Feature Request: Customizable Memory Allocation

[houssemeddine-mbarek]

Add support for customizing the memory allocation functions used by the library.

Currently, memory allocations rely on the default calloc()/free() implementation and therefore use the default heap. The requested enhancement is to allow users to provide their own allocation and deallocation functions.

For example, the library should provide a mechanism to configure:

• A custom calloc() implementation
• A custom free() implementation

This would allow applications to redirect dynamic allocations to a specific memory region or custom memory manager instead of the default heap.

Example use case:
void *custom_calloc(size_t size);
void custom_free(void *ptr);

library_set_memory_functions(custom_calloc, custom_free);

This is particularly useful for embedded systems where different memory regions may have different properties or may be dedicated to specific purposes (e.g. internal SRAM, external RAM, DMA-accessible RAM, etc.).

The default behavior should remain unchanged when no custom allocator is provided.

[sidcha]

I can provide weak symbols osdp_calloc() and osdp_free() which defaults to calloc() and fee() when a stronger symbol is not provided. Is that sufficient?

A custom library_set_memory_functions an API surface plus a pointer indirection which I would prefer to avoid.

[houssemeddine-mbarek]

Hi,

Actually, I think providing weak symbols as you suggested is the best approach for this use case. There is no need to introduce a full memory-management API or additional pointer indirection that could unnecessarily impact the library.

Providing weak osdp_calloc() and osdp_free() symbols that keep the default calloc() and free() behavior in the standard project while gives users the flexibility to override them when needed and redirect allocations to a custom memory region.

This approach keeps the implementation simple, preserves the current default behavior, and gives the user the ability to provide a custom implementation when required.