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/* A replacement malloc with:
   - Much reduced code size;
   - Smaller RAM footprint;
   - The ability to handle downward-growing heaps;
   but
   - Slower;
   - Probably higher memory fragmentation;
   - Doesn't support threads (but, if it did support threads,
     it wouldn't need a global lock, only a compare-and-swap instruction);
   - Assumes the maximum alignment required is the alignment of a pointer;
   - Assumes that memory is already there and doesn't need to be allocated.
 
* Synopsis of public routines
 
  malloc(size_t n);
     Return a pointer to a newly allocated chunk of at least n bytes, or null
     if no space is available.
  free(void* p);
     Release the chunk of memory pointed to by p, or no effect if p is null.
  realloc(void* p, size_t n);
     Return a pointer to a chunk of size n that contains the same data
     as does chunk p up to the minimum of (n, p's size) bytes, or null
     if no space is available. The returned pointer may or may not be
     the same as p. If p is null, equivalent to malloc.  Unless the
     #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
     size argument of zero (re)allocates a minimum-sized chunk.
  memalign(size_t alignment, size_t n);
     Return a pointer to a newly allocated chunk of n bytes, aligned
     in accord with the alignment argument, which must be a power of
     two.  Will fail if 'alignment' is too large.
  calloc(size_t unit, size_t quantity);
     Returns a pointer to quantity * unit bytes, with all locations
     set to zero.
  cfree(void* p);
     Equivalent to free(p).
  malloc_trim(size_t pad);
     Release all but pad bytes of freed top-most memory back
     to the system. Return 1 if successful, else 0.
  malloc_usable_size(void* p);
     Report the number usable allocated bytes associated with allocated
     chunk p. This may or may not report more bytes than were requested,
     due to alignment and minimum size constraints.
  malloc_stats();
     Prints brief summary statistics on stderr.
  mallinfo()
     Returns (by copy) a struct containing various summary statistics.
  mallopt(int parameter_number, int parameter_value)
     Changes one of the tunable parameters described below. Returns
     1 if successful in changing the parameter, else 0.  Actually, returns 0
     always, as no parameter can be changed.
*/
 
#ifdef __xstormy16__
#define MALLOC_DIRECTION -1
#endif
 
#ifndef MALLOC_DIRECTION
#define MALLOC_DIRECTION 1
#endif
 
#include <stddef.h>
 
void* malloc(size_t);
void    free(void*);
void* realloc(void*, size_t);
void* memalign(size_t, size_t);
void* valloc(size_t);
void* pvalloc(size_t);
void* calloc(size_t, size_t);
void    cfree(void*);
int     malloc_trim(size_t);
size_t  malloc_usable_size(void*);
void    malloc_stats(void);
int     mallopt(int, int);
struct mallinfo mallinfo(void);
 
typedef struct freelist_entry {
  size_t size;
  struct freelist_entry *next;
} *fle;
 
extern void * __malloc_end;
extern fle __malloc_freelist;
 
/* Return the number of bytes that need to be added to X to make it
   aligned to an ALIGN boundary.  ALIGN must be a power of 2.  */
#define M_ALIGN(x, align) (-(size_t)(x) & ((align) - 1))
 
/* Return the number of bytes that need to be subtracted from X to make it
   aligned to an ALIGN boundary.  ALIGN must be a power of 2.  */
#define M_ALIGN_SUB(x, align) ((size_t)(x) & ((align) - 1))
 
extern void __malloc_start;
 
/* This is the minimum gap allowed between __malloc_end and the top of
   the stack.  This is only checked for when __malloc_end is
   decreased; if instead the stack grows into the heap, silent data
   corruption will result.  */
#define MALLOC_MINIMUM_GAP 32
 
#ifdef __xstormy16__
register void * stack_pointer asm ("r15");
#define MALLOC_LIMIT stack_pointer
#else
#define MALLOC_LIMIT __builtin_frame_address (0)
#endif
 
#if MALLOC_DIRECTION < 0
#define CAN_ALLOC_P(required)                           \
  (((size_t) __malloc_end - (size_t)MALLOC_LIMIT        \
    - MALLOC_MINIMUM_GAP) >= (required))
#else
#define CAN_ALLOC_P(required)                           \
  (((size_t)MALLOC_LIMIT - (size_t) __malloc_end        \
    - MALLOC_MINIMUM_GAP) >= (required))
#endif
 
/* real_size is the size we actually have to allocate, allowing for
   overhead and alignment.  */
#define REAL_SIZE(sz)                                           \
  ((sz) < sizeof (struct freelist_entry) - sizeof (size_t)      \
   ? sizeof (struct freelist_entry)                             \
   : sz + sizeof (size_t) + M_ALIGN(sz, sizeof (size_t)))
 
