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Diffstat (limited to 'deps/jemalloc/include/jemalloc/internal/bitmap.h')
| -rw-r--r-- | deps/jemalloc/include/jemalloc/internal/bitmap.h | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/deps/jemalloc/include/jemalloc/internal/bitmap.h b/deps/jemalloc/include/jemalloc/internal/bitmap.h new file mode 100644 index 0000000..dc19454 --- /dev/null +++ b/deps/jemalloc/include/jemalloc/internal/bitmap.h @@ -0,0 +1,368 @@ +#ifndef JEMALLOC_INTERNAL_BITMAP_H +#define JEMALLOC_INTERNAL_BITMAP_H + +#include "jemalloc/internal/bit_util.h" +#include "jemalloc/internal/sc.h" + +typedef unsigned long bitmap_t; +#define LG_SIZEOF_BITMAP LG_SIZEOF_LONG + +/* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */ +#if SC_LG_SLAB_MAXREGS > LG_CEIL(SC_NSIZES) +/* Maximum bitmap bit count is determined by maximum regions per slab. */ +# define LG_BITMAP_MAXBITS SC_LG_SLAB_MAXREGS +#else +/* Maximum bitmap bit count is determined by number of extent size classes. */ +# define LG_BITMAP_MAXBITS LG_CEIL(SC_NSIZES) +#endif +#define BITMAP_MAXBITS (ZU(1) << LG_BITMAP_MAXBITS) + +/* Number of bits per group. */ +#define LG_BITMAP_GROUP_NBITS (LG_SIZEOF_BITMAP + 3) +#define BITMAP_GROUP_NBITS (1U << LG_BITMAP_GROUP_NBITS) +#define BITMAP_GROUP_NBITS_MASK (BITMAP_GROUP_NBITS-1) + +/* + * Do some analysis on how big the bitmap is before we use a tree. For a brute + * force linear search, if we would have to call ffs_lu() more than 2^3 times, + * use a tree instead. + */ +#if LG_BITMAP_MAXBITS - LG_BITMAP_GROUP_NBITS > 3 +# define BITMAP_USE_TREE +#endif + +/* Number of groups required to store a given number of bits. */ +#define BITMAP_BITS2GROUPS(nbits) \ + (((nbits) + BITMAP_GROUP_NBITS_MASK) >> LG_BITMAP_GROUP_NBITS) + +/* + * Number of groups required at a particular level for a given number of bits. + */ +#define BITMAP_GROUPS_L0(nbits) \ + BITMAP_BITS2GROUPS(nbits) +#define BITMAP_GROUPS_L1(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(nbits)) +#define BITMAP_GROUPS_L2(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits)))) +#define BITMAP_GROUPS_L3(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS( \ + BITMAP_BITS2GROUPS((nbits))))) +#define BITMAP_GROUPS_L4(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS( \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits)))))) + +/* + * Assuming the number of levels, number of groups required for a given number + * of bits. + */ +#define BITMAP_GROUPS_1_LEVEL(nbits) \ + BITMAP_GROUPS_L0(nbits) +#define BITMAP_GROUPS_2_LEVEL(nbits) \ + (BITMAP_GROUPS_1_LEVEL(nbits) + BITMAP_GROUPS_L1(nbits)) +#define BITMAP_GROUPS_3_LEVEL(nbits) \ + (BITMAP_GROUPS_2_LEVEL(nbits) + BITMAP_GROUPS_L2(nbits)) +#define BITMAP_GROUPS_4_LEVEL(nbits) \ + (BITMAP_GROUPS_3_LEVEL(nbits) + BITMAP_GROUPS_L3(nbits)) +#define BITMAP_GROUPS_5_LEVEL(nbits) \ + (BITMAP_GROUPS_4_LEVEL(nbits) + BITMAP_GROUPS_L4(nbits)) + +/* + * Maximum number of groups required to support LG_BITMAP_MAXBITS. + */ +#ifdef BITMAP_USE_TREE + +#if LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS +# define BITMAP_GROUPS(nbits) BITMAP_GROUPS_1_LEVEL(nbits) +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_1_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 2 +# define BITMAP_GROUPS(nbits) BITMAP_GROUPS_2_LEVEL(nbits) +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_2_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 3 +# define BITMAP_GROUPS(nbits) BITMAP_GROUPS_3_LEVEL(nbits) +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_3_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 4 +# define BITMAP_GROUPS(nbits) BITMAP_GROUPS_4_LEVEL(nbits) +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_4_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 5 +# define BITMAP_GROUPS(nbits) BITMAP_GROUPS_5_LEVEL(nbits) +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_5_LEVEL(BITMAP_MAXBITS) +#else +# error "Unsupported bitmap size" +#endif + +/* + * Maximum number of levels possible. This could be statically computed based + * on LG_BITMAP_MAXBITS: + * + * #define BITMAP_MAX_LEVELS \ + * (LG_BITMAP_MAXBITS / LG_SIZEOF_BITMAP) \ + * + !!