1 files changed, 1232 insertions, 0 deletions

diff --git a/src/lj_alloc.c b/src/lj_alloc.c
new file mode 100644
index 00000000..8ad4f8fb
--- /dev/null
+++ b/src/lj_alloc.c
@@ -0,0 +1,1232 @@
+/*
+** Bundled memory allocator.
+**
+** Beware: this is a HEAVILY CUSTOMIZED version of dlmalloc.
+** The original bears the following remark:
+**
+**   This is a version (aka dlmalloc) of malloc/free/realloc written by
+**   Doug Lea and released to the public domain, as explained at
+**   http://creativecommons.org/licenses/publicdomain.
+**
+**   * Version pre-2.8.4 Wed Mar 29 19:46:29 2006    (dl at gee)
+**
+** No additional copyright is claimed over the customizations.
+** Please do NOT bother the original author about this version here!
+**
+** If you want to use dlmalloc in another project, you should get
+** the original from: ftp://gee.cs.oswego.edu/pub/misc/
+** For thread-safe derivatives, take a look at:
+** - ptmalloc: http://www.malloc.de/
+** - nedmalloc: http://www.nedprod.com/programs/portable/nedmalloc/
+*/
+
+#define lj_alloc_c
+#define LUA_CORE
+
+/* To get the mremap prototype. Must be defind before any system includes. */
+#if defined(__linux__) && !defined(_GNU_SOURCE)
+#define _GNU_SOURCE
+#endif
+
+#include "lj_def.h"
+#include "lj_arch.h"
+#include "lj_alloc.h"
+
+#ifndef LUAJIT_USE_SYSMALLOC
+
+#define MAX_SIZE_T              (~(size_t)0)
+#define MALLOC_ALIGNMENT        ((size_t)8U)
+
+#define DEFAULT_GRANULARITY     ((size_t)128U * (size_t)1024U)
+#define DEFAULT_TRIM_THRESHOLD  ((size_t)2U * (size_t)1024U * (size_t)1024U)
+#define DEFAULT_MMAP_THRESHOLD  ((size_t)128U * (size_t)1024U)
+#define MAX_RELEASE_CHECK_RATE  255
+
+/* ------------------- size_t and alignment properties -------------------- */
+
+/* The byte and bit size of a size_t */
+#define SIZE_T_SIZE             (sizeof(size_t))
+#define SIZE_T_BITSIZE          (sizeof(size_t) << 3)
+
+/* Some constants coerced to size_t */
+/* Annoying but necessary to avoid errors on some platforms */
+#define SIZE_T_ZERO             ((size_t)0)
+#define SIZE_T_ONE              ((size_t)1)
+#define SIZE_T_TWO              ((size_t)2)
+#define TWO_SIZE_T_SIZES        (SIZE_T_SIZE<<1)
+#define FOUR_SIZE_T_SIZES       (SIZE_T_SIZE<<2)
+#define SIX_SIZE_T_SIZES        (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES)
+
+/* The bit mask value corresponding to MALLOC_ALIGNMENT */
+#define CHUNK_ALIGN_MASK        (MALLOC_ALIGNMENT - SIZE_T_ONE)
+
+/* the number of bytes to offset an address to align it */
+#define align_offset(A)\
+ ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\
+  ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK))
+
+/* -------------------------- MMAP support ------------------------------- */
+
+#define MFAIL                   ((void *)(MAX_SIZE_T))
+#define CMFAIL                  ((char *)(MFAIL)) /* defined for convenience */
+
+#define IS_DIRECT_BIT           (SIZE_T_ONE)
+
+#ifdef LUA_USE_WIN
+
+#if LJ_64
+#error "missing support for WIN64 to allocate in lower 2G"
+#endif
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+/* Win32 MMAP via VirtualAlloc */
+static LJ_AINLINE void *CALL_MMAP(size_t size)
+{
+  void *ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
+  return (ptr != 0)? ptr: MFAIL;
+}
+
+/* For direct MMAP, use MEM_TOP_DOWN to minimize interference */
+static LJ_AINLINE void *DIRECT_MMAP(size_t size)
+{
+  void *ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN,
+                           PAGE_READWRITE);
+  return (ptr != 0)? ptr: MFAIL;
+}
+
+/* This function supports releasing coalesed segments */
+static LJ_AINLINE int CALL_MUNMAP(void *ptr, size_t size)
+{
+  MEMORY_BASIC_INFORMATION minfo;
+  char *cptr = (char *)ptr;
+  while (size) {
+    if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0)
+      return -1;
+    if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr ||
+        minfo.State != MEM_COMMIT || minfo.RegionSize > size)
+      return -1;
+    if (VirtualFree(cptr, 0, MEM_RELEASE) == 0)
+      return -1;
+    cptr += minfo.RegionSize;
+    size -= minfo.RegionSize;
+  }
+  return 0;
+}
+
+#else
+
+#include <sys/mman.h>
+
+#define MMAP_PROT               (PROT_READ|PROT_WRITE)
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+#define MAP_ANONYMOUS           MAP_ANON
+#endif /* MAP_ANON */
+
+#if LJ_64
+#define MMAP_FLAGS              (MAP_PRIVATE|MAP_ANONYMOUS|MAP_32BIT)
+#else
+#define MMAP_FLAGS              (MAP_PRIVATE|MAP_ANONYMOUS)
+#endif
+
+#define CALL_MMAP(s)            mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0)
+#define DIRECT_MMAP(s)          CALL_MMAP(s)
+#define CALL_MUNMAP(a, s)       munmap((a), (s))
+
+#ifdef __linux__
+/* Need to define _GNU_SOURCE to get the mremap prototype. */
+#define CALL_MREMAP(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv))
+#endif
+
+#endif
+
+#ifndef CALL_MREMAP
