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Diffstat (limited to 'deps/jemalloc/src/bitmap.c')
-rw-r--r-- | deps/jemalloc/src/bitmap.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/deps/jemalloc/src/bitmap.c b/deps/jemalloc/src/bitmap.c new file mode 100644 index 0000000..468b317 --- /dev/null +++ b/deps/jemalloc/src/bitmap.c @@ -0,0 +1,121 @@ +#define JEMALLOC_BITMAP_C_ +#include "jemalloc/internal/jemalloc_preamble.h" +#include "jemalloc/internal/jemalloc_internal_includes.h" + +#include "jemalloc/internal/assert.h" + +/******************************************************************************/ + +#ifdef BITMAP_USE_TREE + +void +bitmap_info_init(bitmap_info_t *binfo, size_t nbits) { + unsigned i; + size_t group_count; + + assert(nbits > 0); + assert(nbits <= (ZU(1) << LG_BITMAP_MAXBITS)); + + /* + * Compute the number of groups necessary to store nbits bits, and + * progressively work upward through the levels until reaching a level + * that requires only one group. + */ + binfo->levels[0].group_offset = 0; + group_count = BITMAP_BITS2GROUPS(nbits); + for (i = 1; group_count > 1; i++) { + assert(i < BITMAP_MAX_LEVELS); + binfo->levels[i].group_offset = binfo->levels[i-1].group_offset + + group_count; + group_count = BITMAP_BITS2GROUPS(group_count); + } + binfo->levels[i].group_offset = binfo->levels[i-1].group_offset + + group_count; + assert(binfo->levels[i].group_offset <= BITMAP_GROUPS_MAX); + binfo->nlevels = i; + binfo->nbits = nbits; +} + +static size_t +bitmap_info_ngroups(const bitmap_info_t *binfo) { + return binfo->levels[binfo->nlevels].group_offset; +} + +void +bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo, bool fill) { + size_t extra; + unsigned i; + + /* + * Bits are actually inverted with regard to the external bitmap + * interface. + */ + + if (fill) { + /* The "filled" bitmap starts out with all 0 bits. */ + memset(bitmap, 0, bitmap_size(binfo)); + return; + } + + /* + * The "empty" bitmap starts out with all 1 bits, except for trailing + * unused bits (if any). Note that each group uses bit 0 to correspond + * to the first logical bit in the group, so extra bits are the most + * significant bits of the last group. + */ + memset(bitmap, 0xffU, bitmap_size(binfo)); + extra = (BITMAP_GROUP_NBITS - (binfo->nbits & BITMAP_GROUP_NBITS_MASK)) + & BITMAP_GROUP_NBITS_MASK; + if (extra != 0) { + bitmap[binfo->levels[1].group_offset - 1] >>= extra; + } + for (i = 1; i < binfo->nlevels; i++) { + size_t group_count = binfo->levels[i].group_offset - + binfo->levels[i-1].group_offset; + extra = (BITMAP_GROUP_NBITS - (group_count & + BITMAP_GROUP_NBITS_MASK)) & BITMAP_GROUP_NBITS_MASK; + if (extra != 0) { + bitmap[binfo->levels[i+1].group_offset - 1] >>= extra; + } + } +} + +#else /* BITMAP_USE_TREE */ + +void +bitmap_info_init(bitmap_info_t *binfo, size_t nbits) { + assert(nbits > 0); + assert(nbits <= (ZU(1) << LG_BITMAP_MAXBITS)); + + binfo->ngroups = BITMAP_BITS2GROUPS(nbits); + binfo->nbits = nbits; +} + +static size_t +bitmap_info_ngroups(const bitmap_info_t *binfo) { + return binfo->ngroups; +} + +void +bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo, bool fill) { + size_t extra; + + if (fill) { + memset(bitmap, 0, bitmap_size(binfo)); + return; + } + + memset(bitmap, 0xffU, bitmap_size(binfo)); + extra = (BITMAP_GROUP_NBITS - (binfo->nbits & BITMAP_GROUP_NBITS_MASK)) + & BITMAP_GROUP_NBITS_MASK; + if (extra != 0) { + bitmap[binfo->ngroups - 1] >>= extra; + } +} + +#endif /* BITMAP_USE_TREE */ + +size_t +bitmap_size(const bitmap_info_t *binfo) { + return (bitmap_info_ngroups(binfo) << LG_SIZEOF_BITMAP); +} |