- Absolute Pathname
A pathname that begins with the root directory, such as /SYS/PUB/TDP.
See also pathname and relative pathname.
- Artificial Member
Workgroup membership is composed of natural and artificial members. A process
becomes an artificial member when it is explicitly placed into the workgroup
via :ALTPROC or AIFPROCPUT. A process remains an artificial member of its
assigned workgroup until:
the workgroup is purged, or
the process is explicitly released from its artificial assignment via the
:ALTPROC command or AIFPROCPUT.
That is, an artificial member is not affected by changing one of the process
attributes used in workgroup assignment. In addition, a scan would only
effect the process if the process' workgroup had a purge pending.
- Asynchronous Port
A port that provides the capability of interrupting
the creator upon receipt of a message to that port. User code will only be
interrupted when it is executing at privileged levels 2 or 3, and it is
not set critical or in system code. Asynchronous ports may only have one
receiver and it must be the port creator. Asynchronous ports are NOT
permanent.
- Base
The base is the highest priority value (lowest numeric value) of processes
within that workgroup (BASE=Value). Values can range between the priority
values of 150 and 255. Internally the priorities range from 32767 to 0.
AIFSCGET/PUT return or modify internal priorities. Processes will begin their
transactions at the base priority and decay as they consume CPU. The base is
a required workgroup characteristic.
- Boost Property
The boost property can be set to either decay or oscillate (BOOST={
DECAY,OSCILLATE}). A value of decay is the default and means the priority
of a process within that workgroup will begin at the base and decay as
the process consumes CPU. A value of oscillate indicates that the priority
of the process will be reset to the base if it decays to the limit (the
priority of the process will oscillate between the base and limit priorities).
The boost property is an optional workgroup characteristic with a default
value of DECAY.
- CI
CI is an abbreviation for the command interpreter. The CI
analyzes and processes commands entered during a session or submitted as part of
a job.
- Connectionless Send
The ability to send to an AIF port without having
previously done an AIFPORTOPENi on that port. The only type of
Vconnectionless send that can be done is a "no wait" send.
- Constant Priority Process
This process does not
decay and remains at the same level regardless of the queue the process is
in. By default, only the processes in AS, BS, and certain processes in CS
queue of type UCOP and System belong to this process category.
- CM Files
The MPE/iX file system currently consists partially of NM files and CM
files. Consequently, CM code handles certain types of files after
switching to CM. Files that require switching to CM are called
CM files.
- Current Working Directory (CWD)
The directory in which you are working and from which relative pathnames are
resolved. See also directory and relative pathname.
- CWD
An acronym for Current Working Directory.
- Decayable Boosting
This causes the priority to descend gradually through a series of drops until
a transaction is completed or decays to the
bottom of a queue. After this occurs the priority
resets to the base of the CS queue.
- Default Workgroups
One of five system-defined workgroups created to provide backward compatibility
with the five scheduling queues. These workgroups, AS_Default, BS_Default,
CS_Default, DS_Default, and ES_Default, are created with the same scheduling
characteristics as their namesake and have the scheduling queue as their only
membership criterion. The characteristics of the AS_Default and BS_Default
workgroups cannot be changed. The characteristics of the CS_Default, DS_Default,
and ES_Default can be changed through AIFSCPUT and AIFWGPUT.
- directory
A special kind of file that contains entries that point to other files.
It acts like a container for files and other directories.
On MPE/iX, accounts and groups are special types of directories.
- Envelope
The envelope in the context of
IPC and message-passing is analogous to the
envelope you use to send a letter through the
Postal Service. The envelope is the
overhead portion of the total data required to send a message
from a sender process to a receiver process.
The envelope contains the priority of the message,
reply information (the return address), and other miscellaneous
information needed for routing and scheduling.
- Envelope Code
The envelope code is an integer value that can be passed with any
message. This value is available to a receiver process without
reading the actual message. If the message sent can fit within
an integer value, a zero length message can be sent with the actual
message contained entirely in the envelope code.
- FIFO
FIFO is an abbreviation for first in first out.