+#define CALL_MREMAP(addr, osz, nsz, mv) ((void)osz, MFAIL)
+#endif
+
+/* -----------------------  Chunk representations ------------------------ */
+
+struct malloc_chunk {
+  size_t               prev_foot;  /* Size of previous chunk (if free).  */
+  size_t               head;       /* Size and inuse bits. */
+  struct malloc_chunk *fd;         /* double links -- used only if free. */
+  struct malloc_chunk *bk;
+};
+
+typedef struct malloc_chunk  mchunk;
+typedef struct malloc_chunk *mchunkptr;
+typedef struct malloc_chunk *sbinptr;  /* The type of bins of chunks */
+typedef unsigned int bindex_t;         /* Described below */
+typedef unsigned int binmap_t;         /* Described below */
+typedef unsigned int flag_t;           /* The type of various bit flag sets */
+
+/* ------------------- Chunks sizes and alignments ----------------------- */
+
+#define MCHUNK_SIZE             (sizeof(mchunk))
+
+#define CHUNK_OVERHEAD          (SIZE_T_SIZE)
+
+/* Direct chunks need a second word of overhead ... */
+#define DIRECT_CHUNK_OVERHEAD   (TWO_SIZE_T_SIZES)
+/* ... and additional padding for fake next-chunk at foot */
+#define DIRECT_FOOT_PAD         (FOUR_SIZE_T_SIZES)
+
+/* The smallest size we can malloc is an aligned minimal chunk */
+#define MIN_CHUNK_SIZE\
+  ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
+
+/* conversion from malloc headers to user pointers, and back */
+#define chunk2mem(p)            ((void *)((char *)(p) + TWO_SIZE_T_SIZES))
+#define mem2chunk(mem)          ((mchunkptr)((char *)(mem) - TWO_SIZE_T_SIZES))
+/* chunk associated with aligned address A */
+#define align_as_chunk(A)       (mchunkptr)((A) + align_offset(chunk2mem(A)))
+
+/* Bounds on request (not chunk) sizes. */
+#define MAX_REQUEST             ((~MIN_CHUNK_SIZE+1) << 2)
+#define MIN_REQUEST             (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE)
+
+/* pad request bytes into a usable size */
+#define pad_request(req) \
+   (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
+
+/* pad request, checking for minimum (but not maximum) */
+#define request2size(req) \
+  (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req))
+
+/* ------------------ Operations on head and foot fields ----------------- */
+
+#define PINUSE_BIT              (SIZE_T_ONE)
+#define CINUSE_BIT              (SIZE_T_TWO)
+#define INUSE_BITS              (PINUSE_BIT|CINUSE_BIT)
+
+/* Head value for fenceposts */
+#define FENCEPOST_HEAD          (INUSE_BITS|SIZE_T_SIZE)
+
+/* extraction of fields from head words */
+#define cinuse(p)               ((p)->head & CINUSE_BIT)
+#define pinuse(p)               ((p)->head & PINUSE_BIT)
+#define chunksize(p)            ((p)->head & ~(INUSE_BITS))
+
+#define clear_pinuse(p)         ((p)->head &= ~PINUSE_BIT)
+#define clear_cinuse(p)         ((p)->head &= ~CINUSE_BIT)
+
+/* Treat space at ptr +/- offset as a chunk */
+#define chunk_plus_offset(p, s)         ((mchunkptr)(((char *)(p)) + (s)))
+#define chunk_minus_offset(p, s)        ((mchunkptr)(((char *)(p)) - (s)))
+
+/* Ptr to next or previous physical malloc_chunk. */
+#define next_chunk(p)   ((mchunkptr)(((char *)(p)) + ((p)->head & ~INUSE_BITS)))
+#define prev_chunk(p)   ((mchunkptr)(((char *)(p)) - ((p)->prev_foot) ))
+
+/* extract next chunk's pinuse bit */
+#define next_pinuse(p)  ((next_chunk(p)->head) & PINUSE_BIT)
+
+/* Get/set size at footer */
+#define get_foot(p, s)  (((mchunkptr)((char *)(p) + (s)))->prev_foot)
+#define set_foot(p, s)  (((mchunkptr)((char *)(p) + (s)))->prev_foot = (s))
+
+/* Set size, pinuse bit, and foot */
+#define set_size_and_pinuse_of_free_chunk(p, s)\
+  ((p)->head = (s|PINUSE_BIT), set_foot(p, s))
+
+/* Set size, pinuse bit, foot, and clear next pinuse */
+#define set_free_with_pinuse(p, s, n)\
+  (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s))
+
+#define is_direct(p)\
+  (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_DIRECT_BIT))
+
+/* Get the internal overhead associated with chunk p */
+#define overhead_for(p)\
+ (is_direct(p)? DIRECT_CHUNK_OVERHEAD : CHUNK_OVERHEAD)
+
+/* ---------------------- Overlaid data structures ----------------------- */
+
+struct malloc_tree_chunk {
+  /* The first four fields must be compatible with malloc_chunk */
+  size_t                    prev_foot;
+  size_t                    head;
+  struct malloc_tree_chunk *fd;
+  struct malloc_tree_chunk *bk;
+
+  struct malloc_tree_chunk *child[2];
+  struct malloc_tree_chunk *parent;
+  bindex_t                  index;
+};
+
+typedef struct malloc_tree_chunk  tchunk;
+typedef struct malloc_tree_chunk *tchunkptr;
+typedef struct malloc_tree_chunk *tbinptr; /* The type of bins of trees */
+
+/* A little helper macro for trees */
+#define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1])
+
+/* ----------------------------- Segments -------------------------------- */
