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binutils-gdb/gdb/gmalloc.c
John Gilmore 1d0709e2a5 * gmalloc.c: Fix bug that causes malloc & free to 
fail on systems where pointers have the high bit set (0x800efcf0
for example).  The problem is that the difference between two
pointers is a signed integer, so the computation

	(char *) 0x800efcf0 - (char *) 0

yields a negative value.  The sign of the result of the modulus
operator is machine dependent for negative operands, thus it is
possible for it to end up negative.  From Fred Fish.
1991-12-07 12:16:13 +00:00

1153 lines
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/* gmalloc.c - THIS FILE IS AUTOMAGICALLY GENERATED SO DON'T EDIT IT. */
/* Single-file skeleton for GNU malloc.
Copyright 1989 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#define __ONEFILE
/* DO NOT DELETE THIS LINE -- ansidecl.h INSERTED HERE. */
/* Copyright (C) 1989 Free Software Foundation, Inc.
This file is part of the GNU C Library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ANSI and traditional C compatibility macros
ANSI C is assumed if __STDC__ is #defined.
Macros
PTR - Generic pointer type
LONG_DOUBLE - `long double' type
CONST - `const' keyword
VOLATILE - `volatile' keyword
SIGNED - `signed' keyword
PTRCONST - Generic const pointer (void *const)
EXFUN(name, prototype) - declare external function NAME
with prototype PROTOTYPE
DEFUN(name, arglist, args) - define function NAME with
args ARGLIST of types in ARGS
DEFUN_VOID(name) - define function NAME with no args
AND - argument separator for ARGS
NOARGS - null arglist
DOTS - `...' in args
For example:
extern int EXFUN(printf, (CONST char *format DOTS));
int DEFUN(fprintf, (stream, format),
FILE *stream AND CONST char *format DOTS) { ... }
void DEFUN_VOID(abort) { ... }
*/
#ifndef _ANSIDECL_H
#define _ANSIDECL_H 1
/* Every source file includes this file,
so they will all get the switch for lint. */
/* LINTLIBRARY */
#ifdef __STDC__
#define PTR void *
#define PTRCONST void *CONST
#define LONG_DOUBLE long double
#define AND ,
#define NOARGS void
#define CONST const
#define VOLATILE volatile
#define SIGNED signed
#define DOTS , ...
#define EXFUN(name, proto) name proto
#define DEFUN(name, arglist, args) name(args)
#define DEFUN_VOID(name) name(NOARGS)
#else /* Not ANSI C. */
#define PTR char *
#define PTRCONST PTR
#define LONG_DOUBLE double
#define AND ;
#define NOARGS
#define CONST
#define VOLATILE
#define SIGNED
#define DOTS
#define EXFUN(name, proto) name()
#define DEFUN(name, arglist, args) name arglist args;
#define DEFUN_VOID(name) name()
#endif /* ANSI C. */
#endif /* ansidecl.h */
#ifdef __STDC__
#include <limits.h>
#else
/* DO NOT DELETE THIS LINE -- limits.h INSERTED HERE. */
/* Number of bits in a `char'. */
#define CHAR_BIT 8
/* No multibyte characters supported yet. */
#define MB_LEN_MAX 1
/* Minimum and maximum values a `signed char' can hold. */
#define SCHAR_MIN -128
#define SCHAR_MAX 127
/* Maximum value an `unsigned char' can hold. (Minimum is 0). */
#define UCHAR_MAX 255U
/* Minimum and maximum values a `char' can hold. */
#ifdef __CHAR_UNSIGNED__
#define CHAR_MIN 0
#define CHAR_MAX 255U
#else
#define CHAR_MIN -128
#define CHAR_MAX 127
#endif
/* Minimum and maximum values a `signed short int' can hold. */
#define SHRT_MIN -32768
#define SHRT_MAX 32767
/* Maximum value an `unsigned short int' can hold. (Minimum is 0). */
#define USHRT_MAX 65535U
/* Minimum and maximum values a `signed int' can hold. */
#define INT_MIN -2147483648
#define INT_MAX 2147483647
/* Maximum value an `unsigned int' can hold. (Minimum is 0). */
#define UINT_MAX 4294967295U
/* Minimum and maximum values a `signed long int' can hold.
