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/******************************************************************************/
#ifdef JEMALLOC_H_TYPES
/* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */
#define LG_BITMAP_MAXBITS LG_SLAB_MAXREGS
#define BITMAP_MAXBITS (ZU(1) << LG_BITMAP_MAXBITS)
typedef struct bitmap_level_s bitmap_level_t;
typedef struct bitmap_info_s bitmap_info_t;
typedef unsigned long bitmap_t;
#define LG_SIZEOF_BITMAP LG_SIZEOF_LONG
/* 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_MAX BITMAP_GROUPS_1_LEVEL(BITMAP_MAXBITS)
#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 2
# define BITMAP_GROUPS_MAX BITMAP_GROUPS_2_LEVEL(BITMAP_MAXBITS)
#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 3
# define BITMAP_GROUPS_MAX BITMAP_GROUPS_3_LEVEL(BITMAP_MAXBITS)
#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 4
# define BITMAP_GROUPS_MAX BITMAP_GROUPS_4_LEVEL(BITMAP_MAXBITS)
#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 5
# 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_MAX BITMAP_BITS2GROUPS(BITMAP_MAXBITS)
#define BITMAP_INFO_INITIALIZER(nbits) { \
/* nbits. */ \
nbits, \
/* ngroups. */ \
BITMAP_BITS2GROUPS(nbits) \
}
#endif /* BITMAP_USE_TREE */
#endif /* JEMALLOC_H_TYPES */
/******************************************************************************/
#ifdef JEMALLOC_H_STRUCTS
struct bitmap_level_s {
/* Offset of this level's groups within the array of groups. */
size_t group_offset;
};
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 */
};
#endif /* JEMALLOC_H_STRUCTS */
/******************************************************************************/
#ifdef JEMALLOC_H_EXTERNS
void bitmap_info_init(bitmap_info_t *binfo, size_t nbits);
void bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo);
size_t bitmap_size(const bitmap_info_t *binfo);
#endif /* JEMALLOC_H_EXTERNS */
/******************************************************************************/
#ifdef JEMALLOC_H_INLINES
#ifndef JEMALLOC_ENABLE_INLINE
bool bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo);
bool bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit);
void bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit);
size_t bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo);
void bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit);
#endif
#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_BITMAP_C_))
JEMALLOC_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
}
JEMALLOC_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))));
}
JEMALLOC_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
}
/* sfu: set first unset. */
JEMALLOC_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) - 1;
while (i > 0) {
i--;
g = bitmap[binfo->levels[i].group_offset + bit];
bit = (bit << LG_BITMAP_GROUP_NBITS) + (ffs_lu(g) - 1);
}
#else
i = 0;
g = bitmap[0];
while ((bit = ffs_lu(g)) == 0) {
i++;
g = bitmap[i];
}
bit = (i << LG_BITMAP_GROUP_NBITS) + (bit - 1);
#endif
bitmap_set(bitmap, binfo, bit);
return (bit);
}
JEMALLOC_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
#endif /* JEMALLOC_H_INLINES */
/******************************************************************************/
|