#ifdef DEFINE_MALLOC
 
void * __malloc_end = &__malloc_start;
fle __malloc_freelist;
 
void *
malloc (size_t sz)
{
  fle *nextfree;
  fle block;
 
  /* real_size is the size we actually have to allocate, allowing for
     overhead and alignment.  */
  size_t real_size = REAL_SIZE (sz);
 
  /* Look for the first block on the freelist that is large enough.  */
  for (nextfree = &__malloc_freelist;
       *nextfree;
       nextfree = &(*nextfree)->next)
    {
      block = *nextfree;
 
      if (block->size >= real_size)
        {
          /* If the block found is just the right size, remove it from
             the free list.  Otherwise, split it.  */
          if (block->size < real_size + sizeof (struct freelist_entry))
            {
              *nextfree = block->next;
              return (void *)&block->next;
            }
          else
            {
              size_t newsize = block->size - real_size;
              fle newnext = block->next;
              *nextfree = (fle)((size_t)block + real_size);
              (*nextfree)->size = newsize;
              (*nextfree)->next = newnext;
              goto done;
            }
        }
 
      /* If this is the last block on the freelist, and it was too small,
         enlarge it.  */
      if (! block->next
          && __malloc_end == (void *)((size_t)block + block->size))
        {
          size_t moresize = real_size - block->size;
          if (! CAN_ALLOC_P (moresize))
            return NULL;
 
          *nextfree = NULL;
          if (MALLOC_DIRECTION < 0)
            {
              block = __malloc_end = (void *)((size_t)block - moresize);
            }
          else
            {
              __malloc_end = (void *)((size_t)block + real_size);
            }
 
          goto done;
        }
    }
 
  /* No free space at the end of the free list.  Allocate new space
     and use that.  */
 
  if (! CAN_ALLOC_P (real_size))
    return NULL;
 
  if (MALLOC_DIRECTION > 0)
    {
      block = __malloc_end;
      __malloc_end = (void *)((size_t)__malloc_end + real_size);
    }
  else
    {
      block = __malloc_end = (void *)((size_t)__malloc_end - real_size);
    }
 done:
  block->size = real_size;
  return (void *)&block->next;
}
 
#endif
 
#ifdef DEFINE_FREE
 
void
free (void *block_p)
{
  fle *nextfree;
  fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));
 
  if (block_p == NULL)
    return;
 
  /* Look on the freelist to see if there's a free block just before
     or just after this block.  */
  for (nextfree = &__malloc_freelist;
       *nextfree;
       nextfree = &(*nextfree)->next)
    {
      fle thisblock = *nextfree;
      if ((size_t)thisblock + thisblock->size == (size_t) block)
        {
          thisblock->size += block->size;
          if (MALLOC_DIRECTION > 0
              && thisblock->next
              && (size_t) block + block->size == (size_t) thisblock->next)
            {
              thisblock->size += thisblock->next->size;
              thisblock->next = thisblock->next->next;
            }
          return;
        }
      else if ((size_t) thisblock == (size_t) block + block->size)
        {
          if (MALLOC_DIRECTION < 0
              && thisblock->next
              && (size_t) block == ((size_t) thisblock->next
                                    + thisblock->next->size))
            {
              *nextfree = thisblock->next;
              thisblock->next->size += block->size + thisblock->size;
            }
          else
            {
              block->size += thisblock->size;
              block->next = thisblock->next;
              *nextfree = block;
            }
          return;
        }
      else if ((MALLOC_DIRECTION > 0
                && (size_t) thisblock > (size_t) block)
               || (MALLOC_DIRECTION < 0
                   && (size_t) thisblock < (size_t) block))
        break;
    }
 
  block->next = *nextfree;
  *nextfree = block;
  return;
}
#endif
 
#ifdef DEFINE_REALLOC
void *
realloc (void *block_p, size_t sz)
{
  fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));
  size_t real_size = REAL_SIZE (sz);
  size_t old_real_size;
 
  if (block_p == NULL)
    return malloc (sz);
 
  old_real_size = block->size;
 
  /* Perhaps we need to allocate more space.  */
  if (old_real_size < real_size)
    {
      void *result;
      size_t old_size = old_real_size - sizeof (size_t);
 
      /* Need to allocate, copy, and free.  */
      result = malloc (sz);
      if (result == NULL)
        return NULL;
      memcpy (result, block_p, old_size < sz ? old_size : sz);
      free (block_p);
      return result;
    }
  /* Perhaps we can free some space.  */
  if (old_real_size - real_size >= sizeof (struct freelist_entry))
    {
      fle newblock = (fle)((size_t)block + real_size);
      block->size = real_size;
      newblock->size = old_real_size - real_size;
      free (&newblock->next);
    }
  return block_p;
}
#endif
 
#ifdef DEFINE_CALLOC
void *
calloc (size_t n, size_t elem_size)
{
  void *result;
  size_t sz = n * elem_size;
  result = malloc (sz);
  if (result != NULL)
    memset (result, 0, sz);
  return result;
}
#endif
 