(LG_BITMAP_MAXBITS % LG_SIZEOF_BITMAP) + * + * However, that would not allow the generic BITMAP_INFO_INITIALIZER() macro, so + * instead hardcode BITMAP_MAX_LEVELS to the largest number supported by the + * various cascading macros. The only additional cost this incurs is some + * unused trailing entries in bitmap_info_t structures; the bitmaps themselves + * are not impacted. + */ +#define BITMAP_MAX_LEVELS 5 + +#define BITMAP_INFO_INITIALIZER(nbits) { \ + /* nbits. */ \ + nbits, \ + /* nlevels. */ \ + (BITMAP_GROUPS_L0(nbits) > BITMAP_GROUPS_L1(nbits)) + \ + (BITMAP_GROUPS_L1(nbits) > BITMAP_GROUPS_L2(nbits)) + \ + (BITMAP_GROUPS_L2(nbits) > BITMAP_GROUPS_L3(nbits)) + \ + (BITMAP_GROUPS_L3(nbits) > BITMAP_GROUPS_L4(nbits)) + 1, \ + /* levels. */ \ + { \ + {0}, \ + {BITMAP_GROUPS_L0(nbits)}, \ + {BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)}, \ + {BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits) + \ + BITMAP_GROUPS_L0(nbits)}, \ + {BITMAP_GROUPS_L3(nbits) + BITMAP_GROUPS_L2(nbits) + \ + BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)}, \ + {BITMAP_GROUPS_L4(nbits) + BITMAP_GROUPS_L3(nbits) + \ + BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits) \ + + BITMAP_GROUPS_L0(nbits)} \ + } \ +} + +#else /* BITMAP_USE_TREE */ + +#define BITMAP_GROUPS(nbits) BITMAP_BITS2GROUPS(nbits) +#define BITMAP_GROUPS_MAX BITMAP_BITS2GROUPS(BITMAP_MAXBITS) + +#define BITMAP_INFO_INITIALIZER(nbits) { \ + /* nbits. */ \ + nbits, \ + /* ngroups. */ \ + BITMAP_BITS2GROUPS(nbits) \ +} + +#endif /* BITMAP_USE_TREE */ + +typedef struct bitmap_level_s { + /* Offset of this level's groups within the array of groups. */ + size_t group_offset; +} bitmap_level_t; + +typedef struct bitmap_info_s { + /* Logical number of bits in bitmap (stored at bottom level). */ + size_t nbits; + +#ifdef BITMAP_USE_TREE + /* Number of levels necessary for nbits. */ + unsigned nlevels; + + /* + * Only the first (nlevels+1) elements are used, and levels are ordered + * bottom to top (e.g. the bottom level is stored in levels[0]). + */ + bitmap_level_t levels[BITMAP_MAX_LEVELS+1]; +#else /* BITMAP_USE_TREE */ + /* Number of groups necessary for nbits. */ + size_t ngroups; +#endif /* BITMAP_USE_TREE */ +} bitmap_info_t; + +void bitmap_info_init(bitmap_info_t *binfo, size_t nbits); +void bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo, bool fill); +size_t bitmap_size(const bitmap_info_t *binfo); + +static inline bool +bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo) { +#ifdef BITMAP_USE_TREE + size_t rgoff = binfo->levels[binfo->nlevels].group_offset - 1; + bitmap_t rg = bitmap[rgoff]; + /* The bitmap is full iff the root group is 0. */ + return (rg == 0); +#else + size_t i; + + for (i = 0; i < binfo->ngroups; i++) { + if (bitmap[i] != 0) { + return false; + } + } + return true; +#endif +} + +static inline bool +bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) { + size_t goff; + bitmap_t g; + + assert(bit < binfo->nbits); + goff = bit >> LG_BITMAP_GROUP_NBITS; + g = bitmap[goff]; + return !