diff options
Diffstat (limited to 'com32/include/malloc.h')
-rw-r--r-- | com32/include/malloc.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/com32/include/malloc.h b/com32/include/malloc.h new file mode 100644 index 00000000..57b76526 --- /dev/null +++ b/com32/include/malloc.h @@ -0,0 +1,54 @@ +/* + * malloc.h + * + * Internals for the memory allocator + */ + +#include <stdint.h> +#include <stddef.h> + +/* + * This is the minimum chunk size we will ask the kernel for; this should + * be a multiple of the page size on all architectures. + */ +#define MALLOC_CHUNK_SIZE 65536 +#define MALLOC_CHUNK_MASK (MALLOC_CHUNK_SIZE-1) + +/* + * This structure should be a power of two. This becomes the + * alignment unit. + */ +struct free_arena_header; + +struct arena_header { + size_t type; + size_t size; /* Also gives the location of the next entry */ + struct free_arena_header *next, *prev; +}; + +#ifdef DEBUG_MALLOC +#define ARENA_TYPE_USED 0x64e69c70 +#define ARENA_TYPE_FREE 0x012d610a +#define ARENA_TYPE_HEAD 0x971676b5 +#define ARENA_TYPE_DEAD 0xeeeeeeee +#else +#define ARENA_TYPE_USED 0 +#define ARENA_TYPE_FREE 1 +#define ARENA_TYPE_HEAD 2 +#endif + +#define ARENA_SIZE_MASK (~(sizeof(struct arena_header)-1)) + +#define ARENA_ALIGN_UP(p) ((char *)(((uintptr_t)(p) + ARENA_SIZE_MASK) & ARENA_SIZE_MASK)) +#define ARENA_ALIGN_DOWN(p) ((char *)((uintptr_t)(p) & ARENA_SIZE_MASK)) + +/* + * This structure should be no more than twice the size of the + * previous structure. + */ +struct free_arena_header { + struct arena_header a; + struct free_arena_header *next_free, *prev_free; +}; + +extern struct free_arena_header __malloc_head; |