2186   size_t               head;       /* Size and inuse bits. */  member
2256 #define cinuse(p)           ((p)->head & CINUSE_BIT)
2257 #define pinuse(p)           ((p)->head & PINUSE_BIT)
2258 #define flag4inuse(p)       ((p)->head & FLAG4_BIT)
2259 #define is_inuse(p)         (((p)->head & INUSE_BITS) != PINUSE_BIT)
2260 #define is_mmapped(p)       (((p)->head & INUSE_BITS) == 0)
2262 #define chunksize(p)        ((p)->head & ~(FLAG_BITS))
2264 #define clear_pinuse(p)     ((p)->head &= ~PINUSE_BIT)
2265 #define set_flag4(p)        ((p)->head |= FLAG4_BIT)
2266 #define clear_flag4(p)      ((p)->head &= ~FLAG4_BIT)
2273 #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~FLAG_BITS)))
2277 #define next_pinuse(p)  ((next_chunk(p)->head) & PINUSE_BIT)
2285   ((p)->head = (s|PINUSE_BIT), set_foot(p, s))
2396   size_t                    head;  member
3054   ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\
3055   ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT)
3059   ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\
3060   ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT)
3064   ((p)->head = (s|PINUSE_BIT|CINUSE_BIT))
3077   ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\
3078   (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \
3082   ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\
3083   (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\
3087   ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\
3234   assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD));  in do_check_any_chunk()
3241   size_t  sz = p->head & ~INUSE_BITS; /* third-lowest bit can be set! */  in do_check_top_chunk()
3243   assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD));  in do_check_top_chunk()
3258   assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD));  in do_check_mmapped_chunk()
3262   assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD);  in do_check_mmapped_chunk()
3263   assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0);  in do_check_mmapped_chunk()
3304     size_t sz = p->head & ~INUSE_BITS;  in do_check_malloced_chunk()
3316   tchunkptr head = 0;  in do_check_tree()  local
3340       assert(head == 0); /* only one node on chain has parent */  in do_check_tree()
3341       head = u;  in do_check_tree()
3362   assert(head != 0);  in do_check_tree()
3394       if (q->head != FENCEPOST_HEAD)  in do_check_smallbin()
3447              q != m->top && q->head != FENCEPOST_HEAD) {  in traverse_and_check()
3514                q != m->top && q->head != FENCEPOST_HEAD) {  in internal_mallinfo()
3560                q != m->top && q->head != FENCEPOST_HEAD) {  in internal_malloc_stats()
3856       p->head = psize;  in mmap_alloc()
3858       chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD;  in mmap_alloc()
3859       chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0;  in mmap_alloc()
3892       newp->head = psize;  in mmap_resize()
3894       chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD;  in mmap_resize()
3895       chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0;  in mmap_resize()
3920   p->head = psize | PINUSE_BIT;  in init_top()
3922   chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE;  in init_top()
3973     q->head = tsize | PINUSE_BIT;  in prepend_alloc()
4029     p->head = FENCEPOST_HEAD;  in add_segment()
4031     if ((char*)(&(nextp->head)) < old_end)  in add_segment()
4257       r->head = rsize | PINUSE_BIT;  in sys_alloc()
4405       else if ((next->head & INUSE_BITS) == INUSE_BITS) {  in dispose_chunk()
4421         p->head = tsize | PINUSE_BIT;  in dispose_chunk()
4686       r->head = rsize | PINUSE_BIT;  in dlmalloc()
4745               else if ((next->head & INUSE_BITS) == INUSE_BITS) {  in dlfree()
4761               p->head = tsize | PINUSE_BIT;  in dlfree()
4861         newtop->head = newtopsize |PINUSE_BIT;  in try_realloc_chunk()
4956           newp->head = newsize;  in internal_memalign()
5176       while (segment_holds(s, q) && q->head != FENCEPOST_HEAD) {  in internal_inspect_all()
5439   msp->head = (msize|INUSE_BITS);  in init_user_mstate()
5629       r->head = rsize | PINUSE_BIT;  in mspace_malloc()
5681               else if ((next->head & INUSE_BITS) == INUSE_BITS) {  in mspace_free()
5697               p->head = tsize | PINUSE_BIT;  in mspace_free()