The program that interprets
SVC requests for control program services.
macro identifier
The byte in an SVC macro
instruction used by the TPF system to locate appropriate control program
services.
macroinstruction
An instruction that when
executed causes the execution of a predefined sequence of instructions in the
same source language.
macro invocation
An identifier followed by a
parenthesized list of arguments that the preprocessor replaces with the
replacement code located in a preprocessor define statement.
main function
A
function that has the identifier main. In non-TPF systems,
each program must have exactly one function named main, which is
the first user function that gets control when program execution
begins. TPF does not allow the use of a main function, and
will flag it as an error, if defined.
mail
See e-mail and Internet
mail.
mail account
In TPF Internet mail server
support, a user with a mailbox.
mailbox
A file storage area that holds
electronic mail (e-mail).
mail item
A single piece of electronic mail
(e-mail).
mail queue
A list used for Internet mail
that keeps track of mail items to be delivered.
main I-stream engine
In a CPC with multiple
I-stream engines, the I-stream that executes most non-DASD-related I/O
commands and the only I-stream engine that can be IPLed. When the MPIF
feature is installed and 2 or more I-stream engines exist, MPIF I/O
commands are executed on the second I-stream. Contrast with
application I-stream engine.
main storage allocations lists
The lists of
available block addresses, in each block type, that are used by the control
program when programs request or release main storage.
major device number
A number that locates a
device driver.
mapping
(1) A data organization procedure
that binds application data to a unique hardware address. (2) The
programs that permit a user to format and control the data routed between a
terminal and an application, or between applications.
MASM
Multiple assembler.
master clock processor
The processor that
controls the complex's TOD time and date changes in a loosely coupled
system. The master clock processor is usually the first active
processor in a loosely coupled system. In 1052 state, the processor
where the ZATIM TOD command is entered becomes the master clock
processor.
master extra program record
The record used
to control the pool of extra program records. Extra program records are
the fixed file records within the #XPRGn record type.
master synchronization source
The originator
of the oscillator pulses that keep all the TOD clocks in a loosely coupled
complex synchronized.
matrix
An array arranged in rows and
columns.
MBI
Message block identifier.
MCA
Message channel agent.
MCR
Message control record.
MDBF
Multiple database function.
member
(1) A data object in a structure or a
union. (2) A file of object code that is a component of a dynamic load
module (DLM), dynamic link library (DLL), or library load module (LLM).
messages
Transactions or entries received by
a TPF system for immediate action. TPF system messages (system errors)
such as dump messages, and online and offline messages are intended for
operators and system programmers responsible for operating and maintaining the
TPF system.
message block identifier (MBI)
A field found
in the SLC link keypoint that permits chaining of SLC data message
blocks.
message channel
In distributed message
queuing, a mechanism for moving messages from one queue manager to
another. A message channel comprises two message channel agents (a
sender at one end and a receiver at the other end) and a communication
link. Contrast with MQI channel.
message channel agent (MCA)
A program that
transmits prepared messages from a transmission queue to a communication link,
or from a communication link to a destination queue. See also
Message Queue Interface (MQI).
message collector
The data collection
program that records network message traffic data.
message control record (MCR)
A record used
to preserve SLC message references until they are acknowledged.
Message Queue Interface (MQI)
The
programming interface provided by the MQSeries queue managers. This
programming interface allows application programs to access message queuing
services.
message recovery
A facility used to retain
messages on file until the message is completely processed.
message router
A data communication
procedure that directs data messages from or to a host network, to or from a
specified terminal, station, application program, or another host
network.
message switching (MESW) state
The system
state in which message switching entries are the only entries
processed. All other entries are queued to be processed when the system
reaches NORM state.
MESW state
Message switching state.
method
A procedure contained within a
collection object that is made available to other collections for the purpose
of requesting the services of that collection. Most communication
between collections takes place through methods.
