1 |
greg |
1.12 |
/* Copyright (c) 1991 Regents of the University of California */ |
2 |
greg |
1.1 |
|
3 |
|
|
#ifndef lint |
4 |
|
|
static char SCCSid[] = "$SunId$ LBL"; |
5 |
|
|
#endif |
6 |
|
|
|
7 |
|
|
/* |
8 |
|
|
* Fast malloc for memory hogs and VM environments. |
9 |
|
|
* Performs a minimum of searching through free lists. |
10 |
greg |
1.4 |
* malloc(), realloc() and free() use buckets |
11 |
|
|
* 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 |
greg |
1.3 |
* just a buffered call to sbrk(2). However, bmalloc will |
15 |
|
|
* call mscrounge() if sbrk fails. |
16 |
greg |
1.8 |
* mscrounge() returns whatever free memory it can find to satisfy the |
17 |
greg |
1.3 |
* request along with the number of bytes (modified). |
18 |
greg |
1.1 |
* |
19 |
|
|
* Greg Ward Lawrence Berkeley Laboratory |
20 |
|
|
*/ |
21 |
|
|
|
22 |
greg |
1.6 |
#include <errno.h> |
23 |
|
|
|
24 |
greg |
1.9 |
#ifdef MSTATS |
25 |
|
|
#include <stdio.h> |
26 |
|
|
static unsigned b_nalloced = 0; |
27 |
|
|
static unsigned b_nfreed = 0; |
28 |
|
|
static unsigned b_nscrounged = 0; |
29 |
|
|
static unsigned m_nalloced = 0; |
30 |
|
|
static unsigned m_nfreed = 0; |
31 |
|
|
static unsigned m_nwasted = 0; |
32 |
|
|
#else |
33 |
greg |
1.1 |
#define NULL 0 |
34 |
greg |
1.9 |
#endif |
35 |
greg |
1.1 |
|
36 |
|
|
#ifndef ALIGN |
37 |
|
|
#define ALIGN int /* align type */ |
38 |
|
|
#endif |
39 |
|
|
#define BYTES_WORD sizeof(ALIGN) |
40 |
|
|
|
41 |
greg |
1.9 |
#define MAXINCR (1<<16) /* largest sbrk(2) increment */ |
42 |
greg |
1.3 |
|
43 |
greg |
1.1 |
#ifdef NOVMEM |
44 |
greg |
1.11 |
#define getpagesize() 1024 |
45 |
greg |
1.1 |
#endif |
46 |
|
|
/* malloc free lists */ |
47 |
|
|
typedef union m_head { |
48 |
|
|
union m_head *next; |
49 |
greg |
1.12 |
struct { |
50 |
|
|
short magic; |
51 |
|
|
short bucket; |
52 |
|
|
} a; |
53 |
greg |
1.1 |
ALIGN dummy; |
54 |
|
|
} M_HEAD; |
55 |
|
|
|
56 |
greg |
1.12 |
#define MAGIC 0x1a2 /* magic number for allocated memory */ |
57 |
|
|
|
58 |
greg |
1.1 |
#define FIRSTBUCKET 3 |
59 |
|
|
#define NBUCKETS 30 |
60 |
|
|
|
61 |
|
|
static M_HEAD *free_list[NBUCKETS]; |
62 |
|
|
|
63 |
greg |
1.12 |
static ALIGN dummy_mem; |
64 |
greg |
1.1 |
|
65 |
greg |
1.12 |
#define DUMMYLOC ((char *)&dummy_mem) |
66 |
greg |
1.10 |
|
67 |
greg |
1.12 |
|
68 |
greg |
1.1 |
char * |
69 |
greg |
1.4 |
mscrounge(np) /* search free lists to satisfy request */ |
70 |
greg |
1.3 |
register unsigned *np; |
71 |
|
|
{ |
72 |
|
|
char *p; |
73 |
|
|
register int bucket; |
74 |
|
|
register unsigned bsiz; |
75 |
|
|
|
76 |
|
|
for (bucket = FIRSTBUCKET, bsiz = 1<<FIRSTBUCKET; |
77 |
|
|
