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| 1 | +/******************************************************************************/ |
| 2 | +#ifdef JEMALLOC_H_TYPES |
| 3 | + |
| 4 | +/* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */ |
| 5 | +#define LG_BITMAP_MAXBITS 18 |
| 6 | + |
| 7 | +typedef struct bitmap_level_s bitmap_level_t; |
| 8 | +typedef struct bitmap_info_s bitmap_info_t; |
| 9 | +typedef unsigned long bitmap_t; |
| 10 | +#define LG_SIZEOF_BITMAP LG_SIZEOF_LONG |
| 11 | + |
| 12 | +/* Number of bits per group. */ |
| 13 | +#define LG_BITMAP_GROUP_NBITS (LG_SIZEOF_BITMAP + 3) |
| 14 | +#define BITMAP_GROUP_NBITS (ZU(1) << LG_BITMAP_GROUP_NBITS) |
| 15 | +#define BITMAP_GROUP_NBITS_MASK (BITMAP_GROUP_NBITS-1) |
| 16 | + |
| 17 | +/* Maximum number of levels possible. */ |
| 18 | +#define BITMAP_MAX_LEVELS \ |
| 19 | + (LG_BITMAP_MAXBITS / LG_SIZEOF_BITMAP) \ |
| 20 | + + !!(LG_BITMAP_MAXBITS % LG_SIZEOF_BITMAP) |
| 21 | + |
| 22 | +#endif /* JEMALLOC_H_TYPES */ |
| 23 | +/******************************************************************************/ |
| 24 | +#ifdef JEMALLOC_H_STRUCTS |
| 25 | + |
| 26 | +struct bitmap_level_s { |
| 27 | + /* Offset of this level's groups within the array of groups. */ |
| 28 | + size_t group_offset; |
| 29 | +}; |
| 30 | + |
| 31 | +struct bitmap_info_s { |
| 32 | + /* Logical number of bits in bitmap (stored at bottom level). */ |
| 33 | + size_t nbits; |
| 34 | + |
| 35 | + /* Number of levels necessary for nbits. */ |
| 36 | + unsigned nlevels; |
| 37 | + |
| 38 | + /* |
| 39 | + * Only the first (nlevels+1) elements are used, and levels are ordered |
| 40 | + * bottom to top (e.g. the bottom level is stored in levels[0]). |
| 41 | + */ |
| 42 | + bitmap_level_t levels[BITMAP_MAX_LEVELS+1]; |
| 43 | +}; |
| 44 | + |
| 45 | +#endif /* JEMALLOC_H_STRUCTS */ |
| 46 | +/******************************************************************************/ |
| 47 | +#ifdef JEMALLOC_H_EXTERNS |
| 48 | + |
| 49 | +void bitmap_info_init(bitmap_info_t *binfo, size_t nbits); |
| 50 | +size_t bitmap_info_ngroups(const bitmap_info_t *binfo); |
| 51 | +size_t bitmap_size(size_t nbits); |
| 52 | +void bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo); |
| 53 | + |
| 54 | +#endif /* JEMALLOC_H_EXTERNS */ |
| 55 | +/******************************************************************************/ |
| 56 | +#ifdef JEMALLOC_H_INLINES |
| 57 | + |
| 58 | +#ifndef JEMALLOC_ENABLE_INLINE |
| 59 | +bool bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo); |
| 60 | +bool bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit); |
| 61 | +void bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit); |
| 62 | +size_t bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo); |
| 63 | +void bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit); |
| 64 | +#endif |
| 65 | + |
| 66 | +#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_BITMAP_C_)) |
| 67 | +JEMALLOC_INLINE bool |
| 68 | +bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo) |
| 69 | +{ |
| 70 | + unsigned rgoff = binfo->levels[binfo->nlevels].group_offset - 1; |
| 71 | + bitmap_t rg = bitmap[rgoff]; |
| 72 | + /* The bitmap is full iff the root group is 0. */ |
| 73 | + return (rg == 0); |
| 74 | +} |
| 75 | + |
| 76 | +JEMALLOC_INLINE bool |
| 77 | +bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) |
| 78 | +{ |
| 79 | + size_t goff; |
| 80 | + bitmap_t g; |
| 81 | + |
| 82 | + assert(bit < binfo->nbits); |
| 83 | + goff = bit >> LG_BITMAP_GROUP_NBITS; |
