Next Block Address

Task

Implement the function next_block_addr

• Given a block_header* to the start of the heap with one allocated block, return the address of the next block
• Don’t modify the struct definition at the top of the file
• Don’t modify the fake_heaps.h, fake_heaps.o, or Makefile files

Function Signature

// Given a block_header* to the start of the heap with one allocated block, 
// return the address of the next block
//
struct block_header* next_block_addr(struct block_header* start);

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Testing

Compiling

Use the given Makefile to compile your program

• To use the Makefile just type make into the terminal

Test Cases

• To test your code, you can use the variables heap1, heap2, heap3, heap4, heap5, which are defined in the fake_heaps.h header file
  • These are pointers to the start of different heaps and have different allocated blocks in each of them

Examples

To use the heaps in testing in main function

int main() {
 
    struct block_header* myNextBlock = next_block_addr(heap1);
 
    printf("Start of the heap addr: %p\n", (void*)heap1);
    printf("Next block addr: %p\n", (void*)myNextBlock);
 
    return 0;
}

Test Case 1

Input: heap1
Output: The difference between the start of heap memory address and the returned memory address should be 64 (decimal) or 0x40 (in hexadecimal)

Test Case 2

Input: heap3
Output: The difference between the start of heap memory address and the returned memory address should be 256 (decimal) or 0x100 (in hexadecimal)

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Code

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stddef.h>
#include "fake_heaps.h"
 
struct block_header {
    size_t size_status;
};
 
struct block_header* next_block_addr(struct block_header* start){
    uint64_t size = start->size_status >> 2;
    void* next = ((void *)start + (size << 2));
    return (struct block_header*)next;
}