB$READ_MESSAGE_ITEM routine uses to determine
the next message item to be returned. When this value is 0,
it indicates that SMB$READ_MESSAGE_ITEM is to return the first
message item.
The SMB$READ_MESSAGE_ITEM routine updates this value each time it
reads a message item. SMB$READ_MESSAGE_ITEM sets the value to 0
when it has returned all the message items in the buffer.
item_code
OpenVMS usage:smb_item
type: longword (unsigned)
access: write only
mechanism: by reference
Item code specified in the message item that identifies its type.
The item_code argument is the address of a longword into which
SMB$READ_MESSAGE_ITEM writes the code that identifies which item
it is returning.
The codes that identify message items are defined at the end of
the Description help topic for this routine.
buffer
OpenVMS usage:char_string
type: character string
access: write only
mechanism: by descriptor
Message item. The buffer argument is the address of a descriptor
of a buffer. The buffer is the one in which the SMB$READ_MESSAGE_
ITEM routine is to place the message item data. SMB$READ_MESSAGE_
ITEM uses the Run-Time Library string-handling (STR$) routines to
copy the message item data into the buffer.
size
OpenVMS usage:word_unsigned
type: word (unsigned)
access: write only
mechanism: by reference
Size of the message item. The size argument is the address of a
word in which the SMB$READ_MESSAGE_ITEM is to place the size, in
bytes, of the item's data.
4.3 – Description
The job controller can request seven functions from the symbiont.
They are identified by the following codes:
SMBMSG$K_START_STREAM SMBMSG$K_STOP_STREAM
SMBMSG$K_START_TASK SMBMSG$K_PAUSE_TASK
SMBMSG$K_RESUME_TASK SMBMSG$K_STOP_TASK
SMBMSG$K_RESET_STREAM
The job controller passes the symbiont a request containing
a code and, optionally, a number of message items containing
information the symbiont might need to perform the function. The
code specifies what function the request is for, and the message
items contain information that the symbiont needs to carry out
the function.
By calling SMB$READ_MESSAGE, the symbiont reads the request
and writes the message items into the specified buffer. The
symbiont then obtains the individual message items by calling
the SMB$READ_MESSAGE_ITEM routine.
Each message item consists of a code that identifies the
information the item represents, and the item itself. For
example, the SMB$K_JOB_NAME code tells the symbiont that the
item specifies a job's name.
The number of items in a request varies with each type of
request. Therefore, you must call SMB$READ_MESSAGE_ITEM
repeatedly for each request to ensure that all message items
are read. Each time SMB$READ_MESSAGE_ITEM reads a message item,
it updates the value in the longword specified by the context
argument. SMB$READ_MESSAGE_ITEM returns the code SMB$_NOMOREITEMS
after it has read the last message item.
The following table shows the message items that can be delivered
with each request:
Request Message Item
SMBMSG$K_START_TASK SMBMSG$K_ACCOUNT_NAME
SMBMSG$K_AFTER_TIME
SMBMSG$K_BOTTOM_MARGIN
SMBMSG$K_CHARACTERISTICS
SMBMSG$K_CHECKPOINT_DATA
SMBMSG$K_ENTRY_NUMBER
SMBMSG$K_FILE_COPIES
SMBMSG$K_FILE_COUNT
SMBMSG$K_FILE_IDENTIFICATION
SMBMSG$K_FILE_SETUP_MODULES
SMBMSG$K_FILE_SPECIFICATION
SMBMSG$K_FIRST_PAGE
SMBMSG$K_FORM_LENGTH
SMBMSG$K_FORM_NAME
SMBMSG$K_FORM_SETUP_MODULES
SMBMSG$K_FORM_WIDTH
SMBMSG$K_JOB_COPIES
SMBMSG$K_JOB_COUNT
SMBMSG$K_JOB_NAME
SMBMSG$K_JOB_RESET_MODULES
SMBMSG$K_LAST_PAGE
SMBMSG$K_LEFT_MARGIN
SMBMSG$K_MESSAGE_VECTOR
SMBMSG$K_NOTE
SMBMSG$K_PAGE_SETUP_MODULES
SMBMSG$K_PARAMETER_1
.
.
.