bucket < NBUCKETS; bucket++, bsiz <<= 1) |
78 |
|
|
if (free_list[bucket] != NULL && bsiz+sizeof(M_HEAD) >= *np) { |
79 |
|
|
*np = bsiz+sizeof(M_HEAD); |
80 |
|
|
p = (char *)free_list[bucket]; |
81 |
|
|
free_list[bucket] = free_list[bucket]->next; |
82 |
greg |
1.9 |
#ifdef MSTATS |
83 |
|
|
b_nscrounged += *np; |
84 |
|
|
#endif |
85 |
greg |
1.3 |
return(p); |
86 |
|
|
} |
87 |
|
|
*np = 0; |
88 |
|
|
return(NULL); |
89 |
|
|
} |
90 |
|
|
|
91 |
|
|
|
92 |
|
|
char * |
93 |
greg |
1.1 |
bmalloc(n) /* allocate a block of n bytes, sans header */ |
94 |
|
|
register unsigned n; |
95 |
|
|
{ |
96 |
|
|
extern char *sbrk(); |
97 |
greg |
1.3 |
static unsigned pagesz = 0; |
98 |
|
|
static unsigned amnt; |
99 |
greg |
1.1 |
static char *bpos; |
100 |
greg |
1.3 |
static unsigned nrem; |
101 |
|
|
unsigned thisamnt; |
102 |
greg |
1.1 |
register char *p; |
103 |
|
|
|
104 |
greg |
1.9 |
#ifdef MSTATS |
105 |
|
|
b_nalloced += n; |
106 |
|
|
#endif |
107 |
greg |
1.1 |
if (pagesz == 0) { /* initialize */ |
108 |
greg |
1.2 |
pagesz = amnt = getpagesize(); |
109 |
greg |
1.1 |
nrem = (int)sbrk(0); /* page align break */ |
110 |
|
|
nrem = pagesz - (nrem&(pagesz-1)); |
111 |
|
|
bpos = sbrk(nrem); /* word aligned! */ |
112 |
|
|
if ((int)bpos == -1) |
113 |
|
|
return(NULL); |
114 |
|
|
} |
115 |
|
|
|
116 |
|
|
n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align rqst. */ |
117 |
|
|
|
118 |
|
|
if (n > nrem) { /* need more core */ |
119 |
greg |
1.3 |
if (n > amnt) { /* big chunk */ |
120 |
|
|
thisamnt = (n+(pagesz-1))&~(pagesz-1); |
121 |
|
|
if (thisamnt <= MAXINCR) /* increase amnt */ |
122 |
|
|
amnt = thisamnt; |
123 |
|
|
} else |
124 |
|
|
thisamnt = amnt; |
125 |
|
|
p = sbrk(thisamnt); |
126 |
greg |
1.4 |
if ((int)p == -1) { /* uh-oh, ENOMEM */ |
127 |
greg |
1.3 |
thisamnt = n; /* search free lists */ |
128 |
|
|
p = mscrounge(&thisamnt); |
129 |
|
|
if (p == NULL) /* we're really out */ |
130 |
|
|
return(NULL); |
131 |
|
|
} |
132 |
|
|
if (p != bpos+nrem) { /* not an increment */ |
133 |
greg |
1.4 |
bfree(bpos, nrem); /* free what we have */ |
134 |
greg |
1.1 |
bpos = p; |
135 |
greg |
1.3 |
nrem = thisamnt; |
136 |
greg |
1.4 |
} else /* otherwise tack on */ |
137 |
greg |
1.3 |
nrem += thisamnt; |
138 |
greg |
1.1 |
} |
139 |
|
|
p = bpos; |
140 |
|
|
bpos += n; /* advance */ |
141 |
|
|
nrem -= n; |
142 |
|
|
return(p); |
143 |
|
|
} |
144 |
|
|
|
145 |
|
|
|
146 |
|
|
bfree(p, n) /* free n bytes of random memory */ |
147 |
greg |
1.2 |
register char *p; |
148 |
|
|
register unsigned n; |
149 |
greg |
1.1 |
{ |
150 |
|
|
register int bucket; |
151 |
|
|
register unsigned bsiz; |
152 |
greg |
