BCS303 Program 6

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#define MEMORY_SIZE 1000 

typedef struct {
    int start;
    int size;
    bool isFree;
} Block;

Block memory[MEMORY_SIZE]; 

void initializeMemory() {
    for (int i = 0; i < MEMORY_SIZE; i++) {
        memory[i].start = i;
        memory[i].size = 1;
        memory[i].isFree = true;
    }
}

void displayMemory() {
    printf("Memory Status:\n");
    for (int i = 0; i < MEMORY_SIZE; i++) {
        if (!memory[i].isFree) {
            printf("Block from %d to %d is occupied\n", memory[i].start, memory[i].start + memory[i].size - 1);
        }
    }
}

void allocateMemory(int size, char method) {
    int bestIdx = -1, worstIdx = -1, firstIdx = -1;
    int bestSize = MEMORY_SIZE + 1, worstSize = -1;

    for (int i = 0; i < MEMORY_SIZE; i++) {
        if (memory[i].isFree) {
            int j = i;
            int currentSize = 0;

            while (j < MEMORY_SIZE && memory[j].isFree) {
                currentSize++;
                j++;
            }

            if (currentSize >= size) {
                if (method == 'b' && currentSize < bestSize) {
                    bestSize = currentSize;
                    bestIdx = i;
                } else if (method == 'w' && currentSize > worstSize) {
                    worstSize = currentSize;
                    worstIdx = i;
                } else if (method == 'f' && firstIdx == -1) {
                    firstIdx = i;
                }
            }

            i = j - 1; 
        }
    }

    int idx = (method == 'b') ? bestIdx : (method == 'w') ? worstIdx : firstIdx;

    if (idx != -1) {
        int allocated = 0;

        // Allocate the memory
        for (int i = idx; i < MEMORY_SIZE && allocated < size; i++) {
            if (memory[i].isFree) {
                memory[i].isFree = false;
                allocated++;
            }
        }

        printf("Allocated %d units using %s fit starting at %d\n", size, (method == 'b') ? "Best" : (method == 'w') ? "Worst" : "First", idx);
    } else {
        printf("Failed to allocate %d units of memory\n", size);
    }
}

void deallocateMemory(int start, int size) {
    for (int i = start; i < start + size && i < MEMORY_SIZE; i++) {
        memory[i].isFree = true;
    }
    printf("Deallocated %d units of memory starting from %d\n", size, start);
}

int main() {
    char method;
    int size, start;

    initializeMemory();

    while (1) {
        printf("\nMemory Allocation Simulator\n");
        printf("1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')\n");
        printf("2. Deallocate Memory\n");
        printf("3. Display Memory\n");
        printf("4. Exit\n");
        printf("Enter your choice: ");
        int choice;
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter allocation size: ");
                scanf("%d", &size);
                printf("Enter fit method (f for First fit, b for Best fit, w for Worst fit): ");
                scanf(" %c", &method); 
                allocateMemory(size, method);
                break;
            case 2:
                printf("Enter deallocation start and size: ");
                scanf("%d %d", &start, &size);
                deallocateMemory(start, size);
                break;
            case 3:
                displayMemory();
                break;
            case 4:
                exit(0);
            default:
                printf("Invalid choice. Please try again.\n");
        }
    }

    return 0;
}

braham@braham:~/Desktop/program$ gcc memory.c -o memory
braham@braham:~/Desktop/program$ ./memory

Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit

Enter your choice: 1
Enter allocation size: 50
Enter fit method (f for First fit, b for Best fit, w for Worst fit): f
Allocated 50 units using First fit starting at 0

Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit

Enter your choice: 1
Enter allocation size: 30
Enter fit method (f for First fit, b for Best fit, w for Worst fit): b
Allocated 30 units using Best fit starting at 50

Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit

Enter your choice: 1
Enter allocation size: 100
Enter fit method (f for First fit, b for Best fit, w for Worst fit): w
Allocated 100 units using Worst fit starting at 80

Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit

Enter your choice: 2
Enter deallocation start and size: 0 50
Deallocated 50 units of memory starting from 0

Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit

Enter your choice: 3
Memory Status:
Block from 50 to 50 is occupied
Block from 51 to 51 is occupied
Block from 52 to 52 is occupied
Block from 53 to 53 is occupied
Block from 54 to 54 is occupied
Block from 55 to 55 is occupied
Block from 56 to 56 is occupied
Block from 57 to 57 is occupied
Block from 58 to 58 is occupied
Block from 59 to 59 is occupied
Block from 60 to 60 is occupied
Block from 61 to 61 is occupied
Block from 62 to 62 is occupied
Block from 63 to 63 is occupied
Block from 64 to 64 is occupied
Block from 65 to 65 is occupied


Memory Allocation Simulator
1. Allocate Memory (First fit: 'f', Best fit: 'b', Worst fit: 'w')
2. Deallocate Memory
3. Display Memory
4. Exit
Enter your choice: 4