SMBMSG$K_PARAMETER_8
SMBMSG$K_PRINT_CONTROL
SMBMSG$K_SEPARATION_CONTROL
SMBMSG$K_REQUEST_CONTROL
SMBMSG$K_PRIORITY
SMBMSG$K_QUEUE
SMBMSG$K_RIGHT_MARGIN
SMBMSG$K_TIME_QUEUED
SMBMSG$K_TOP_MARGIN
SMBMSG$K_UIC
SMBMSG$K_USER_NAME
SMBMSG$K_STOP_TASK SMBMSG$K_STOP_CONDITION
SMBMSG$K_PAUSE_TASK None
SMBMSG$K_RESUME_ SMBMSG$K_ALIGNMENT_PAGES
TASK
SMBMSG$K_RELATIVE_PAGE
SMBMSG$K_REQUEST_CONTROL
SMBMSG$K_SEARCH_STRING
SMBMSG$K_START_ SMBMSG$K_DEVICE_NAME
STREAM
SMBMSG$K_EXECUTOR_QUEUE
SMBMSG$K_JOB_RESET_MODULES
SMBMSG$K_LIBRARY_SPECIFICATION
SMBMSG$K_STOP_ None
STREAM
SMBMSG$K_RESET_ None
STREAM
The following list describes each item code. For each code, the
list describes the contents of the message item identified by
the code and whether the code identifies an item sent from the
job controller to the symbiont or from the symbiont to the job
controller.
Many of the codes described are specifically oriented toward
print symbionts. The symbiont you implement, which might not
print files or serve an output device, need not recognize all
these codes. In addition, it need not respond in the same way as
the print symbiont to the codes it recognizes. The descriptions
in the list describe how the standard print symbiont (PRTSMB.EXE)
processes these items.
NOTE
Because new codes might be added in the future, you should
write your symbiont so that it ignores codes it does not
recognize.
4.4 – Codes for Message Items
SMBMSG$K_ACCOUNT_NAME
This code identifies a string containing the name of the account
to be charged for the job, that is, the account of the process
that submitted the print job.
SMBMSG$K_AFTER_TIME
This code identifies a 64-bit, absolute-time value specifying the
system time after which the job controller can process this job.
SMBMSG$K_ALIGNMENT_PAGES
This code identifies a longword specifying the number of
alignment pages that the symbiont is to print.
SMBMSG$K_BOTTOM_MARGIN
This code identifies a longword containing the number of lines to
be left blank at the bottom of a page.
The symbiont inserts a form feed character into the output stream
if it determines that all of the following conditions are true:
o The number of lines left at the bottom of the page is equal to
the value in SMBMSG$K_BOTTOM_MARGIN.
o Sending more data to the printer to be output on this page
would cause characters to be printed within this bottom margin
of the page.
o The /FEED qualifier was specified with the PRINT command that
caused the symbiont to perform this task.
(Line feed, form feed, carriage-return, and vertical-tab
characters in the output stream are collectively known as
embedded carriage control.)
SMBMSG$K_CHARACTERISTICS
This code identifies a 16-byte structure specifying
characteristics of the job. A detailed description of the format
of this structure is contained in the description of the QUI$_
CHARACTERISTICS code in the $GETQUI system service in the VSI
OpenVMS System Services Reference Manual.
SMBMSG$K_DEVICE_NAME
This code identifies a string that is the name of the device to
which the symbiont is to send data. The symbiont interprets this
information. The name need not be the name of a physical device,
and the symbiont can interpret this string as something other
than the name of a device.
SMBMSG$K_ENTRY_NUMBER
This code identifies a longword containing the number that the
job controller assigned to the job.
SMBMSG$K_EXECUTOR_QUEUE
This code identifies a string that is the name of the queue on
which the symbiont stream is to be started.
SMBMSG$K_FILE_COPIES
This code identifies a longword containing the number of copies
of the file that were requested.
SMBMSG$K_FILE_COUNT
This code identifies a longword that specifies, out of the number
of copies requested for this job (SMBMSG$K_FILE_COPIES), the
number of the copy of the file currently printing.
SMBMSG$K_FILE_IDENTIFICATION
This code identifies a 28-byte structure identifying the file
to be processed. This structure consists of the following three
file-identification fields in the OpenVMS RMS NAM block:
1. The 16-byte NAM$T_DVI field
2. The 6-byte NAM$W_FID field
3. The 6-byte NAM$W_DID field
These fields occur consecutively in the NAM block in the order
listed.