Since messages can
be assigned a priority between 0 and 31, where 0 has the highest
priority, a message of priority 0 is received before a
message of priority 1, even if the priority 1 message arrived
in the port first. Messages sent with the same priority are
delivered in the same order they were sent, or FIFO.
- File Code
A file code is a four-digit integer that identifies the
function of a special purpose file. For example, a V/3000 forms file has a file
code of 1035. For a list of file code numbers and their meanings, consult the
File System Reference Manual.
- File Equation
A file equation directs the input to, or output from, a program, job, or
session. You create a
file equation by using the File command to
equate a file name to another file or device.
- File Name
Most of the AIF interfaces accept and return fully qualified file names
in a single standard format.
- File Number
Each OPEN (FOPEN or HPFOPEN) returns a number to the caller
which is a process-specific handle for this instance of the OPEN. For the
remainder of the section, a file number always signifies the file context
addressed by this process-specific handle.
- Handler
The code that is specified to handle interrupts from an asynchronous port.
This user-written routine will be required to have only one parameter,
an AIF port ID. This ID is passed to the handler upon its invocation,
by the AIF subsystem. The address of the handler must be provided at creation
time to the AIFPORTOPEN for an asynchronous port.
- HFS
An acronym for the hierarchical file system.
- hierarchical file system (HFS)
A file system that is tree structured and can contain files at many different
levels. This file organization is obtained through the use of directories,
which can contain files and other directories.
- Home Group
The home group is the group
assigned to a user when the user name is defined
with the Newuser command. The group is the user's default logon group if a
group name is not specified with the Hello or Job command.
- IPC
IPC is an abbreviation for
Inter Process Communication, which is message-passing between
processes. Although normally occurring between two or more different
processes, the communication can also occur between a single process and
itself.
- Job
A job is a sequence of instructions issued to the computer that does
not require an interactive dialog between the user and the computer. Each job
on the system is uniquely identified by a job number.
- Job/Session Number
A job/session number uniquely identifies either a
job or session.
- Job State
A generic term used for the stages that a job or session
might pass through during its lifespan.
- Limit
The limit is the lowest priority (highest numeric value) of processes
within that workgroup (LIMIT=value). Values can range between the priority
values of 150 and 255. Internally the priorities range from 32767 to 0.
AIFSCGET/PUT return or modify internal priorities. Process priorities within
the workgroup will not decay beyond the limit. If the boost property for the
workgroup is oscillate, process priorities will be reset to the base value
once they decay to the limit. The limit is a required workgroup characteristic.
- Linked Spoolfile
A linked spoolfile has an entry in the SPFDIR and
resides in the HPSPOOL account. Input spoolfiles reside in @.IN.HPSPOOL.
Output spoolfiles reside in @.OUT.HPSPOOL. If a user copies a spoolfile
from OUT.HPSPOOL to his or
her local group and account, the copy has no entry
in the SPFDIR and is therefore not a linked spoolfile. Refer to the spooler
management routine AIFSpoolfLink for further information.
- Logon
Logon is the job/session, user and account name associated with a process.
The logon of a process can change dynamically through AIFCHANGELOGON.
Logon is one of the process attributes
used to determine workgroup membership. Therefore, a change in logon may
result in an immediate change in workgroup assignment.
- Mail Slot
The front panel storage slot used to insert or remove Magneto-Optical
Media in an optical disk library system.
- Maximum CPU Percentage
The maximum CPU percentage is a upper bound for the amount of CPU the
processes in a workgroup can consume relative to other workgroups. The
maximum CPU percentage value can be used to limit the amount of CPU
consumed by a workgroup. This control may result in the system idling
if the workgroup hits its maximum percentage and there are no other
users who want the CPU. The default value is 100%.
- Maximum Quantum
The maximum quantum is an upper bound for the dynamically calculated
quantum ( average transaction time ) value for that workgroup
( MAXQUANT=Value ). Values range between 0 and 32767. The maximum quantum
is an optional workgroup characteristic with a default value of 1000.
