gtpd3m0sLibrary Guide with Master Index and Glossary

P

package
A group of TPF-unique programs necessary to process one particular function or a group of related functions.

package test
The testing procedure, unique to TPF, that checks the validity of interrelated functions in a program package. This is sometimes called Phase III test.

package unit
In the program test vehicle (PTV), a gradient of program testing that allows several application programs to be tested together to verify the performance of specified functions. Also see transaction unit and full scale.

packet
In TCP/IP, the unit of data passed across the interface between the internet layer and the link layer. A packet includes an IP header and data. A packet can be a complete IP datagram or a fragment of an IP datagram. See also datagram.

pad
To fill unused positions in a field with data, usually zeros, ones, or blanks.

page
A 4 KB area of memory; an entry in a page table.

page and segment table area
The segment and page table area (SPTA) is the control table for the ECB virtual memory. It is allocated by CCCTIN. The address of each ECB's SPTA is saved in the Key F section of the ECB.

page frame real address (PFRA)
The real address of the hardware frame identified by a given virtual address.

page protection
A facility that controls access to virtual storage by using the page-protection bit in each page table entry.

page zero
Storage locations 0 to 4095.

PAL
Deprecated term for IBMPAL.

parallel session
In SNA, 2 or more concurrently active sessions between the same 2 logical units (LUs).

parallel session logical unit
A logical unit (LU) that can have 1 or more concurrently active sessions with a given partner LU.

parameter
The name of a value that a function receives.

parameter declaration
A description of a value that a function receives. A parameter declaration determines the storage class and the data type of the value.

parametric recoup
The attribute of the file recoup program that allows it to be activated and controlled by parameter lists.

parent directory
The directory that is one level above the current directory. When discussing a given directory, the directory that contains a directory entry for the given directory and is represented by the path name dot-dot (..) in the given directory. (POSIX.1) When discussing other types of files, a directory containing a directory entry for the file under discussion. (POSIX.1)

parent process
A process that creates a child process. See also child process and process.

PARS
Programmed airlines reservation system.

PARS list
A partitioned data set member that contains the names and versions of the E-type programs to be loaded to the loader general file.

parser
A program that allows the use and interpretation of data. The XML4C parser is used for data written in the XML language. In XML4C, there are two specifications used to interact with the parser: Document Object Model (DOM) and Simple API for XML (SAX). See also Document Object Model and Simple API for XML.

part objects
See collection part objects.

partial load
Synonym for short load.

partially duplicated files
A design for a TPF database where some records have duplicate copies while other records do not.

partitioned emulation program (PEP)
An extension of the network control program that allows the emulator program (EP) and the Network Control Program (NCP) to cohabit the 37x5 processor.

PAT
Program allocation table.

path
The logical structure used to communicate between 2 processors. A communication unit path provides two-way communication between 2 processors. Each path consists of 2 units, each supporting one-way communication for reading or writing.

path information unit (PIU)
The basic unit of information sent between the TPF system and System Network Architecture (SNA) devices. A path information unit (PIU) is SNA terminology for a message.

path length
The number of ESA machine instructions required to process an input message from the time it is received until the response is sent to the communication facilities.

path name
A file name specifying all directories leading to the file. See also relative path name. A file name specifying all directories leading to a file plus the file name itself. A string that is used to identify a file. A path name consists of, at most, PATH_MAX bytes, including the terminating null character. It has an optional beginning slash (/) followed by zero or more file names separated by slashes. If the path name refers to a directory, it may also have a trailing slash.

path switch
An action taken by one of the high-performance routing (HPR) endpoints to request a new path for a rapid transport protocol (RTP) connection when the HPR endpoint detects a failure in the network. This action is nondisruptive; that is, no LU-LU sessions or data are lost.

path switch timer
A timer used by the TPF system to detect path switch failures in a high-performance routing (HPR) network.

pattern A regular expression or series of regular expressions that define the search pattern.
A sequence of characters used either with regular expression notation or for path name expansion as a means of selecting various character strings or path names, respectively. The syntaxes of the two patterns are similar, but not identical; the standard always indicates the type of pattern being referred to in the immediate context of the use of the term. (POSIX.2)
A sequence of characters used by commands that search for strings. Some characters have special meanings in patterns; for example, $ refers to the end of a line and abc$ refers to the sequence abc appearing at the end of a line. Some patterns can be matched by many different strings.