SMBMSG$K_FILE_SETUP_MODULES
This code identifies a string specifying the names (separated by
commas) of one or more text modules that the symbiont should copy
from the library into the output stream before processing the
file.
SMBMSG$K_FILE_SPECIFICATION
This code identifies a string specifying the name of the file
that the symbiont is to process. This file name is formatted as a
standard RMS file specification.
SMBMSG$K_FIRST_PAGE
This code identifies a longword containing the number of the page
at which the symbiont should begin printing. The job controller
sends this item to the symbiont. When not specified, the symbiont
begins processing at page 1.
SMBMSG$K_FORM_LENGTH
This code identifies a longword value specifying the length (in
lines) of the physical form (the paper).
SMBMSG$K_FORM_NAME
This code identifies a string specifying the name of the form.
SMBMSG$K_FORM_SETUP_MODULES
This code identifies a string consisting of the names (separated
by commas) of one or more modules that the symbiont should copy
from the device-control library before processing the file.
SMBMSG$K_FORM_WIDTH
This code identifies a longword specifying the width (in
characters) of the print area on the physical form (the paper).
SMBMSG$K_JOB_COPIES
This code identifies a longword specifying the requested number
of copies of the job.
SMBMSG$K_JOB_COUNT
This code identifies a longword specifying, out of the number of
copies requested (SMBMSG$K_JOB_COPIES), the number of the copy of
the job currently printing.
SMBMSG$K_JOB_NAME
This code identifies a string specifying the name of the job.
SMBMSG$K_JOB_RESET_MODULES
This code identifies a string specifying a list of one or more
module names (separated by commas) that the symbiont should copy
from the device-control library after processing the task. These
modules can be used to reset programmable devices to a known
state.
SMBMSG$K_LAST_PAGE
This code identifies a longword specifying the number of the
last page that the symbiont is to print. When not specified, the
symbiont attempts to print all the pages in the file.
SMBMSG$K_LEFT_MARGIN
This code identifies a longword specifying the number of spaces
to be inserted at the beginning of each line.
SMBMSG$K_LIBRARY_SPECIFICATION
This code identifies a string specifying the name of the device-
control library.
SMBMSG$K_MESSAGE_VECTOR
This code identifies a vector of longword condition codes, each
of which contains information about the job to be printed.
When LOGINOUT cannot open a log file for a batch job, a code in
the message vector specifies the reason for the failure. The job
controller does not send the SMBMSG$K_FILE_IDENTIFICATION item
if it has detected such a failure but instead sends the message
vector, which the symbiont prints, along with a message stating
that there is no file to print.
SMBMSG$K_NOTE
This code identifies a user-supplied string that the symbiont is
to print on the job flag page and on the file flag page.
SMBMSG$K_PAGE_SETUP_MODULES
This code identifies a string consisting of the names (separated
by commas) of one or more modules that the symbiont should copy
from the device-control library before printing each page.
SMBMSG$K_PARAMETER_1 through SMBMSG$K_PARAMETER_8
Each of these eight codes identifies a user-supplied string. Both
the semantics and syntax of each string are determined by the
user-defined symbiont. The OpenVMS-supplied symbiont makes no use
of these eight items.
SMBMSG$K_PRINT_CONTROL
This code identifies a longword bit vector, each bit of which
supplies information that the symbiont is to use in controlling
the printing of the file.
Symbol Description
SMBMSG$V_DOUBLE_SPACE The symbiont uses a double-spaced
format; it skips a line after each
line it prints.
SMBMSG$V_NO_INITIAL_FF The symbiont suppresses the initial
form feed if this bit is turned on.
SMBMSG$V_NORECORD_ The symbiont performs single record
BLOCKING output, issuing a single output record
for each input record.
SMBMSG$V_PAGE_HEADER The symbiont prints a page header at
the top of each page.
SMBMSG$V_PAGINATE The symbiont inserts a form feed
character when it detects an attempt
to print in the bottom margin of the
current form.
SMBMSG$V_PASSALL The symbiont prints the file without
formatting and bypasses all formatting
normally performed. Furthermore, the
symbiont outputs the file without
formatting, by causing the output QIO
to suppress formatting by the driver.
