Specifications

Glossary
Glossary-
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kernel buffer cache
A set of buffers used to minimize the number of times a block-type device must be
accessed.
lightweight process
A lightweight process or LWP is the set of data and interfaces at user level that provide
support for the threads abstraction.
loadable module
A kernel module (such as a device driver) that can be added to a running system without
rebooting the system or rebuilding the kernel.
low water mark
The point at which more data is requested from a terminal because the amount of data
being processed in the character lists has fallen creating room for more. It also applies to
STREAMS queues regarding flow control.
MAC
Media Access Control, a sub-layer of the data link layer for media specific data link func-
tions.
memory management
The memory management scheme of the UNIX operating system imposes certain restric-
tions on drivers that transfer data between devices.
message block
A STREAMS message is made up of one or more message blocks. A message block is
referenced by a pointer to a mblk_t structure, which in turn points to the data block
(dblk_t) structure and the data buffer.
message
All information flowing in a stream, including transferred data, control information, queue
flushing, errors and signals. The information is referenced by a pointer to a mblk_t
structure.
modem
A contraction of modulator-demodulator. A modulator converts digital signals from the
computer into tones that can be transmitted across phone lines. A demodulator converts
the tones received from the phone lines into digital signals so that the computer can pro-
cess the data.