+
+struct malloc_segment {
+  char        *base;             /* base address */
+  size_t       size;             /* allocated size */
+  struct malloc_segment *next;   /* ptr to next segment */
+};
+
+typedef struct malloc_segment  msegment;
+typedef struct malloc_segment *msegmentptr;
+
+/* ---------------------------- malloc_state ----------------------------- */
+
+/* Bin types, widths and sizes */
+#define NSMALLBINS              (32U)
+#define NTREEBINS               (32U)
+#define SMALLBIN_SHIFT          (3U)
+#define SMALLBIN_WIDTH          (SIZE_T_ONE << SMALLBIN_SHIFT)
+#define TREEBIN_SHIFT           (8U)
+#define MIN_LARGE_SIZE          (SIZE_T_ONE << TREEBIN_SHIFT)
+#define MAX_SMALL_SIZE          (MIN_LARGE_SIZE - SIZE_T_ONE)
+#define MAX_SMALL_REQUEST  (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD)
+
+struct malloc_state {
+  binmap_t   smallmap;
+  binmap_t   treemap;
+  size_t     dvsize;
+  size_t     topsize;
+  mchunkptr  dv;
+  mchunkptr  top;
+  size_t     trim_check;
+  size_t     release_checks;
+  mchunkptr  smallbins[(NSMALLBINS+1)*2];
+  tbinptr    treebins[NTREEBINS];
+  msegment   seg;
+};
+
+typedef struct malloc_state *mstate;
+
+#define is_initialized(M)       ((M)->top != 0)
+
+/* -------------------------- system alloc setup ------------------------- */
+
+/* page-align a size */
+#define page_align(S)\
+ (((S) + (LJ_PAGESIZE - SIZE_T_ONE)) & ~(LJ_PAGESIZE - SIZE_T_ONE))
+
+/* granularity-align a size */
+#define granularity_align(S)\
+  (((S) + (DEFAULT_GRANULARITY - SIZE_T_ONE))\
+   & ~(DEFAULT_GRANULARITY - SIZE_T_ONE))
+
+#ifdef LUA_USE_WIN
+#define mmap_align(S)   granularity_align(S)
+#else
+#define mmap_align(S)   page_align(S)
+#endif
+
+/*  True if segment S holds address A */
+#define segment_holds(S, A)\
+  ((char *)(A) >= S->base && (char *)(A) < S->base + S->size)
+
+/* Return segment holding given address */
+static msegmentptr segment_holding(mstate m, char *addr)
+{
+  msegmentptr sp = &m->seg;
+  for (;;) {
+    if (addr >= sp->base && addr < sp->base + sp->size)
+      return sp;
+    if ((sp = sp->next) == 0)
+      return 0;
+  }
+}
+
+/* Return true if segment contains a segment link */
+static int has_segment_link(mstate m, msegmentptr ss)
+{
+  msegmentptr sp = &m->seg;
+  for (;;) {
+    if ((char *)sp >= ss->base && (char *)sp < ss->base + ss->size)
+      return 1;
+    if ((sp = sp->next) == 0)
+      return 0;
+  }
+}
+
+/*
+  TOP_FOOT_SIZE is padding at the end of a segment, including space
+  that may be needed to place segment records and fenceposts when new
+  noncontiguous segments are added.
+*/
+#define TOP_FOOT_SIZE\
+  (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE)
+
+/* ---------------------------- Indexing Bins ---------------------------- */
+
+#define is_small(s)             (((s) >> SMALLBIN_SHIFT) < NSMALLBINS)
+#define small_index(s)          ((s)  >> SMALLBIN_SHIFT)
+#define small_index2size(i)     ((i)  << SMALLBIN_SHIFT)
+#define MIN_SMALL_INDEX         (small_index(MIN_CHUNK_SIZE))
+
+/* addressing by index. See above about smallbin repositioning */
+#define smallbin_at(M, i)       ((sbinptr)((char *)&((M)->smallbins[(i)<<1])))
+#define treebin_at(M,i)         (&((M)->treebins[i]))
+
+/* assign tree index for size S to variable I */
+#define compute_tree_index(S, I)\
+{\
+  unsigned int X = S >> TREEBIN_SHIFT;\
+  if (X == 0) {\
+    I = 0;\
+  } else if (X > 0xFFFF) {\
+    I = NTREEBINS-1;\
+  } else {\
+    unsigned int K = lj_fls(X);\
+    I =  (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\
+  }\
+}
+
+/* Bit representing maximum resolved size in a treebin at i */
+#define bit_for_tree_index(i) \
+   (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2)
+
+/* Shift placing maximum resolved bit in a treebin at i as sign bit */
+#define leftshift_for_tree_index(i) \
+   ((i == NTREEBINS-1)? 0 : \
+    ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2)))
+
+/* The size of the smallest chunk held in bin with index i */
+#define minsize_for_tree_index(i) \
+   ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) |  \
+   (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1)))
+
+/* ------------------------ Operations on bin maps ----------------------- */
+
+/* bit corresponding to given index */
+#define idx2bit(i)              ((binmap_t)(1) << (i))
+
+/* Mark/Clear bits with given index */
+#define mark_smallmap(M,i)      ((M)->smallmap |=  idx2bit(i))
+#define clear_smallmap(M,i)     ((M)->smallmap &= ~idx2bit(i))
+#define smallmap_is_marked(M,i) ((M)->smallmap &   idx2bit(i))
+
+#define mark_treemap(M,i)       ((M)->treemap  |=  idx2bit(i))
+#define clear_treemap(M,i)      ((M)->treemap  &= ~idx2bit(i))
+#define treemap_is_marked(M,i)  ((M)->treemap  &   idx2bit(i))
+
+/* mask with all bits to left of least bit of x on */
+#define left_bits(x)            ((x<<1) | (~(x<<1)+1))