(Same as `int'). */
#define LONG_MIN (-LONG_MAX-1)
#define LONG_MAX 2147483647
/* Maximum value an `unsigned long int' can hold. (Minimum is 0). */
#define ULONG_MAX 4294967295U
#endif
#ifdef __STDC__
#include <stddef.h>
#else
/* DO NOT DELETE THIS LINE -- stddef.h INSERTED HERE. */
#ifndef _STDDEF_H
#define _STDDEF_H
/* Signed type of difference of two pointers. */
typedef long ptrdiff_t;
/* Unsigned type of `sizeof' something. */
#ifndef _SIZE_T /* in case <sys/types.h> has defined it. */
#define _SIZE_T
typedef unsigned long size_t;
#endif /* _SIZE_T */
/* A null pointer constant. */
#undef NULL /* in case <stdio.h> has defined it. */
#define NULL 0
/* Offset of member MEMBER in a struct of type TYPE. */
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif /* _STDDEF_H */
#endif
/* DO NOT DELETE THIS LINE -- stdlib.h INSERTED HERE. */
/* Fake stdlib.h supplying the stuff needed by malloc. */
#ifndef __ONEFILE
#include <stddef.h>
#endif
extern void EXFUN(abort, (void));
extern void EXFUN(free, (PTR));
extern PTR EXFUN(malloc, (size_t));
extern PTR EXFUN(realloc, (PTR, size_t));
/* DO NOT DELETE THIS LINE -- string.h INSERTED HERE. */
/* Fake string.h supplying stuff used by malloc. */
#ifndef __ONEFILE
#include <stddef.h>
#endif
extern PTR EXFUN(memcpy, (PTR, CONST PTR, size_t));
extern PTR EXFUN(memset, (PTR, int, size_t));
#define memmove memcpy
#define _MALLOC_INTERNAL
/* DO NOT DELETE THIS LINE -- malloc.h INSERTED HERE. */
/* Declarations for `malloc' and friends.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef _MALLOC_H
#define _MALLOC_H 1
#ifndef __ONEFILE
#define __need_NULL
#define __need_size_t
#define __need_ptrdiff_t
#include <stddef.h>
#endif
#ifdef _MALLOC_INTERNAL
#ifndef __ONEFILE
#include <limits.h>
#endif
/* The allocator divides the heap into blocks of fixed size; large
requests receive one or more whole blocks, and small requests
receive a fragment of a block. Fragment sizes are powers of two,
and all fragments of a block are the same size. When all the
fragments in a block have been freed, the block itself is freed. */
#define INT_BIT (CHAR_BIT * sizeof(int))
#define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
#define BLOCKSIZE (1 << BLOCKLOG)
#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
/* Determine the amount of memory spanned by the initial heap table
(not an absolute limit). */
#define HEAP (INT_BIT > 16 ? 4194304 : 65536)
/* Number of contiguous free blocks allowed to build up at the end of
memory before they will be returned to the system. */
#define FINAL_FREE_BLOCKS 8
/* Where to start searching the free list when looking for new memory.
