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Backported malloc and realloc from avr-libc 1.8.0 (without test code) #1329

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Merged
merged 1 commit into from
Mar 28, 2013
Merged

Backported malloc and realloc from avr-libc 1.8.0 (without test code) #1329

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151 changes: 19 additions & 132 deletions hardware/arduino/cores/arduino/malloc.c → ...e/arduino/cores/arduino/avr-libc/malloc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,9 +2,6 @@
Copyright (c) 2010 Gerben van den Broeke
All rights reserved.

malloc, free, realloc from avr-libc 1.7.0
with minor modifications, by Paul Stoffregen

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

Expand Down Expand Up @@ -33,20 +30,14 @@
POSSIBILITY OF SUCH DAMAGE.
*/


/* $Id: malloc.c 2149 2010-06-09 20:45:37Z joerg_wunsch $ */

#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include <avr/io.h>


#define __MALLOC_MARGIN__ 120
#include "sectionname.h"
#include "stdlib_private.h"


struct __freelist {
size_t sz;
struct __freelist *nx;
};
#include <avr/io.h>

/*
* Exported interface:
Expand All @@ -59,13 +50,16 @@ struct __freelist {
* with the data segment.
*/

/* May be changed by the user only before the first malloc() call. */

size_t __malloc_margin = 32;
char *__malloc_heap_start = &__heap_start;
char *__malloc_heap_end = &__heap_end;

#define STACK_POINTER() ((char *)AVR_STACK_POINTER_REG)
extern char __heap_start;
char *__brkval = &__heap_start; // first location not yet allocated
struct __freelist *__flp; // freelist pointer (head of freelist)
char *__brkval_maximum = 100;
char *__brkval;
struct __freelist *__flp;

ATTRIBUTE_CLIB_SECTION
void *
malloc(size_t len)
{
Expand Down Expand Up @@ -160,7 +154,11 @@ malloc(size_t len)
* Since we don't have an operating system, just make sure
* that we don't collide with the stack.
*/
cp = STACK_POINTER() - __MALLOC_MARGIN__;
if (__brkval == 0)
__brkval = __malloc_heap_start;
cp = __malloc_heap_end;
if (cp == 0)
cp = STACK_POINTER() - __malloc_margin;
if (cp <= __brkval)
/*
* Memory exhausted.
Expand All @@ -173,7 +171,6 @@ malloc(size_t len)
if (avail >= len && avail >= len + sizeof(size_t)) {
fp1 = (struct __freelist *)__brkval;
__brkval += len + sizeof(size_t);
__brkval_maximum = __brkval;
fp1->sz = len;
return &(fp1->nx);
}
Expand All @@ -184,6 +181,7 @@ malloc(size_t len)
}


ATTRIBUTE_CLIB_SECTION
void
free(void *p)
{
Expand Down Expand Up @@ -267,114 +265,3 @@ free(void *p)
}
}



void *
realloc(void *ptr, size_t len)
{
struct __freelist *fp1, *fp2, *fp3, *ofp3;
char *cp, *cp1;
void *memp;
size_t s, incr;

/* Trivial case, required by C standard. */
if (ptr == 0)
return malloc(len);

cp1 = (char *)ptr;
cp1 -= sizeof(size_t);
fp1 = (struct __freelist *)cp1;

cp = (char *)ptr + len; /* new next pointer */
if (cp < cp1)
/* Pointer wrapped across top of RAM, fail. */
return 0;

/*
* See whether we are growing or shrinking. When shrinking,
* we split off a chunk for the released portion, and call
* free() on it. Therefore, we can only shrink if the new
* size is at least sizeof(struct __freelist) smaller than the
* previous size.
*/
if (len <= fp1->sz) {
/* The first test catches a possible unsigned int
* rollover condition. */
if (fp1->sz <= sizeof(struct __freelist) ||
len > fp1->sz - sizeof(struct __freelist))
return ptr;
fp2 = (struct __freelist *)cp;
fp2->sz = fp1->sz - len - sizeof(size_t);
fp1->sz = len;
free(&(fp2->nx));
return ptr;
}