MFST
Module file status table.
minor device number
An optional number that
can be passed to a device driver subroutine.
mode
A collection of attributes that
specifies a file's type and its access permissions.
(POSIX.1)
module file status table (MFST)
The index of
online disk assignments for all direct access storage devices (DASD).
module-to-module duplication
A method of
allocating duplicate files whereby the duplicate record in a record type
(fixed or pool) is assigned to the same relative position on an alternate disk
module.
movable virtual IP address
A virtual
Internet Protocol address (VIPA) that can be moved from one processor to
another in the same loosely coupled TPF complex.
MPIF
Multi-Processor Interconnect
Facility.
MPIF complex
Multiple TPF complexes that are
channel connected.
MPIF user
One or more programs associated
with one or more functions.
MPLF
Multi-path lock facility.
MQI
Message Queue Interface.
MQI channel
Connects an MQI client to a
queue manager on a server system, and transfers only MQI calls and responses
in a bi-directional manner.
MQI channel directory
The TPF system
implementation of an MQSeries channel definition file. The MQI channel
directory contains client connection channel type (CLNTCONN) definitions
stored in #MQICD fixed file records.
MQ series
Part of an MQSeries product that
allows a queue manager to service MQI client systems.
MQI trace table
The TPF system
implementation of an MQI function trace facility.
MQSeries
A family of IBM licensed programs
that provides message queuing services.
MQSeries client
Part of an MQSeries product
that can be installed on a system without installing the full queue
manager. The MQSeries client accepts MQI calls from applications and
communicates with a queue manager on a server system.
MQSeries server
A queue manager that
provides queuing services to one or more clients. All the MQSeries
objects (for example, queues) exist only on the queue manager system;
that is, on the MQI server machine. A server can support normal local
MQI applications as well.
MSRB
Multiple system request block.
multibyte characters
Multibyte characters
are a mixture of SBCS and DBCS characters.
multi-path lock facility (MPLF)
A hardware
locking facility that can be optionally installed on 3990 Model 3 DASD control
units. This facility, or the limited lock facility (LLF), is required
in loosely coupled complexes.
Multi-Processor Interconnect Facility (MPIF)
A
feature of the TPF system that allows an installation to implement the
interconnection of CPCs through the use of channel-to-channel support.
multiple assembler (MASM)
The program that
can assemble many programs in partitioned data sets with minimal use of
JCL.
multiple assembly print
An offline program
that produces one or more printed listings retrieved from the tape or disk
data set produced by the multiple assembly program (MASM).
multiple central processing complexes
Several
central processing complexes, which can be either uniprocessors or
multiprocessors, that are explicitly identified to the channel subsystem by
device addresses. See also central processing
complex.
multiple database function (MDBF)
A facility
in the HPO feature that allows concurrent processing of multiple applications,
each with dedicated database support.
multiple images
A facility that allows an
installation to define as many as 8 images of the TPF system on a single
processor. Maintaining multiple and separate TPF images allows an
installation to perform loads while the TPF system is processing messages and
to have the ability to fall back immediately to a previous program base
without reloading the previous program versions.
multiple inheritance
A design characteristic
of an object-oriented database in which a given class can inherit directly
from more than one immediate superclass.
multiple release
A pool address that has
been released more than once without being dispensed again. See also
online multiple release and offline multiple
release.
multiple system request block (MSRB)
A data
definition describing the format of the request block used to ship each MPIF
request type to the appropriate destination. The MSRB contains
information defining the sending and receiving MPIF user as well as
information describing the specific request type.
multiple TPF image
See
image.
multiprocessing
(1) A mode of operation for
parallel processing by 2 or more processors of a multiprocessor. (2)
Pertaining to the simultaneous processing of 2 or more computer programs or
sequences of instructions by a computer.
multiprocessor
(1) A computer including 2 or
more processors that have common access to shared main storage. (2) A
system of 2 or more processing units, ALUs, or processors that can communicate
without manual intervention.