gtpd3m0vLibrary Guide with Master Index and Glossary

S

SA
Session address.

SAA
Systems Application Architecture.

SABRETALK
A high-level program language used to code ECB-controlled programs. Additional main storage must be attached to the ECB when SABRETALK segments are processed.

SAL
System allocator table.

SALO
System allocator.

SAT
Subarea address table.

SAX
Simple API for XML.

SBCS
Single-byte character set.

SCB
Session control block.

SCK
System communication keypoint records.

scalar
An arithmetic object, or a pointer to an object of any type.

schema
(1) The set of statements, expressed in data definition language, that completely describe the structure of a database. (2) Statements that define the tags used in an XML document. A schema defines the structure with elements and attributes, and it establishes constraints for how each element and attribute may be used within the particular class of documents. A schema can be either a DTD or an XML Schema.
  1. The DTD is one method of defining the acceptable tags for an XML document. It has a strict syntax and can be included internally in the XML document or externally through a reference in the XML document. A DTD is a type of schema, but is not written in XML language. DTDs are supported on TPF through the XML4C parser.
  2. The XML Schema is actually written using the XML language and was developed by the World Wide Web Consortium (W3C). It is more inclusive and more detailed than a DTD for the following reasons:
    • It can be parsed as an XML document.
    • It can specify what type of data can be in a particular element (for example, integer versus character data).
    • It allows you to specify element that must be used the same throughout the XML document as well as elements that have special meanings in different contexts.

    For more information about the XML Schema, go to http://www.w3.org/.

scope
The level on which a function or variable is "visible" or accessible. File scope means that the function or variable is visible only within the source file in which it is defined. Block scope means that the function or variable is only visible within the block (defined by curly braces { }).

scratch pad area (SPA)
The terminal control block associated with each SNA network addressable unit defined in the system. Applications use SPA records to pass information among the entries of a transaction.

SCT
SWB control table.

SDA
Symbolic device address.

SDAT
Symbolic device address table.

SDMF
Standard data/message file.

secondary directory
A table of addresses used to branch to secondary library routines.

secondary library routine
A C library function coded in assembler language that resides in its own control program CSECT and does not follow the conventions required for the TPF system E-type programs.

secondary linkage
A TPF method that provides linkage to C library functions written in assembler language and installed as control program CSECTs.

segment
Real-time code or offline code that is not part of the control program (CP).

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

selected equate macro
An assembler macro, such as REGEQU, that provides equate support.

selective activation
The E-type loader process of restricting the use of the programs in a loadset to specific ECBs.

selective file dump (SFD)
A debugging tool that writes the contents of specified file records to the real-time tape.

selective file dump and trace (SFDT)
Two debugging tools (selective file dump [SFD]) and (selective file trace [SFT]) designed to help users locate file-related errors during online operations or while testing under the control of the program test vehicle (PTV). Both functions are activated by commands.

selective file trace (SFT)
A debugging tool that monitors the updating of selected file addresses during a specified file trace period.

selectively duplicated file
See partially duplicated file.

selective memory dump table (SMDT)
A table that maps keywords (representing different areas of main storage) to addresses. It is used by the dump override table (DOT) for system error processing.

self-discovery
In SNA, the process that restarts adjacent link stations (ALSs), NCPs, and CTCs that were previously active.

SENDB postprocessor
A program used for multisegment message transmission over a binary synchronous link.

sender channel
In message queuing, a channel that initiates transfers, removes messages from a transmission queue, and moves them over a communication link to a receiver or requester channel.

SENDL postprocessor
See long message transmitter (LMT).

sequential number wrap value
In MQSeries, a method of ensuring that both ends of a communication link reset their current message sequence numbers at the same time. Transmitting messages with a sequence number ensures that the receiving channel can reestablish the message sequence when storing the messages.

sequence collection
A type of collection with ordered, nonunique elements that are not accessible by a key. Elements are ordered by arrival sequence, but elements can be inserted or deleted before existing elements.

serialize
To change from parallel-by-byte to serial-by-bit.

server
In TCP/IP, a program or process that provides services for a program at another site. See also client.