PBI
Program base identification.

PDU In Simple Network Management Protocol (SNMP) agent support, a protocol data unit.
In TPF file pool support, pool directory update processing.

PEP
Partitioned emulation program.

PER
Program event recording.

permanent storage
Storage that is the final repository for the data that TPF systems share and might be on DASD. TPF systems can read the data from permanent storage to local storage buffers for their use and then maintain the data in the local cache buffers and use the directory-only caching method to track the validity of the data.

permission (file permission)
The right to access a file. See also access permissions.

persistence
A process that guarantees collection access beyond the life of the creating entry control block (ECB) and beyond a system re-IPL. Access is guaranteed until a collection is specifically deleted.

persistent collection
An abstract representation of data having common attributes and functions that maintain their state after the entry control block (ECB) that creates them exits.

persistent identifier (PID)
An identification number that is assigned to all collections in TPF collection support (TPFCS). The PID is architected as a 32-byte number consisting of a format indicator and other information used to locate the collection.

persistent long-term collection
A collection that lives beyond the life of the creating ECB, resides on DASD in long-term pool records, and can survive a re-IPL. The collection will be deleted only with an explicit delete call.

persistent message
A message that survives a restart of the queue manager. Contrast with nonpersistent message.

persistent short-term collection
A collection that lives beyond the life of the creating ECB, resides on DASD in short-term pool records, and can survive a re-IPL. The collection will be deleted when the short-term pools are recycled.

persistent structure
A coupling facility (CF) structure that remains allocated when there are no active connections.

pessimistic concurrency
In TPF collection support (TPFCS), a way of controlling data access. Pessimistic concurrency uses an exclusive lock to allow a user to read a collection, update it, and replace it.

PFRA
Page frame real address.

Phase III test
See package test.

physical address
The absolute address after configuration (the final address). See also absolute address, logical address, real address, and virtual address.

physical storage block
Types of working storage blocks used as I/O blocks, system work blocks, entry control blocks, frames, and common frames.

PID
Persistent identifier.

pilot tape
A general tape that can be processed by the online data loader to load new fixed file data into the online system.

pinned data
Data held until it is destaged to DASD or explicitly discarded by a host command because of a permanent error condition in a 3990 caching control unit.

PIO
Preemptive I/O. A TPF control program routine that manages I/O operations to a single device while suspending normal I/O (CIO) services for all other devices. This is used primarily by the system error routine.

pipe To direct data so that the output from one process becomes the input to another process.
A one-way communication path between a sending process and a receiving process. See also pipeline.

pipeline A chain of two or more processes connected by pipes. Each process in the chain acts as a filter, reading data from the standard input (stdin), performing some transformation, and writing the results to the standard output (stdout).
A direct, one-way connection between two or more processes.
To perform processes in a series.

PIU
Path information unit.

PKST
Processor keypoint status table.

PNA
Program nesting area.

pointer
A variable that holds the address of a data object or function.

polling
In a communication network, the act of checking for input from a device.

pool conversion
In pool file support, to convert the pool data structures on file in DASD from pool expansion (PXP) support format to 32-way loosely coupled pool support format. For pool conversion to take place, all processors in the complex must be migrated to 32-way loosely coupled pool support. When pool conversion is completed, the pool data structures in main processor storage (core) on each processor and on file in DASD are in 32-way loosely coupled pool support format. Contrast with pool migration and pool conversion fallback.

pool conversion fallback
In pool file support, to return the pool data structures on file in DASD from 32-way loosely coupled pool support format to pool expansion (PXP) format. When pool conversion fallback is completed, the pool data structure in main processor storage (core) on each processor is 32-way loosely coupled pool support format, while the pool data structure on file in DASD has been returned to PXP support format. Processors in unmigrated state can now join the complex. See also pool conversion, pool migration, and unmigrated state.

pool directory
An index of all pool records maintained by the control program file directory system.

pool directory generation
A storage management process that creates pool directories.

pool directory record
The array of status bits that indicates whether a pool record is available or unavailable.

pool fallback
The technique for selecting an alternate compatible pool section for address dispensing if a depleted pool section is selected.

pool file record
A DASD record used for temporary data storage; it is given to programs when requested and returned when no longer needed by the programs.

