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malloc.c
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malloc.c
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/*
* malloc, free, realloc: dynamic memory allocation
*
* Substitute for Pure-C implementation,
* which keeps getting out of memory
* with lots of malloc()/free calls.
*
* Taken from MiNTlib 0.60.0
*/
#include <compiler.h>
#if defined(__TOS__) || defined(__atarist__) /* rest of file */
#include <stddef.h> /* for size_t */
#include <stdlib.h>
#include <memory.h>
#include <string.h>
#include <unistd.h>
#include <osbind.h>
#include <errno.h>
#define libc_strongcall(name) (name)
#define MINFREE (8L * 1024L) /* free at least this much mem on top */
#define MINKEEP (64L * 1024L) /* keep at least this much mem on stack */
/* CAUTION: use _mallocChunkSize() to tailor to your environment,
* do not make the default too large, as the compiler
* gets screwed on a 1M machine otherwise (stack/heap clash)
*/
/* minimum chunk to ask OS for */
static size_t MINHUNK = 8192L; /* default */
static size_t MAXHUNK = 32 * 1024L; /* max. default */
/* tune chunk size */
void _mallocChunkSize(size_t chunksize)
{
if (chunksize == 0)
{
_DISKINFO d;
size_t count;
size_t thissize;
size_t coresize;
void **buf;
void **list;
/* this is like fsstat(u:/proc) */
if (Dfree(&d, 35) >= 0)
{
coresize = d.b_free * d.b_secsiz * d.b_clsiz;
} else
{
coresize = 0;
list = NULL;
while ((thissize = (size_t)Malloc(-1l)) >= sizeof(void *))
{
buf = (void **)Malloc(thissize);
if (buf == NULL)
continue;
coresize += thissize;
*buf = list;
list = buf;
}
while (list != NULL)
{
buf = (void **)(*list);
Mfree(list);
list = buf;
}
}
chunksize = 8192;
while (chunksize < 0x00100000UL && (chunksize * 2048UL) < coresize)
{
chunksize <<= 1;
}
/*
* increase chunksize until we can cover at least half of memory.
* This is mainly for poor old SingleTOS which may fail
* after a certain amount of Malloc's()
*/
for (;;)
{
list = NULL;
count = 0;
while ((buf = (void **)Malloc(chunksize)) != NULL)
{
count++;
*buf = list;
list = buf;
if ((count * chunksize * 2) >= coresize)
break;
}
while (list != NULL)
{
buf = (void **)(*list);
Mfree(list);
list = buf;
}
if ((count * chunksize * 2) >= coresize)
break;
chunksize <<= 1;
if (chunksize == 0)
break;
}
if (chunksize == 0)
chunksize = 8192;
/*
* increase chunksize until we get a reasonable count.
*/
while (count > 1024 && chunksize < 0x40000000UL)
{
chunksize <<= 1;
count >>= 1;
}
#if 0
fprintf(stderr, "coresize = %lu, allocation %lu blocks of size %lu\n", coresize, count, chunksize);
#endif
}
MAXHUNK = MINHUNK = chunksize;
}
#if 1
#undef malloc
#undef calloc
#undef strdup
#undef g_strdup
#undef realloc
#undef free
#define MEM_MAGIC_NEW_ALLOCATED 0xbb
#define MEM_MAGIC_FREED 0x99
#define MEM_MAGIC_END 0xaa
/* definitions needed in malloc.c and realloc.c */
struct mem_chunk
{
unsigned long valid;
#define VAL_FREE 0xf4ee0abcUL
#define VAL_ALLOC 0xa11c0abcUL
#define VAL_SBRK 0xb04d0abcUL
struct mem_chunk *next;
struct mem_chunk *prev;
size_t size;
/* size_t alloc_size; */
};
#define MALLOC_ALIGNMENT 4
#define ALLOC_EXTRA ((sizeof(struct mem_chunk) + MALLOC_ALIGNMENT - 1) & ~(MALLOC_ALIGNMENT - 1))
#define SBRK_EXTRA ((sizeof(struct mem_chunk) + sizeof(size_t) + (MALLOC_ALIGNMENT - 1)) & ~(MALLOC_ALIGNMENT - 1))
#define SBRK_SIZE(ch) (*(size_t *)((char *)(ch) + sizeof(*(ch))))