1.9 |
|
153 |
|
|
#ifdef MSTATS |
154 |
|
|
b_nfreed += n; |
155 |
|
|
#endif |
156 |
greg |
1.4 |
/* align pointer */ |
157 |
greg |
1.6 |
bsiz = BYTES_WORD - ((unsigned)p&(BYTES_WORD-1)); |
158 |
greg |
1.4 |
if (bsiz < BYTES_WORD) { |
159 |
|
|
p += bsiz; |
160 |
|
|
n -= bsiz; |
161 |
greg |
1.1 |
} |
162 |
greg |
1.4 |
/* fill big buckets first */ |
163 |
|
|
for (bucket = NBUCKETS-1, bsiz = 1<<(NBUCKETS-1); |
164 |
|
|
bucket >= FIRSTBUCKET; bucket--, bsiz >>= 1) |
165 |
|
|
if (n >= bsiz+sizeof(M_HEAD)) { |
166 |
|
|
((M_HEAD *)p)->next = free_list[bucket]; |
167 |
|
|
free_list[bucket] = (M_HEAD *)p; |
168 |
|
|
p += bsiz+sizeof(M_HEAD); |
169 |
|
|
n -= bsiz+sizeof(M_HEAD); |
170 |
|
|
} |
171 |
greg |
1.1 |
} |
172 |
|
|
|
173 |
|
|
|
174 |
|
|
char * |
175 |
|
|
malloc(n) /* allocate n bytes of memory */ |
176 |
|
|
unsigned n; |
177 |
|
|
{ |
178 |
greg |
1.6 |
extern int errno; |
179 |
greg |
1.1 |
register M_HEAD *mp; |
180 |
|
|
register int bucket; |
181 |
|
|
register unsigned bsiz; |
182 |
greg |
1.10 |
/* don't return NULL on 0 request */ |
183 |
|
|
if (n == 0) |
184 |
|
|
return(DUMMYLOC); |
185 |
greg |
1.2 |
/* find first bucket that fits */ |
186 |
greg |
1.6 |
for (bucket = FIRSTBUCKET, bsiz = 1<<FIRSTBUCKET; |
187 |
|
|
bucket < NBUCKETS; bucket++, bsiz <<= 1) |
188 |
|
|
if (bsiz >= n) |
189 |
|
|
break; |
190 |
|
|
if (bucket >= NBUCKETS) { |
191 |
|
|
errno = EINVAL; |
192 |
|
|
return(NULL); |
193 |
|
|
} |
194 |
greg |
1.9 |
#ifdef MSTATS |
195 |
|
|
m_nalloced += bsiz + sizeof(M_HEAD); |
196 |
|
|
m_nwasted += bsiz + sizeof(M_HEAD) - n; |
197 |
|
|
#endif |
198 |
greg |
1.4 |
if (free_list[bucket] == NULL) { /* need more core */ |
199 |
greg |
1.1 |
mp = (M_HEAD *)bmalloc(bsiz+sizeof(M_HEAD)); |
200 |
|
|
if (mp == NULL) |
201 |
|
|
return(NULL); |
202 |
greg |
1.4 |
} else { /* got it */ |
203 |
greg |
1.1 |
mp = free_list[bucket]; |
204 |
|
|
free_list[bucket] = mp->next; |
205 |
|
|
} |
206 |
greg |
1.12 |
mp->a.magic = MAGIC; /* tag block */ |
207 |
|
|
mp->a.bucket = bucket; |
208 |
greg |
1.1 |
return((char *)(mp+1)); |
209 |
|
|
} |
210 |
|
|
|
211 |
|
|
|
212 |
|
|
char * |
213 |
|
|
realloc(op, n) /* reallocate memory using malloc() */ |
214 |
greg |
1.6 |
register char *op; |
215 |
greg |
1.1 |
unsigned n; |
216 |
|
|
{ |
217 |
greg |
1.6 |
char *p; |
218 |
greg |
1.1 |
register unsigned on; |
219 |
greg |
1.6 |
/* get old size */ |
220 |
greg |
1.12 |
if (op != NULL && op != DUMMYLOC && ((M_HEAD *)op-1)->a.magic == MAGIC) |
221 |
|
|
on = 1 << ((M_HEAD *)op-1)->a.bucket; |
222 |
greg |
1.5 |
else |
223 |
|
|
on = 0; |
224 |
greg |
1.6 |
if (n <= on && (n > on>>1 || on == 1<<FIRSTBUCKET)) |
