| 7 |
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/* |
| 8 |
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* Fast malloc for memory hogs and VM environments. |
| 9 |
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* Performs a minimum of searching through free lists. |
| 10 |
– |
* bmalloc() doesn't keep track of free lists -- it's basically |
| 11 |
– |
* just a buffered call to sbrk(2). However, bmalloc will |
| 12 |
– |
* call mscrounge() if sbrk fails. |
| 13 |
– |
* bfree() puts memory from any source into malloc free lists. |
| 10 |
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* malloc(), realloc() and free() use buckets |
| 11 |
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* containing blocks in powers of two, similar to CIT routines. |
| 12 |
+ |
* bfree() puts memory from any source into malloc free lists. |
| 13 |
+ |
* bmalloc() doesn't keep track of free lists -- it's usually |
| 14 |
+ |
* just a buffered call to sbrk(2). However, bmalloc will |
| 15 |
+ |
* call mscrounge() if sbrk fails. |
| 16 |
|
* mscrounge() returns whatever memory it can find to satisfy the |
| 17 |
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* request along with the number of bytes (modified). |
| 18 |
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* |
| 19 |
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* Greg Ward Lawrence Berkeley Laboratory |
| 20 |
|
*/ |
| 21 |
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|
| 22 |
+ |
#include <errno.h> |
| 23 |
+ |
|
| 24 |
|
#define NULL 0 |
| 25 |
|
|
| 26 |
|
#ifndef ALIGN |
| 47 |
|
|
| 48 |
|
|
| 49 |
|
char * |
| 50 |
< |
mscrounge(np) /* search free lists trying to satisfy request */ |
| 50 |
> |
mscrounge(np) /* search free lists to satisfy request */ |
| 51 |
|
register unsigned *np; |
| 52 |
|
{ |
| 53 |
|
char *p; |
| 98 |
|
} else |
| 99 |
|
thisamnt = amnt; |
| 100 |
|
p = sbrk(thisamnt); |
| 101 |
< |
if ((int)p == -1) { /* uh-oh */ |
| 101 |
> |
if ((int)p == -1) { /* uh-oh, ENOMEM */ |
| 102 |
|
thisamnt = n; /* search free lists */ |
| 103 |
|
p = mscrounge(&thisamnt); |
| 104 |
|
if (p == NULL) /* we're really out */ |
| 105 |
|
return(NULL); |
| 106 |
|
} |
| 107 |
|
if (p != bpos+nrem) { /* not an increment */ |
| 108 |
< |
bfree(bpos, nrem); |
| 108 |
> |
bfree(bpos, nrem); /* free what we have */ |
| 109 |
|
bpos = p; |
| 110 |
|
nrem = thisamnt; |
| 111 |
< |
} else |
| 111 |
> |
} else /* otherwise tack on */ |
| 112 |
|
nrem += thisamnt; |
| 113 |
|
} |
| 114 |
|
p = bpos; |
| 124 |
|
{ |
| 125 |
|
register int bucket; |
| 126 |
|
register unsigned bsiz; |
| 127 |
< |
/* find largest bucket */ |
| 128 |
< |
bucket = 0; |
| 129 |
< |
for (bsiz = 1; bsiz+sizeof(M_HEAD) <= n; bsiz <<= 1) |
| 130 |
< |
bucket++; |
| 131 |
< |
while (bucket > FIRSTBUCKET) { |
| 130 |
< |
bsiz >>= 1; |