SMBMSG$V_RECORD_BLOCKING The symbiont performs record blocking,
buffering output to the device.
SMBMSG$V_SEQUENCED This bit is reserved by VSI.
SMBMSG$V_SHEET_FEED The symbiont pauses the queue after
each page it prints.
SMBMSG$V_TRUNCATE The symbiont truncates input lines that
exceed the right margin of the current
form.
SMBMSG$V_WRAP The symbiont wraps input lines that
exceed the right margin, printing the
additional characters on a new line.
SMBMSG$K_PRIORITY
This code identifies a longword specifying the priority this job
has in the queue in which it is entered.
SMBMSG$K_QUEUE
This code identifies a string specifying the name of the queue
in which this job is entered. When generic queues are used, this
item specifies the name of the generic queue, and the SMBMSG$K_
EXECUTOR item specifies the name of the device queue or the
server queue.
SMBMSG$K_RELATIVE_PAGE
This code identifies a signed, longword value specifying the
number of pages that the symbiont is to move forward (positive
value) or backward (negative value) from the current position in
the file.
SMBMSG$K_REQUEST_CONTROL
This code identifies a longword bit vector, each bit of which
specifies information that the symbiont is to use in processing
the request that the job controller is making.
Symbol Description
SMBMSG$V_ALIGNMENT_MASK The symbiont is to replace all
alphabetic characters with the
letter X, and all numeric characters
with the number 9. Other characters
(punctuation, carriage control, and
so on) are left unchanged. This bit is
ordinarily specified in connection with
the SMBMSG$K_ALIGNMENT_PAGES item.
SMBMSG$V_PAUSE_COMPLETE The symbiont is to pause when it
completes the current request.
SMBMSG$V_RESTARTING Indicates that this job was previously
interrupted and requeued, and is now
restarting.
SMBMSG$V_TOP_OF_FILE The symbiont is to rewind the input
file before it resumes printing.
SMBMSG$K_RIGHT_MARGIN
This code identifies a longword specifying the number of
character positions to be left empty at the end of each line.
When the right margin is exceeded, the symbiont truncates the
line, wraps the line, or continues processing, depending on the
settings of the WRAP and TRUNCATE bits in the SMBMSG$K_PRINT_
CONTROL item.
SMBMSG$K_SEARCH_STRING
This code identifies a string containing the value specified in
the START/QUEUE/SEARCH command. This string identifies the page
at which to restart the current printing task on a paused queue.
SMBMSG$K_SEPARATION_CONTROL
This code identifies a longword bit vector, each bit of which
specifies an operation that the symbiont is to perform between
jobs or between files within a job. The $SMBDEF macro defines the
following symbols for each bit:
Symbol Description
SMBMSG$V_FILE_BURST The symbiont is to print a file burst
page.
SMBMSG$V_FILE_FLAG The symbiont is to print a file flag
page.
SMBMSG$V_FILE_TRAILER The symbiont is to print a file trailer
page.
SMBMSG$V_FILE_TRAILER_ The symbiont is to print a file trailer
ABORT page when a task completes abnormally.
SMBMSG$V_FIRST_FILE_OF_ The current file is the first file of
JOB the job. When specified with SMBMSG$V_
LAST_FILE_OF_JOB, the current job
contains a single file.
SMBMSG$V_JOB_FLAG The symbiont is to print a job flag
page.
SMBMSG$V_JOB_BURST The symbiont is to print a job burst
page.
SMBMSG$V_JOB_RESET The symbiont is to execute a job reset
sequence when the task completes.
SMBMSG$V_JOB_RESET_ABORT The symbiont is to execute a job
reset sequence when a task completes
abnormally.
SMBMSG$V_JOB_TRAILER The symbiont is to print a job trailer
page.
SMBMSG$V_JOB_TRAILER_ The symbiont is to print a job trailer
ABORT page when a task completes abnormally.
SMBMSG$V_LAST_FILE_OF_ The current file is the last file of
JOB the job. When specified with SMBMSG$V_
FIRST_FILE_OF_JOB, the current job
contains a single job.
SMBMSG$K_STOP_CONDITION
This code identifies a longword containing a condition specifying
the reason the job controller issued a STOP_TASK request.