- Media Label
A record defining the label for Magneto-Optical Media which consists
of three parts including media_name, subname1, and subname2.
- Media Name
A packed array of 1 to 32 characters used to identify the first part
of the media label
- Media Slot
A number specifying a Magneto-Optical disk library system media storage slot.
- Membership Criteria
The membership criteria of a workgroup is composed of a number of category
specifications. Three categories are currently supported (logon,
program, and scheduling queue). For a given workgroup, at least one
category must be specified. If multiple specifications are specified, a
process must match one specification from each category. Categories not
specified take their default values.
The following table lists the default values for the membership criteria:
Table D-1 Membership Criteria Default Values
Membership Criteria | Default Values
|
---|
Logon | @,@.@ (any jobname,user.account) |
Program | @.@.@ (any program) |
Scheduling Queue | AS, BS, CS, DS, ES (any queue)
|
- Message
The Message is the portion of the overall package
handled internally by the AIF Ports code that is delivered
to the receiver process. It is the data that is "sent."
- Message File
A message file acts as a first-in-first-out queue of
records, with entries made by FWRITE and deletions made by FREAD. These are
often used for interprocess communication by having one process submit records
while another process removes them.
- Minimum CPU Percentage
The minimum CPU percentage is a lower bound for the amount of CPU the
processes in a workgroup can consume relative to other workgroups. The
minimum CPU percentage value can be used to guarantee a certain
amount of CPU to a workgroup. Note that the CPU consumption of the
workgroup may not precisely match the specified minimum CPU percentage
if there is insufficient demand within the workgroup. The default value
is 0%.
- Minimum Quantum
The minimum quantum is a lower bound for the dynamically calculated
quantum ( average transaction time ) value for that workgroup
( MINQUANT=Value ). Values range between 0 and 32767. The mimimum quantum
is an optional workgroup characteristic with a default value of 1 for
user workgroups and CS_Default workgroup. The default value for
DS_Default and ES_Default is 2000.
- MPE file
The term MPE file refers to a file that can be represented using MPE semantics
(for example, CI.PUB.SYS).
- Natural Member
A process becomes a natural member of a workgroup when it is placed into the
workgroup via the system. The system will scan the ordered list of workgroups,
selecting the first workgroup whose membership criteria match the process'
attribute.
- NM Files
The MPE/iX file system currently consists partially of NM files and CM
files. Consequently, CM code handles certain types of files after
switching to CM. Files that do not require switching to CM are called
NM files.
- NMS
NMS is an abbreviation for
the Native Mode Spooler. This new MPE/iX native mode
spooler replaces the previous CM SPOOLER and SPOOK.
- pathname
A pathname specifies where a particular file or directory is within the
directory structure; that is what path the system must take when traversing the
directory. See also absolute pathname and relative pathname.
- PID
PID is an abbreviation for Process ID. Just as every process
is assigned a PIN #, in MPE/iX every process is also assigned
a PID. The PID is a 64-bit long integer comprised of the
machine #, the PIN #, and a reuse counter.
- PIN
PIN is an abbreviation for Process Identification Number.
In MPE/iX every process is assigned a PIN #. The PIN is a
16-bit short integer.
- Port
A Port refers to the collection of
data structures managed by the AIF Ports procedures. It
provides a level of abstraction when sending a message form
one process to another. The sending process does not need to
be explicitly aware of exactly which process reads the message;
it simply sends a message to a given Port knowing that some process
will eventually read it.
Likewise, the receiver does not
necessarily need to know which process sent it a message; the receiver
only needs to know
that the message came from a given Port. A message is considered
to pass through a Port during the send/receive cycle.
- Port Manager
As part of the feature set provided with
the AIF Ports facility, a process can be designated as the
Port Manager for the Port. When a Port Manager is
not involved in the message transfer, the AIF Ports code prioritizes
a message from the sender along with any
previously sent but unreceived messages, then signals
a receiver process ready for another message that
a message is available.
When a Port Manager process is
involved, the AIF Ports code simply stores the message from
the sender in the Port data structures, then
sends the envelope portion of the message to the Port Manager
so it can assume processing of the message.
