Stack allocation/deallocation does not fragment memory, that’s a yuge difference for embedded systems and the main reason to avoid the heap
Stack allocation/deallocation does not fragment memory, that’s a yuge difference for embedded systems and the main reason to avoid the heap
Even with the stack the memory can fragment. Just consider one created 10 features on the stack and the last completed last. Then memory for the first 9 will not be released until the last completes.
This problem does not happen with a custom allocator where things to allocate are of roughly the same size and allocator uses same-sized cells to allocate.
Indeed, arena allocators are quite fast and allow you to really lock down the amount of memory that is in use for a particular kind of data. My own approach in the embedded world has always been to simply pre-allocate all of my data structures. If it boots it will run. Dynamic allocation of any kind is always going to have edge cases that will cause run-time issues. Much better to know that you have a deterministic system.