#ifdef DEFINE_CFREE
void
cfree (void *p)
{
  free (p);
}
#endif
 
#ifdef DEFINE_MEMALIGN
void *
memalign (size_t align, size_t sz)
{
  fle *nextfree;
  fle block;
 
  /* real_size is the size we actually have to allocate, allowing for
     overhead and alignment.  */
  size_t real_size = REAL_SIZE (sz);
 
  /* Some sanity checking on 'align'. */
  if ((align & (align - 1)) != 0
      || align <= 0)
    return NULL;
 
  /* Look for the first block on the freelist that is large enough.  */
  /* One tricky part is this: We want the result to be a valid pointer
     to free.  That means that there has to be room for a size_t
     before the block.  If there's additional space before the block,
     it should go on the freelist, or it'll be lost---we could add it
     to the size of the block before it in memory, but finding the
     previous block is expensive.  */
  for (nextfree = &__malloc_freelist;
       ;
       nextfree = &(*nextfree)->next)
    {
      size_t before_size;
      size_t old_size;
 
      /* If we've run out of free blocks, allocate more space.  */
      if (! *nextfree)
        {
          old_size = real_size;
          if (MALLOC_DIRECTION < 0)
            {
              old_size += M_ALIGN_SUB (((size_t)__malloc_end
                                        - old_size + sizeof (size_t)),
                                       align);
              if (! CAN_ALLOC_P (old_size))
                return NULL;
              block = __malloc_end = (void *)((size_t)__malloc_end - old_size);
            }
          else
            {
              block = __malloc_end;
              old_size += M_ALIGN ((size_t)__malloc_end + sizeof (size_t),
                                   align);
              if (! CAN_ALLOC_P (old_size))
                return NULL;
              __malloc_end = (void *)((size_t)__malloc_end + old_size);
            }
          *nextfree = block;
          block->size = old_size;
          block->next = NULL;
        }
      else
        {
          block = *nextfree;
          old_size = block->size;
        }
 
 
      before_size = M_ALIGN (&block->next, align);
      if (before_size != 0)
        before_size = sizeof (*block) + M_ALIGN (&(block+1)->next, align);
 
      /* If this is the last block on the freelist, and it is too small,
         enlarge it.  */
      if (! block->next
          && old_size < real_size + before_size
          && __malloc_end == (void *)((size_t)block + block->size))
        {
          if (MALLOC_DIRECTION < 0)
            {
              size_t moresize = real_size - block->size;
              moresize += M_ALIGN_SUB ((size_t)&block->next - moresize, align);
              if (! CAN_ALLOC_P (moresize))
                return NULL;
              block = __malloc_end = (void *)((size_t)block - moresize);
              block->next = NULL;
              block->size = old_size = old_size + moresize;
              before_size = 0;
            }
          else
            {
              if (! CAN_ALLOC_P (before_size + real_size - block->size))
                return NULL;
              __malloc_end = (void *)((size_t)block + before_size + real_size);
              block->size = old_size = before_size + real_size;
            }
 
          /* Two out of the four cases below will now be possible; which
             two depends on MALLOC_DIRECTION.  */
        }
 
      if (old_size >= real_size + before_size)
        {
          /* This block will do.  If there needs to be space before it,
             split the block.  */
          if (before_size != 0)
            {
              fle old_block = block;
 
              old_block->size = before_size;
              block = (fle)((size_t)block + before_size);
 
              /* If there's no space after the block, we're now nearly
                 done; just make a note of the size required.
                 Otherwise, we need to create a new free space block.  */
              if (old_size - before_size
                  <= real_size + sizeof (struct freelist_entry))
                {
                  block->size = old_size - before_size;
                  return (void *)&block->next;
                }
              else
                {
                  fle new_block;
                  new_block = (fle)((size_t)block + real_size);
                  new_block->size = old_size - before_size - real_size;
                  if (MALLOC_DIRECTION > 0)
                    {
                      new_block->next = old_block->next;
                      old_block->next = new_block;
                    }
                  else
                    {
                      new_block->next = old_block;
                      *nextfree = new_block;
                    }
                  goto done;
                }
            }
          else
            {
              /* If the block found is just the right size, remove it from
                 the free list.  Otherwise, split it.  */
              if (old_size <= real_size + sizeof (struct freelist_entry))
                {
                  *nextfree = block->next;
                  return (void *)&block->next;
                }
              else
                {
                  size_t newsize = old_size - real_size;
                  fle newnext = block->next;
                  *nextfree = (fle)((size_t)block + real_size);
                  (*nextfree)->size = newsize;
                  (*nextfree)->next = newnext;
                  goto done;
                }
            }
        }
    }
 
 done:
  block->size = real_size;
  return (void *)&block->next;
}
#endif
 
#ifdef DEFINE_VALLOC
void *
valloc (size_t sz)
{
  return memalign (128, sz);
}
#endif
#ifdef DEFINE_PVALLOC
void *
pvalloc (size_t sz)
{
  return memalign (128, sz + M_ALIGN (sz, 128));
}
#endif
 