- Port Name
A Port name is a
name given to a Port, which can consist of from 1 to 16
characters and can contain any characters. The name is
upshifted before use.
- Port Password
A Port password is
a password to be associated with a Port. The
process that creates a Port establishes the Port password. All
subsequent opens must use the same password.
- POSIX
Portable Operating System Interface. A set of standards that
address various areas of operating system technology.
The POSIX standards describe functions of an operating system
interface that applications use to become POSIX-compliant.
The main point of POSIX is to facilitate software portability
and minimize porting costs.
- Priority Boost
A priority boost
raises the priority of a process. This occurs
at the end of a transaction when a process holds a resource that a higher
priority process needs, when a process has a stalled transaction, or when
Break or Ctrl-Y must be processed.
- Private Spoolfile
A private spoolfile is HPFOPENed with the PRIVATE
option. Under NMS all input spoolfiles are private spoolfiles, and
a user can designate output spoolfiles private for
security purposes. Refer to
the NMS manual for further information on private spoolfiles.
- Process-specific File
The same physical file maybe opened more than
once by the same process. Some of the file context is common for all the
OPENs issued by a process against a physical file. This kind of information
is referred to as process-specific information.
- Program File
The name of the program file that is currently loaded for execution by the
process. This name may change if the process makes use of the POSIX exec
system call. The program file is one of the process attributes used to
determine the workgroup membership. Therefore, changing the program file may
result in an immediate change in workgroup assignment.
- Receiver Process
The receiver process is the
complement to a sender process.
If one process is sends messages, the receiver process
reads these messages.
- Record Pointer
The file system maintains information about where the user is located in the
file (what the next read fetches and where
the next write is dispatched). The record pointer, the record number, and
the offset within the record all provide the complete context. When a
record pointer is shared, all three are shared.
- Relative Pathname
A pathname that is interpreted from the current working directory.
For example, ./dir1/longfilename refers to the file longfilename
in directory dir1 in the current working directory.
- Return_array
The system-wide interface returns values
in arrays of this type. The actual structure of the array varies
depending on the type of keys passed, but the general form is:
Array [1..x] of appropriate type. x represents any integer
and appropriate type is specified in AIFSysWideGet.
- Scheduling Characteristics
The scheduling characteristics of the workgroup determine the scheduling
policies which govern the processes within that workgroup. The base
and limit priorities determine the range of the priority values for
processes within the workgroup, while the quantum bounds define the range
over which the quantum can change. The timeslice and boost property
values also determine the scheduling behavior. The other scheduling
characteristic is CPU Percentage bounds.
The following table lists the default values for the scheduling
characteristics:
Table D-2 Scheduling Characteristics Default Values
Scheduling Characteristics | Default Values
|
---|
Boost Property | Decay |
Minimum CPU Percentage | 0% |
Minimum Quantum | 1 (2000 for DS_Default and ES_Default) |
Maximum CPU Percentage | 100% |
Maximum Quantum | 2000 |
Timeslice | 200 (1000 for AS_Default and BS_Default)
|
- Scheduling Queue
In the current implementation, scheduling queue can mean one of two things.
First, a scheduling queue is a process attribute that can be set by the
user (e.g., :RUN foo;PRI=BS). This attribute can also be changed dynamically
through :ALTPROC , the intrinsic GETPRIORITY, or the AIF, AIFPROCPUT. Second,
scheduling queue refers to a collection of processes with similar scheduling
characteristics. MPE/iX currently supports five queues. The AS and BS queues
are typically used for system processes, the CS queue is typically used for
interactive users, while the DS and ES queues are typically used for batch
jobs.
Scheduling queue, as a process attribute, is an integral part of the
workgroup concept. This is one of the process attributes used to determine
workgroup membership. Because of its dynamic nature, a change in the process'
queue attribute results in an immediate change in the process' workgroup
assignment.
- Search_key
The system-wide interface returns arrays
of keys. The number of keys returned in a call depends on the
space that you allocate. If more keys can be returned then
this is indicated in the status, a special key is returned
that can be used in a subsequent call to AIFSysWideGet to start the
scan from that search key without repeating the keys returned before.