+
+/* Set cinuse bit and pinuse bit of next chunk */
+#define set_inuse(M,p,s)\
+  ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\
+  ((mchunkptr)(((char *)(p)) + (s)))->head |= PINUSE_BIT)
+
+/* Set cinuse and pinuse of this chunk and pinuse of next chunk */
+#define set_inuse_and_pinuse(M,p,s)\
+  ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\
+  ((mchunkptr)(((char *)(p)) + (s)))->head |= PINUSE_BIT)
+
+/* Set size, cinuse and pinuse bit of this chunk */
+#define set_size_and_pinuse_of_inuse_chunk(M, p, s)\
+  ((p)->head = (s|PINUSE_BIT|CINUSE_BIT))
+
+/* ----------------------- Operations on smallbins ----------------------- */
+
+/* Link a free chunk into a smallbin  */
+#define insert_small_chunk(M, P, S) {\
+  bindex_t I = small_index(S);\
+  mchunkptr B = smallbin_at(M, I);\
+  mchunkptr F = B;\
+  if (!smallmap_is_marked(M, I))\
+    mark_smallmap(M, I);\
+  else\
+    F = B->fd;\
+  B->fd = P;\
+  F->bk = P;\
+  P->fd = F;\
+  P->bk = B;\
+}
+
+/* Unlink a chunk from a smallbin  */
+#define unlink_small_chunk(M, P, S) {\
+  mchunkptr F = P->fd;\
+  mchunkptr B = P->bk;\
+  bindex_t I = small_index(S);\
+  if (F == B) {\
+    clear_smallmap(M, I);\
+  } else {\
+    F->bk = B;\
+    B->fd = F;\
+  }\
+}
+
+/* Unlink the first chunk from a smallbin */
+#define unlink_first_small_chunk(M, B, P, I) {\
+  mchunkptr F = P->fd;\
+  if (B == F) {\
+    clear_smallmap(M, I);\
+  } else {\
+    B->fd = F;\
+    F->bk = B;\
+  }\
+}
+
+/* Replace dv node, binning the old one */
+/* Used only when dvsize known to be small */
+#define replace_dv(M, P, S) {\
+  size_t DVS = M->dvsize;\
+  if (DVS != 0) {\
+    mchunkptr DV = M->dv;\
+    insert_small_chunk(M, DV, DVS);\
+  }\
+  M->dvsize = S;\
+  M->dv = P;\
+}
+
+/* ------------------------- Operations on trees ------------------------- */
+
+/* Insert chunk into tree */
+#define insert_large_chunk(M, X, S) {\
+  tbinptr *H;\
+  bindex_t I;\
+  compute_tree_index(S, I);\
+  H = treebin_at(M, I);\
+  X->index = I;\
+  X->child[0] = X->child[1] = 0;\
+  if (!treemap_is_marked(M, I)) {\
+    mark_treemap(M, I);\
+    *H = X;\
+    X->parent = (tchunkptr)H;\
+    X->fd = X->bk = X;\
+  } else {\
+    tchunkptr T = *H;\
+    size_t K = S << leftshift_for_tree_index(I);\
+    for (;;) {\
+      if (chunksize(T) != S) {\
+        tchunkptr *C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\
+        K <<= 1;\
+        if (*C != 0) {\
+          T = *C;\
+        } else {\
+          *C = X;\
+          X->parent = T;\
+          X->fd = X->bk = X;\
+          break;\
+        }\
+      } else {\
+        tchunkptr F = T->fd;\
+        T->fd = F->bk = X;\
+        X->fd = F;\
+        X->bk = T;\
+        X->parent = 0;\
+        break;\
+      }\
+    }\
+  }\
+}
+
+#define unlink_large_chunk(M, X) {\
+  tchunkptr XP = X->parent;\
+  tchunkptr R;\
+  if (X->bk != X) {\
+    tchunkptr F = X->fd;\
+    R = X->bk;\
+    F->bk = R;\
+    R->fd = F;\
+  } else {\
+    tchunkptr *RP;\
+    if (((R = *(RP = &(X->child[1]))) != 0) ||\
+        ((R = *(RP = &(X->child[0]))) != 0)) {\
+      tchunkptr *CP;\
+      while ((*(CP = &(R->child[1])) != 0) ||\
+             (*(CP = &(R->child[0])) != 0)) {\
+        R = *(RP = CP);\
+      }\
+      *RP = 0;\
+    }\
+  }\
+  if (XP != 0) {\
+    tbinptr *H = treebin_at(M, X->index);\
+    if (X == *H) {\
+      if ((*H = R) == 0) \
+        clear_treemap(M, X->index);\
+    } else {\
+      if (XP->child[0] == X) \
+        XP->child[0] = R;\
+      else \
+        XP->child[1] = R;\
+    }\
+    if (R != 0) {\
+      tchunkptr C0, C1;\
+      R->parent = XP;\
+      if ((C0 = X->child[0]) != 0) {\
+        R->child[0] = C0;\
+        C0->parent = R;\
+      }\
+      if ((C1 = X->child[1]) != 0) {\
+        R->child[1] = C1;\
+        C1->parent = R;\
+      }\
+    }\
+  }\
+}
+
+/* Relays to large vs small bin operations */
+
+#define insert_chunk(M, P, S)\
+  if (is_small(S)) { insert_small_chunk(M, P, S)\
+  } else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); }
+
+#define unlink_chunk(M, P, S)\
+  if (is_small(S)) { unlink_small_chunk(M, P, S)\
+  } else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); }
+
+/* -----------------------  Direct-mmapping chunks ----------------------- */
+
+static void *direct_alloc(size_t nb)
+{
+  size_t mmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
+  if (LJ_LIKELY(mmsize > nb)) {     /* Check for wrap around 0 */
+    char *mm = (char *)(DIRECT_MMAP(mmsize));
+    if (mm != CMFAIL) {
+      size_t offset = align_offset(chunk2mem(mm));
+      size_t psize = mmsize - offset - DIRECT_FOOT_PAD;
+      mchunkptr p = (mchunkptr)(mm + offset);
+      p->prev_foot = offset | IS_DIRECT_BIT;
+      p->head = psize|CINUSE_BIT;
+      chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD;