pool file storage
See pool file record.

pool migration
To IPL a processor on an image that contains 32-way loosely coupled pool support while the data structure on file in DASD remains pool expansion (PXP) support format. The 32-way loosely coupled pool support data structure format is used in main processor storage (core). Contrast with pool conversion.

pool record
See pool file record.

pool record type
See pool type.

pool section
Storage space allocated for a particular pool type. The pool type may be allocated across several device types in which case the pool type will consist of several pool sections.

pool segment
Two noncontiguous areas in a pool section.

pool type
One of 10 groups of pool records: small long-term (SLT), small short-term (SST), small long-term duplicate (SDP), large long-term (LLT), large short-term (LST), large long-term duplicate (LDP), 4K long-term (4LT), 4K short-term (4ST), 4K long-term duplicate (4DP), and 4K long-term duplicate FARF6 (4D6).

POP
Post Office Protocol.

portability
The ability to move a subsystem to a different local or remote CPU site without impacting the operation of the subsystem being moved or any subsystem remaining at the original site.

Portable Operating System Interface for Computer Environments
Synonym for POSIX.

POSIX
Portable Operating System Interface for Computer Environments. An interface standard governed by the IEEE and based on UNIX. POSIX is not a product. Rather, it is an evolving family of standards describing a wide spectrum of operating system components ranging from C language and shell interfaces to system administration.

post-interrupt branch address
The standard field in system control blocks used to point to the system routines invoked when a work item reaches the top of a queue.

post-interrupt processing
(1) The housekeeping routine to set up further processing for an application after the control program has completed a service request. (2) When an IOB reaches the top of the ready list, post-interrupt processing removes the IOB address from the ready list and links the application to the input data by moving the core block address to the ECB, moves the output data core block address to the ECB, and returns the core block to the system pool. If all I/O is completed, control returns to the linked application.

post-interrupt routine
The housekeeping routine that performs further processing for an application after the control program has completed a service request.

Post Office Protocol (POP)
In the Internet suite of protocols, an application protocol that allows a client to retrieve Internet mail from a server. POP transfers mail to the client, and optionally, removes the original copy from the server. See also Internet Message Access Protocol (IMAP) and Simple Mail Transfer Protocol (SMTP).

pragma
See #pragma.

PRC
Prime CRAS.

precedence
The priority system used to determine the grouping of different types of operators with their operands.

precision
A measure of the ability to distinguish between nearly equal values. See single precision and double precision.

preemptive I/O
Synonym for PIO, which is the commonly used term. A TPF control program routine that manages I/O operations to a single device while suspending normal I/O (CIO) services for all other devices. This is used primarily by the system error routines. See also common I/O (CIO).

prefix register
Positions 1-19 of the prefix register contain the value used to transfer from a real address to an absolute address when prefixing is applied.

prelinker
A program that prepares code with writable static data, long names, and dynamic link libraries (DLLs) for the linkage editor.

preprocessor
A program that examines the source program for preprocessor statements that are then executed, resulting in the alteration of the source program.

preprocessor statement
A statement that begins with the symbol # and is interpreted by the preprocessor.

primary directory
See quick enter directory.

primary expression
An identifier, an expression enclosed within parentheses, a function call, an array element specification, or a structure or union member specification.

primary image
The image that is used during a hard IPL.

primary key path
A structure that exists from the moment a collection is created and dictates the location of elements within that collection. See also alternate key path.

primary record
When DASD records are duplicated, the 2 copies of a data record are called the primary record and the duplicate record. When used in the context of TPF collection support (TPFCS), this term has a different meaning. See TPFCS primary record.

prime CRAS (PRC)
The main system console designated to direct system processing.

prime module
The online module used for IPLs and system restarts. In a fully duplicated database, the disk pack containing the primary records. Contrast with duplicate module. See also primary record and duplicate record.

prime restart area
The part of the restart area used for online system restarts.

private code
An unnamed executable control section.

process
A function being performed or waiting to be performed. An executing function or one waiting to execute. A sequence of actions required to produce a desired result. (OSF) An entity receiving a portion of the processor's time for executing a program. (OSF) A unique, finite course of events defined by its purpose or by its effect, achieved under given conditions. Any operation or combination of operations on data. A running program, including the memory occupied, the open files, the environment, and other attributes specific to a running program. An address space and the single thread of control that executes within that address space and its required system resources. (POSIX.2)

process identifier (ID)
A unique, positive number that represents a process. In the TPF system, the process ID is a unique identifier for a process.