(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))); +} + +static inline void +bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) { + size_t goff; + bitmap_t *gp; + bitmap_t g; + + assert(bit < binfo->nbits); + assert(!bitmap_get(bitmap, binfo, bit)); + goff = bit >> LG_BITMAP_GROUP_NBITS; + gp = &bitmap[goff]; + g = *gp; + assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))); + g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK); + *gp = g; + assert(bitmap_get(bitmap, binfo, bit)); +#ifdef BITMAP_USE_TREE + /* Propagate group state transitions up the tree. */ + if (g == 0) { + unsigned i; + for (i = 1; i < binfo->nlevels; i++) { + bit = goff; + goff = bit >> LG_BITMAP_GROUP_NBITS; + gp = &bitmap[binfo->levels[i].group_offset + goff]; + g = *gp; + assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))); + g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK); + *gp = g; + if (g != 0) { + break; + } + } + } +#endif +} + +/* ffu: find first unset >= bit. */ +static inline size_t +bitmap_ffu(const bitmap_t *bitmap, const bitmap_info_t *binfo, size_t min_bit) { + assert(min_bit < binfo->nbits); + +#ifdef BITMAP_USE_TREE + size_t bit = 0; + for (unsigned level = binfo->nlevels; level--;) { + size_t lg_bits_per_group = (LG_BITMAP_GROUP_NBITS * (level + + 1)); + bitmap_t group = bitmap[binfo->levels[level].group_offset + (bit + >> lg_bits_per_group)]; + unsigned group_nmask = (unsigned)(((min_bit > bit) ? (min_bit - + bit) : 0) >> (lg_bits_per_group - LG_BITMAP_GROUP_NBITS)); + assert(group_nmask <= BITMAP_GROUP_NBITS); + bitmap_t group_mask = ~((1LU << group_nmask) - 1); + bitmap_t group_masked = group & group_mask; + if (group_masked == 0LU) { + if (group == 0LU) { + return binfo->nbits; + } + /* + * min_bit was preceded by one or more unset bits in + * this group, but there are no other unset bits in this + * group. Try again starting at the first bit of the + * next sibling. This will recurse at most once per + * non-root level. + */ + size_t sib_base = bit + (ZU(1) << lg_bits_per_group); + assert(sib_base > min_bit); + assert(sib_base > bit); + if (sib_base >= binfo->nbits) { + return binfo->nbits; + } + return bitmap_ffu(bitmap, binfo, sib_base); + } + bit += ((size_t)ffs_lu(group_masked)) << + (lg_bits_per_group - LG_BITMAP_GROUP_NBITS); + } + assert(bit >= min_bit); + assert(bit < binfo->nbits); + return bit; +#else + size_t i = min_bit >> LG_BITMAP_GROUP_NBITS; + bitmap_t g = bitmap[i] & ~((1LU << (min_bit & BITMAP_GROUP_NBITS_MASK)) + - 1); + size_t bit; + do { + if (g != 0) { + bit = ffs_lu(g); + return (i << LG_BITMAP_GROUP_NBITS) + bit; + } + i++; + g = bitmap[i]; + } while (i < binfo->ngroups); + return binfo->nbits; +#endif +} + +/* sfu: set first unset. */ +static inline size_t +bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo) { + size_t bit; + bitmap_t g; + unsigned i; + + assert(!bitmap_full(bitmap, binfo)); + +#ifdef BITMAP_USE_TREE + i = binfo->nlevels - 1; + g = bitmap[binfo->levels[i].group_offset]; + bit = ffs_lu(g); + while (i > 0) { + i--; + g = bitmap[binfo->levels[i].group_offset + bit]; + bit = (bit << LG_BITMAP_GROUP_NBITS) + ffs_lu(g); + } +#else + i = 0; + g = bitmap[0]; + while (g == 0) { + i++; + g = bitmap[i]; + } + bit = (i << LG_BITMAP_GROUP_NBITS) + ffs_lu(g); +#endif + bitmap_set(bitmap, binfo, bit); + return bit; +} + +static inline void +bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) { + size_t goff; + bitmap_t *gp; + bitmap_t g; + UNUSED bool propagate; + + assert(bit < binfo->nbits); + assert(bitmap_get(bitmap, binfo, bit)); + goff = bit >> LG_BITMAP_GROUP_NBITS; + gp = &bitmap[goff]; + g = *gp; + propagate = (g == 0); + assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))) == 0); + g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK); + *gp = g; + assert(!bitmap_get(bitmap, binfo, bit)); +#ifdef BITMAP_USE_TREE + /* Propagate group state transitions up the tree. */ + if (propagate) { + unsigned i; + for (i = 1; i < binfo->nlevels; i++) { + bit = goff; + goff = bit >> LG_BITMAP_GROUP_NBITS; + gp = &bitmap[binfo->levels[i].group_offset + goff]; + g = *gp; + propagate = (g == 0); + assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))) + == 0); + g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK); + *gp = g; + if (!propagate) { + break; + } + } + } +#endif /* BITMAP_USE_TREE */ +} + +#endif /* JEMALLOC_INTERNAL_BITMAP_H */ |