The two possible values are 0 and _heapindex. Starting at 0 seems
to reduce total memory usage, while starting at _heapindex seems to
run faster. */
#define MALLOC_SEARCH_START _heapindex
/* Data structure giving per-block information. */
typedef union
{
/* Heap information for a busy block. */
struct
{
/* Zero for a large block, or positive giving the
logarithm to the base two of the fragment size. */
int type;
union
{
struct
{
size_t nfree; /* Free fragments in a fragmented block. */
size_t first; /* First free fragment of the block. */
} frag;
/* Size (in blocks) of a large cluster. */
size_t size;
} info;
} busy;
/* Heap information for a free block (that may be the first of
a free cluster). */
struct
{
size_t size; /* Size (in blocks) of a free cluster. */
size_t next; /* Index of next free cluster. */
size_t prev; /* Index of previous free cluster. */
} free;
} malloc_info;
/* Pointer to first block of the heap. */
extern char *_heapbase;
/* Table indexed by block number giving per-block information. */
extern malloc_info *_heapinfo;
/* Address to block number and vice versa. */
#define BLOCK(A) (((char *) (A) - _heapbase) / BLOCKSIZE + 1)
#define ADDRESS(B) ((PTR) (((B) - 1) * BLOCKSIZE + _heapbase))
/* Current search index for the heap table. */
extern size_t _heapindex;
/* Limit of valid info table indices. */
extern size_t _heaplimit;
/* Doubly linked lists of free fragments. */
struct list
{
struct list *next;
struct list *prev;
};
/* Free list headers for each fragment size. */
extern struct list _fraghead[];
/* Instrumentation. */
extern size_t _chunks_used;
extern size_t _bytes_used;
extern size_t _chunks_free;
extern size_t _bytes_free;
/* Internal version of free() used in morecore(). */
extern void EXFUN(__free, (PTR __ptr));
#endif /* _MALLOC_INTERNAL. */
/* Underlying allocation function; successive calls should
return contiguous pieces of memory. */
extern PTR EXFUN((*__morecore), (ptrdiff_t __size));
/* Default value of previous. */
extern PTR EXFUN(__default_morecore, (ptrdiff_t __size));
/* Flag whether malloc has been called. */
extern int __malloc_initialized;
/* Hooks for debugging versions. */
extern void EXFUN((*__free_hook), (PTR __ptr));
extern PTR EXFUN((*__malloc_hook), (size_t __size));
extern PTR EXFUN((*__realloc_hook), (PTR __ptr, size_t __size));
/* Activate a standard collection of debugging hooks. */
extern void EXFUN(mcheck, (void EXFUN((*func), (void))));
/* Statistics available to the user. */
struct mstats
{
size_t bytes_total; /* Total size of the heap. */
size_t chunks_used; /* Chunks allocated by the user. */
size_t bytes_used; /* Byte total of user-allocated chunks. */
size_t chunks_free; /* Chunks in the free list. */
size_t bytes_free; /* Byte total of chunks in the free list. */
};
/* Pick up the current statistics. */
extern struct mstats EXFUN(mstats, (NOARGS));
#endif /* malloc.h */
/* DO NOT DELETE THIS LINE -- free.c INSERTED HERE. */
/* Free a block of memory allocated by `malloc'.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stddef.h>
#include <stdlib.h>
#define _MALLOC_INTERNAL
#include "malloc.h"
#endif /* __ONEFILE */
/* Debugging hook for free. */
void EXFUN((*__free_hook), (PTR __ptr));
/* Return memory to the heap. Like free() but don't call a __free_hook
if there is one. */
void
DEFUN(__free, (ptr), PTR ptr)
{
int type;
size_t block, blocks;
register size_t i;
struct list *prev, *next;
block = BLOCK(ptr);
type = _heapinfo[block].busy.type;
switch (type)
{
case 0:
/* Get as many statistics as early as we can. */
--_chunks_used;
_bytes_used -= _heapinfo[block].busy.info.size * BLOCKSIZE;
_bytes_free += _heapinfo[block].busy.info.size * BLOCKSIZE;
/* Find the free cluster previous to this one in the free list.
