Answer Posted / selvakumar
"Mutexes are typically used to serialise access to a
section of re-entrant code that cannot be executed
concurrently by more than one thread. A mutex object only
allows one thread into a controlled section, forcing other
threads which attempt to gain access to that section to
wait until the first thread has exited from that section."
"A semaphore restricts the number of simultaneous users of
a shared resource up to a maximum number. Threads can
request access to the resource (decrementing the
semaphore), and can signal that they have finished using
the resource (incrementing the semaphore)."
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The OS is a program that uses various data structures. Like
all programs in execution, you can determine the
performance and other behavior of the OS by inspecting its
state - the values stored in its data structures. In this
part of the assignment, we study some aspects of the
organization and behavior of a Linux system by observing
values of kernel data structures exposed through the /proc
virtual file system.
The /proc virtual file system:
Linux uses the /proc file system to collect information
from kernel data structures. The /proc implementation
provided with Linux can read many different kernel data
structures. If you cd to /proc on a Linux machine, you will
see a number of files and directories at that location.
Files in this directory subtree each corresponds to some
kernel data structure. The subdirectories with numeric
names contain virtual files with information about the
process whose process ID is the same as the directory name.
Files in /proc can be read like ordinary ASCII files. You
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Requirements in detail:
In this part, you are asked to write a program to report
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• Amount of time since the system was last booted
A second version of the program should run continuously and
print lists of the following dynamic values (each value in
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user mode, system mode, and the percentage of time the
processor(s) are idle
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memory
• The rate (number of sectors per second) of disk
read/write in the system
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the kernel
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in the system
If your program (compiled executable) is called proc_parse,
running it without any parameter should print out
information required for the first version. Running it with
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