369 lines
11 KiB
C
369 lines
11 KiB
C
#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 */
|