/* flag to control zero'ing of malloc'ed chunks */
#define ZeroMallocs 0
/* linked list of free blocks struct defined in lib.h */
static struct mem_chunk _mchunk_free_list = { VAL_FREE, &_mchunk_free_list, &_mchunk_free_list, 0 };
#define DEF_PAGESIZE 8192 /* default page size for TOS */
int getpagesize(void)
{
return DEF_PAGESIZE;
}
void *malloc(size_t n)
{
struct mem_chunk *head, *q, *p, *s;
size_t sz;
/* add a mem_chunk to required size and round up */
n = ALLOC_EXTRA + ((n + MALLOC_ALIGNMENT - 1) & ~(MALLOC_ALIGNMENT - 1));
/* look for first block big enough in free list */
head = &_mchunk_free_list;
q = head->next;
while (q != head && (q->size < n || q->valid == VAL_SBRK))
q = q->next;
/* if not enough memory, get more from the system */
if (q == head)
{
if ((n + SBRK_EXTRA) > MINHUNK)
{
sz = n;
sz += SBRK_EXTRA;
} else
{
sz = MINHUNK;
if (MINHUNK < MAXHUNK)
MINHUNK <<= 1;
}
{
size_t page_size;
page_size = getpagesize();
sz = (sz + page_size - 1) & -page_size;
}
q = (struct mem_chunk *) sbrk(sz);
if (q == (void *)-1) /* can't alloc any more? */
return NULL;
/* Note: q may be below the highest allocated chunk */
p = head->next;
while (p != head && q > p)
p = p->next;
q->size = SBRK_EXTRA;
sz -= SBRK_EXTRA;
q->valid = VAL_SBRK;
SBRK_SIZE(q) = sz;
q->next = s = (struct mem_chunk *) ((char *) q + SBRK_EXTRA);
q->prev = p->prev;
q->prev->next = q;
q->next->prev = q;
s->size = sz;
s->valid = VAL_FREE;
s->next = p;
s->next->prev = s;
q = s;
}
if (q->size > (n + ALLOC_EXTRA))
{
/* split, leave part of free list */
q->size -= n;
q = (struct mem_chunk *)(((char *) q) + q->size);
q->size = n;
q->valid = VAL_ALLOC;
} else
{
/* just unlink it */
q->next->prev = q->prev;
q->prev->next = q->next;
q->valid = VAL_ALLOC;
}
/* hand back ptr to after chunk desc */
s = (struct mem_chunk *)(((char *) q) + ALLOC_EXTRA);
#if ZeroMallocs
memset(s, 0, n - ALLOC_EXTRA);
#endif
return (void *) s;
}
#ifdef __GNUC__
#pragma GCC optimize("-O1")
#endif
void *calloc(size_t nitems, size_t size)
{
void *ptr;
nitems *= size;
ptr = malloc(nitems);
#if !ZeroMallocs
if (ptr != NULL)
memset(ptr, 0, nitems);
#endif
return ptr;
}
#ifdef __GNUC__
#pragma GCC optimize("-O2")
#endif
void free(void *param)
{
struct mem_chunk *head, *next, *prev;
struct mem_chunk *r = (struct mem_chunk *) param;
/* free(NULL) should do nothing */
if (r == NULL)
return;
/* move back to uncover the mem_chunk */
r = (struct mem_chunk *)(((char *) r) - ALLOC_EXTRA);
if (r->valid != VAL_ALLOC)
{
return;
}
r->valid = VAL_FREE;
/* stick it into free list, preserving ascending address order */
head = &_mchunk_free_list;
next = head->next;
while (next != head && next < r)
next = next->next;
r->next = next;
r->prev = next->prev;
r->prev->next = r;
r->next->prev = r;
/* merge after if possible */
if ((struct mem_chunk *)(((char *) r) + r->size) == next && next->valid == VAL_FREE)
{
r->size += next->size;
r->next = next->next;
next->next->prev = r;
}
/* merge before if possible, otherwise link it in */
prev = r->prev;
if (prev != head && prev->valid == VAL_FREE && (struct mem_chunk *)(((char *) (prev) + (prev)->size)) == r)
{
prev->size += r->size;
prev->next = r->next;
r->next->prev = prev;
r = prev;
}
prev = r->prev;
if (prev != head && prev->valid == VAL_SBRK && SBRK_SIZE(prev) == r->size)
{
prev->prev->next = r->next;
r->next->prev = prev->prev;
