The following implementations are included herein:
- context -- getting and setting user context within a process
- fileLocking -- local and remote file locking programs
- gmemusage -- a graphical memory usage display tool
- load_avg -- obtain the current system load average
- playEngine -- sproc/semaphore source
- scripts -- various c-shell scripts
- sockets -- introduction to sockets with a client and a server program
- uucpVadmin -- UUCP visual administration tool
- tools -- unix/system-level programs
Be sure to also check out the toolbox/documents/cc_c++_make_csh subtree for an assemblage of documents relating to compilers, make, and [c]shell, as well as the toolbox/documents/ {irix, irix5.2, irix5.3, irix6.2} subtrees for documentation relating to general and release-specific information on IRIX.
provides an example of using the getcontext(2), setcontext(2)
and makecontext(3C) functions introduced in IRIX 5.x. These functions
are useful for implementing user level context switching between
multiple threads of control within a single IRIX process.
This program originate from the Pipeline article, "Getting and Setting
User Context Within a Process," which lives in the toolbox/documents/irix directory.
Programmers that write large multi-user applications which access
databases are commonly faced with the question of data locking and
integrity. These programs demonstrate data locking on local and
remote systems.
These programs originate from the Pipeline article,
"Local and Remote File
Locking," which lives in the toolbox/documents/irix directory.
This program was developed at Silicon Graphics to help programmers
analyze how their programs, and the system as a whole, is using memory.
gmemusage displays a bar chart depicting the breakdown of memory use,
with each bar labeled with the name of the program using the
memory and the number of kilobytes of memory used.
In addition, gmemusage will display a breakdown of the
regions within a program. Clicking on a bar or program name
in the main chart will replace the main chart with a chart
for that program, with each region labeled with one of Text,
Data, Break, Stack, Shmem, Physical Device, RW, RO, and (if
possible) the base name of the file or device corresponding
to each region. If gmemusage is unable to determine the
base name of the file or device for a region that does
correspond to a file or device, gmemusage will display the
inode number of the file or device.
A developer of an application may want to know how busy the processor is
prior to launching a process; it might choose to allocate the process to
another machine or it might choose to defer the launch to a later time.
Although the kernel keeps track of load average, it provides no interface
to programmers who wish to see that information. There is a powerful
tool available for situations where there is no interface to a piece of
kernel data; the program may read kernel memory directly. This power
is accompanied by a certain risk: programs that read kernel memory are
unlikely to be portable from one Unix system to another, and they may not
even be portable on the same system from one release to another.
The example in this directory may be used as a model of how to browse
kernel memory for a useful data element, or the example may be used
without modification in your application.
Employing sproc and semaphore, playEngine implements raising a
sub-process's priority so as to be able to circumvent
preemption. playEngine provides a set of routines permitting
an audio track to be played without interference from operating
system multitasking activities. sproc (similar to fork) is
employed to raise the forked sub-process priority high enough so
the other operating system activities cannot preempt it. The
main application provides this new process with a pointer to
the data to be played and starts and stops the process through
signals and/or semaphores.
The C-shell scripts, created/used by colleagues possibly
useful to others, if for no other purpose than as examples
of shell programming source:
Sockets are an application programming interface (API) for network
applications in a UNIX environment. Sockets are a UNIX interface to
the TCP/IP protocol and were developed at the University of
California at Berkeley.
The example discussed in this article uses a connection-oriented (TCP)
client/server model. The programs establish a connection between two
systems (or two processes on the same system), and data is passed
from the client to the server. The programs are designed to be very
simple and straightforward.
These programs originate from the Pipeline article, "Getting Started
With Socket Programming," which lives in the toolbox/documents/irix directory.
This tool allows the user to set up the UUCP files using a
Graphical User Interface and make sure communication to a modem
is good. uucpVadmin contains inst images as well as src for
the UUCP vadmin tool.
Documentation
Reference
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