server-skynet-source-3rd-je.../include/jemalloc/internal/sz.h

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#ifndef JEMALLOC_INTERNAL_SIZE_H
#define JEMALLOC_INTERNAL_SIZE_H
#include "jemalloc/internal/bit_util.h"
#include "jemalloc/internal/pages.h"
#include "jemalloc/internal/size_classes.h"
#include "jemalloc/internal/util.h"
/*
* sz module: Size computations.
*
* Some abbreviations used here:
* p: Page
* ind: Index
* s, sz: Size
* u: Usable size
* a: Aligned
*
* These are not always used completely consistently, but should be enough to
* interpret function names. E.g. sz_psz2ind converts page size to page size
* index; sz_sa2u converts a (size, alignment) allocation request to the usable
* size that would result from such an allocation.
*/
/*
* sz_pind2sz_tab encodes the same information as could be computed by
* sz_pind2sz_compute().
*/
extern size_t const sz_pind2sz_tab[NPSIZES+1];
/*
* sz_index2size_tab encodes the same information as could be computed (at
* unacceptable cost in some code paths) by sz_index2size_compute().
*/
extern size_t const sz_index2size_tab[NSIZES];
/*
* sz_size2index_tab is a compact lookup table that rounds request sizes up to
* size classes. In order to reduce cache footprint, the table is compressed,
* and all accesses are via sz_size2index().
*/
extern uint8_t const sz_size2index_tab[];
static const size_t sz_large_pad =
#ifdef JEMALLOC_CACHE_OBLIVIOUS
PAGE
#else
0
#endif
;
JEMALLOC_ALWAYS_INLINE pszind_t
sz_psz2ind(size_t psz) {
if (unlikely(psz > LARGE_MAXCLASS)) {
return NPSIZES;
}
{
pszind_t x = lg_floor((psz<<1)-1);
pszind_t shift = (x < LG_SIZE_CLASS_GROUP + LG_PAGE) ? 0 : x -
(LG_SIZE_CLASS_GROUP + LG_PAGE);
pszind_t grp = shift << LG_SIZE_CLASS_GROUP;
pszind_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_PAGE + 1) ?
LG_PAGE : x - LG_SIZE_CLASS_GROUP - 1;
size_t delta_inverse_mask = ZD(-1) << lg_delta;
pszind_t mod = ((((psz-1) & delta_inverse_mask) >> lg_delta)) &
((ZU(1) << LG_SIZE_CLASS_GROUP) - 1);
pszind_t ind = grp + mod;
return ind;
}
}
static inline size_t
sz_pind2sz_compute(pszind_t pind) {
if (unlikely(pind == NPSIZES)) {
return LARGE_MAXCLASS + PAGE;
}
{
size_t grp = pind >> LG_SIZE_CLASS_GROUP;
size_t mod = pind & ((ZU(1) << LG_SIZE_CLASS_GROUP) - 1);
size_t grp_size_mask = ~((!!grp)-1);
size_t grp_size = ((ZU(1) << (LG_PAGE +
(LG_SIZE_CLASS_GROUP-1))) << grp) & grp_size_mask;
size_t shift = (grp == 0) ? 1 : grp;
size_t lg_delta = shift + (LG_PAGE-1);
size_t mod_size = (mod+1) << lg_delta;
size_t sz = grp_size + mod_size;
return sz;
}
}
static inline size_t
sz_pind2sz_lookup(pszind_t pind) {
size_t ret = (size_t)sz_pind2sz_tab[pind];
assert(ret == sz_pind2sz_compute(pind));
return ret;
}
static inline size_t
sz_pind2sz(pszind_t pind) {
assert(pind < NPSIZES+1);
return sz_pind2sz_lookup(pind);
}
static inline size_t
sz_psz2u(size_t psz) {
if (unlikely(psz > LARGE_MAXCLASS)) {
return LARGE_MAXCLASS + PAGE;
}
{
size_t x = lg_floor((psz<<1)-1);
size_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_PAGE + 1) ?
