K Malloc

This repository includes two dynamic memory allocation functions, kmalloc() and kcalloc(), which are closely related to the malloc() and calloc() functions included in the C standard library. Dynamic memory allocation in C is used to allocate memory at runtime, allowing the program to adjust th amount of memory it needs based on input or conditions. It provides flexibility, as the programmer can request memory of varying sizes, unlike static allocation. This helps in managing memory more efficiently, especially for large data structures like arrays or linked lists that are not known in advance. After the data is used, it should be freed to allow the memory to be reallocated, although this is technically not necessary.

How to Use

First, clone the repository and create a new C/C++ file in the kmalloc repository:

git clone https://github.com/keyaloding/kmalloc
cd kmalloc

kmalloc(unsigned int num_bytes)

Here is an example of how you might use kmalloc() and kfree() to dynamically allocate, then free an integer array of length n. Note that the memory allocated by kmalloc() is uninitialized and contains garbage values.

#include "kmalloc.h"

int main(int argc, char **argv) {
  unsigned int heap_size = ...;
  if (!heap_init(heap_size)) {
    // Heap cannot be allocated. Add desired error handling
    return;
  }
  int *arr = (int*)kmalloc(sizeof(int) * n);
  if (!arr) {
    // Insufficient contiguous memory. Add desired error handling
    return;
  }
  // Do something with `arr`
  kfree(arr);
}

kcalloc(unsigned int num_elements, unsigned int element_size)

Here is an example of how you might use kcalloc() and kfree() to dynamically allocate, then free an integer array of length n. Note that the memory allocated by kmalloc() is initialized to zero.

#include "kmalloc.h"

int main(int argc, char **argv) {
  unsigned int heap_size = ...;
  if (!heap_init(heap_size)) {
    // Heap cannot be allocated. Add desired error handling
    return;
  }
  int *arr = (int*)kcalloc(n, sizeof(int));
  if (!arr) {
    // Insufficient contiguous memory. Add desired error handling
    return;
  }
  // Do something with `arr`
  kfree(arr);
}

Note that unlike the C malloc() and calloc() functions, the heap area must be allocated manually.

Technical Details

For more information, see kmalloc.h for function descriptions or kmalloc.c for source code.