| 131 |
< |
bucket--; |
| 132 |
< |
if (n < bsiz+sizeof(M_HEAD)) /* nothing for this bucket */ |
| 133 |
< |
continue; |
| 134 |
< |
((M_HEAD *)p)->next = free_list[bucket]; |
| 135 |
< |
free_list[bucket] = (M_HEAD *)p; |
| 136 |
< |
p += bsiz+sizeof(M_HEAD); |
| 137 |
< |
n -= bsiz+sizeof(M_HEAD); |
| 127 |
> |
/* align pointer */ |
| 128 |
> |
bsiz = BYTES_WORD - ((unsigned)p&(BYTES_WORD-1)); |
| 129 |
> |
if (bsiz < BYTES_WORD) { |
| 130 |
> |
p += bsiz; |
| 131 |
> |
n -= bsiz; |
| 132 |
|
} |
| 133 |
+ |
/* fill big buckets first */ |
| 134 |
+ |
for (bucket = NBUCKETS-1, bsiz = 1<<(NBUCKETS-1); |
| 135 |
+ |
bucket >= FIRSTBUCKET; bucket--, bsiz >>= 1) |
| 136 |
+ |
if (n >= bsiz+sizeof(M_HEAD)) { |
| 137 |
+ |
((M_HEAD *)p)->next = free_list[bucket]; |
| 138 |
+ |
free_list[bucket] = (M_HEAD *)p; |
| 139 |
+ |
p += bsiz+sizeof(M_HEAD); |
| 140 |
+ |
n -= bsiz+sizeof(M_HEAD); |
| 141 |
+ |
} |
| 142 |
|
} |
| 143 |
|
|
| 144 |
|
|
| 146 |
|
malloc(n) /* allocate n bytes of memory */ |
| 147 |
|
unsigned n; |
| 148 |
|
{ |
| 149 |
+ |
extern int errno; |
| 150 |
|
register M_HEAD *mp; |
| 151 |
|
register int bucket; |
| 152 |
|
register unsigned bsiz; |
| 154 |
|
if (n == 0) |
| 155 |
|
return(NULL); |
| 156 |
|
/* find first bucket that fits */ |
| 157 |
< |
bucket = FIRSTBUCKET; |
| 158 |
< |
for (bsiz = 1<<FIRSTBUCKET; bsiz < n; bsiz <<= 1) |
| 159 |
< |
bucket++; |
| 160 |
< |
if (free_list[bucket] == NULL) { |
| 157 |
> |
for (bucket = FIRSTBUCKET, bsiz = 1<<FIRSTBUCKET; |
| 158 |
> |
bucket < NBUCKETS; bucket++, bsiz <<= 1) |
| 159 |
> |
if (bsiz >= n) |
| 160 |
> |
break; |
| 161 |
> |
if (bucket >= NBUCKETS) { |
| 162 |
> |
errno = EINVAL; |
| 163 |
> |
return(NULL); |
| 164 |
> |
} |
| 165 |
> |
if (free_list[bucket] == NULL) { /* need more core */ |
| 166 |
|
mp = (M_HEAD *)bmalloc(bsiz+sizeof(M_HEAD)); |
| 167 |
|
if (mp == NULL) |
| 168 |
|
return(NULL); |
| 169 |
< |
} else { |
| 169 |
> |
} else { /* got it */ |
| 170 |
|
mp = free_list[bucket]; |
| 171 |
|
free_list[bucket] = mp->next; |
| 172 |
|
} |
| 173 |
< |
mp->bucket = bucket; |
| 173 |
> |
mp->bucket = bucket; /* tag block */ |
| 174 |
|
return((char *)(mp+1)); |
| 175 |
|
} |
| 176 |
|
|
| 177 |
|
|
| 178 |
|
char * |
| 179 |
|
realloc(op, n) /* reallocate memory using malloc() */ |
| 180 |
< |
char *op; |
| 180 |
> |
register char *op; |
| 181 |
|
unsigned n; |
| 182 |
|
{ |
| 183 |
< |
register char *p; |
| 183 |
> |
char *p; |
| 184 |
|
register unsigned on; |
| 185 |
< |
|
| 185 |
> |
/* get old size */ |
| 186 |
|
if (op != NULL) |
| 187 |
|
on = 1 << ((M_HEAD *)op-1)->bucket; |
| 188 |
|
else |
| 189 |
|
on = 0; |
| 190 |
< |
if (n <= on && n > on>>1) |
| 190 |
> |
if (n <= on && (n > on>>1 || on == 1<<FIRSTBUCKET)) |
| 191 |
|
return(op); /* same bucket */ |
| 192 |
|
p = malloc(n); |
| 193 |
|
if (p != NULL) |
