SDL_SetMemoryFunctions(3)

💖 SDL_SetMemoryFunctions 💖

okay bestie, so this is a page from the SDL3 FUNCTIONS manual — yes, that SDL, the Simple Directmedia Layer one — and it's all about SDL_SetMemoryFunctions, the function that lets you swap out SDL's whole memory-allocation situation for your own custom set. glow-up for your allocator, basically. ✨

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🌸 NAME 🌸

SDL_SetMemoryFunctions — replace SDL's memory allocation functions with a custom set. like, out with the old, in with your little guys. 💅

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🦋 SYNOPSIS 🦋

#include <SDL3/SDL_stdinc.h>

bool SDL_SetMemoryFunctions(SDL_malloc_func malloc_func,
                                SDL_calloc_func calloc_func,
                                SDL_realloc_func realloc_func,
                                SDL_free_func free_func);

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✨ DESCRIPTION ✨

okay so here's the tea, and it is serious tea: it is not safe to call this function once any allocations have been made, because future calls to SDL_free will use the new allocator — even if they came from an SDL_malloc made with the old one! 😭 that's a mismatch, that's a disaster, that's the kind of thing that makes a program simply evaporate.

no cap: allocate first, swap later, and you get frees going to the wrong allocator. do not do this. 🙈

so if you're gonna use it, usually this needs to be the first call made into the SDL library — if not the very first thing done at program startup time. main character energy for the very first line of your main, fr fr. 👑

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🎀 FUNCTION PARAMETERS 🎀

• malloc_func — your custom malloc function. the one that goes and gets the memory. 🍓
• calloc_func — your custom calloc function. same vibe, but zeroed out. ✨
• realloc_func — your custom realloc function. for when the memory needs to ✨change size✨. 🦋
• free_func — your custom free function. the one that lets it all go. 💜

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🌈 RETURN VALUE 🌈

Returns true on success or false on failure. and if it fails? call SDL_GetError() for more information — she will tell you exactly what went wrong, iykyk. 💅

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🔥 THREAD SAFETY 🔥

It is safe to call this function from any thread — slay, versatile queen — but one should not replace the memory functions once any allocations are made! so yes she's thread-safe, and no you still can't just swap her out mid-flight. both things are true, periodt. ⭐

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⭐ AVAILABILITY ⭐

This function is available since SDL 3.2.0. so if you're on anything older, bestie, it's simply not giving. 🧚

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👑 SEE ALSO 👑

• SDL_GetMemoryFunctions(3)
• SDL_GetOriginalMemoryFunctions(3)

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and that's the whole page, bestie!! this absolute icon of a manpage comes to you from Simple Directmedia Layer, version SDL 3.4.18, and yes it really is titled SDL_SetMemoryFunctions(3) — go forth, set your memory functions first thing, and stay safe out there 💖✨🎀🦋🌸💅🫶