SESINIT
A private SNA protocol RU sent by the VTAM logon manager to request session initiation across a particular link.

session
A logical connection between two application programs that allows them to communicate.

session address (SA)
In high-performance routing (HPR) support, a unique identifier that flows in the FID5 transmission header (TH) of a network layer packet (NLP). The SA is used to identify a particular LU-LU session over a rapid transport protocol (RTP) connection.

session control block (SCB)
An area in main storage used to control sessions for TPF/APPC support.

session index table (SIT)
A table that maps the LU-LU session identifier (SID) to the SLU resource identifier (RID) when the TPF system communicates as a PU 2.1.

session manager (SM)
The SNA component responsible for insuring that the underlying LU-LU session needed for a conversation is available.

set collection
A type of collection with unordered, unique elements that are not accessible by a key.

SFD
Selective file dump.

SFDT
Selective file dump and trace.

SFT
Selective file trace.

shadow
A TPF collection support (TPFCS) option that allows you to specify that a collection will maintain an extra copy of that collection. When using the shadow option with normal TPF duplicate files of the collection, there will actually be four copies of the data.

shared library indicator directory (SLID)
A table that consists of 1-byte flags for each of the library load modules.

shared library names table (SLNT)
A table that contains the 4-character names of each of the library load modules.

shared memory
An area of memory that allows two or more processes to share a given region of memory.

shared record
A fixed file record that is shared by all subsystem users, processors, or I-streams. Contrast with unique record.

shared resources
In a loosely coupled complex, resources that can be used concurrently by I-streams, processors, subsystems, or subsystem users. Contrast with unique resources.

short load
A software load where only a subset of a full load is loaded. Synonymous with partial load.

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

short-term pool records
File pool records that are usually maintained only for the time required to complete a transaction.

shutdown level
A predefined value that is used to control access to a specified system resource. When the availability of the resource reaches the shutdown level, operation of the system can be inhibited until availability increases.

SIB
SNA I/O buffers.

SICF
System interprocessor communication facility. See interprocessor communications.

side information table
A table used by TPF/APPC mapped conversations that contains the currently defined set of symbolic destination names and the corresponding transaction program names, LU names, and node names.

signal
A simple method of communication between two processes. One process can inform the other process when an event occurs using signals.

signaling
A feature that allows the operating system to notify a program when an expected message arrives on a queue.

Simple API for XML (SAX)
A specification that allows an application to interact with XML data as a series of events.

Simple Mail Transfer Protocol (SMTP)
In the Internet suite of protocols, an application protocol for sending mail to users in the Internet environment. SMTP specifies the mail exchange sequences and message format. It assumes that the Transmission Control Protocol (TCP) is the underlying protocol. See also Internet Message Access Protocol (IMAP) and Post Office Protocol (POP).

single-byte character set (SBCS)
A set of characters in which each character is represented by one byte.

single inheritance
A design characteristic of an object-oriented database in which each class inherits directly from only one immediate superclass.

SIP
System initialization program.

SIP skeleton and internal macro
A macro or skeleton (such as SPPBLD or SPCOMP) that is used by the system initialization program (SIP).

SIP stage I
The first part of system initialization during which macros defined by the user are assembled, analyzed, and expanded to produce an MVS job stream used by SIP stage II.

SIP stage II
The second phase of system initialization during which the MVS job stream generated by SIP stage I is processed. Stage II generates the modules and libraries that comprise the user-specified system.

SIPC
System interprocessor communications. See interprocessor communications.

SIT
Session index table.

slash
The literal character /. This character is also known as a solidus in ISO 8859-1 (B34) (POSIX.1) The / character. UNIX and POSIX-conforming systems use the slash (/) to separate the components of a path name. A slash (/) at the beginning of a path name represents the root directory.

SLC
Synchronous link control.

SLID
Shared library indicator directory.

SLNT
Shared library names table.

SLST
Symbolic line status table.

slow queue
A queue in which the rate of service is slower than the rate that messages are added to the queue. See also sweep.

SM
Session manager.