SMBMSG$K_TIME_QUEUED
This code identifies a quadword specifying the time the file was
entered into the queue. The time is expressed as 64-bit, absolute
time.
SMBMSG$K_TOP_MARGIN
This code identifies a longword specifying the number of lines
that the symbiont is to leave blank at the top of each page.
PRTSMB inserts line feeds into the output stream after every form
feed until the margin is cleared.
SMBMSG$K_UIC
This code identifies a longword specifying the user
identification code (UIC) of the user who submitted the job.
SMBMSG$K_USER_NAME
This code identifies a string specifying the name of the user who
submitted the job.
4.5 – Condition Values Returned
SS$_NORMAL Normal successful completion.
SMB$_NOMOREITEMS End of item list reached.
This routine also returns any condition code returned by the
Run-Time Library string-handling (STR$) routines.
5 – SMB$SEND_TO_JOBCTL
The SMB$SEND_TO_JOBCTL routine is used by your symbiont to send
messages to the job controller. Three types of messages can be
sent: request-completion messages, task-completion messages, and
task-status messages.
Format
SMB$SEND_TO_JOBCTL stream [,request] [,accounting]
[,checkpoint] [,device_status] [,error]
5.1 – Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
5.2 – Arguments
stream
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
Stream number specifying the stream to which the message refers.
The stream argument is the address of a longword containing the
number of the stream to which the message refers.
request
OpenVMS usage:identifier
type: longword (unsigned)
access: read only
mechanism: by reference
Request code identifying the request being completed. The request
argument is the address of a longword containing the code that
identifies the request that has been completed.
The code usually corresponds to the code the job controller
passed to the symbiont by means of a call to SMB$READ_MESSAGE.
But the symbiont can also initiate task-completion and task-
status messages that are not in response to a request. (See the
Description help topic.)
accounting
OpenVMS usage:char_string
type: character string
access: read only
mechanism: by descriptor
Accounting information about a task. The accounting argument
is the address of a descriptor pointing to the accounting
information about a task. Note that this structure is passed
by descriptor and not by reference.
The job controller accumulates task statistics into a job-
accounting record, which it writes to the accounting file when
the job is completed.
The following diagram depicts the contents of the 16-byte
structure:
31 0
-----------------------------------------------------
Number of pages printed for the job
-----------------------------------------------------
Number of reads from disk or tape
-----------------------------------------------------
Number of writes to the printing device
-----------------------------------------------------
Unused
-----------------------------------------------------
checkpoint
OpenVMS usage:char_string
type: character string
access: read only
mechanism: by descriptor
Checkpoint data about the currently executing task. The
checkpoint argument is the address of the descriptor that points
to checkpointing information that relates to the status of
a task. When the symbiont sends this information to the job
controller, the job controller saves it in the queue database.
When a restart-from-checkpoint request is executed for the queue,
the job controller retrieves the checkpointing information from
the queue database and sends it to the symbiont in the SMBMSG$K_
CHECKPOINT_DATA item that accompanies a SMBMSG$K_START_TASK
request.
Print symbionts can use the checkpointing information to
reposition the input file to the point corresponding to the page
being output when the last checkpoint was taken. Other symbionts
might use checkpoint information to specify restart information
for partially completed tasks.
NOTE
Because each checkpoint causes information to be written
into the job controller's queue database, taking a
checkpoint incurs significant overhead. Use caution in
regard to the size and frequency of checkpoints. When
determining how often to checkpoint, weigh processor and
file-system overhead against the convenience of restarting.
device_status
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
Status of the device served by the symbiont. The device_
status argument is the address of a longword passed to the job
controller, which contains the status of the device to which the
symbiont is connected.
This longword contains a longword bit vector, each bit of which
specifies device-status information. Each programming language
provides an appropriate mechanism for defining these device-
status bits. The following table describes each bit:
Device Status Bit Description
SMBMSG$V_LOWERCASE The device to which the symbiont is
connected supports lowercase characters.
SMBMSG$V_PAUSE_ The symbiont sends this message to inform
TASK the job controller that the symbiont has
paused on its own initiative.
SMBMSG$V_REMOTE The device is connected to the symbiont by
means of a modem.
SMBMSG$V_SERVER The symbiont is not connected to a device.
