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 |
1.14 |
* mcompact() takes the same arguments as mscrounge() (and is in fact |
19 |
|
|
* called by mscrounge() under dire circumstances), but it uses |
20 |
|
|
* memory compaction to return a larger block. (MCOMP) |
21 |
greg |
1.1 |
* |
22 |
|
|
* Greg Ward Lawrence Berkeley Laboratory |
23 |
|
|
*/ |
24 |
|
|
|
25 |
greg |
1.6 |
#include <errno.h> |
26 |
|
|
|
27 |
greg |
1.9 |
#ifdef MSTATS |
28 |
|
|
#include <stdio.h> |
29 |
greg |
1.14 |
static unsigned b_nsbrked = 0; |
30 |
greg |
1.9 |
static unsigned b_nalloced = 0; |
31 |
|
|
static unsigned b_nfreed = 0; |
32 |
|
|
static unsigned b_nscrounged = 0; |
33 |
greg |
1.14 |
static unsigned b_ncompacted = 0; |
34 |
greg |
1.9 |
static unsigned m_nalloced = 0; |
35 |
|
|
static unsigned m_nfreed = 0; |
36 |
|
|
static unsigned m_nwasted = 0; |
37 |
|
|
#else |
38 |
greg |
1.1 |
#define NULL 0 |
39 |
greg |
1.9 |
#endif |
40 |
greg |
1.1 |
|
41 |
|
|
#ifndef ALIGN |
42 |
|
|
#define ALIGN int /* align type */ |
43 |
|
|
#endif |
44 |
|
|
#define BYTES_WORD sizeof(ALIGN) |
45 |
|
|
|
46 |
greg |
1.16 |
#ifndef MAXINCR |
47 |
greg |
1.9 |
#define MAXINCR (1<<16) /* largest sbrk(2) increment */ |
48 |
greg |
1.1 |
#endif |
49 |
|
|
/* malloc free lists */ |
50 |
|
|
typedef union m_head { |
51 |
|
|
union m_head *next; |
52 |
greg |
1.12 |
struct { |
53 |
|
|
short magic; |
54 |
|
|
short bucket; |
55 |
|
|
} a; |
56 |
greg |
1.1 |
ALIGN dummy; |
57 |
|
|
} M_HEAD; |
58 |
|
|
|
59 |
greg |
1.12 |
#define MAGIC 0x1a2 /* magic number for allocated memory */ |
60 |
|
|
|
61 |
greg |
1.1 |
#define FIRSTBUCKET 3 |
62 |
|
|
#define NBUCKETS 30 |
63 |
|
|
|
64 |
|
|
static M_HEAD *free_list[NBUCKETS]; |
65 |
|
|
|
66 |
greg |
1.12 |
static ALIGN dummy_mem; |
67 |
greg |
1.1 |
|
68 |
greg |
1.12 |
#define DUMMYLOC ((char *)&dummy_mem) |
69 |
greg |
1.10 |
|
70 |
greg |
1.14 |
#ifdef MCOMP /* memory compaction routines */ |
71 |
|
|
static char seedtab[1024]; /* seed for compaction table */ |
72 |
greg |
1.12 |
|
73 |
greg |
1.14 |
static struct mblk { |
74 |
|
|
char *ptr; /* pointer to memory block */ |
75 |
|
|
unsigned siz; /* size of memory block */ |
76 |
|
|
} cptab = {seedtab, sizeof(seedtab)}; |
77 |
|
|
|
78 |
|
|
#define mtab(mb) ((struct mblk *)(mb)->ptr) |
79 |
|
|
#define mtablen(mb) ((mb)->siz/sizeof(struct mblk)) |
80 |
|
|
|
81 |
|
|
|
82 |
|
|
static int |
83 |
|
|
mbcmp(m1, m2) /* compare memory block locations */ |
84 |
|
|
register struct mblk *m1, *m2; |
85 |
|
|
{ |
86 |
|
|
/* put empty blocks at end */ |
87 |
|
|
if (m1->siz == 0) |
88 |
|
|
return(m2->siz == 0 ? 0 : 1); |
89 |
|
|
if (m2->siz == 0) |
90 |
|
|
return(-1); |
91 |
|
|
/* otherwise, ascending order */ |
