Learning Odin

Memory Management

Odin gives you explicit control over memory.
- No garbage collection.
- No hidden allocations.
- You decide when memory is allocated and freed.
Stack
- Fast
- Automatic
- Limited lifetime
Heap
- Manual
- You choose the lifetime
new and free
- new allocates a single value on the heap and returns a pointer.
make and delete
- make is for slices and dynamic arrays.
defer runs a statement when the current scope exits. Normally used to pair allocations with frees. Idomatic odin: always cleanup right after allocating.
Built-in allocators:
- heap_allocator: general purpose, default.
- arena_allocator: many short-lived allocs, free all at once.
- temp_allocator: scratch allocator meant to be reset periodically.
- tracking_allocator: debugging; detects leaks and double-frees.
Every proc has an implicit context parameter carrying the current allocator. This makes it possible to swap allocators for a whole call subtree. You can isolate allocations per request, per frame, per thread, without changing any code.
Slices don't own memory: deleting a sub-slice is wrong, only delete the original.
Stack memory doesn't outlive its scope: don't return pointers or slices pointing into a stack frame.
Swap allocators via context: don't thread allocator pointers manually through every function.