1 #define JEMALLOC_BITMAP_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
4 /******************************************************************************/
9 bitmap_info_init(bitmap_info_t *binfo, size_t nbits)
15 assert(nbits <= (ZU(1) << LG_BITMAP_MAXBITS));
18 * Compute the number of groups necessary to store nbits bits, and
19 * progressively work upward through the levels until reaching a level
20 * that requires only one group.
22 binfo->levels[0].group_offset = 0;
23 group_count = BITMAP_BITS2GROUPS(nbits);
24 for (i = 1; group_count > 1; i++) {
25 assert(i < BITMAP_MAX_LEVELS);
26 binfo->levels[i].group_offset = binfo->levels[i-1].group_offset
28 group_count = BITMAP_BITS2GROUPS(group_count);
30 binfo->levels[i].group_offset = binfo->levels[i-1].group_offset
32 assert(binfo->levels[i].group_offset <= BITMAP_GROUPS_MAX);
38 bitmap_info_ngroups(const bitmap_info_t *binfo)
41 return (binfo->levels[binfo->nlevels].group_offset);
45 bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo)
51 * Bits are actually inverted with regard to the external bitmap
52 * interface, so the bitmap starts out with all 1 bits, except for
53 * trailing unused bits (if any). Note that each group uses bit 0 to
54 * correspond to the first logical bit in the group, so extra bits
55 * are the most significant bits of the last group.
57 memset(bitmap, 0xffU, bitmap_size(binfo));
58 extra = (BITMAP_GROUP_NBITS - (binfo->nbits & BITMAP_GROUP_NBITS_MASK))
59 & BITMAP_GROUP_NBITS_MASK;
61 bitmap[binfo->levels[1].group_offset - 1] >>= extra;
62 for (i = 1; i < binfo->nlevels; i++) {
63 size_t group_count = binfo->levels[i].group_offset -
64 binfo->levels[i-1].group_offset;
65 extra = (BITMAP_GROUP_NBITS - (group_count &
66 BITMAP_GROUP_NBITS_MASK)) & BITMAP_GROUP_NBITS_MASK;
68 bitmap[binfo->levels[i+1].group_offset - 1] >>= extra;
75 bitmap_info_init(bitmap_info_t *binfo, size_t nbits)
80 assert(nbits <= (ZU(1) << LG_BITMAP_MAXBITS));
82 i = nbits >> LG_BITMAP_GROUP_NBITS;
83 if (nbits % BITMAP_GROUP_NBITS != 0)
90 bitmap_info_ngroups(const bitmap_info_t *binfo)
93 return (binfo->ngroups);
97 bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo)
101 memset(bitmap, 0xffU, bitmap_size(binfo));
102 extra = (binfo->nbits % (binfo->ngroups * BITMAP_GROUP_NBITS));
104 bitmap[binfo->ngroups - 1] >>= (BITMAP_GROUP_NBITS - extra);
107 #endif /* USE_TREE */
110 bitmap_size(const bitmap_info_t *binfo)
113 return (bitmap_info_ngroups(binfo) << LG_SIZEOF_BITMAP);