Mfree(prev);
}
}
void *realloc(void *r, size_t n)
{
struct mem_chunk *p;
size_t sz;
/* obscure features:
*
* realloc(NULL,n) is the same as malloc(n)
* realloc(p, 0) is the same as free(p)
*/
if (!r)
return libc_strongcall(malloc)(n);
if (n == 0)
{
libc_strongcall(free)(r);
return NULL;
}
p = (struct mem_chunk *)(((char *) r) - ALLOC_EXTRA);
if (p->valid != VAL_ALLOC)
{
__set_errno(EINVAL);
return NULL;
}
sz = ALLOC_EXTRA + ((n + MALLOC_ALIGNMENT - 1) & ~(MALLOC_ALIGNMENT - 1));
if (p->size > (sz + 2 * ALLOC_EXTRA))
{
/* resize down */
void *newr;
newr = libc_strongcall(malloc)(n);
if (newr)
{
memcpy(newr, r, n);
libc_strongcall(free)(r);
r = newr;
}
/* else
* malloc failed; can be safely ignored as the new block
* is smaller
*/
} else if (p->size < sz)
{
/* block too small, get new one */
struct mem_chunk *head, *s, *next;
head = &_mchunk_free_list;
next = head->next;
while (next != head && next < p)
{
next = next->next;
}
/* merge after if possible */
s = (struct mem_chunk *)(((char *) p) + p->size);
if (s == next && (p->size + next->size) >= sz && next->valid == VAL_FREE)
{
struct mem_chunk *prev;
p->size += next->size;
/*
* disconnect 'next' from free list.
* remember that 'p' is currently alloced
* and therefore not on the free list
*/
prev = next->prev;
prev->next = next->next;
next->next->prev = prev;
} else
{
void *newr;
newr = libc_strongcall(malloc)(n);
if (newr)
{
memcpy(newr, r, p->size - ALLOC_EXTRA);
libc_strongcall(free)(r);
}
r = newr;
}
}
return (void *) r;
}
void *sbrk(intptr_t n)
{
void *rval;
rval = (void *) Malloc(n);
if (rval == NULL)
{
__set_errno(ENOMEM);
rval = (void *) (-1L);
}
return rval;
}
#endif
#ifdef MAIN
static void *xmalloc(size_t size)
{
void *p = malloc(size);
if (p == NULL)
{
fprintf(stderr, "malloc(%lu) failed\n", (unsigned long)size);
fprintf(stderr, "Mallocs: %lu (max %lu), Mfrees %lu, cur %ld\n",
total_mallocs,
max_mallocs,
total_frees,
cur_mallocs);
exit(1);
}
return p;
}
extern long _stksize;
int main(void)
{
#if 1
size_t i, count, size;
void **ptrs;
_mallocChunkSize(0);
{
BASEPAGE *bp = _base;
printf("_base: 0x%08lx\n", (unsigned long)(uintptr_t)_base);
printf("_stksize: 0x%08lx\n", _stksize);
printf("bss start & length: 0x%08lx 0x%08lx\n", (unsigned long)(uintptr_t)bp->p_bbase, bp->p_blen);
printf("hitpa: 0x%08lx\n", (unsigned long)(uintptr_t)bp->p_hitpa);
printf("chunksize: 0x%08lx\n", MINHUNK);
}
printf("pass 1\n");
count = (((long)rand() * 1000) / RAND_MAX) + 500;
ptrs = xmalloc(count * sizeof(void *));
for (i = 0; i < count; i++)
{
size = (((long)rand() * 3000) / RAND_MAX) + 3000;
ptrs[i] = xmalloc(size);
}
for (i = 0; i < count; i++)
free(ptrs[i]);
free(ptrs);
fprintf(stderr, "Mallocs: %lu (max %lu), Mfrees %lu, cur %ld\n",
total_mallocs,
max_mallocs,
total_frees,
cur_mallocs);
printf("pass 2\n");
count = (((long)rand() * 5000) / RAND_MAX) + 5000;
ptrs = xmalloc(count * sizeof(void *));
for (i = 0; i < count; i++)
{
size = (((long)rand() * 5000) / RAND_MAX) + 5000;
ptrs[i] = xmalloc(size);
}
while (count)
{
i = (((long)rand() * count) / RAND_MAX);
--count;
free(ptrs[i]);
ptrs[i] = ptrs[count];
}
free(ptrs);
#else
void *p1, *p2, *p3;
p1 = malloc(5000);
p2 = malloc(5000);
p3 = malloc(5000);
free(p1);
free(p2);
free(p3);
#endif
_crtexit();
return 0;
}
#endif
#else
extern int _I_dont_care_that_ISO_C_forbids_an_empty_source_file_;
#endif