The following program must be written in JAVA. Will promptly rate, if program compiles and executes.

Please and Thank you!

Where to look for information in (/proc) directory ?

File /proc/uptime has the information for this lab. You can refer to the online manual for more information on proc (man proc). You can type the following in the command line

more /proc/uptime

to find the uptime of the system and the amount of time the system spending in the idle processes.

Exercise : Write a program in Java to display the following information.

1. Time information. In this section you will print out how long the system has been up and how busy it has been. Once you have some baseline numbers printed, you will run a short program that places a load on the system. You will then take a second set of numbers and calculate the load that your program placed on the system.

Duration of uptime # get these information from /proc/uptime

Duration of idletime

Calculating load average.

Write a function that does some work (to put some load on the system) and make a note of the uptime and idletime before and after the call of the function. The following can be used as sample code for the work function. This program simple runs a math calculation a large number of times, just trying to keep the CPU busy. You can include it as a function in your overall program. Note that because you are using a math function (pow) you will need to explicitly include the math library when you compile your program, i.e., gcc o test test.c lm. (the lm option for program compiling in C or C++.)

void work() { double y; double x = 3.0; double e = 2.0; int i,j; for (i = 0; i < 5; i++) { for (j = 0; j < 400000; j++) { y = pow(x, e); } printf("Loop %d of work cycle ", i ); // pause for one second between loops so that the work cycle takes a little time. sleep (1); // in C or C++ you will need to include the unistd.h library for this function } }

The skeleton of the program

(1) read file /proc/uptime to obtain beginTotaltime and beginIdletime

(2) call work( ) to put some work into the system

(7) read file /proc/uptime to obtain endTotaltime and endIdletime

(8) Calculate the percentage of the time that CPU was busy during this program:

programTotalTime = endTotalTime - beginTotalTime;

programIdleTime = endIdleTime - beginIdleTime;

programWorkTime = programTotalTime - programIdleTime;

percentage = (programWorkTime / programTotalTime)* 100;