#ifdef DEFINE_MALLINFO
#include "malloc.h"
 
struct mallinfo
mallinfo (void)
{
  struct mallinfo r;
  fle fr;
  size_t free_size;
  size_t total_size;
  size_t free_blocks;
 
  memset (&r, 0, sizeof (r));
 
  free_size = 0;
  free_blocks = 0;
  for (fr = __malloc_freelist; fr; fr = fr->next)
    {
      free_size += fr->size;
      free_blocks++;
      if (! fr->next)
        {
          int atend;
          if (MALLOC_DIRECTION > 0)
            atend = (void *)((size_t)fr + fr->size) == __malloc_end;
          else
            atend = (void *)fr == __malloc_end;
          if (atend)
            r.keepcost = fr->size;
        }
    }
 
  if (MALLOC_DIRECTION > 0)
    total_size = (char *)__malloc_end - (char *)&__malloc_start;
  else
    total_size = (char *)&__malloc_start - (char *)__malloc_end;
 
#ifdef DEBUG
  /* Fixme: should walk through all the in-use blocks and see if
     they're valid.  */
#endif
 
  r.arena = total_size;
  r.fordblks = free_size;
  r.uordblks = total_size - free_size;
  r.ordblks = free_blocks;
  return r;
}
#endif
 
#ifdef DEFINE_MALLOC_STATS
#include "malloc.h"
#include <stdio.h>
 
void
malloc_stats(void)
{
  struct mallinfo i;
  FILE *fp;
 
  fp = stderr;
  i = mallinfo();
  fprintf (fp, "malloc has reserved %u bytes between %p and %p\n",
           i.arena, &__malloc_start, __malloc_end);
  fprintf (fp, "there are %u bytes free in %u chunks\n",
           i.fordblks, i.ordblks);
  fprintf (fp, "of which %u bytes are at the end of the reserved space\n",
           i.keepcost);
  fprintf (fp, "and %u bytes are in use.\n", i.uordblks);
}
#endif
 
#ifdef DEFINE_MALLOC_USABLE_SIZE
size_t
malloc_usable_size (void *block_p)
{
  fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));
  return block->size - sizeof (size_t);
}
#endif
 
#ifdef DEFINE_MALLOPT
int
mallopt (int n, int v)
{
  (void)n; (void)v;
  return 0;
}
#endif

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[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [xstormy16/] [tiny-malloc.c] - Blame information for rev 853