Start searching at the last block referenced; this may benefit
programs with locality of allocation. */
i = _heapindex;
if (i > block)
while (i > block)
i = _heapinfo[i].free.prev;
else
{
do
i = _heapinfo[i].free.next;
while (i > 0 && i < block);
i = _heapinfo[i].free.prev;
}
/* Determine how to link this block into the free list. */
if (block == i + _heapinfo[i].free.size)
{
/* Coalesce this block with its predecessor. */
_heapinfo[i].free.size += _heapinfo[block].busy.info.size;
block = i;
}
else
{
/* Really link this block back into the free list. */
_heapinfo[block].free.size = _heapinfo[block].busy.info.size;
_heapinfo[block].free.next = _heapinfo[i].free.next;
_heapinfo[block].free.prev = i;
_heapinfo[i].free.next = block;
_heapinfo[_heapinfo[block].free.next].free.prev = block;
++_chunks_free;
}
/* Now that the block is linked in, see if we can coalesce it
with its successor (by deleting its successor from the list
and adding in its size). */
if (block + _heapinfo[block].free.size == _heapinfo[block].free.next)
{
_heapinfo[block].free.size
+= _heapinfo[_heapinfo[block].free.next].free.size;
_heapinfo[block].free.next
= _heapinfo[_heapinfo[block].free.next].free.next;
_heapinfo[_heapinfo[block].free.next].free.prev = block;
--_chunks_free;
}
/* Now see if we can return stuff to the system. */
blocks = _heapinfo[block].free.size;
if (blocks >= FINAL_FREE_BLOCKS && block + blocks == _heaplimit
&& (*__morecore)(0) == ADDRESS(block + blocks))
{
register size_t bytes = blocks * BLOCKSIZE;
_heaplimit -= blocks;
(*__morecore)(- bytes);
_heapinfo[_heapinfo[block].free.prev].free.next
= _heapinfo[block].free.next;
_heapinfo[_heapinfo[block].free.next].free.prev
= _heapinfo[block].free.prev;
block = _heapinfo[block].free.prev;
--_chunks_free;
_bytes_free -= bytes;
}
/* Set the next search to begin at this block. */
_heapindex = block;
break;
default:
/* Do some of the statistics. */
--_chunks_used;
_bytes_used -= 1 << type;
++_chunks_free;
_bytes_free += 1 << type;
/* Get the address of the first free fragment in this block. */
prev = (struct list *) ((char *) ADDRESS(block) +
(_heapinfo[block].busy.info.frag.first << type));
if (_heapinfo[block].busy.info.frag.nfree == (BLOCKSIZE >> type) - 1)
{
/* If all fragments of this block are free, remove them
from the fragment list and free the whole block. */
next = prev;
for (i = 1; i < BLOCKSIZE >> type; ++i)
next = next->next;
prev->prev->next = next;
if (next != NULL)
next->prev = prev->prev;
_heapinfo[block].busy.type = 0;
_heapinfo[block].busy.info.size = 1;
/* Keep the statistics accurate. */
++_chunks_used;
_bytes_used += BLOCKSIZE;
_chunks_free -= BLOCKSIZE >> type;
_bytes_free -= BLOCKSIZE;
free(ADDRESS(block));
}
else if (_heapinfo[block].busy.info.frag.nfree != 0)
{
/* If some fragments of this block are free, link this
fragment into the fragment list after the first free
fragment of this block. */
next = (struct list *) ptr;
next->next = prev->next;
next->prev = prev;
prev->next = next;
if (next->next != NULL)
next->next->prev = next;
++_heapinfo[block].busy.info.frag.nfree;
}
else
{
/* No fragments of this block are free, so link this
fragment into the fragment list and announce that
it is the first free fragment of this block. */
prev = (struct list *) ptr;
_heapinfo[block].busy.info.frag.nfree = 1;
_heapinfo[block].busy.info.frag.first = (unsigned int)
(((unsigned int)((char *) ptr - (char *) NULL)) % BLOCKSIZE >> type);
prev->next = _fraghead[type].next;
prev->prev = &_fraghead[type];
prev->prev->next = prev;
if (prev->next != NULL)
prev->next->prev = prev;
}
break;
}
}
/* Return memory to the heap. */
void
DEFUN(free, (ptr), PTR ptr)
{
if (ptr == NULL)
return;
if (__free_hook != NULL)
(*__free_hook)(ptr);
else
__free (ptr);
}
/* DO NOT DELETE THIS LINE -- malloc.c INSERTED HERE. */
/* Memory allocator `malloc'.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#define _MALLOC_INTERNAL
#include "malloc.h"
#endif /* __ONEFILE */
/* How to really get more memory. */
PTR EXFUN((*__morecore), (ptrdiff_t __size)) = __default_morecore;
/* Debugging hook for `malloc'. */
PTR EXFUN((*__malloc_hook), (size_t __size));
/* Pointer to the base of the first block. */
char *_heapbase;
/* Block information table. Allocated with align/__free (not malloc/free). */