+      chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0;
+      return chunk2mem(p);
+    }
+  }
+  return NULL;
+}
+
+static mchunkptr direct_resize(mchunkptr oldp, size_t nb)
+{
+  size_t oldsize = chunksize(oldp);
+  if (is_small(nb)) /* Can't shrink direct regions below small size */
+    return NULL;
+  /* Keep old chunk if big enough but not too big */
+  if (oldsize >= nb + SIZE_T_SIZE &&
+      (oldsize - nb) <= (DEFAULT_GRANULARITY << 1)) {
+    return oldp;
+  } else {
+    size_t offset = oldp->prev_foot & ~IS_DIRECT_BIT;
+    size_t oldmmsize = oldsize + offset + DIRECT_FOOT_PAD;
+    size_t newmmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
+    char *cp = (char *)CALL_MREMAP((char *)oldp - offset,
+                                   oldmmsize, newmmsize, 1);
+    if (cp != CMFAIL) {
+      mchunkptr newp = (mchunkptr)(cp + offset);
+      size_t psize = newmmsize - offset - DIRECT_FOOT_PAD;
+      newp->head = psize|CINUSE_BIT;
+      chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD;
+      chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0;
+      return newp;
+    }
+  }
+  return NULL;
+}
+
+/* -------------------------- mspace management -------------------------- */
+
+/* Initialize top chunk and its size */
+static void init_top(mstate m, mchunkptr p, size_t psize)
+{
+  /* Ensure alignment */
+  size_t offset = align_offset(chunk2mem(p));
+  p = (mchunkptr)((char *)p + offset);
+  psize -= offset;
+
+  m->top = p;
+  m->topsize = psize;
+  p->head = psize | PINUSE_BIT;
+  /* set size of fake trailing chunk holding overhead space only once */
+  chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE;
+  m->trim_check = DEFAULT_TRIM_THRESHOLD; /* reset on each update */
+}
+
+/* Initialize bins for a new mstate that is otherwise zeroed out */
+static void init_bins(mstate m)
+{
+  /* Establish circular links for smallbins */
+  bindex_t i;
+  for (i = 0; i < NSMALLBINS; i++) {
+    sbinptr bin = smallbin_at(m,i);
+    bin->fd = bin->bk = bin;
+  }
+}
+
+/* Allocate chunk and prepend remainder with chunk in successor base. */
+static void *prepend_alloc(mstate m, char *newbase, char *oldbase, size_t nb)
+{
+  mchunkptr p = align_as_chunk(newbase);
+  mchunkptr oldfirst = align_as_chunk(oldbase);
+  size_t psize = (size_t)((char *)oldfirst - (char *)p);
+  mchunkptr q = chunk_plus_offset(p, nb);
+  size_t qsize = psize - nb;
+  set_size_and_pinuse_of_inuse_chunk(m, p, nb);
+
+  /* consolidate remainder with first chunk of old base */
+  if (oldfirst == m->top) {
+    size_t tsize = m->topsize += qsize;
+    m->top = q;
+    q->head = tsize | PINUSE_BIT;
+  } else if (oldfirst == m->dv) {
+    size_t dsize = m->dvsize += qsize;
+    m->dv = q;
+    set_size_and_pinuse_of_free_chunk(q, dsize);
+  } else {
+    if (!cinuse(oldfirst)) {
+      size_t nsize = chunksize(oldfirst);
+      unlink_chunk(m, oldfirst, nsize);
+      oldfirst = chunk_plus_offset(oldfirst, nsize);
+      qsize += nsize;
+    }
+    set_free_with_pinuse(q, qsize, oldfirst);
+    insert_chunk(m, q, qsize);
+  }
+
+  return chunk2mem(p);
+}
+
+/* Add a segment to hold a new noncontiguous region */
+static void add_segment(mstate m, char *tbase, size_t tsize)
+{
+  /* Determine locations and sizes of segment, fenceposts, old top */
+  char *old_top = (char *)m->top;
+  msegmentptr oldsp = segment_holding(m, old_top);
+  char *old_end = oldsp->base + oldsp->size;
+  size_t ssize = pad_request(sizeof(struct malloc_segment));
+  char *rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
+  size_t offset = align_offset(chunk2mem(rawsp));
+  char *asp = rawsp + offset;
+  char *csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp;
+  mchunkptr sp = (mchunkptr)csp;
+  msegmentptr ss = (msegmentptr)(chunk2mem(sp));
+  mchunkptr tnext = chunk_plus_offset(sp, ssize);
+  mchunkptr p = tnext;
+
+  /* reset top to new space */
+  init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);
+
+  /* Set up segment record */
+  set_size_and_pinuse_of_inuse_chunk(m, sp, ssize);
+  *ss = m->seg; /* Push current record */
+  m->seg.base = tbase;
+  m->seg.size = tsize;
+  m->seg.next = ss;
+
+  /* Insert trailing fenceposts */
+  for (;;) {
+    mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE);
+    p->head = FENCEPOST_HEAD;
+    if ((char *)(&(nextp->head)) < old_end)
+      p = nextp;
+    else
+      break;
+  }
+
+  /* Insert the rest of old top into a bin as an ordinary free chunk */
+  if (csp != old_top) {
+    mchunkptr q = (mchunkptr)old_top;
+    size_t psize = (size_t)(csp - old_top);
+    mchunkptr tn = chunk_plus_offset(q, psize);
+    set_free_with_pinuse(q, psize, tn);
+    insert_chunk(m, q, psize);
+  }
+}
+
+/* -------------------------- System allocation -------------------------- */
+
+static void *alloc_sys(mstate m, size_t nb)
+{
+  char *tbase = CMFAIL;
+  size_t tsize = 0;