Line No.	Rev	Author	Line
1	148	jeremybenn	`/* A replacement malloc with:`
2			`- Much reduced code size;`
3			`- Smaller RAM footprint;`
4			`- The ability to handle downward-growing heaps;`
5			`but`
6			`- Slower;`
7			`- Probably higher memory fragmentation;`
8			`- Doesn't support threads (but, if it did support threads,`
9			`it wouldn't need a global lock, only a compare-and-swap instruction);`
10			`- Assumes the maximum alignment required is the alignment of a pointer;`
11			`- Assumes that memory is already there and doesn't need to be allocated.`
12
13			`* Synopsis of public routines`
14
15			`malloc(size_t n);`
16			`Return a pointer to a newly allocated chunk of at least n bytes, or null`
17			`if no space is available.`
18			`free(void* p);`
19			`Release the chunk of memory pointed to by p, or no effect if p is null.`
20			`realloc(void* p, size_t n);`
21			`Return a pointer to a chunk of size n that contains the same data`
22			`as does chunk p up to the minimum of (n, p's size) bytes, or null`
23			`if no space is available. The returned pointer may or may not be`
24			`the same as p. If p is null, equivalent to malloc. Unless the`
25			`#define REALLOC_ZERO_BYTES_FREES below is set, realloc with a`
26			`size argument of zero (re)allocates a minimum-sized chunk.`
27			`memalign(size_t alignment, size_t n);`
28			`Return a pointer to a newly allocated chunk of n bytes, aligned`
29			`in accord with the alignment argument, which must be a power of`
30			`two. Will fail if 'alignment' is too large.`
31			`calloc(size_t unit, size_t quantity);`
32			`Returns a pointer to quantity * unit bytes, with all locations`
33			`set to zero.`
34			`cfree(void* p);`
35			`Equivalent to free(p).`
36			`malloc_trim(size_t pad);`
37			`Release all but pad bytes of freed top-most memory back`
38			`to the system. Return 1 if successful, else 0.`
39			`malloc_usable_size(void* p);`
40			`Report the number usable allocated bytes associated with allocated`
41			`chunk p. This may or may not report more bytes than were requested,`
42			`due to alignment and minimum size constraints.`
43			`malloc_stats();`
44			`Prints brief summary statistics on stderr.`
45			`mallinfo()`
46			`Returns (by copy) a struct containing various summary statistics.`
47			`mallopt(int parameter_number, int parameter_value)`
48			`Changes one of the tunable parameters described below. Returns`
49			`1 if successful in changing the parameter, else 0. Actually, returns 0`
50			`always, as no parameter can be changed.`
51			`*/`
52
53			`#ifdef __xstormy16__`
54			`#define MALLOC_DIRECTION -1`
55			`#endif`
56
57			`#ifndef MALLOC_DIRECTION`
58			`#define MALLOC_DIRECTION 1`
59			`#endif`
60
61			`#include <stddef.h>`
62
63			`void* malloc(size_t);`
64			`void free(void*);`
65			`void* realloc(void*, size_t);`
66			`void* memalign(size_t, size_t);`
67			`void* valloc(size_t);`
68			`void* pvalloc(size_t);`
69			`void* calloc(size_t, size_t);`
70			`void cfree(void*);`
71			`int malloc_trim(size_t);`
72			`size_t malloc_usable_size(void*);`
73			`void malloc_stats(void);`
74			`int mallopt(int, int);`
75			`struct mallinfo mallinfo(void);`
76
77			`typedef struct freelist_entry {`
78			`size_t size;`
79			`struct freelist_entry *next;`
80			`} *fle;`
81
82			`extern void * __malloc_end;`
83			`extern fle __malloc_freelist;`
84
85			`/* Return the number of bytes that need to be added to X to make it`
86			`aligned to an ALIGN boundary. ALIGN must be a power of 2. */`
87			`#define M_ALIGN(x, align) (-(size_t)(x) & ((align) - 1))`
88
89			`/* Return the number of bytes that need to be subtracted from X to make it`
90			`aligned to an ALIGN boundary. ALIGN must be a power of 2. */`
91			`#define M_ALIGN_SUB(x, align) ((size_t)(x) & ((align) - 1))`
92
93			`extern void __malloc_start;`
94
95			`/* This is the minimum gap allowed between __malloc_end and the top of`
96			`the stack. This is only checked for when __malloc_end is`
97			`decreased; if instead the stack grows into the heap, silent data`
98			`corruption will result. */`
99			`#define MALLOC_MINIMUM_GAP 32`
100
101			`#ifdef __xstormy16__`
102			`register void * stack_pointer asm ("r15");`
103			`#define MALLOC_LIMIT stack_pointer`
104			`#else`
105			`#define MALLOC_LIMIT __builtin_frame_address (0)`
106			`#endif`
107
108			`#if MALLOC_DIRECTION < 0`
109			`#define CAN_ALLOC_P(required) \`
110			`(((size_t) __malloc_end - (size_t)MALLOC_LIMIT \`
111			`- MALLOC_MINIMUM_GAP) >= (required))`
112			`#else`
113			`#define CAN_ALLOC_P(required) \`
