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darling-gdb/binutils/gmalloc.c
David Henkel-Wallace c074abeebc Back from Intel with Steve
1991-03-21 21:29:07 +00:00

1117 lines
32 KiB
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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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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.
The GNU C Library 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 1, or (at your option)
any later version.
The GNU C Library 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 the GNU C Library; see the file COPYING. If not, write to
the Free Software Foundation, 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, 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.
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 1, 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.
The author may be reached (Email) at the address mike@@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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)
(((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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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) ((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)
(((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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#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.
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 1, 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.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#ifndef __ONEFILE
#include "ansidecl.h"
#include <stdlib.h>
#endif /* __ONEFILE */
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) ((char *) result - (char *) NULL) % pagesize;
if (adj != 0)
result = (char *) result + pagesize - adj;
return result;
}
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