LG_PAGE : x - LG_SIZE_CLASS_GROUP - 1;
size_t delta = ZU(1) << lg_delta;
size_t delta_mask = delta - 1;
size_t usize = (psz + delta_mask) & ~delta_mask;
return usize;
}
}
static inline szind_t
sz_size2index_compute(size_t size) {
if (unlikely(size > LARGE_MAXCLASS)) {
return NSIZES;
}
#if (NTBINS != 0)
if (size <= (ZU(1) << LG_TINY_MAXCLASS)) {
szind_t lg_tmin = LG_TINY_MAXCLASS - NTBINS + 1;
szind_t lg_ceil = lg_floor(pow2_ceil_zu(size));
return (lg_ceil < lg_tmin ? 0 : lg_ceil - lg_tmin);
}
#endif
{
szind_t x = lg_floor((size<<1)-1);
szind_t shift = (x < LG_SIZE_CLASS_GROUP + LG_QUANTUM) ? 0 :
x - (LG_SIZE_CLASS_GROUP + LG_QUANTUM);
szind_t grp = shift << LG_SIZE_CLASS_GROUP;
szind_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_QUANTUM + 1)
? LG_QUANTUM : x - LG_SIZE_CLASS_GROUP - 1;
size_t delta_inverse_mask = ZD(-1) << lg_delta;
szind_t mod = ((((size-1) & delta_inverse_mask) >> lg_delta)) &
((ZU(1) << LG_SIZE_CLASS_GROUP) - 1);
szind_t index = NTBINS + grp + mod;
return index;
}
}
JEMALLOC_ALWAYS_INLINE szind_t
sz_size2index_lookup(size_t size) {
assert(size <= LOOKUP_MAXCLASS);
{
szind_t ret = (sz_size2index_tab[(size-1) >> LG_TINY_MIN]);
assert(ret == sz_size2index_compute(size));
return ret;
}
}
JEMALLOC_ALWAYS_INLINE szind_t
sz_size2index(size_t size) {
assert(size > 0);
if (likely(size <= LOOKUP_MAXCLASS)) {
return sz_size2index_lookup(size);
}
return sz_size2index_compute(size);
}
static inline size_t
sz_index2size_compute(szind_t index) {
#if (NTBINS > 0)
if (index < NTBINS) {
return (ZU(1) << (LG_TINY_MAXCLASS - NTBINS + 1 + index));
}
#endif
{
size_t reduced_index = index - NTBINS;
size_t grp = reduced_index >> LG_SIZE_CLASS_GROUP;
size_t mod = reduced_index & ((ZU(1) << LG_SIZE_CLASS_GROUP) -
1);
size_t grp_size_mask = ~((!!grp)-1);
size_t grp_size = ((ZU(1) << (LG_QUANTUM +
(LG_SIZE_CLASS_GROUP-1))) << grp) & grp_size_mask;
size_t shift = (grp == 0) ? 1 : grp;
size_t lg_delta = shift + (LG_QUANTUM-1);
size_t mod_size = (mod+1) << lg_delta;
size_t usize = grp_size + mod_size;
return usize;
}
}
JEMALLOC_ALWAYS_INLINE size_t
sz_index2size_lookup(szind_t index) {
size_t ret = (size_t)sz_index2size_tab[index];
assert(ret == sz_index2size_compute(index));
return ret;
}
JEMALLOC_ALWAYS_INLINE size_t
sz_index2size(szind_t index) {
assert(index < NSIZES);
return sz_index2size_lookup(index);
}
JEMALLOC_ALWAYS_INLINE size_t
sz_s2u_compute(size_t size) {
if (unlikely(size > LARGE_MAXCLASS)) {
return 0;
}
#if (NTBINS > 0)
if (size <= (ZU(1) << LG_TINY_MAXCLASS)) {
size_t lg_tmin = LG_TINY_MAXCLASS - NTBINS + 1;
size_t lg_ceil = lg_floor(pow2_ceil_zu(size));
return (lg_ceil < lg_tmin ? (ZU(1) << lg_tmin) :
(ZU(1) << lg_ceil));
}
#endif
{
size_t x = lg_floor((size<<1)-1);
size_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_QUANTUM + 1)
? LG_QUANTUM : x - LG_SIZE_CLASS_GROUP - 1;
size_t delta = ZU(1) << lg_delta;
size_t delta_mask = delta - 1;
size_t usize = (size + delta_mask) & ~delta_mask;
return usize;
}
}
JEMALLOC_ALWAYS_INLINE size_t
sz_s2u_lookup(size_t size) {
size_t ret = sz_index2size_lookup(sz_size2index_lookup(size));
assert(ret == sz_s2u_compute(size));
return ret;
}
/*
* Compute usable size that would result from allocating an object with the
* specified size.
*/
JEMALLOC_ALWAYS_INLINE size_t
sz_s2u(size_t size) {
assert(size > 0);
if (likely(size <= LOOKUP_MAXCLASS)) {
return sz_s2u_lookup(size);
}
return sz_s2u_compute(size);
}
/*
* Compute usable size that would result from allocating an object with the
* specified size and alignment.
*/
JEMALLOC_ALWAYS_INLINE size_t
sz_sa2u(size_t size, size_t alignment) {
size_t usize;
assert(alignment != 0 && ((alignment - 1) & alignment) == 0);
/* Try for a small size class. */
if (size <= SMALL_MAXCLASS && alignment < PAGE) {
/*
* Round size up to the nearest multiple of alignment.
*
* This done, we can take advantage of the fact that for each
* small size class, every object is aligned at the smallest
* power of two that is non-zero in the base two representation
* of the size. For example:
*
* Size | Base 2 | Minimum alignment
* -----+----------+------------------
* 96 | 1100000 | 32
* 144 | 10100000 | 32
* 192 | 11000000 | 64
*/
usize = sz_s2u(ALIGNMENT_CEILING(size, alignment));
if (usize < LARGE_MINCLASS) {
return usize;
}
}
/* Large size class. Beware of overflow. */
if (unlikely(alignment > LARGE_MAXCLASS)) {
return 0;
}
/* Make sure result is a large size class. */
if (size <= LARGE_MINCLASS) {
usize = LARGE_MINCLASS;
} else {
usize = sz_s2u(size);
if (usize < size) {
/* size_t overflow. */
return 0;
}
}
/*
* Calculate the multi-page mapping that large_palloc() would need in
* order to guarantee the alignment.
*/
if (usize + sz_large_pad + PAGE_CEILING(alignment) - PAGE < usize) {
/* size_t overflow. */
return 0;
}
return usize;
}
#endif /* JEMALLOC_INTERNAL_SIZE_H */