hal_malloc(3hal)

💖 hal_malloc — bestie, we're getting memory from the HAL shared pool 💖

okay so this is hal_malloc(3hal), straight out of the HAL manual section, and it's literally the memory hookup for your components. no cap.

✨ NAME ✨

hal_malloc — allocate space in the HAL shared memory area 🎀

🌸 SYNTAX 🌸

void *hal_malloc(long int size)

🦋 ARGUMENTS 🦋

• size — the size of the block, in bytes. that's it, that's the whole vibe.

👑 DESCRIPTION 👑

so hal_malloc grabs a block of memory out of the main HAL shared memory area. every component should be using this to allocate memory for its HAL pins and parameters — it's the move, fr fr. it allocates size bytes and hands you back a pointer to the allocated space, or NULL (0) if something went wrong 😭. the pointer you get back is properly aligned for any type HAL supports, so you can just trust it. and a component should allocate all the memory it needs during initialization — get it all done up front, bestie.

now the part you need to hear: this allocator is very simple, and there is no free 💀. no takebacks, no returns, no giving it back. the entire HAL shared memory area gets freed when the last component calls hal_exit. periodt.

and here's the cautionary tale 🫶 — if you keep continuously installing and removing one component while other components are still present, you will eventually fill up the shared memory and an install will fail. that's not a maybe, that's a when. but! if you remove all the components, memory gets completely cleared and you start fresh ✨ squeaky clean, brand new, main character energy.

💜 RETURN VALUE 💜

a pointer to the allocated space — properly aligned for any variable HAL supports 🎀. and on error? it returns NULL. 😭 guard your pointers, babe.

🌈 reminder bestie: no free. allocate it all at init. the shared area only clears when the last component exits. iykyk 💅

and that's the whole page, mwah 💋 — this was written up in the LinuxCNC Documentation and dated way back on 2006-10-12, so it's an icon, it's a legend, and it is the moment. go allocate something cute 🦋✨