malloc_info *_heapinfo;
/* Number of info entries. */
static size_t heapsize;
/* Search index in the info table. */
size_t _heapindex;
/* Limit of valid info table indices. */
size_t _heaplimit;
/* Free lists for each fragment size. */
struct list _fraghead[BLOCKLOG];
/* Instrumentation. */
size_t _chunks_used;
size_t _bytes_used;
size_t _chunks_free;
size_t _bytes_free;
/* Are you experienced? */
int __malloc_initialized;
/* Aligned allocation. */
static PTR
DEFUN(align, (size), size_t size)
{
PTR result;
unsigned int adj;
result = (*__morecore)(size);
adj = (unsigned int) ((unsigned int)((char *) result - (char *) NULL)) % BLOCKSIZE;
if (adj != 0)
{
adj = BLOCKSIZE - adj;
(void) (*__morecore)(adj);
result = (char *) result + adj;
}
return result;
}
/* Set everything up and remember that we have. */
static int
DEFUN_VOID(initialize)
{
heapsize = HEAP / BLOCKSIZE;
_heapinfo = (malloc_info *) align(heapsize * sizeof(malloc_info));
if (_heapinfo == NULL)
return 0;
memset(_heapinfo, 0, heapsize * sizeof(malloc_info));
_heapinfo[0].free.size = 0;
_heapinfo[0].free.next = _heapinfo[0].free.prev = 0;
_heapindex = 0;
_heapbase = (char *) _heapinfo;
__malloc_initialized = 1;
return 1;
}
/* Get neatly aligned memory, initializing or
growing the heap info table as necessary. */
static PTR
DEFUN(morecore, (size), size_t size)
{
PTR result;
malloc_info *newinfo, *oldinfo;
size_t newsize;
result = align(size);
if (result == NULL)
return NULL;
/* Check if we need to grow the info table. */
if (BLOCK((char *) result + size) > heapsize)
{
newsize = heapsize;
while (BLOCK((char *) result + size) > newsize)
newsize *= 2;
newinfo = (malloc_info *) align(newsize * sizeof(malloc_info));
if (newinfo == NULL)
{
(*__morecore)(- size);
return NULL;
}
memset(newinfo, 0, newsize * sizeof(malloc_info));
memcpy(newinfo, _heapinfo, heapsize * sizeof(malloc_info));
oldinfo = _heapinfo;
newinfo[BLOCK(oldinfo)].busy.type = 0;
newinfo[BLOCK(oldinfo)].busy.info.size
= BLOCKIFY(heapsize * sizeof(malloc_info));
_heapinfo = newinfo;
__free(oldinfo);
heapsize = newsize;
}
_heaplimit = BLOCK((char *) result + size);
return result;
}
/* Allocate memory from the heap. */
PTR
DEFUN(malloc, (size), size_t size)
{
PTR result;
size_t block, blocks, lastblocks, start;
register size_t i;
struct list *next;
if (size == 0)
return NULL;
if (__malloc_hook != NULL)
return (*__malloc_hook)(size);
if (!__malloc_initialized)
if (!initialize())
return NULL;
if (size < sizeof(struct list))
size = sizeof(struct list);
/* Determine the allocation policy based on the request size. */
if (size <= BLOCKSIZE / 2)
{
/* Small allocation to receive a fragment of a block.
Determine the logarithm to base two of the fragment size. */
register size_t log = 1;
--size;
while ((size /= 2) != 0)
++log;
/* Look in the fragment lists for a
free fragment of the desired size. */
next = _fraghead[log].next;
if (next != NULL)
{
/* There are free fragments of this size.
Pop a fragment out of the fragment list and return it.
Update the block's nfree and first counters. */
result = (PTR) next;
next->prev->next = next->next;
if (next->next != NULL)
next->next->prev = next->prev;
block = BLOCK(result);
if (--_heapinfo[block].busy.info.frag.nfree != 0)
_heapinfo[block].busy.info.frag.first = (unsigned int)
(((unsigned int)((char *) next->next - (char *) NULL)) % BLOCKSIZE) >> log;
/* Update the statistics. */
++_chunks_used;
_bytes_used += 1 << log;
--_chunks_free;
_bytes_free -= 1 << log;
}
else
{
/* No free fragments of the desired size, so get a new block
and break it into fragments, returning the first. */
result = malloc(BLOCKSIZE);
if (result == NULL)
return NULL;
/* Link all fragments but the first into the free list. */
for (i = 1; i < BLOCKSIZE >> log; ++i)
{
next = (struct list *) ((char *) result + (i << log));
next->next = _fraghead[log].next;
next->prev = &_fraghead[log];
next->prev->next = next;
if (next->next != NULL)
next->next->prev = next;
}
/* Initialize the nfree and first counters for this block. */
block = BLOCK(result);
_heapinfo[block].busy.type = log;
_heapinfo[block].busy.info.frag.nfree = i - 1;
_heapinfo[block].busy.info.frag.first = i - 1;
_chunks_free += (BLOCKSIZE >> log) - 1;
_bytes_free += BLOCKSIZE - (1 << log);
}
}
else
{
/* Large allocation to receive one or more blocks.