114			`(((size_t)MALLOC_LIMIT - (size_t) __malloc_end \`
115			`- MALLOC_MINIMUM_GAP) >= (required))`
116			`#endif`
117
118			`/* real_size is the size we actually have to allocate, allowing for`
119			`overhead and alignment. */`
120			`#define REAL_SIZE(sz) \`
121			`((sz) < sizeof (struct freelist_entry) - sizeof (size_t) \`
122			`? sizeof (struct freelist_entry) \`
123			`: sz + sizeof (size_t) + M_ALIGN(sz, sizeof (size_t)))`
124
125			`#ifdef DEFINE_MALLOC`
126
127			`void * __malloc_end = &__malloc_start;`
128			`fle __malloc_freelist;`
129
130			`void *`
131			`malloc (size_t sz)`
132			`{`
133			`fle *nextfree;`
134			`fle block;`
135
136			`/* real_size is the size we actually have to allocate, allowing for`
137			`overhead and alignment. */`
138			`size_t real_size = REAL_SIZE (sz);`
139
140			`/* Look for the first block on the freelist that is large enough. */`
141			`for (nextfree = &__malloc_freelist;`
142			`*nextfree;`
143			`nextfree = &(*nextfree)->next)`
144			`{`
145			`block = *nextfree;`
146
147			`if (block->size >= real_size)`
148			`{`
149			`/* If the block found is just the right size, remove it from`
150			`the free list. Otherwise, split it. */`
151			`if (block->size < real_size + sizeof (struct freelist_entry))`
152			`{`
153			`*nextfree = block->next;`
154			`return (void *)&block->next;`
155			`}`
156			`else`
157			`{`
158			`size_t newsize = block->size - real_size;`
159			`fle newnext = block->next;`
160			`*nextfree = (fle)((size_t)block + real_size);`
161			`(*nextfree)->size = newsize;`
162			`(*nextfree)->next = newnext;`
163			`goto done;`
164			`}`
165			`}`
166
167			`/* If this is the last block on the freelist, and it was too small,`
168			`enlarge it. */`
169			`if (! block->next`
170			`&& __malloc_end == (void *)((size_t)block + block->size))`
171			`{`
172			`size_t moresize = real_size - block->size;`
173			`if (! CAN_ALLOC_P (moresize))`
174			`return NULL;`
175
176			`*nextfree = NULL;`
177			`if (MALLOC_DIRECTION < 0)`
178			`{`
179			`block = __malloc_end = (void *)((size_t)block - moresize);`
180			`}`
181			`else`
182			`{`
183			`__malloc_end = (void *)((size_t)block + real_size);`
184			`}`
185
186			`goto done;`
187			`}`
188			`}`
189
190			`/* No free space at the end of the free list. Allocate new space`
191			`and use that. */`
192
193			`if (! CAN_ALLOC_P (real_size))`
194			`return NULL;`
195
196			`if (MALLOC_DIRECTION > 0)`
197			`{`
198			`block = __malloc_end;`
199			`__malloc_end = (void *)((size_t)__malloc_end + real_size);`
200			`}`
201			`else`
202			`{`
203			`block = __malloc_end = (void *)((size_t)__malloc_end - real_size);`
204			`}`
205			`done:`
206			`block->size = real_size;`
207			`return (void *)&block->next;`
208			`}`
209
210			`#endif`
211
212			`#ifdef DEFINE_FREE`
213
214			`void`
215			`free (void *block_p)`
216			`{`
217			`fle *nextfree;`
218			`fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));`
219
220			`if (block_p == NULL)`
221			`return;`
222
223			`/* Look on the freelist to see if there's a free block just before`
224			`or just after this block. */`
225			`for (nextfree = &__malloc_freelist;`
226			`*nextfree;`
227			`nextfree = &(*nextfree)->next)`
228			`{`
229			`fle thisblock = *nextfree;`
230			`if ((size_t)thisblock + thisblock->size == (size_t) block)`
231			`{`
232			`thisblock->size += block->size;`
233			`if (MALLOC_DIRECTION > 0`
234			`&& thisblock->next`
235			`&& (size_t) block + block->size == (size_t) thisblock->next)`
236			`{`
237			`thisblock->size += thisblock->next->size;`
238			`thisblock->next = thisblock->next->next;`
239			`}`
240			`return;`
241			`}`
242			`else if ((size_t) thisblock == (size_t) block + block->size)`
243			`{`
244			`if (MALLOC_DIRECTION < 0`
245			`&& thisblock->next`
246			`&& (size_t) block == ((size_t) thisblock->next`
247			`+ thisblock->next->size))`
248			`{`
249			`*nextfree = thisblock->next;`
250			`thisblock->next->size += block->size + thisblock->size;`
251			`}`
252			`else`
253			`{`
254			`block->size += thisblock->size;`
255			`block->next = thisblock->next;`
256			`*nextfree = block;`
257			`}`
258			`return;`
259			`}`
260			`else if ((MALLOC_DIRECTION > 0`
261			`&& (size_t) thisblock > (size_t) block)`
262			`\|\| (MALLOC_DIRECTION < 0`
263			`&& (size_t) thisblock < (size_t) block))`
264			`break;`
265			`}`
266
267			`block->next = *nextfree;`
268			`*nextfree = block;`
269			`return;`
270			`}`
271			`#endif`
272
273			`#ifdef DEFINE_REALLOC`
274			`void *`
275			`realloc (void *block_p, size_t sz)`
276			`{`
