CosmonautJones / Sprint-Challenge--Processes-and-Scheduling

Sprint Challenge: Processes and Scheduling

Multiple Choice and Short Answer Questions

Add your answers to the Answers.md doc.

1. Assume we have two processes, P1 and P2, that have both been initialized, and let's assume that each process on this machine is initially allocated 32 KB of memory as its address space. What are the possible address space ranges each process could have? Write a short paragraph explaining your answer.

   a. P1: 0 - 32,000; P2: 32,001 - 64,000

   b. P1: 0 - 64,000; P2: 0 - 64,000

   c. P1: 32,001 - 64,000; P2: 0 - 32,000

2. List all of the possible states a process may be in at any point in time. Briefly explain what each of these states mean.

3. On your machine, how much faster does a printf call take compared to how long a write system call takes?

4. printf is a C library function that calls the write system call under the hood. What are some possible reasons as to why printf runs faster than write?

Programming Exercise 1

Add your code in the ex1/ex1.c file.

Write a function that allocates an array of ints of a specified size. (The cols parameter holds the size.)

int *alloc_1d(int cols)
{
	// !!! IMPLEMENT ME
	// (solution is about 2 lines of code)
}

void alloc_1d_example(void)
{
	int *my_array = alloc_1d(12);

	my_array[8] = 3490;

	// The same array access could be made with pointer arithmetic:
	*(my_array+8) = 3490;

	// By the C spec, the array notation and pointer arithmetic notation
	// are 100% equivalent.

	printf("my_array[8] = %d\n", my_array[8]);
}

Programming Exercise 2

Add your code in the ex2/ex2.c file.

Write a function that allocates a two-dimensional array of ints of a specified size. (The rows parameter is how many rows in the array, and cols is how many columns per row.)

int **alloc_2d(int rows, int cols)
{
	// !!! IMPLEMENT ME
	// (solution is about 5 lines of code)
}

void alloc_2d_example(void)
{
	int **my_array = alloc_2d(5, 10);

	// First array index is row, second is column:
	my_array[2][3] = 3490;

	// The same array access could be made with pointer arithmetic:
	*(*(my_array+2)+3) = 3490;

	// By the C spec, the array notation and pointer arithmetic notation
	// are 100% equivalent.
	
	printf("my_array[2][3] = %d\n", my_array[2][3]);
}