+
+  /* Directly map large chunks */
+  if (LJ_UNLIKELY(nb >= DEFAULT_MMAP_THRESHOLD)) {
+    void *mem = direct_alloc(nb);
+    if (mem != 0)
+      return mem;
+  }
+
+  {
+    size_t req = nb + TOP_FOOT_SIZE + SIZE_T_ONE;
+    size_t rsize = granularity_align(req);
+    if (LJ_LIKELY(rsize > nb)) { /* Fail if wraps around zero */
+      char *mp = (char *)(CALL_MMAP(rsize));
+      if (mp != CMFAIL) {
+        tbase = mp;
+        tsize = rsize;
+      }
+    }
+  }
+
+  if (tbase != CMFAIL) {
+    msegmentptr sp = &m->seg;
+    /* Try to merge with an existing segment */
+    while (sp != 0 && tbase != sp->base + sp->size)
+      sp = sp->next;
+    if (sp != 0 && segment_holds(sp, m->top)) { /* append */
+      sp->size += tsize;
+      init_top(m, m->top, m->topsize + tsize);
+    } else {
+      sp = &m->seg;
+      while (sp != 0 && sp->base != tbase + tsize)
+        sp = sp->next;
+      if (sp != 0) {
+        char *oldbase = sp->base;
+        sp->base = tbase;
+        sp->size += tsize;
+        return prepend_alloc(m, tbase, oldbase, nb);
+      } else {
+        add_segment(m, tbase, tsize);
+      }
+    }
+
+    if (nb < m->topsize) { /* Allocate from new or extended top space */
+      size_t rsize = m->topsize -= nb;
+      mchunkptr p = m->top;
+      mchunkptr r = m->top = chunk_plus_offset(p, nb);
+      r->head = rsize | PINUSE_BIT;
+      set_size_and_pinuse_of_inuse_chunk(m, p, nb);
+      return chunk2mem(p);
+    }
+  }
+
+  return NULL;
+}
+
+/* -----------------------  system deallocation -------------------------- */
+
+/* Unmap and unlink any mmapped segments that don't contain used chunks */
+static size_t release_unused_segments(mstate m)
+{
+  size_t released = 0;
+  size_t nsegs = 0;
+  msegmentptr pred = &m->seg;
+  msegmentptr sp = pred->next;
+  while (sp != 0) {
+    char *base = sp->base;
+    size_t size = sp->size;
+    msegmentptr next = sp->next;
+    nsegs++;
+    {
+      mchunkptr p = align_as_chunk(base);
+      size_t psize = chunksize(p);
+      /* Can unmap if first chunk holds entire segment and not pinned */
+      if (!cinuse(p) && (char *)p + psize >= base + size - TOP_FOOT_SIZE) {
+        tchunkptr tp = (tchunkptr)p;
+        if (p == m->dv) {
+          m->dv = 0;
+          m->dvsize = 0;
+        } else {
+          unlink_large_chunk(m, tp);
+        }
+        if (CALL_MUNMAP(base, size) == 0) {
+          released += size;
+          /* unlink obsoleted record */
+          sp = pred;
+          sp->next = next;
+        } else { /* back out if cannot unmap */
+          insert_large_chunk(m, tp, psize);
+        }
+      }
+    }
+    pred = sp;
+    sp = next;
+  }
+  /* Reset check counter */
+  m->release_checks = nsegs > MAX_RELEASE_CHECK_RATE ?
+                      nsegs : MAX_RELEASE_CHECK_RATE;
+  return released;
+}
+
+static int alloc_trim(mstate m, size_t pad)
+{
+  size_t released = 0;
+  if (pad < MAX_REQUEST && is_initialized(m)) {
+    pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */
+
+    if (m->topsize > pad) {
+      /* Shrink top space in granularity-size units, keeping at least one */
+      size_t unit = DEFAULT_GRANULARITY;
+      size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit -
+                      SIZE_T_ONE) * unit;
+      msegmentptr sp = segment_holding(m, (char *)m->top);
+
+      if (sp->size >= extra &&
+          !has_segment_link(m, sp)) { /* can't shrink if pinned */
+        size_t newsize = sp->size - extra;
+        /* Prefer mremap, fall back to munmap */
+        if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) ||
+            (CALL_MUNMAP(sp->base + newsize, extra) == 0)) {
+          released = extra;
+        }
+      }
+
+      if (released != 0) {
+        sp->size -= released;
+        init_top(m, m->top, m->topsize - released);
+      }
+    }
+
+    /* Unmap any unused mmapped segments */
+    released += release_unused_segments(m);
+
+    /* On failure, disable autotrim to avoid repeated failed future calls */
+    if (released == 0 && m->topsize > m->trim_check)
+      m->trim_check = MAX_SIZE_T;
+  }
+
+  return (released != 0)? 1 : 0;
+}
+
+/* ---------------------------- malloc support --------------------------- */
+
+/* allocate a large request from the best fitting chunk in a treebin */
+static void *tmalloc_large(mstate m, size_t nb)
+{
+  tchunkptr v = 0;
+  size_t rsize = ~nb+1; /* Unsigned negation */
+  tchunkptr t;
+  bindex_t idx;
+  compute_tree_index(nb, idx);
+
+  if ((t = *treebin_at(m, idx)) != 0) {
+    /* Traverse tree for this bin looking for node with size == nb */
+    size_t sizebits = nb << leftshift_for_tree_index(idx);
+    tchunkptr rst = 0;  /* The deepest untaken right subtree */
+    for (;;) {
+      tchunkptr rt;
+      size_t trem = chunksize(t) - nb;
+      if (trem < rsize) {
+        v = t;