/*
* If we get here, we are growing. First, see whether there
* is space in the free list on top of our current chunk.
*/
incr = len - fp1->sz;
cp = (char *)ptr + fp1->sz;
fp2 = (struct __freelist *)cp;
for (s = 0, ofp3 = 0, fp3 = __flp;
fp3;
ofp3 = fp3, fp3 = fp3->nx) {
if (fp3 == fp2 && fp3->sz + sizeof(size_t) >= incr) {
/* found something that fits */
if (fp3->sz + sizeof(size_t) - incr > sizeof(struct __freelist)) {
/* split off a new freelist entry */
cp = (char *)ptr + len;
fp2 = (struct __freelist *)cp;
fp2->nx = fp3->nx;
fp2->sz = fp3->sz - incr;
fp1->sz = len;
} else {
/* it just fits, so use it entirely */
fp1->sz += fp3->sz + sizeof(size_t);
fp2 = fp3->nx;
}
if (ofp3)
ofp3->nx = fp2;
else
__flp = fp2;
return ptr;
}
/*
* Find the largest chunk on the freelist while
* walking it.
*/
if (fp3->sz > s)
s = fp3->sz;
}
/*
* If we are the topmost chunk in memory, and there was no
* large enough chunk on the freelist that could be re-used
* (by a call to malloc() below), quickly extend the
* allocation area if possible, without need to copy the old
* data.
*/
if (__brkval == (char *)ptr + fp1->sz && len > s) {
cp = (char *)ptr + len;
cp1 = STACK_POINTER() - __MALLOC_MARGIN__;
if (cp < cp1) {
__brkval = cp;
__brkval_maximum = cp;
fp1->sz = len;
return ptr;
}
/* If that failed, we are out of luck. */
return 0;
}

/*
* Call malloc() for a new chunk, then copy over the data, and
* release the old region.
*/
if ((memp = malloc(len)) == 0)
return 0;
memcpy(memp, ptr, fp1->sz);
free(ptr);
return memp;
}

150 changes: 150 additions & 0 deletions hardware/arduino/cores/arduino/avr-libc/realloc.c
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Original file line number Diff line number Diff line change
@@ -0,0 +1,150 @@
/* Copyright (c) 2004, 2010 Joerg Wunsch
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.

* Neither the name of the copyright holders nor the names of
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
/* $Id: realloc.c 2127 2010-06-07 14:49:37Z joerg_wunsch $ */

#include <stdlib.h>
#include <string.h>
#include "sectionname.h"
#include "stdlib_private.h"

#include <avr/io.h>

ATTRIBUTE_CLIB_SECTION
void *
realloc(void *ptr, size_t len)
{
struct __freelist *fp1, *fp2, *fp3, *ofp3;
char *cp, *cp1;
void *memp;
size_t s, incr;

/* Trivial case, required by C standard. */
if (ptr == 0)
return malloc(len);

cp1 = (char *)ptr;
cp1 -= sizeof(size_t);
fp1 = (struct __freelist *)cp1;

cp = (char *)ptr + len; /* new next pointer */
if (cp < cp1)
/* Pointer wrapped across top of RAM, fail. */
return 0;

/*
* See whether we are growing or shrinking. When shrinking,
* we split off a chunk for the released portion, and call
* free() on it. Therefore, we can only shrink if the new
* size is at least sizeof(struct __freelist) smaller than the
* previous size.
*/
if (len <= fp1->sz) {
/* The first test catches a possible unsigned int
* rollover condition. */
if (fp1->sz <= sizeof(struct __freelist) ||
len > fp1->sz - sizeof(struct __freelist))
return ptr;
fp2 = (struct __freelist *)cp;
fp2->sz = fp1->sz - len - sizeof(size_t);
fp1->sz = len;
free(&(fp2->nx));
return ptr;
}

/*
* If we get here, we are growing. First, see whether there
* is space in the free list on top of our current chunk.
*/
incr = len - fp1->sz;
cp = (char *)ptr + fp1->sz;
fp2 = (struct __freelist *)cp;
for (s = 0, ofp3 = 0, fp3 = __flp;
fp3;
ofp3 = fp3, fp3 = fp3->nx) {
if (fp3 == fp2 && fp3->sz + sizeof(size_t) >= incr) {
/* found something that fits */
if (fp3->sz + sizeof(size_t) - incr > sizeof(struct __freelist)) {
/* split off a new freelist entry */
cp = (char *)ptr + len;
fp2 = (struct __freelist *)cp;
fp2->nx = fp3->nx;
fp2->sz = fp3->sz - incr;
fp1->sz = len;
} else {
/* it just fits, so use it entirely */
fp1->sz += fp3->sz + sizeof(size_t);
fp2 = fp3->nx;
}
if (ofp3)
ofp3->nx = fp2;
else
__flp = fp2;
return ptr;
}
/*
* Find the largest chunk on the freelist while
* walking it.
*/
if (fp3->sz > s)
s = fp3->sz;
}
/*
* If we are the topmost chunk in memory, and there was no
* large enough chunk on the freelist that could be re-used
* (by a call to malloc() below), quickly extend the
* allocation area if possible, without need to copy the old
* data.
*/
if (__brkval == (char *)ptr + fp1->sz && len > s) {
cp1 = __malloc_heap_end;
cp = (char *)ptr + len;
if (cp1 == 0)
cp1 = STACK_POINTER() - __malloc_margin;
if (cp < cp1) {
__brkval = cp;
fp1->sz = len;
return ptr;
}
/* If that failed, we are out of luck. */
return 0;
}

/*
* Call malloc() for a new chunk, then copy over the data, and
* release the old region.
*/
if ((memp = malloc(len)) == 0)
return 0;
memcpy(memp, ptr, fp1->sz);
free(ptr);
return memp;
}

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