SMDT
Selective memory dump table.

SMP
System message processor.

SMTP
Simple Mail Transfer Protocol.

SNA
Systems Network Architecture.

SNA channel-to-channel (CTC)
A facility that provides a high-speed link to local and remote VTAM and TPF systems.

SNA command processing
The processing method where SNA commands are used to communicate among SNA network addressable units in order to control network resources.

SNA CTC
SNA channel-to-channel.

SNA CTC priming
A process that initiates exchange identification (XID) processing over SNA CTC links with an active partner.

SNA I/O buffers (SIB)
Storage areas that are assigned for NCP read operations and CTC read and write operations.

SNA message recovery
An optional feature that uses a system recovery table to track input and output messages to insure successful delivery or recovery options.

SNA node
A junction point in a network that contains a physical unit. A node may contain other network addressable units, path control components, and data link control units.

SNCT
Station name conversion table.

SOBT
Static override bitmap table.

socket
An endpoint for communication between processes or applications.

socket address
An address used by socket applications that contains the address family and address associated with a socket.

socket API
Standard application programming interface functions that provide a standard interface to the transport and internet layers of TCP/IP.

socket block table
A table that contains information about sockets that use TCP/IP native stack support.

socket descriptor
The integer value returned to a socket application on a socket, accept, or activate_on_accept function call. The socket descriptor is used as a parameter for subsequent socket API function calls. See also file descriptor.

socket sweeper program
A program that cleans up sockets that have not been used for a specified period of time.

socket thread
In a TCP/IP system, a process that shares a socket descriptor with other ECB-controlled segments.

socks server
A circuit-level gateway that provides a secure one-way connection through a firewall to server applications in a nonsecure network.
Note:
Socks is an abbreviation for sockets.

soft error
An intermittent error condition that disappears when the operation is retried. Contrast with hard error.

software IPL
The recovery process to restore the system to an operational state after the occurrence of a catastrophic software error. Contrast with hard IPL.

SOM
Start-of-message.

SON
System ordinal number.

SON device
A direct access storage device (DASD).

SON format
A system ordinal number format for the file address reference field supported in earlier TPF versions. FARF3, FARF4, FARF5, and FARF6 format addresses are currently supported.

sorted bag collection
A type of collection with ordered, nonunique elements that are not accessible by a key. Elements are ordered in ascending collating sequence by the nonunique sort field.

sorted set collection
A type of collection with elements sorted by a user-specified unique sort field.

source program
A set of instructions written in a programming language that must be translated to machine language before the program can be run.

SPA
Scratch pad area.

spare RVT entry
An entry in the resource vector table that is not assigned to a resource.

special file
A file that provides an interface to an input/output (I/O) device (such as a line printer), a logical subdevice (such as a large section of a disk drive), or a pseudo-device (such as the null file, /dev/null).

spin lock
A mechanism to cause a process (program), processing on behalf of an entry, to wait until another entry has modified shared system data.

SPM
Structured programming macro.

SPTA
Segment and page table area.

SQL
Structured query language.

SRT
System recovery table.

SS
Subsystem.

SSCP
System services control point.

SSID
Subsystem ID.

SSST
Subsystem status table.

SSU
Subsystem user.

SSUID
Subsystem user ID.

stack block
A storage block containing one or more stack frames.

stack exception routine
A routine that manages the stack blocks, including initializing the first stack frame in the first block that contains the storage used by the TPF system and C library functions. The routine is called by a prolog whenever there is no stack block chain, or when another block is required.

stack frame
The storage reserved by the compiler to hold the C automatic variables, parameter lists, and register save area for an individual function.

stage
The state of the file addresses in the TPF system indicating which file address formats are supported by the FACE table; currently, either FARF3/FARF4 or FARF4/FARF5.

staged NCB directory records
The node control block (NCB) directory records that are used by the NCB reorganization function to change the number of NCB directory records in the TPF system.

standard data/message file (SDMF)
A storage facility for canned (prepared) messages and other data that may be called by any program.