Search the free list in a circle starting at the last place visited.
If we loop completely around without finding a large enough
space we will have to get more memory from the system. */
blocks = BLOCKIFY(size);
start = block = MALLOC_SEARCH_START;
while (_heapinfo[block].free.size < blocks)
{
block = _heapinfo[block].free.next;
if (block == start)
{
/* Need to get more from the system. Check to see if
the new core will be contiguous with the final free
block; if so we don't need to get as much. */
block = _heapinfo[0].free.prev;
lastblocks = _heapinfo[block].free.size;
if (_heaplimit != 0 && block + lastblocks == _heaplimit &&
(*__morecore)(0) == ADDRESS(block + lastblocks) &&
(morecore((blocks - lastblocks) * BLOCKSIZE)) != NULL)
{
_heapinfo[block].free.size = blocks;
_bytes_free += (blocks - lastblocks) * BLOCKSIZE;
continue;
}
result = morecore(blocks * BLOCKSIZE);
if (result == NULL)
return NULL;
block = BLOCK(result);
_heapinfo[block].busy.type = 0;
_heapinfo[block].busy.info.size = blocks;
++_chunks_used;
_bytes_used += blocks * BLOCKSIZE;
return result;
}
}
/* At this point we have found a suitable free list entry.
Figure out how to remove what we need from the list. */
result = ADDRESS(block);
if (_heapinfo[block].free.size > blocks)
{
/* The block we found has a bit left over,
so relink the tail end back into the free list. */
_heapinfo[block + blocks].free.size
= _heapinfo[block].free.size - blocks;
_heapinfo[block + blocks].free.next
= _heapinfo[block].free.next;
_heapinfo[block + blocks].free.prev
= _heapinfo[block].free.prev;
_heapinfo[_heapinfo[block].free.prev].free.next
= _heapinfo[_heapinfo[block].free.next].free.prev
= _heapindex = block + blocks;
}
else
{
/* The block exactly matches our requirements,
so just remove it from the list. */
_heapinfo[_heapinfo[block].free.next].free.prev
= _heapinfo[block].free.prev;
_heapinfo[_heapinfo[block].free.prev].free.next
= _heapindex = _heapinfo[block].free.next;
--_chunks_free;
}
_heapinfo[block].busy.type = 0;
_heapinfo[block].busy.info.size = blocks;
++_chunks_used;
_bytes_used += blocks * BLOCKSIZE;
_bytes_free -= blocks * BLOCKSIZE;
}
return result;
}
/* DO NOT DELETE THIS LINE -- realloc.c INSERTED HERE. */
/* Change the size of a block allocated by `malloc'.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stdlib.h>
#include <string.h>
#define _MALLOC_INTERNAL
#include "malloc.h"
#endif /* __ONEFILE */
#define MIN(A, B) ((A) < (B) ? (A) : (B))
/* Debugging hook for realloc. */
PTR EXFUN((*__realloc_hook), (PTR __ptr, size_t __size));
/* Resize the given region to the new size, returning a pointer
to the (possibly moved) region. This is optimized for speed;
some benchmarks seem to indicate that greater compactness is
achieved by unconditionally allocating and copying to a
new region. This module has incestuous knowledge of the
internals of both free and malloc. */
PTR
DEFUN(realloc, (ptr, size), PTR ptr AND size_t size)
{
PTR result;
int type;
size_t block, blocks, oldlimit;
if (size == 0)
{
free(ptr);
return NULL;
}
else if (ptr == NULL)
return malloc(size);
if (__realloc_hook != NULL)
return (*__realloc_hook)(ptr, size);
block = BLOCK(ptr);
type = _heapinfo[block].busy.type;
switch (type)
{
case 0:
/* Maybe reallocate a large block to a small fragment. */
if (size <= BLOCKSIZE / 2)
{
result = malloc(size);
if (result != NULL)
{
memcpy(result, ptr, size);
free(ptr);
return result;
}
}
/* The new size is a large allocation as well;
see if we can hold it in place. */
blocks = BLOCKIFY(size);
if (blocks < _heapinfo[block].busy.info.size)
{
/* The new size is smaller; return
excess memory to the free list. */
_heapinfo[block + blocks].busy.type = 0;
_heapinfo[block + blocks].busy.info.size
= _heapinfo[block].busy.info.size - blocks;
_heapinfo[block].busy.info.size = blocks;
free(ADDRESS(block + blocks));
result = ptr;
}
else if (blocks == _heapinfo[block].busy.info.size)
/* No size change necessary. */
result = ptr;
else
{
/* Won't fit, so allocate a new region that will.