The search key should be defined as array [1..48] of char.
- Sender Process
The sender process, sometimes referred to as the sender, enables
a message to be sent and received by another process.
- Session
A session is an interactive dialog between the user and the
computer. Each session on the system is uniquely identified by a session
number.
- SPFDIR
This is an abbreviation for
spoolfile directory, which is the table that the
NMS uses to maintain information about spoolfiles.
- SPIT
This is an abbreviation for the
Spooling Process Information Table, which is the table that NMS
uses to maintain information about spooling
processes.
- Spoolfile
The spoolfiles generated by the file system for the NMS
are ordinary disc files. This prevents input and output spoolfiles from
being lost during system boots as they currently are. A new file type
identifies the files as spoolfiles and allows them to be managed in this manner.
Two new file codes have also been assigned: 1515 for input spoolfiles and
1516 for output spoolfiles. Input spoolfiles are created in the IN
group of the reserved account HPSPOOL, and output spoolfiles are
created in the OUT
group of the HPSPOOL account.
- Streams LDEV
The streams LDEV is the device specified
with the Streams command to be used as the input device for all jobs on the
system. This device should not actually exist,
as it is a 'pseudo-device'
that must be configured with the device class JOBTAPE.
- Subname1
A packed array of 1 to 16 characters used to identify the second part of the
media label.
- Subname2
A packed array of 1 to 16 characters used to identify the third part of the
media label.
- Surface
A number of either 0 or 1. The number zero specifies the "A" side
of a Magneto-Optical Media and the number one specifies the "B" side.
Sometimes referred to as "side".
- System Average Quantum (SAQ)
System Average Quantum determines
how rapidly process
priorities decay. There are
different SAQs for the CS, DS and ES queues. Within the CS queue, the SAQ
is adjusted as processes complete transactions and represents the average
transaction time of processes in the CS queue. The SAQ for the DS and the ES
queues is a user-configurable value chosen to represent the average transaction
time of these queues.
- System Logging
System logging is
a facility that records the occurrence of specific events
and system resource usage into the system log files on a job/session basis.
The system manager can enable or disable
system logging types.
- System Process
A system process is one that is a child of PROGEN or has inherited system
process status from its parent. By definition, a system process executes
with a non-decayable (linear) priority. However, a process does not need
to be a system process to have a non-decayable priority. Process Management
considers a system process an integral part of the OS and will abort the
system if a system process dies.
- Timeslice
The timeslice is the maximum number of milliseconds a process in that
workgroup can hold the CPU before returning to the Scheduler to have its
priority recalculated(TIMESLICE=value). Values must be multiples of 100,
with a minimum value of 100 and a maximum value of 32700. The timeslice
is an optional workgroup characteristic with a default value 200
milliseconds for CS_Default, DS_Default, ES_Default and user-defined
workgroups. The default value for AS_Default and BS_Default workgroups is
1000.
- Transaction
A transaction is comprised
of a series of events. Most commonly, a
transaction is the action performed between terminal read waits. A transaction
is also considered complete when a process pauses at length (more than two
seconds), blocks on a call to IO_Wait, or blocks waiting for IPC.
- UFID
UFID is an abbreviation for
for Unique File Identifier. It is a unique name to
a single file throughout the life of a system. It is unique even across
system boots.
- User Files
The files opened for a particular user could have been opened
either by an explicit OPEN (FOPEN or HPFOPEN) by the
user program, or by the system on behalf of the user. The files opened
explicitly are called user files and the remainder are non-user files. This
procedure can be used to modify the information about user files only.
- Workgroup
A workgroup is a collection of processes with identical scheduling
characteristics. The scheduling characteristics include base and limit priority,
timeslice value, boost property, etc.
Workgroup membership is determined by matching specific process attributes
against a set of predefined membership criteria. The process attributes
selected include logon, program file, profile, and scheduling queue.
Workgroup membership criteria and scheduling characteristics are determined
by the System Manager.