225 |
greg |
1.5 |
return(op); /* same bucket */ |
226 |
|
|
p = malloc(n); |
227 |
|
|
if (p != NULL) |
228 |
greg |
1.1 |
#ifdef BSD |
229 |
greg |
1.2 |
bcopy(op, p, n>on ? on : n); |
230 |
greg |
1.1 |
#else |
231 |
greg |
1.2 |
(void)memcpy(p, op, n>on ? on : n); |
232 |
greg |
1.1 |
#endif |
233 |
greg |
1.5 |
free(op); |
234 |
greg |
1.1 |
return(p); |
235 |
|
|
} |
236 |
|
|
|
237 |
|
|
|
238 |
|
|
free(p) /* free memory allocated by malloc */ |
239 |
|
|
char *p; |
240 |
|
|
{ |
241 |
|
|
register M_HEAD *mp; |
242 |
|
|
register int bucket; |
243 |
|
|
|
244 |
greg |
1.10 |
if (p == NULL || p == DUMMYLOC) |
245 |
greg |
1.2 |
return; |
246 |
greg |
1.1 |
mp = (M_HEAD *)p - 1; |
247 |
greg |
1.12 |
if (mp->a.magic != MAGIC) /* sanity check */ |
248 |
|
|
return; |
249 |
|
|
bucket = mp->a.bucket; |
250 |
greg |
1.1 |
mp->next = free_list[bucket]; |
251 |
|
|
free_list[bucket] = mp; |
252 |
greg |
1.9 |
#ifdef MSTATS |
253 |
|
|
m_nfreed += (1 << bucket) + sizeof(M_HEAD); |
254 |
|
|
#endif |
255 |
greg |
1.1 |
} |
256 |
|
|
|
257 |
|
|
|
258 |
|
|
#ifndef NOVMEM |
259 |
|
|
#ifndef BSD |
260 |
|
|
#include <sys/var.h> |
261 |
|
|
int |
262 |
|
|
getpagesize() /* use SYSV var structure to get page size */ |
263 |
|
|
{ |
264 |
|
|
struct var v; |
265 |
|
|
|
266 |
greg |
1.8 |
uvar(&v); |
267 |
|
|
return(1 << v.v_pageshift); |
268 |
greg |
1.1 |
} |
269 |
|
|
#endif |
270 |
greg |
1.9 |
#endif |
271 |
|
|
|
272 |
|
|
|
273 |
|
|
#ifdef MSTATS |
274 |
|
|
printmemstats(fp) /* print memory statistics to stream */ |
275 |
|
|
FILE *fp; |
276 |
|
|
{ |
277 |
|
|
register int i; |
278 |
|
|
int n; |
279 |
|
|
register M_HEAD *mp; |
280 |
|
|
unsigned int total = 0; |
281 |
|
|
|
282 |
|
|
fprintf(fp, "Memory statistics:\n"); |
283 |
|
|
fprintf(fp, "\tbmalloc: %d bytes allocated\n", b_nalloced); |
284 |
|
|
fprintf(fp, "\tbmalloc: %d bytes freed\n", b_nfreed); |
285 |
|
|
fprintf(fp, "\tbmalloc: %d bytes scrounged\n", b_nscrounged); |
286 |
|
|
fprintf(fp, "\tmalloc: %d bytes allocated\n", m_nalloced); |
287 |
|
|
fprintf(fp, "\tmalloc: %d bytes wasted (%.1f%%)\n", m_nwasted, |
288 |
|
|
100.0*m_nwasted/m_nalloced); |
289 |
|
|
fprintf(fp, "\tmalloc: %d bytes freed\n", m_nfreed); |
290 |
|
|
for (i = NBUCKETS-1; i >= FIRSTBUCKET; i--) { |
291 |
|
|
n = 0; |
292 |
|
|
for (mp = free_list[i]; mp != NULL; mp = mp->next) |
293 |
|
|
n++; |
294 |
|
|
if (n) { |
295 |
|
|
fprintf(fp, "\t%d * %u\n", n, 1<<i); |
296 |
|
|
total += n * ((1<<i) + sizeof(M_HEAD)); |
297 |
|
|
} |
298 |
|
|
} |
299 |
|
|
fprintf(fp, "\t %u total bytes in free list\n", total); |
300 |
|
|
} |
301 |
greg |
1.1 |
#endif |