standard error (stderr)
The place where many programs place error messages; for the TPF file system, this is the /dev/null special file unless redirected. An output stream usually intended to be used for diagnostic messages. (POSIX.2) In the TPF file system, UNIX, and POSIX, stderr is associated with file descriptor 2.

standard input (stdin)
The primary source of data going into a program. For the TPF file system, this is the /dev/tpf.imsg special file unless redirected. The conventional name for file descriptor 0.

standard output (stdout)
The primary destination of data coming from a program. For the TPF file system, this is the /dev/null special file unless redirected. The conventional name for file descriptor 1.

standby tapes
Tapes that are available to the system for forced or voluntary tape switch. Standby tapes must have the same symbolic name as the tapes that they supplement.

start-of-message (SOM)
The output message character that directs terminal hardware to a location on specific kinds of terminals where the message should be displayed.

state change interruption
A combination of bits in the status byte of a DASD I/O operation that occurs for a change in the 3990 record cache subsystem or device. The status bit combination includes attention, device end, and unit exception. This interruption is sent to all hosts to inform them of the state change.

statement
An instruction that ends with the ; (semicolon) character or several instructions that are surrounded by the characters { and }.

static block
A storage block containing one or more static frames.

static exception routine
A routine that manages static blocks. This routine is called by the C compiler-generated function prolog whenever static variables are declared for the function.

static frame
The storage reserved by the C compiler to hold all of the static variables declared in a given compile unit (TPF E-type program segment).

static function
A function called only by other functions residing in the same C source module. Synonymous with internal function.

static override bitmap table (SOBT)
A table that associates system error numbers with keywords representing storage areas to include in dumps. Entries in the SOBT are generated by the IDOTB macro.

static virtual IP address
A virtual Internet Protocol address (VIPA) that cannot be moved between processors.

station name conversion table (SNCT)
The system table that associates every bisynchronous station address with a 4-character symbolic name and provides pointers to the application name table.

STC
System test compiler.

stderr
Standard error.

stdin
Standard input.

stdout
Standard output.

stepping mode
When a stepping signal is synchronized to a Sysplex Timer (STR) oscillator signal, the configuration is in STR stepping mode. Otherwise, the configuration is in local stepping mode.

stepping port
The port of a CPC that receives the Sysplex Timer (STR) oscillator signal. Used to synchronize the stepping signal.

stepping signal
The stepping signal is used to increment all TOD clocks and to decrement all CPU timers in a configuration. The signal may be synchronized to a Sysplex Timer (STR) oscillator signal received from either of the 2 CPC ports, or synchronized to a local or remote oscillator.

storage protection
Three hardware protection facilities are provided to protect the contents of main storage from destruction or misuse by programs that contain errors or are unauthorized: key-controlled protection, page protection, and low-address protection. The protection facilities are applied independently. Access to main storage is only permitted when none of the facilities prohibit the access. See key-controlled protection, low-address protection, and page protection.

STR
Sysplex Timer.

stream
A continuous sequence of data elements being transmitted, or intended for transmission, in character or binary-digit form, using a defined format.

string constant
Zero or more characters enclosed in double quotation marks.

structure
(1) In coupling facility (CF) support, a construct used by the TPF system to map and manage storage on a CF. See coupling facility (CF) list structure. (2) A variable that contains an ordered group of data objects. Unlike an array, the data objects within a structure can have varied data types.

structured programming macro (SPM)
A macro that is used to add structured programming verbs to existing assembler language.

structure object
An object that TPF collection support (TPFCS) uses to sort or retrieve the data of a given collection. A structure object falls into either of two categories: compact structure or extended structure. See also compact structure and extended structure.

structure record
The pool record that contains the structure object of a collection.

structure tag
The identifier that names a structure data type.

structured query language (SQL)
A programming language used to define and access relational data and control access to relational database resources.

STSA
System temporary save area.

STTS
System test terminal simulation.