277			`fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));`
278			`size_t real_size = REAL_SIZE (sz);`
279			`size_t old_real_size;`
280
281			`if (block_p == NULL)`
282			`return malloc (sz);`
283
284			`old_real_size = block->size;`
285
286			`/* Perhaps we need to allocate more space. */`
287			`if (old_real_size < real_size)`
288			`{`
289			`void *result;`
290			`size_t old_size = old_real_size - sizeof (size_t);`
291
292			`/* Need to allocate, copy, and free. */`
293			`result = malloc (sz);`
294			`if (result == NULL)`
295			`return NULL;`
296			`memcpy (result, block_p, old_size < sz ? old_size : sz);`
297			`free (block_p);`
298			`return result;`
299			`}`
300			`/* Perhaps we can free some space. */`
301			`if (old_real_size - real_size >= sizeof (struct freelist_entry))`
302			`{`
303			`fle newblock = (fle)((size_t)block + real_size);`
304			`block->size = real_size;`
305			`newblock->size = old_real_size - real_size;`
306			`free (&newblock->next);`
307			`}`
308			`return block_p;`
309			`}`
310			`#endif`
311
312			`#ifdef DEFINE_CALLOC`
313			`void *`
314			`calloc (size_t n, size_t elem_size)`
315			`{`
316			`void *result;`
317			`size_t sz = n * elem_size;`
318			`result = malloc (sz);`
319			`if (result != NULL)`
320			`memset (result, 0, sz);`
321			`return result;`
322			`}`
323			`#endif`
324
325			`#ifdef DEFINE_CFREE`
326			`void`
327			`cfree (void *p)`
328			`{`
329			`free (p);`
330			`}`
331			`#endif`
332
333			`#ifdef DEFINE_MEMALIGN`
334			`void *`
335			`memalign (size_t align, size_t sz)`
336			`{`
337			`fle *nextfree;`
338			`fle block;`
339
340			`/* real_size is the size we actually have to allocate, allowing for`
341			`overhead and alignment. */`
342			`size_t real_size = REAL_SIZE (sz);`
343
344			`/* Some sanity checking on 'align'. */`
345			`if ((align & (align - 1)) != 0`
346			`\|\| align <= 0)`
347			`return NULL;`
348
349			`/* Look for the first block on the freelist that is large enough. */`
350			`/* One tricky part is this: We want the result to be a valid pointer`
351			`to free. That means that there has to be room for a size_t`
352			`before the block. If there's additional space before the block,`
353			`it should go on the freelist, or it'll be lost---we could add it`
354			`to the size of the block before it in memory, but finding the`
355			`previous block is expensive. */`
356			`for (nextfree = &__malloc_freelist;`
357			`;`
358			`nextfree = &(*nextfree)->next)`
359			`{`
360			`size_t before_size;`
361			`size_t old_size;`
362
363			`/* If we've run out of free blocks, allocate more space. */`
364			`if (! *nextfree)`
365			`{`
366			`old_size = real_size;`
367			`if (MALLOC_DIRECTION < 0)`
368			`{`
369			`old_size += M_ALIGN_SUB (((size_t)__malloc_end`
370			`- old_size + sizeof (size_t)),`
371			`align);`
372			`if (! CAN_ALLOC_P (old_size))`
373			`return NULL;`
374			`block = __malloc_end = (void *)((size_t)__malloc_end - old_size);`
375			`}`
376			`else`
377			`{`
378			`block = __malloc_end;`
379			`old_size += M_ALIGN ((size_t)__malloc_end + sizeof (size_t),`
380			`align);`
381			`if (! CAN_ALLOC_P (old_size))`
382			`return NULL;`
383			`__malloc_end = (void *)((size_t)__malloc_end + old_size);`
384			`}`
385			`*nextfree = block;`
386			`block->size = old_size;`
387			`block->next = NULL;`
388			`}`
389			`else`
390			`{`
391			`block = *nextfree;`
392			`old_size = block->size;`
393			`}`
394
395
396			`before_size = M_ALIGN (&block->next, align);`
397			`if (before_size != 0)`
398			`before_size = sizeof (*block) + M_ALIGN (&(block+1)->next, align);`
399
400			`/* If this is the last block on the freelist, and it is too small,`
401			`enlarge it. */`
402			`if (! block->next`
403			`&& old_size < real_size + before_size`
404			`&& __malloc_end == (void *)((size_t)block + block->size))`
405			`{`
406			`if (MALLOC_DIRECTION < 0)`
407			`{`
408			`size_t moresize = real_size - block->size;`
409			`moresize += M_ALIGN_SUB ((size_t)&block->next - moresize, align);`
410			`if (! CAN_ALLOC_P (moresize))`
411			`return NULL;`
412			`block = __malloc_end = (void *)((size_t)block - moresize);`
413			`block->next = NULL;`
414			`block->size = old_size = old_size + moresize;`
415			`before_size = 0;`
416			`}`
417			`else`
418			`{`
419			`if (! CAN_ALLOC_P (before_size + real_size - block->size))`
420			`return NULL;`
421			`__malloc_end = (void *)((size_t)block + before_size + real_size);`
422			`block->size = old_size = before_size + real_size;`
423			`}`
424
425			`/* Two out of the four cases below will now be possible; which`
