heap_page_struct.c

struct heap_page {
    short total_slots;
    short free_slots;
    short pinned_slots;
    short final_slots;
    struct {
	unsigned int before_sweep : 1;
	unsigned int has_remembered_objects : 1;
	unsigned int has_uncollectible_shady_objects : 1;
	unsigned int in_tomb : 1;
    } flags;

    struct heap_page *free_next;
    RVALUE *start;
    RVALUE *freelist;
    struct list_node page_node;

    bits_t wb_unprotected_bits[HEAP_PAGE_BITMAP_LIMIT];
    /* the following three bitmaps are cleared at the beginning of full GC */
    bits_t mark_bits[HEAP_PAGE_BITMAP_LIMIT];
    bits_t uncollectible_bits[HEAP_PAGE_BITMAP_LIMIT];
    bits_t marking_bits[HEAP_PAGE_BITMAP_LIMIT];

    /* If set, the object is not movable */
    bits_t pinned_bits[HEAP_PAGE_BITMAP_LIMIT];
};