STV
System test vehicle.

suballocation
The carving of a 4K frame into 1 or more storage blocks.

subarea address table (SAT)
The system table that contains the path information required to reach any subarea in an ACF/SNA network.

subclass
A specific class of a more generic class.

subdirectory
A directory contained within another directory.

submailbox
In mailbox naming hierarchy, a lower-level mailbox. For example, user1.projects.work.mail and user1.projects.fun.swingset are both submailboxes of the mailbox user1.projects.

subscript
One or more expressions, each enclosed in brackets, that follow an array name. A subscript references an element in an array.

subsystem (SS)
An application or group of applications sharing a database. See also multiple database function (MDBF).

subsystem ID (SSID)
The field that identifies a subsystem in an MDBF or RCS environment. The SSID may be used to access information pertaining to that subsystem. An identifier used by RCS support to uniquely identify each caching subsystem.

subsystem status table (SSST)
A record cache subsystem control table used to represent the active 3990 caching control unit complex and its attached devices.

subsystem user (SSU)
A unique subset of a subsystem database. A collection of subsystem users that share a database constitutes a subsystem.

subsystem user ID (SSUID)
The field that identifies a subsystem user in a subsystem. The SSUID may be used to access information pertaining to that subsystem user.

superclass
A generic class of a more specific class.

superuser
A system user who operates without restrictions. A superuser has the special rights and privileges needed to perform administrative tasks.

superuser authority
The unrestricted ability to access and modify any part of the operating system, usually associated with the user who manages the system.

suspend list
A secondary CPU loop list which contains entries that were suspended after exceeding a system resource threshold. The suspend list is used for the LODIC macro when the availability of a particular block type has fallen below a defined shutdown level, or the TMSLC macro when the entry has run for a defined time limit.

SVA
System virtual address.

SVAT
System virtual address table.

SVM
System virtual memory.

SWB
System work block.

SWB control table (SCT)
A table that keeps track of which system work blocks (SWBs) are in use and the address of the routine that obtained and released the blocks.

sweep
The process of relocating messages on a slowly serviced queue from main storage memory to DASD. See also slow queue.

swing
The process of moving all current messages from one transmission queue to another specified transmission queue and forcing all future messages intended for the original queue to be placed on the new destination queue.

switch expression
The controlling expression of a switch statement.

switchable resources
In a loosely coupled complex, resources that can be used by only 1 processor at a time. Examples of switchable resources are unit record devices, tape devices, system utilities, and communication control units.

symbolic address
The address of a record in file storage that consists of a record type and ordinal number.

symbolic device address (SDA)
A logical device address. For device types 37x5 and SNA CTC, the address must be in the X'0001' to X'7FFF' range. For DASD, the symbolic device address is made up of a logical channel/control unit/device address with more restrictions. The mapping of symbolic device addresses to real device addresses is done when the input/output configuration program (IOCP) is generated.

symbolic device address table (SDAT)
A table created by SIP from the IODEV macros and copied into the SNA keypoint containing 37x5 NCP and channel-to-channel (CTC) symbolic device addresses.

symbolic line status table (SLST)
The table used by the control program to control and maintain status of the communication network. It is the primary control table for the non-SNA communication network.

symbolic link
A type of file that contains the path name of, and acts as a pointer to, another file or directory.

symbolic module number
A field in the file status table that points to a particular DASD device.

synchronous link control (SLC)
A line control procedure that uses full-duplex voice-grade lines, and transmits at 2400-9600 bits per second.

synchronous messaging
A method of communication between programs in which programs place messages on message queues. With synchronous messaging, the sending program waits for a reply to its message before resuming its own processing. Contrast with asynchronous messaging.

syncpoint
An intermediate or end point during the processing of a transaction at which the protected resources of a transaction are consistent. At a syncpoint, changes to the resources can safely be committed or they can be backed out to the previous syncpoint.

syntax
The rules for the construction of a command or a program.

SYSEQ tag
A system equate that provides a symbolic name for a system parameter or commonly used constant.

syslog daemon
A server process that provides a message logging facility for application and system processes.