process selection vector (PSV)
An optional exit program that allows the user to extend TPF communication support for additional terminal types without modifying the user's application programs.

processing unit
A functional unit that consists of 1 or more processors and their internal storage.

processor
In a computer, a functional unit that interprets and processes instructions.

processor complex
A configuration that consists of all the machines required for operation.

processor keypoint status table (PKST)
The communication control unit keypoint status record used for non-SNA communication.

processor lock
Used to permit system control programs, processing in 2 or more I-stream engines in a CPC, to modify shared system data.

processor resource ownership table (PROT)
A table maintaining the ownership status of tape drives and system utilities in a loosely coupled complex.

processor shared cache
In logical record cache support, a cache that contains cache entries that are kept synchronized between all processors in a loosely coupled complex that are using the cache.

processor shared keypoint (PSK)
The keypoint records that identify resources shared among processors. All processors in a loosely coupled complex share the same copy of these keypoint records.

processor shared resource
A resource that is shared among processors in a loosely coupled environment.

processor unique cache
In logical record cache support, a cache that contains cache entries that are used by only one processor in a loosely coupled complex.

processor unique keypoint (PUK)
The keypoint records that identify resources dedicated to each processor. Each processor in a loosely coupled complex has its own unique copy of these keypoint records.

processor unique resource
A resource that cannot be shared by or switched among loosely coupled processors.

program
One or more files containing a set of instructions conforming to a particular programming language syntax.

program allocation table (PAT)
A table built by the allocator program that provides an enter-by-name capability and program allocation attributes. The program allocation table allows dynamic determination of the address of the program being entered.

program allocator list (PAL)
Deprecated term for IBM program allocator list (IBMPAL).

program base identification (PBI)
The ECB field that identifies the program base of a particular subsystem.

program collector
The data collection program that records the macro types, the programs called, and the residency of the called programs. The data is written to the data collection tape and processed by the offline data reduction programs.

program event recording (PER)
A facility that provides assistance in debugging programs in a native TPF system environment by monitoring the following events: storage alteration, instruction fetching, and successful branching.

program ID field
A 4-byte field in the header of every data record that contains the name of the last program updating that record.

program nesting area (PNA)
The fields used to hold chains of ENTER/BACK requests controlled by an ECB. Base address, return address (next sequential instruction), and program base ID are saved for each program issuing an ENTRC.

program test vehicle (PTV)
An online utility that permits the user to test applications in progressive levels of system involvement.

programmed airlines reservation system (PARS)
The application programs developed specifically for airline reservations.

prolog
The code that is processed each time a C language function is activated. Its purpose is to allocate a block of main storage to contain local variables for use during function processing.

property
An attribute with values that a user can dynamically associate with a persistent collection.

property service
A service for created persistent collections that lets a user dynamically associate named attributes (properties) with an already existing persistent collection. Once the properties are defined, their values and access modes can be obtained and changed.

PROT
Processor resource ownership table.

protocol
In open systems interconnection architecture, a set of semantic and syntactic rules that determine the behavior of entities on the same layer in performing communication functions.

pseudo directory
An accurate account of long-term pool records at some discrete instant of time.

pseudo module
For pool file, a DASD module on which pool addresses are allocated, but the module does not currently exist. This allows for adding devices to the database without the need to regenerate pool directories.

PSV
Process selection vector.

PSW
Program status word.

PTV
Program test vehicle.

PU type 2.1
PU type 2.1 attachment to an SNA network involves TPF appearing to a local NCP as a type 2.1 node with independent LUs. TPF is the primary side of the link and performs an exchange identification format 3 (XID3) to establish connection. TPF application LUs appear to reside in the local NCP, which requires a unique name for each TPF application per channel-attached NCP.

PU type 5
PU type 5 attachment to an SNA network involves TPF appearing to a local NCP as a type 5 subarea node with an SSCP and a CDRM component. TPF is a data host (that is, does not send ACTPU to the NCP) and performs exchange identification format 2 (XID2) to establish connection. TPF application LUs appear as CDRMs to a VTAM CMC.

PUK
Processor unique keypoint.