+        if ((rsize = trem) == 0)
+          break;
+      }
+      rt = t->child[1];
+      t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1];
+      if (rt != 0 && rt != t)
+        rst = rt;
+      if (t == 0) {
+        t = rst; /* set t to least subtree holding sizes > nb */
+        break;
+      }
+      sizebits <<= 1;
+    }
+  }
+
+  if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */
+    binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap;
+    if (leftbits != 0)
+      t = *treebin_at(m, lj_ffs(leftbits));
+  }
+
+  while (t != 0) { /* find smallest of tree or subtree */
+    size_t trem = chunksize(t) - nb;
+    if (trem < rsize) {
+      rsize = trem;
+      v = t;
+    }
+    t = leftmost_child(t);
+  }
+
+  /*  If dv is a better fit, return NULL so malloc will use it */
+  if (v != 0 && rsize < (size_t)(m->dvsize - nb)) {
+    mchunkptr r = chunk_plus_offset(v, nb);
+    unlink_large_chunk(m, v);
+    if (rsize < MIN_CHUNK_SIZE) {
+      set_inuse_and_pinuse(m, v, (rsize + nb));
+    } else {
+      set_size_and_pinuse_of_inuse_chunk(m, v, nb);
+      set_size_and_pinuse_of_free_chunk(r, rsize);
+      insert_chunk(m, r, rsize);
+    }
+    return chunk2mem(v);
+  }
+  return NULL;
+}
+
+/* allocate a small request from the best fitting chunk in a treebin */
+static void *tmalloc_small(mstate m, size_t nb)
+{
+  tchunkptr t, v;
+  mchunkptr r;
+  size_t rsize;
+  bindex_t i = lj_ffs(m->treemap);
+
+  v = t = *treebin_at(m, i);
+  rsize = chunksize(t) - nb;
+
+  while ((t = leftmost_child(t)) != 0) {
+    size_t trem = chunksize(t) - nb;
+    if (trem < rsize) {
+      rsize = trem;
+      v = t;
+    }
+  }
+
+  r = chunk_plus_offset(v, nb);
+  unlink_large_chunk(m, v);
+  if (rsize < MIN_CHUNK_SIZE) {
+    set_inuse_and_pinuse(m, v, (rsize + nb));
+  } else {
+    set_size_and_pinuse_of_inuse_chunk(m, v, nb);
+    set_size_and_pinuse_of_free_chunk(r, rsize);
+    replace_dv(m, r, rsize);
+  }
+  return chunk2mem(v);
+}
+
+/* ----------------------------------------------------------------------- */
+
+void *lj_alloc_create(void)
+{
+  size_t tsize = DEFAULT_GRANULARITY;
+  char *tbase = (char *)(CALL_MMAP(tsize));
+  if (tbase != CMFAIL) {
+    size_t msize = pad_request(sizeof(struct malloc_state));
+    mchunkptr mn;
+    mchunkptr msp = align_as_chunk(tbase);
+    mstate m = (mstate)(chunk2mem(msp));
+    memset(m, 0, msize);
+    msp->head = (msize|PINUSE_BIT|CINUSE_BIT);
+    m->seg.base = tbase;
+    m->seg.size = tsize;
+    m->release_checks = MAX_RELEASE_CHECK_RATE;
+    init_bins(m);
+    mn = next_chunk(mem2chunk(m));
+    init_top(m, mn, (size_t)((tbase + tsize) - (char *)mn) - TOP_FOOT_SIZE);
+    return m;
+  }
+  return NULL;
+}
+
+void lj_alloc_destroy(void *msp)
+{
+  mstate ms = (mstate)msp;
+  msegmentptr sp = &ms->seg;
+  while (sp != 0) {
+    char *base = sp->base;
+    size_t size = sp->size;
+    sp = sp->next;
+    CALL_MUNMAP(base, size);
+  }
+}
+
+static LJ_NOINLINE void *lj_alloc_malloc(void *msp, size_t nsize)
+{
+  mstate ms = (mstate)msp;
+  void *mem;
+  size_t nb;
+  if (nsize <= MAX_SMALL_REQUEST) {
+    bindex_t idx;
+    binmap_t smallbits;
+    nb = (nsize < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(nsize);
+    idx = small_index(nb);
+    smallbits = ms->smallmap >> idx;
+
+    if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */
+      mchunkptr b, p;
+      idx += ~smallbits & 1;       /* Uses next bin if idx empty */
+      b = smallbin_at(ms, idx);
+      p = b->fd;
+      unlink_first_small_chunk(ms, b, p, idx);
+      set_inuse_and_pinuse(ms, p, small_index2size(idx));
+      mem = chunk2mem(p);
+      return mem;
+    } else if (nb > ms->dvsize) {
+      if (smallbits != 0) { /* Use chunk in next nonempty smallbin */
+        mchunkptr b, p, r;
+        size_t rsize;
+        binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx));
+        bindex_t i = lj_ffs(leftbits);
+        b = smallbin_at(ms, i);
+        p = b->fd;
+        unlink_first_small_chunk(ms, b, p, i);
+        rsize = small_index2size(i) - nb;
+        /* Fit here cannot be remainderless if 4byte sizes */
+        if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) {
+          set_inuse_and_pinuse(ms, p, small_index2size(i));
+        } else {
+          set_size_and_pinuse_of_inuse_chunk(ms, p, nb);
+          r = chunk_plus_offset(p, nb);
+          set_size_and_pinuse_of_free_chunk(r, rsize);
+          replace_dv(ms, r, rsize);
+        }
+        mem = chunk2mem(p);
+        return mem;
+      } else if (ms->treemap != 0 && (mem = tmalloc_small(ms, nb)) != 0) {
+        return mem;
+      }
+    }
+  } else if (nsize >= MAX_REQUEST) {
+    nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */
+  } else {
+    nb = pad_request(nsize);
+    if (ms->treemap != 0 && (mem = tmalloc_large(ms, nb)) != 0) {
