How to allocate aligned memory only using the standard library?

How to Allocate Aligned Memory Using the Standard Library ✨

Have you ever encountered a situation where you needed to allocate memory and ensure it is aligned to a specific boundary? If so, you're in the right place! In this blog post, we'll explore how to allocate aligned memory using the standard library.

The Challenge 💥

Recently, during a job interview, a candidate stumbled upon a tricky question that left them scratching their head. The question pertained to allocating memory and ensuring it is properly aligned to a 16-byte boundary. 🤔

Here's the challenge they faced:

void *mem;
void *ptr;

// answer a) here

memset_16aligned(ptr, 0, 1024);

// answer b) here

As you can see, the memset_16aligned function required a 16-byte aligned pointer. Failing to provide an aligned pointer would result in a crash. The goal was to allocate 1024 bytes of memory and align it to a 16-byte boundary.

Solution to the Challenge 🚀

Answer to Part (a): Allocating Aligned Memory

To allocate memory aligned to a 16-byte boundary, we can make use of the aligned_alloc function provided by the standard library. This function takes two arguments: the alignment and the size.

Here's how we can modify the code to address part (a) of the challenge:

void *mem;
void *ptr;

// answer a) here
mem = aligned_alloc(16, 1024); // Allocating aligned memory

memset_16aligned(ptr, 0, 1024);

// answer b) here

By using aligned_alloc(16, 1024), we ensure that the memory is aligned to a 16-byte boundary.

Answer to Part (b): Freeing Allocated Memory

After executing memset_16aligned, it is crucial to free the allocated memory to avoid memory leaks. In C, we can accomplish this by using the free function.

Here's the updated code with part (b) of the challenge addressed:

void *mem;
void *ptr;

// answer a) here
mem = aligned_alloc(16, 1024); // Allocating aligned memory

memset_16aligned(ptr, 0, 1024);

free(mem); // Freeing the allocated memory

// answer b) here

Now the memory is properly allocated, the memset_16aligned function can be safely executed, and the memory is freed using the free function.

Conclusion and Call-to-Action 🎉

Allocating aligned memory can be a tricky task, but with the help of the aligned_alloc function from the standard library, we can easily achieve the desired alignment. Remember to always free the allocated memory using the free function to prevent memory leaks.

If you found this blog post helpful or have any additional insights to share, feel free to leave a comment below. Let's dive into the world of aligned memory allocation together! 🚀✨