SaferAlloc

SaferAlloc is a small JNI binding that provides hardened native memory allocation for java. The underlying implementations are platform-specific and might change over time.

Current Platform Behavior

Platform	Underlying Allocator	Notes
Linux x86_64	mimalloc	mimalloc with MI_SECURE=ON
Linux aarch64	mimalloc	mimalloc with MI_SECURE=ON
macOS x86_64	mimalloc	mimalloc with MI_SECURE=ON
macOS aarch64	mimalloc	mimalloc with MI_SECURE=ON
Windows x86_64	mimalloc	mimalloc with MI_SECURE=ON
Android 11+	passthrough	Modern Android has its own hardened allocator (Scudo), so we just pass through.

Public API

org.ngengine.saferalloc.SaferAlloc exposes:

• ByteBuffer malloc(int size)
• ByteBuffer calloc(int count, int size)
• ByteBuffer realloc(ByteBuffer buffer, int newSize)
• ByteBuffer mallocAligned(int size, int alignment)
• void free(ByteBuffer buffer)
• void free(long address)
• long address(ByteBuffer buffer)

Notes:

• malloc/calloc/mallocAligned return null on allocation failure.
• realloc(buffer, newSize) throws OutOfMemoryError if growth fails and the old allocation is still valid.
• realloc(buffer, 0) may return null and free the old allocation.
• invalid sizes throw IllegalArgumentException.
• mallocAligned(size, alignment) requires alignment to be a power of two and a multiple of pointer size.
• calloc(count, size) rejects capacities larger than Integer.MAX_VALUE.

Note

• This API manages native memory manually. Always call free(buffer).
• After successful realloc, treat the old buffer as invalid and use the returned one only. If realloc throws, keep using the old buffer (it is still allocated).
• free(null) is a no-op.