I – glossary entries

IA: Interchange address.
IATA: Interchange address/terminal address.
ICDF: In-core dump formatter.
ICR: Image control record.
IDCF: Internet Daemon configuration file.
IDCT: Internet Daemon configuration table.
IDL: Interface definition language.
identifier: A sequence of letters, digits, and underscores used to designate a data object or function.
IHR: Image history record.
image: One of a number of selectable versions of the z/TPF system software, consisting of an IPL area, core image restart (CIMR) area, E-type program area, CTKX, and keypoint staging area.
image control record (ICR): A record containing image and processor status information that resides at fixed location record 2, cylinder 0, track 1 on each pack.
image history record (IHR): A record containing the current load status for IPLA, IPLB, CTKX, and all of the CIMR components for all of the images.
image loader: A program that loads z/TPF components to a disabled image. The image loader is capable of loading a complete set of z/TPF system software (full load) or selected components (short load). It consists of an offline load and an online load. See also E-type loader, general file loader, and alternate face table (FCTB) loader.
image pointer record (IPR) (CTKX): An image-unique structure that contains information on keypoints and core image restart area (CIMR) components.
immediate filing: A virtual file access (VFA) attribute indicating that when an application program issues a file-type macro, the record is written to DASD immediately. Contrast with delay filing.
immutable cache attribute: An attribute for a logical record cache that can be updated only by deleting and re-creating the cache. You cannot refresh an active cache to update an immutable cache attribute.
implementation-specific C/C++ language header files: Header files used by only IBM® and the z/TPF system. These header files are internal to the implementation of certain C/C++ functions.
in-use I-stream: An active I-stream that application work can be dispatched to. See also active I-stream.
in-use synchronization source: The originator of the oscillator pulses that keep all the TOD clocks in a loosely coupled complex synchronized.
inactive FACE table (FCTB): The FCTB that is not the active FCTB. See active FACE table (FCTB).
inactive processor: A loosely coupled processor that is temporarily not being used. An inactive processor can be reactivated.
inactive subsystem: A subsystem that was included during initialization but is currently not in use because of a system error. The error condition must be corrected before the subsystem can be reactivated.
in-core dump formatter (ICDF): A program that formats main storage dumps online when the system error options indicate that dumps are to be routed to the system printer.
index: For persistent collections, a relative offset into a collection.
index name: In z/TPF support for MongoDB, the name that is assigned for a path from one z/TPFDF subfile to another z/TPFDF subfile. Index names can be assigned to z/TPFDF algorithms and to custom indexes.
index record: See key record.
i-node: An object in a file system that represents a file. There is a one-to-one correspondence between an i-node and a file.
input list: A CPU loop list containing work items for new input messages that need an entry control block (ECB) to be processed. The CPU loop checks this list after ready list processing has been completed. See also cross list, deferred list, low priority utility list, OSA input message list, ready list, suspend list, time dispatch list, and virtual file access count (VCT) list.
input/output block (IOB): A control block created by the control program to schedule, control, and hold information required to process a DASD I/O operation. See also system work block (SWB) and extended system work block (XWB).
instruction-stream: See I-stream.
instruction-stream engine: See I-stream engine.
intercept point: See function intercept.
interchange address (IA): The term used to identify the terminal interchange that controls a cluster of terminals. The IA is a part of the ALC address format.
interface definition language (IDL): In RPC, the language that describes the set of procedures (the interface definition) that is contained in the .idl file.
internal data definition: A description of a variable appearing at the beginning of a block that causes storage to be allocated for the lifetime of the block.
Internet Daemon configuration file (IDCF): The #IBMM4 fixed file records that contain definitions for all the Internet server applications defined to the Internet Daemon. The IDCF is subsystem unique and processor shared. The IDCF is created and managed using the ZINET commands.
Internet Daemon configuration table (IDCT): A table in the system heap that contains entries for each Internet server application that the Internet Daemon has started. The IDCT contains all the information found in the Internet Daemon configuration file (IDCF) plus additional fields to maintain Internet Daemon state information.
Internet Daemon listener: A major component of the Internet Daemon in the z/TPF system that creates and monitors a socket for the Internet server application for a specify Internet Protocol (IP) address. See also Internet daemon monitor.
Internet Daemon monitor: A major component of the Internet Daemon in the z/TPF system that is responsible for starting and stopping the Internet Daemon listeners for Internet server applications and for error recovery when an Internet Daemon listener fails. See also Internet daemon listener.
Internet Protocol address processor-shared table (IPAST): A table that contains information about each active native stack Internet Protocol (IP) address in the loosely coupled complex and is used by Domain Name System (DNS) server support.
Internet Protocol message table (IPMT): A table that contains the input and output messages for sockets that use TCP/IP native stack support.
Internet Protocol routing table (IPRT): A table that associates a z/TPF client local Internet Protocol (IP) address with a specific remote IP address or a subset of remote IP addresses.
Interprocedural Analysis (IPA): A process for performing optimizations across compilation units.
interprocessor communications (IPC): The program facility used to transfer system data, control commands, and messages between CPCs or I-streams in a loosely coupled complex. In the z/TPF system, IPC uses the multi-processor interconnect facility (MPIF) as a transport medium for system data, control commands, or messages being sent to a different CPC.
interrupt stack: The list of information fields that describe I/O interrupts that have occurred but have not been analyzed.
IOB: Input/output block.
IPA: Interprocedural Analysis.
IPAST: Internet Protocol address processor-shared table.
IPAT: See program attribute table (PAT).
IPC: Interprocessor communications.
IPMT: Internet Protocol message table.
IPR: Image pointer record.
IPRT: Internet Protocol routing table.
I-stream: An IBM central processing unit (CPU). Although there is a conceptual distinction between I-stream and I-stream engine, in the z/TPF system the terms are used synonymously.
I-stream cap: The highest I-stream number of any I-stream that application work can be dispatched to.
I-stream engine: Synonym for I-stream.
I-stream floor: The highest I-stream number of any I-stream that cannot be collapsed by the z/TPF system.
I-stream engine 2: In a multiprocessing environment, the I-stream engine assigned to handle input/output (I/O) for the multi-processor interconnect facility (MPIF).
iteration order: The order in which elements are visited by using cursor C functions such as TO2_allElementsDo and TO2_next in a persistent collection.