426			`two depends on MALLOC_DIRECTION. */`
427			`}`
428
429			`if (old_size >= real_size + before_size)`
430			`{`
431			`/* This block will do. If there needs to be space before it,`
432			`split the block. */`
433			`if (before_size != 0)`
434			`{`
435			`fle old_block = block;`
436
437			`old_block->size = before_size;`
438			`block = (fle)((size_t)block + before_size);`
439
440			`/* If there's no space after the block, we're now nearly`
441			`done; just make a note of the size required.`
442			`Otherwise, we need to create a new free space block. */`
443			`if (old_size - before_size`
444			`<= real_size + sizeof (struct freelist_entry))`
445			`{`
446			`block->size = old_size - before_size;`
447			`return (void *)&block->next;`
448			`}`
449			`else`
450			`{`
451			`fle new_block;`
452			`new_block = (fle)((size_t)block + real_size);`
453			`new_block->size = old_size - before_size - real_size;`
454			`if (MALLOC_DIRECTION > 0)`
455			`{`
456			`new_block->next = old_block->next;`
457			`old_block->next = new_block;`
458			`}`
459			`else`
460			`{`
461			`new_block->next = old_block;`
462			`*nextfree = new_block;`
463			`}`
464			`goto done;`
465			`}`
466			`}`
467			`else`
468			`{`
469			`/* If the block found is just the right size, remove it from`
470			`the free list. Otherwise, split it. */`
471			`if (old_size <= real_size + sizeof (struct freelist_entry))`
472			`{`
473			`*nextfree = block->next;`
474			`return (void *)&block->next;`
475			`}`
476			`else`
477			`{`
478			`size_t newsize = old_size - real_size;`
479			`fle newnext = block->next;`
480			`*nextfree = (fle)((size_t)block + real_size);`
481			`(*nextfree)->size = newsize;`
482			`(*nextfree)->next = newnext;`
483			`goto done;`
484			`}`
485			`}`
486			`}`
487			`}`
488
489			`done:`
490			`block->size = real_size;`
491			`return (void *)&block->next;`
492			`}`
493			`#endif`
494
495			`#ifdef DEFINE_VALLOC`
496			`void *`
497			`valloc (size_t sz)`
498			`{`
499			`return memalign (128, sz);`
500			`}`
501			`#endif`
502			`#ifdef DEFINE_PVALLOC`
503			`void *`
504			`pvalloc (size_t sz)`
505			`{`
506			`return memalign (128, sz + M_ALIGN (sz, 128));`
507			`}`
508			`#endif`
509
510			`#ifdef DEFINE_MALLINFO`
511			`#include "malloc.h"`
512
513			`struct mallinfo`
514			`mallinfo (void)`
515			`{`
516			`struct mallinfo r;`
517			`fle fr;`
518			`size_t free_size;`
519			`size_t total_size;`
520			`size_t free_blocks;`
521
522			`memset (&r, 0, sizeof (r));`
523
524			`free_size = 0;`
525			`free_blocks = 0;`
526			`for (fr = __malloc_freelist; fr; fr = fr->next)`
527			`{`
528			`free_size += fr->size;`
529			`free_blocks++;`
530			`if (! fr->next)`
531			`{`
532			`int atend;`
533			`if (MALLOC_DIRECTION > 0)`
534			`atend = (void *)((size_t)fr + fr->size) == __malloc_end;`
535			`else`
536			`atend = (void *)fr == __malloc_end;`
537			`if (atend)`
538			`r.keepcost = fr->size;`
539			`}`
540			`}`
541
542			`if (MALLOC_DIRECTION > 0)`
543			`total_size = (char )__malloc_end - (char )&__malloc_start;`
544			`else`
545			`total_size = (char )&__malloc_start - (char )__malloc_end;`
546
547			`#ifdef DEBUG`
548			`/* Fixme: should walk through all the in-use blocks and see if`
549			`they're valid. */`
550			`#endif`
551
552			`r.arena = total_size;`
553			`r.fordblks = free_size;`
554			`r.uordblks = total_size - free_size;`
555			`r.ordblks = free_blocks;`
556			`return r;`
557			`}`
558			`#endif`
559
560			`#ifdef DEFINE_MALLOC_STATS`
561			`#include "malloc.h"`
562			`#include <stdio.h>`
563
564			`void`
565			`malloc_stats(void)`
566			`{`
567			`struct mallinfo i;`
568			`FILE *fp;`
569
570			`fp = stderr;`
571			`i = mallinfo();`
572			`fprintf (fp, "malloc has reserved %u bytes between %p and %p\n",`
573			`i.arena, &__malloc_start, __malloc_end);`
574			`fprintf (fp, "there are %u bytes free in %u chunks\n",`
575			`i.fordblks, i.ordblks);`
576			`fprintf (fp, "of which %u bytes are at the end of the reserved space\n",`
577			`i.keepcost);`
578			`fprintf (fp, "and %u bytes are in use.\n", i.uordblks);`
579			`}`
580			`#endif`
581
582			`#ifdef DEFINE_MALLOC_USABLE_SIZE`
583			`size_t`
584			`malloc_usable_size (void *block_p)`
585			`{`
586			`fle block = (fle)((size_t) block_p - offsetof (struct freelist_entry, next));`
587			`return block->size - sizeof (size_t);`
588			`}`
589			`#endif`
590
591			`#ifdef DEFINE_MALLOPT`
592			`int`
593			`mallopt (int n, int v)`
594			`{`
595			`(void)n; (void)v;`
596			`return 0;`
597			`}`
598			`#endif`