92 |
|
|
return(m1->ptr - m2->ptr); |
93 |
|
|
} |
94 |
|
|
|
95 |
|
|
|
96 |
|
|
int |
97 |
|
|
compactfree() /* compact free lists (moving to table) */ |
98 |
|
|
{ |
99 |
|
|
register struct mblk *tp; |
100 |
|
|
register int bucket; |
101 |
|
|
unsigned n, bsiz, ncomp; |
102 |
|
|
/* fill table from free lists */ |
103 |
|
|
tp = mtab(&cptab); n = mtablen(&cptab); |
104 |
|
|
bucket = NBUCKETS-1; bsiz = 1<<(NBUCKETS-1); |
105 |
|
|
ncomp = 0; |
106 |
|
|
for ( ; ; ) { |
107 |
|
|
while (tp->siz) { /* find empty slot */ |
108 |
|
|
if (--n == 0) |
109 |
|
|
goto loopexit; |
110 |
|
|
tp++; |
111 |
|
|
} |
112 |
|
|
while (free_list[bucket] == NULL) { /* find block */ |
113 |
|
|
if (--bucket < FIRSTBUCKET) |
114 |
|
|
goto loopexit; |
115 |
|
|
bsiz >>= 1; |
116 |
|
|
} |
117 |
|
|
tp->ptr = (char *)free_list[bucket]; |
118 |
|
|
ncomp += (tp->siz = bsiz + sizeof(M_HEAD)); |
119 |
|
|
free_list[bucket] = free_list[bucket]->next; |
120 |
|
|
} |
121 |
|
|
loopexit: |
122 |
|
|
if (ncomp == 0) |
123 |
|
|
return(0); /* nothing new to compact */ |
124 |
|
|
#ifdef MSTATS |
125 |
|
|
b_ncompacted += ncomp; |
126 |
|
|
#endif |
127 |
|
|
tp = mtab(&cptab); n = mtablen(&cptab); /* sort table */ |
128 |
|
|
qsort((char *)tp, n, sizeof(struct mblk), mbcmp); |
129 |
|
|
ncomp = 0; /* collect blocks */ |
130 |
|
|
while (--n && tp[1].siz) { |
131 |
|
|
if (tp[0].ptr + tp[0].siz == tp[1].ptr) { |
132 |
|
|
tp[1].ptr = tp[0].ptr; |
133 |
|
|
tp[1].siz += tp[0].siz; |
134 |
|
|
ncomp += tp[0].siz; |
135 |
|
|
tp[0].siz = 0; |
136 |
|
|
} |
137 |
|
|
tp++; |
138 |
|
|
} |
139 |
|
|
return(ncomp); |
140 |
|
|
} |
141 |
|
|
|
142 |
|
|
|
143 |
greg |
1.1 |
char * |
144 |
greg |
1.14 |
mcompact(np) /* compact free lists to satisfy request */ |
145 |
|
|
unsigned *np; |
146 |
|
|
{ |
147 |
|
|
struct mblk *tab; |
148 |
|
|
unsigned tablen; |
149 |
|
|
register struct mblk *bp, *big; |
150 |
|
|
|
151 |
|
|
for ( ; ; ) { |
152 |
|
|
/* compact free lists */ |
153 |
|
|
compactfree(); |
154 |
|
|
/* find largest block */ |
155 |
|
|
tab = mtab(&cptab); tablen = mtablen(&cptab); |
156 |
|
|
big = tab; |
157 |
|
|
bp = tab + tablen; |
158 |
|
|
while (--bp > tab) |
159 |
|
|
if (bp->siz > big->siz) |
160 |
|
|
big = bp; |
161 |
|
|
if (big->siz >= *np) { /* big enough? */ |
162 |
|
|
*np = big->siz; |
163 |
|
|
big->siz = 0; /* remove from table */ |
164 |
|
|
return(big->ptr); /* return it */ |
165 |
|
|
} |
166 |
|
|
if (mtablen(big) < tablen+1) { |
167 |
|
|
*np = 0; /* cannot grow table */ |
168 |
|
|
return(NULL); /* report failure */ |
169 |
|
|
} |
170 |
|
|
/* enlarge table, free old one */ |
171 |
|
|
mtab(big)[0].ptr = cptab.ptr; |
172 |
|
|
mtab(big)[0].siz = cptab.siz; |
173 |
|
|