Free the old region first in case there is sufficient
adjacent free space to grow without moving. */
blocks = _heapinfo[block].busy.info.size;
/* Prevent free from actually returning memory to the system. */
oldlimit = _heaplimit;
_heaplimit = 0;
free(ptr);
_heaplimit = oldlimit;
result = malloc(size);
if (result == NULL)
{
(void) malloc(blocks * BLOCKSIZE);
return NULL;
}
if (ptr != result)
memmove(result, ptr, blocks * BLOCKSIZE);
}
break;
default:
/* Old size is a fragment; type is logarithm
to base two of the fragment size. */
if (size > 1 << (type - 1) && size <= 1 << type)
/* The new size is the same kind of fragment. */
result = ptr;
else
{
/* The new size is different; allocate a new space,
and copy the lesser of the new size and the old. */
result = malloc(size);
if (result == NULL)
return NULL;
memcpy(result, ptr, MIN(size, 1 << type));
free(ptr);
}
break;
}
return result;
}
/* DO NOT DELETE THIS LINE -- unix.c INSERTED HERE. */
/* unix.c - get more memory with a UNIX system call.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stddef.h>
#define _MALLOC_INTERNAL
#include "malloc.h"
#endif /* __ONEFILE */
extern PTR EXFUN(sbrk, (ptrdiff_t size));
PTR
DEFUN(__default_morecore, (size), ptrdiff_t size)
{
PTR result;
result = sbrk(size);
if (result == (PTR) -1)
return NULL;
return result;
}
#define __getpagesize getpagesize
/* DO NOT DELETE THIS LINE -- valloc.c INSERTED HERE. */
/* Allocate memory on a page boundary.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stdlib.h>
#endif /* __ONEFILE */
#if defined(M_UNIX)
/*
* M_UNIX is defined by the SCO compilers, including the port of gcc.
*/
/* On SunOS 4.1.1, <sys/param.h> typedefs size_t, which is bad since
we typedef it above. Maybe it's better just to have people compile
-Dgetpagesize()=4096. */
/* Deal with page size. */
#ifndef HAVE_GETPAGESIZE
#include <sys/param.h>
#if !defined (PAGESIZE)
#ifdef EXEC_PAGESIZE
#define PAGESIZE EXEC_PAGESIZE
#else
#ifdef NBPG
#define PAGESIZE NBPG * CLSIZE
#ifndef CLSIZE
#define CLSIZE 1
#endif /* no CLSIZE */
#else /* no NBPG */
#define PAGESIZE NBPC
#endif /* no NBPG */
#endif /* no EXEC_PAGESIZE */
#endif /* no PAGESIZE */
size_t
DEFUN_VOID(__getpagesize)
{
return PAGESIZE;
}
#endif /* not HAVE_GETPAGESIZE */
#endif /* M_UNIX */
extern size_t EXFUN(__getpagesize, (NOARGS));
static size_t pagesize;
PTR
DEFUN(valloc, (size), size_t size)
{
PTR result;
unsigned int adj;
if (pagesize == 0)
pagesize = __getpagesize();
result = malloc(size + pagesize);
if (result == NULL)
return NULL;
adj = (unsigned int) ((unsigned int)((char *) result - (char *) NULL)) % pagesize;
if (adj != 0)
result = (char *) result + pagesize - adj;
return result;
}
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