ccgargantua / arena-allocator Goto Github PK

FR: Short-hand wrapper functions for memcpy (probably ARENA_MEMCPY) for simplified copying of an arena or an arena allocation would be nice, especially copying the arena. inline-friendly would be ideal, which should be relatively easy considering a wrapper for memcpy (or similar) is what should be done.

Calling arena_destroy() after using arena_clear() causes a double free.

Arena *arena = arena_create(1024);
arena_alloc(arena, 16);
arena_clear(arena);
arena_destroy(arena);

Unaligned memory can impact performance, and thus alignment should be encouraged on allocations.

Maybe have a #define for default alignment.

The arena_expand() function relies on implementation for deallocation

As for as I can tell: deallocation of the ptr argument for realloc (the default realloc for ARENA_REALLOC) is not officially guaranteed until C99.

(C99, 7.20.3.4p2) "The realloc function deallocates the old object pointed to by ptr and returns a pointer to a new object that has the size specified by size."

This means memory leaks are possible depending on the implementation's decision to free existing allocations for the pointer passed to it.

There are currently no examples in example_code/ that showcase the use of the arena_expand and arena_copy functions. These would be beneficial to add.

The current Makefile only functions as intended on Linux, but not Windows. Here is a description of problems and potential solutions.

1. Valgrind is not supported on Windows. Since PRs require absence of memory leaks with $ make test, finding an alternative command line memory profiler is necessary and should be conditionally applied to Windows builds.
2. The absence of the .exe file extensions on generated executables results in failure of automated runs, also present on $ make test. This could likely be solved with a simple macro. EXT := .exe or something similar.
3. The default compiler for $(CC) chosen when building on Windows is cc, which is not ideal. I would prefer MSVC be used, or at the very least mingw. I'm not really sure how to handle this one to be completely honest.

I tested this using make installed through the chocolatey package manager for windows.

The arena_alloc_aligned() method does not align properly. This is because the offset is being calculated based on the index instead of the region pointer here