Sysplex Timer (STR)
An IBM 9037 unit that synchronizes the time-of-day (TOD) clocks in as many as 16 processors or processor sides. A common time source for clock synchronization across central processing complexes (CPCs).

system
The computer and its associated devices and programs.

system allocator (SALO)
The program that generates the PAT and SAL tables from the program allocator list (IBMPAL).

system allocator table (SAL)
One of the tables output by the system allocator (SALO). It is used by the TPF linkage editor (LEDT) to resolve external references.

system collector
The data collection program that records system activity data (core block availability, ECBs in use, entries on CPU queues, CPU clocks, input messages by source) at timed intervals.

system communication keypoint records (SCK)
The main storage resident records used to define the non-SNA portion of the communication network.

system contraction
The online deletion of processors from a loosely coupled complex.

system expansion
The online addition of processors to a loosely coupled complex.

system heap
In a TPF system, a virtual address space located at the end of system virtual memory, which is only backed by system frames when requested. The storage is not attached to any ECB, but is accessible by all ECBs because it is not mapped as ECB virtual memory (EVM) unique storage.

system ID
A three-part name identifying a particular TPF CPU. The system ID consists of an enterprise name, a TPF complex name, and a CPU ID.

system initialization program (SIP)
The two-phase process that generates a TPF system according to user requirements. Hardware, software, and communications configurations are defined according to the SIP macro parameters selected by the user. The macros are passed to the assembler and an MVS JCL job stream is produced (SIP stage I). is produced. When this job stream is processed (SIP stage II), it produces the initial TPF system.

system interprocessor communication facility (SICF) or (SIPC)
See interprocessor communications.

system loader
See auxiliary loader or E-type loader.

system macros
Macros that are restricted to system use. There are three types of system macros: those that require authorization, those that do not require authorization, and those that are restricted to the control program (CP).

system message processor (SMP)
The system ECB-controlled programs that process commands.

system ordinal number (SON)
Deprecated term for database ordinal number (DBON). In earlier TPF system releases, system ordinal number was used to identify the logical/relative record numbers across the entire database. The term is no longer used.

system performance measurement
Online data collection programs and offline data reduction programs that provide statistics with which the user can analyze system performance.

system program save area
The ECB area used to save the current contents of general registers when an application program issues a control program macro.

system recovery table (SRT)
A table used to reintroduce lost or timed-out input messages and retransmit lost or timed-out output messages.

system restart
See restart.

Systems Application Architecture (SAA)
A set of IBM software interfaces, conventions, and protocols that provide a foundation for designing and developing consistent applications across systems.

system services control point (SSCP)
A focal point in the SNA network that manages the network, coordinates operator and problem determination requests, and provides general support for users of the network. Multiple SSCPs divide the network into domains of control. Each SSCP controls the logical units and physical units in its domain.

Systems Network Architecture (SNA)
The description of the logical structure, formats, protocols, and operational sequences for transmitting information units through, and controlling the configuration and operation of, networks.

system state
The condition of the operating system in terms of the level of functions that can be performed. Beginning with the lowest or least active system state, the 5 states are: 1052, UTIL (utility), CRAS, MESW (message switching), and NORM.

system state change
The function called by a command or by an internal request that makes a transition among the 5 system states.

system temporary save area
The control block that provides an extended save area for the TPF system.

system test
The PTV testing procedure where all programs undergo multithread testing in an environment that simulates the actual system.

system test compiler (STC)
The offline program that creates tapes to be used for test units for PTV or pilot tapes for the data loader.

system test terminal simulation (STTS)
A package of simulator programs that format and print input and output messages as the messages would appear on specified terminals.

system test vehicle (STV)
A facility under PTV used to introduce input messages during system testing.

system virtual address (SVA)
A location inside of system virtual memory for an I-stream.

system virtual address table (SVAT)
The table in the ECB that is used to keep track of the system virtual addresses of all pages mapped in the ECB virtual memory.

system virtual memory (SVM)
Virtual memory, used only by control program code, that maps all of the memory in each of the ECB address spaces, plus some memory that is not available at all in the ECB address spaces. There is 1 system virtual memory per I-stream in a tightly coupled complex.

system work block (SWB)
A storage block provided by the system for system use; cannot be used as a TPF block. Contrast with input/output block (IOB).