SMBMSG$V_STALLED Symbiont processing is temporarily stalled.
SMBMSG$V_STOP_ The symbiont requests that the job
STREAM controller stop the queue.
SMBMSG$V_TERMINAL The symbiont is connected to a terminal.
SMBMSG$V_ The device to which the symbiont is
UNAVAILABLE connected is not available.
error
OpenVMS usage:vector_longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
Condition codes returned by the requested task. The error
argument is the address of a vector of longword condition codes.
The first longword contains the number of longwords following it.
If the low bit of the first condition code is clear, the job
controller aborts further processing of the job. Output of
any remaining files, copies of files, or copies of the job is
canceled. In addition, the job controller saves up to three
condition values in the queue database. The first condition value
is included in the job-accounting record that is written to the
system's accounting file (SYS$MANAGER:ACCOUNTNG.DAT).
5.3 – Description
The symbiont uses the SMB$SEND_TO_JOBCTL routine to send messages
to the job controller.
Most messages the symbiont sends to the job controller are
responses to requests made by the job controller. These responses
inform the job controller that the request has been completed,
either successfully or with an error. When the symbiont sends
the message, it usually indicates that the request has been
completed.
In such messages, the request argument corresponds to the
function code of the request that has been completed. Thus, if
the job controller sends a request using the SMBMSG$K_START_
TASK code, the symbiont responds by sending a SMB$SEND_TO_JOBCTL
message using SMBMSG$K_START_TASK as the request argument.
The responses to some requests use additional arguments to send
more information in addition to the request code. The following
table shows which additional arguments are allowed in response to
each different request:
Request Arguments
SMBMSG$K_START_STREAM request
device_status
error
SMBMSG$K_STOP_STREAM request
SMBMSG$K_RESET_STREAM request
SMBMSG$K_START_TASK request
SMBMSG$K_PAUSE_TASK request
SMBMSG$K_RESUME_TASK request
SMBMSG$K_STOP_TASK request
error (See footnote.)
Footnote: This is usually the value specified in the SMBMSG$K_
STOP_CONDITION item that was sent by the job controller with the
SMBMSG$K_STOP_TASK request.)
In addition to responding to requests from the job controller,
the symbiont can send other messages to the job controller. If
the symbiont sends a message that is not a response to a request,
it uses either the SMBMSG$K_TASK_COMPLETE or SMBMSG$K_TASK_STATUS
code. Following are the additional arguments that you can use
with the messages identified by these codes:
Code Arguments
SMBMSG$K_TASK_ request
COMPLETE
accounting
error
SMBMSG$K_TASK_STATUS request
checkpoint
device_status
The symbiont uses the SMBMSG$K_TASK_STATUS message to update the
job controller on the status of a task during the processing
of that task. The checkpoint information passed to the job
controller with this message permits the job controller to
restart an interrupted task from an appropriate point. The
device-status information permits the symbiont to report changes
in device's status (device stalled, for example).
The symbiont can use the SMBMSG$K_TASK_STATUS message to request
that the job controller send a stop-stream request. It does this
by setting the stop-stream bit in the device-status argument.
The symbiont can also use the SMBMSG$K_TASK_STATUS message
to notify the job controller that the symbiont has paused in
processing a task. It does so by setting the pause-task bit in
the device-status argument.
The symbiont uses the SMBMSG$K_TASK_COMPLETE message to signal
the completion of a task. Note that, when the symbiont receives a
START_TASK request, it responds by sending a SMB$SEND_TO_JOBCTL
message with SMBSMG$K_START_TASK as the request argument. This
response means that the symbiont has started the task; it does
not mean the task has been completed. When the symbiont has
completed a task, it sends a SMB$SEND_TO_JOBCTL message with
SMBMSG$K_TASK_COMPLETE as the request argument.
Optionally, the symbiont can specify accounting information when
sending a task-completion message. The accounting statistics
accumulate to give a total for the job when the job is completed.
Also, if the symbiont is aborting the task because of a symbiont-
detected error, you can specify up to three condition values in
the error argument. Aborting a task causes the remainder of the
job to be aborted.
5.4 – Condition Values Returned
SS$_NORMAL Normal successful completion.
This routine also returns any condition value returned by the
$QIO system service and the LIB$GET_VM routine.