A TPF processor that
receives input messages routed from a front-end processor; that is, a
back-end processor has no communication support in it. A back-end
processor provides application program processing and database management
functions, usually on a large database. In a loosely coupled complex,
multiple back-end processors share a common database. Contrast with
front-end processor.
backup record
See duplicate
record.
bag collection
A type of collection with
unordered, nonunique elements. There is no access by key.
band number
In a FARF3 file address, a
unique random value between 0 and 4095 that is associated with a fixed file
record type.
base class
A class from which all instances
are inherited.
basic subsystem (BSS)
The primary subsystem
that contains the control program and all support programs necessary for a
stand-alone TPF system. All system-related tasks, including I/O
processing, are processed by the BSS.
BBT
Buffer block table.
BCC
Block check character.
BDW
Block descriptor word.
Berkeley Software Distribution (BSD) socket
A
standard interface for user application programs. Programs written to
this standard can interface with sockets to access the Internet. The
BSD socket interface was developed at the University of California at
Berkeley.
big endian
A method of representing data
such that the lower numbered bytes of the data are more significant.
IBM S/390 and AS/400 machines use this format.
binary
(1) A base two numbering system;
the binary digits are 0 and 1. (2) Involving a choice of two
conditions, such as on-off or yes-no.
binary expression
An expression containing
two operands and one operator.
binary file
A file that is not organized as
lines of text that can be read by a human. A binary file is intended to
be interpreted by a program.
binary large object (BLOB) collection
A type
of collection with ordered, nonunique elements that are 1 byte each.
There is no access by key. Elements are ordered by ascending relative
byte address (RBA). Elements cannot be inserted or deleted before an
existing element. Operations can be performed in the range from 1 to
32 000 bytes at a time. Synonymous with byteArray
collection.
binary synchronous communication (BSC)
A
communication protocol that uses synchronous transmissions to support
multipoint and point-to-point half-duplex lines.
Bind Establishes access paths on DB2 for
each SQL statement
in an application.
binding
A method that allows processes to
refer to a socket by using a name. Communicating processes are bound by
an association. The binding system call allows a process to specify
half of the association; that is, the local name.
bit field
A member of a structure or union
that contains a specified number of bits.
BLOB collection
Binary large object.
block check character (BCC)
The BCC provides
longitudinal even parity for each bit column (b7 to b1), excluding parity
bits.
block descriptor word (BDW)
The first 4
bytes of a variable block length (format-VB) physical block.
block statement
Any number of data
definitions, declarations, and statements that appear between the symbols
{ and }. The block statement is
considered to be a single C-language statement.
blocked records
See blocked
tape.
blocked tape
A tape recorded with nonspanned
variable block length (format-VB) blocks. The logical records on the
tape are usually referred to as blocked records. A tape of
physical records that can be composed of several contiguous logical records or
parts of logical records. Physically, the blocked tape is read one
record at a time; logically, the TPF system manages the blocked tape
record by record. Contrast with unblocked tape.
blocking mode
A program may be suspended
indefinitely until data requested using a socket API function, for example
read or write, is available. See nonblocking
mode.
boundary alignment
The position in main
storage of a fixed-length field (such as halfword or doubleword) on an
integral boundary for that unit of information. For example, a word
boundary is a storage address evenly divisible by four.
breakpoint
When a C program is compiled
using the TEST option, the computer generates a breakpoint, or an EX
instruction with a hook statement as its subject. The EX instruction is
initialized to a no-operation instruction. An entry breakpoint is
generated at the beginning of a function. An exit breakpoint is
generated at the completion of a function. Other breakpoints are
generated under control of the suboptions of the compiler TEST option, for
example, the PATH suboption generates path breakpoints.
browse support
Support that allows TPF
persistent collections classes, methods, and collections to be located,
displayed, interrogated, dumped, and validated.
BSC
Binary synchronous communication.
BSC message routing
The process that directs
an input message to a particular application through the use of the RCPL
associated with the message.
BSD socket
Berkeley Software Distribution
socket.
BSN
Byte sequence number.
BSS
Basic subsystem.
BSS resident
An application or resource that
may be allocated only to the basic subsystem.
buffer block table (BBT)
A table containing
the addresses of all 4K (KB) working storage blocks currently in use as part
of a buffer for a tape in blocked mode.
build script
A file that defines the module
type and specifies the components of a dynamic link library (DLL), dynamic
load module (DLM), or library load module (LLM), and is used by the CBLD
program to create the finished DLL, DLM, or LLM.
built-in function
A function call that the
compiler replaces with an in-line object code expansion. Because a
built-in function call does not generate any linkage, no prolog or epilog code
is invoked when the built-in function executes. Built-in functions
provide more efficient code by reducing the instruction path length.
byte
A unit of measure. For IBM C
compilers, 8 bits equal 1 byte.
byteArray collection
A type of collection
with ordered, nonunique elements that are 1 byte each. There is no
access by key. Elements are ordered by ascending relative byte address
(RBA). Elements cannot be inserted or deleted before an existing
element. Operations can be performed in the range from 1 to
32 000 bytes at a time. Synonymous with binary large
object (BLOB) collection.
byte sequence number (BSN)
A number in the
transport header (THDR) of a network layer packet (NLP) that indicates the
order in which data was transmitted by the sending node.