| 84 | + g = bitmap[goff]; |
| 85 | + return (!(g & (1LU << (bit & BITMAP_GROUP_NBITS_MASK)))); |
| 86 | +} |
| 87 | + |
| 88 | +JEMALLOC_INLINE void |
| 89 | +bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) |
| 90 | +{ |
| 91 | + size_t goff; |
| 92 | + bitmap_t *gp; |
| 93 | + bitmap_t g; |
| 94 | + |
| 95 | + assert(bit < binfo->nbits); |
| 96 | + assert(bitmap_get(bitmap, binfo, bit) == false); |
| 97 | + goff = bit >> LG_BITMAP_GROUP_NBITS; |
| 98 | + gp = &bitmap[goff]; |
| 99 | + g = *gp; |
| 100 | + assert(g & (1LU << (bit & BITMAP_GROUP_NBITS_MASK))); |
| 101 | + g ^= 1LU << (bit & BITMAP_GROUP_NBITS_MASK); |
| 102 | + *gp = g; |
| 103 | + assert(bitmap_get(bitmap, binfo, bit)); |
| 104 | + /* Propagate group state transitions up the tree. */ |
| 105 | + if (g == 0) { |
| 106 | + unsigned i; |
| 107 | + for (i = 1; i < binfo->nlevels; i++) { |
| 108 | + bit = goff; |
| 109 | + goff = bit >> LG_BITMAP_GROUP_NBITS; |
| 110 | + gp = &bitmap[binfo->levels[i].group_offset + goff]; |
| 111 | + g = *gp; |
| 112 | + assert(g & (1LU << (bit & BITMAP_GROUP_NBITS_MASK))); |
| 113 | + g ^= 1LU << (bit & BITMAP_GROUP_NBITS_MASK); |
| 114 | + *gp = g; |
| 115 | + if (g != 0) |
| 116 | + break; |
| 117 | + } |
| 118 | + } |
| 119 | +} |
| 120 | + |
| 121 | +/* sfu: set first unset. */ |
| 122 | +JEMALLOC_INLINE size_t |
| 123 | +bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo) |
| 124 | +{ |
| 125 | + size_t bit; |
| 126 | + bitmap_t g; |
| 127 | + unsigned i; |
| 128 | + |
| 129 | + assert(bitmap_full(bitmap, binfo) == false); |
| 130 | + |
| 131 | + i = binfo->nlevels - 1; |
| 132 | + g = bitmap[binfo->levels[i].group_offset]; |
| 133 | + bit = ffsl(g) - 1; |
| 134 | + while (i > 0) { |
| 135 | + i--; |
| 136 | + g = bitmap[binfo->levels[i].group_offset + bit]; |
| 137 | + bit = (bit << LG_BITMAP_GROUP_NBITS) + (ffsl(g) - 1); |
| 138 | + } |
| 139 | + |
| 140 | + bitmap_set(bitmap, binfo, bit); |
| 141 | + return (bit); |
| 142 | +} |
| 143 | + |
| 144 | +JEMALLOC_INLINE void |
| 145 | +bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) |
| 146 | +{ |
| 147 | + size_t goff; |
| 148 | + bitmap_t *gp; |
| 149 | + bitmap_t g; |
| 150 | + bool propagate; |
| 151 | + |
| 152 | + assert(bit < binfo->nbits); |
| 153 | + assert(bitmap_get(bitmap, binfo, bit)); |
| 154 | + goff = bit >> LG_BITMAP_GROUP_NBITS; |
| 155 | + gp = &bitmap[goff]; |
| 156 | + g = *gp; |
| 157 | + propagate = (g == 0); |
| 158 | + assert((g & (1LU << (bit & BITMAP_GROUP_NBITS_MASK))) == 0); |
| 159 | + g ^= 1LU << (bit & BITMAP_GROUP_NBITS_MASK); |
| 160 | + *gp = g; |
| 161 | + assert(bitmap_get(bitmap, binfo, bit) == false); |
| 162 | + /* Propagate group state transitions up the tree. */ |
| 163 | + if (propagate) { |
| 164 | + unsigned i; |
| 165 | + for (i = 1; i < binfo->nlevels; i++) { |
| 166 | + bit = goff; |
| 167 | + goff = bit >> LG_BITMAP_GROUP_NBITS; |
| 168 | + gp = &bitmap[binfo->levels[i].group_offset + goff]; |
| 169 | + g = *gp; |
| 170 | + propagate = (g == 0); |
| 171 | + assert((g & (1LU << (bit & BITMAP_GROUP_NBITS_MASK))) |
| 172 | + == 0); |
| 173 | + g ^= 1LU << (bit & BITMAP_GROUP_NBITS_MASK); |
| 174 | + *gp = g; |
| 175 | + if (propagate == false) |
| 176 | + break; |
| 177 | + } |
| 178 | + } |
| 179 | +} |
| 180 | + |
| 181 | +#endif |
| 182 | + |
| 183 | +#endif /* JEMALLOC_H_INLINES */ |
| 184 | +/******************************************************************************/ |
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