The purpose of this assignment is to get you comfortable with the use of processes and threads in the operating system of your choice. Select either Windows or Unix/Linux (use Unix shell for Apple systems) and complete the following problems.

Problem 1: Write a program that accepts an integer N as a command line input and then proceeds to launch N processes on your system. Each process should consist of an infinite loop that prints out Process k running (once every second) where k is a process index (from 0 to N-1). After 5 seconds of running, your main program should kill process 0, then after another 5 seconds, should kill process 1, and so on until all processes have been terminated. At that time, your main program should itself terminate.

Hints: In Windows, you can use the function CreateProcess to launch a new process. My general approach to this problem is to create a separate source file for the launched mini-processes and compile it into an executable. Then, you can call that executable with CreateProcess. In Unix/Linux, this problem can be solved using the fork function. Using either OS, there is great online documentation (... Google it!...) for how to launch new processes from within a process.

Problem 2: Write a program that accepts an integer N as a command line input and then proceeds to launch N threads within that process. The remainder of the exercise is identical to Problem 1 except that you should print out Thread k running.

Hints: In Windows, you can use the function CreateThread to launch a new thread. In Unix/Linux, you can use the pthread library. There is great documentation online for both (thank you Google).

Problem 3: Discuss the similarities and differences between your solutions to Problem 1 and Problem 2. When might you want to use multiple processes for multi-tasking and when is it more appropriate to use multiple threads?

Your solution to these problems should be written in C or C++. I will accept solutions written for Windows or Unix/Linux. You should submit all of your source files (.c, .cpp, .h, etc.) as well as a text file or Word file with your answer to Problem 3.