+      return mem;
+    }
+  }
+
+  if (nb <= ms->dvsize) {
+    size_t rsize = ms->dvsize - nb;
+    mchunkptr p = ms->dv;
+    if (rsize >= MIN_CHUNK_SIZE) { /* split dv */
+      mchunkptr r = ms->dv = chunk_plus_offset(p, nb);
+      ms->dvsize = rsize;
+      set_size_and_pinuse_of_free_chunk(r, rsize);
+      set_size_and_pinuse_of_inuse_chunk(ms, p, nb);
+    } else { /* exhaust dv */
+      size_t dvs = ms->dvsize;
+      ms->dvsize = 0;
+      ms->dv = 0;
+      set_inuse_and_pinuse(ms, p, dvs);
+    }
+    mem = chunk2mem(p);
+    return mem;
+  } else if (nb < ms->topsize) { /* Split top */
+    size_t rsize = ms->topsize -= nb;
+    mchunkptr p = ms->top;
+    mchunkptr r = ms->top = chunk_plus_offset(p, nb);
+    r->head = rsize | PINUSE_BIT;
+    set_size_and_pinuse_of_inuse_chunk(ms, p, nb);
+    mem = chunk2mem(p);
+    return mem;
+  }
+  return alloc_sys(ms, nb);
+}
+
+static LJ_NOINLINE void *lj_alloc_free(void *msp, void *ptr)
+{
+  if (ptr != 0) {
+    mchunkptr p = mem2chunk(ptr);
+    mstate fm = (mstate)msp;
+    size_t psize = chunksize(p);
+    mchunkptr next = chunk_plus_offset(p, psize);
+    if (!pinuse(p)) {
+      size_t prevsize = p->prev_foot;
+      if ((prevsize & IS_DIRECT_BIT) != 0) {
+        prevsize &= ~IS_DIRECT_BIT;
+        psize += prevsize + DIRECT_FOOT_PAD;
+        CALL_MUNMAP((char *)p - prevsize, psize);
+        return NULL;
+      } else {
+        mchunkptr prev = chunk_minus_offset(p, prevsize);
+        psize += prevsize;
+        p = prev;
+        /* consolidate backward */
+        if (p != fm->dv) {
+          unlink_chunk(fm, p, prevsize);
+        } else if ((next->head & INUSE_BITS) == INUSE_BITS) {
+          fm->dvsize = psize;
+          set_free_with_pinuse(p, psize, next);
+          return NULL;
+        }
+      }
+    }
+    if (!cinuse(next)) {  /* consolidate forward */
+      if (next == fm->top) {
+        size_t tsize = fm->topsize += psize;
+        fm->top = p;
+        p->head = tsize | PINUSE_BIT;
+        if (p == fm->dv) {
+          fm->dv = 0;
+          fm->dvsize = 0;
+        }
+        if (tsize > fm->trim_check)
+          alloc_trim(fm, 0);
+        return NULL;
+      } else if (next == fm->dv) {
+        size_t dsize = fm->dvsize += psize;
+        fm->dv = p;
+        set_size_and_pinuse_of_free_chunk(p, dsize);
+        return NULL;
+      } else {
+        size_t nsize = chunksize(next);
+        psize += nsize;
+        unlink_chunk(fm, next, nsize);
+        set_size_and_pinuse_of_free_chunk(p, psize);
+        if (p == fm->dv) {
+          fm->dvsize = psize;
+          return NULL;
+        }
+      }
+    } else {
+      set_free_with_pinuse(p, psize, next);
+    }
+
+    if (is_small(psize)) {
+      insert_small_chunk(fm, p, psize);
+    } else {
+      tchunkptr tp = (tchunkptr)p;
+      insert_large_chunk(fm, tp, psize);
+      if (--fm->release_checks == 0)
+        release_unused_segments(fm);
+    }
+  }
+  return NULL;
+}
+
+static LJ_NOINLINE void *lj_alloc_realloc(void *msp, void *ptr, size_t nsize)
+{
+  if (nsize >= MAX_REQUEST) {
+    return NULL;
+  } else {
+    mstate m = (mstate)msp;
+    mchunkptr oldp = mem2chunk(ptr);
+    size_t oldsize = chunksize(oldp);
+    mchunkptr next = chunk_plus_offset(oldp, oldsize);
+    mchunkptr newp = 0;
+    size_t nb = request2size(nsize);
+
+    /* Try to either shrink or extend into top. Else malloc-copy-free */
+    if (is_direct(oldp)) {
+      newp = direct_resize(oldp, nb);  /* this may return NULL. */
+    } else if (oldsize >= nb) { /* already big enough */
+      size_t rsize = oldsize - nb;
+      newp = oldp;
+      if (rsize >= MIN_CHUNK_SIZE) {
+        mchunkptr remainder = chunk_plus_offset(newp, nb);
+        set_inuse(m, newp, nb);
+        set_inuse(m, remainder, rsize);
+        lj_alloc_free(m, chunk2mem(remainder));
+      }
+    } else if (next == m->top && oldsize + m->topsize > nb) {
+      /* Expand into top */
+      size_t newsize = oldsize + m->topsize;
+      size_t newtopsize = newsize - nb;
+      mchunkptr newtop = chunk_plus_offset(oldp, nb);
+      set_inuse(m, oldp, nb);
+      newtop->head = newtopsize |PINUSE_BIT;
+      m->top = newtop;
+      m->topsize = newtopsize;
+      newp = oldp;
+    }
+
+    if (newp != 0) {
+      return chunk2mem(newp);
+    } else {
+      void *newmem = lj_alloc_malloc(m, nsize);
+      if (newmem != 0) {
+        size_t oc = oldsize - overhead_for(oldp);
+        memcpy(newmem, ptr, oc < nsize ? oc : nsize);
+        lj_alloc_free(m, ptr);
+      }
+      return newmem;
+    }
+  }
+}
+
+void *lj_alloc_f(void *msp, void *ptr, size_t osize, size_t nsize)
+{
+  (void)osize;
+  if (nsize == 0) {
+    return lj_alloc_free(msp, ptr);
+  } else if (ptr == NULL) {
+    return lj_alloc_malloc(msp, nsize);
+  } else {
+    return lj_alloc_realloc(msp, ptr, nsize);
+  }
+}
+
+#endif