cptab.ptr = big->ptr; |
174 |
|
|
cptab.siz = big->siz; |
175 |
|
|
big->siz = 0; /* clear and copy */ |
176 |
|
|
#ifdef BSD |
177 |
|
|
bcopy((char *)tab, (char *)(mtab(&cptab)+1), |
178 |
|
|
tablen*sizeof(struct mblk)); |
179 |
|
|
bzero((char *)(mtab(&cptab)+tablen+1), |
180 |
|
|
(mtablen(&cptab)-tablen-1)*sizeof(struct mblk)); |
181 |
|
|
#else |
182 |
|
|
(void)memcpy((char *)(mtab(&cptab)+1), (char *)tab, |
183 |
|
|
tablen*sizeof(struct mblk)); |
184 |
|
|
memset((char *)(mtab(&cptab)+tablen+1), 0, |
185 |
|
|
(mtablen(&cptab)-tablen-1)*sizeof(struct mblk)); |
186 |
|
|
#endif |
187 |
|
|
} /* next round */ |
188 |
|
|
} |
189 |
|
|
#endif /* MCOMP */ |
190 |
|
|
|
191 |
|
|
|
192 |
|
|
char * |
193 |
greg |
1.4 |
mscrounge(np) /* search free lists to satisfy request */ |
194 |
greg |
1.3 |
register unsigned *np; |
195 |
|
|
{ |
196 |
|
|
char *p; |
197 |
|
|
register int bucket; |
198 |
|
|
register unsigned bsiz; |
199 |
|
|
|
200 |
|
|
for (bucket = FIRSTBUCKET, bsiz = 1<<FIRSTBUCKET; |
201 |
|
|
bucket < NBUCKETS; bucket++, bsiz <<= 1) |
202 |
|
|
if (free_list[bucket] != NULL && bsiz+sizeof(M_HEAD) >= *np) { |
203 |
|
|
*np = bsiz+sizeof(M_HEAD); |
204 |
|
|
p = (char *)free_list[bucket]; |
205 |
|
|
free_list[bucket] = free_list[bucket]->next; |
206 |
greg |
1.9 |
#ifdef MSTATS |
207 |
|
|
b_nscrounged += *np; |
208 |
|
|
#endif |
209 |
greg |
1.3 |
return(p); |
210 |
|
|
} |
211 |
greg |
1.14 |
#ifdef MCOMP |
212 |
|
|
return(mcompact(np)); /* try compaction */ |
213 |
|
|
#else |
214 |
greg |
1.3 |
*np = 0; |
215 |
|
|
return(NULL); |
216 |
greg |
1.14 |
#endif |
217 |
greg |
1.3 |
} |
218 |
|
|
|
219 |
|
|
|
220 |
|
|
char * |
221 |
greg |
1.1 |
bmalloc(n) /* allocate a block of n bytes, sans header */ |
222 |
|
|
register unsigned n; |
223 |
|
|
{ |
224 |
|
|
extern char *sbrk(); |
225 |
greg |
1.3 |
static unsigned pagesz = 0; |
226 |
|
|
static unsigned amnt; |
227 |
greg |
1.1 |
static char *bpos; |
228 |
greg |
1.3 |
static unsigned nrem; |
229 |
|
|
unsigned thisamnt; |
230 |
greg |
1.1 |
register char *p; |
231 |
|
|
|
232 |
|
|
if (pagesz == 0) { /* initialize */ |
233 |
greg |
1.2 |
pagesz = amnt = getpagesize(); |
234 |
greg |
1.1 |
nrem = (int)sbrk(0); /* page align break */ |
235 |
|
|
nrem = pagesz - (nrem&(pagesz-1)); |
236 |
|
|
bpos = sbrk(nrem); /* word aligned! */ |
237 |
|
|
if ((int)bpos == -1) |
238 |
|
|
return(NULL); |
239 |
greg |
1.14 |
#ifdef MSTATS |
240 |
|
|
b_nsbrked += nrem; |
241 |
|
|
#endif |
242 |
greg |
1.1 |
} |
243 |
|
|
|
244 |
|
|
n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align rqst. */ |
245 |
|
|
|
246 |
|
|
if (n > nrem) { /* need more core */ |
247 |
greg |
1.3 |
if (n > amnt) { /* big chunk */ |
248 |
|
|
thisamnt = (n+(pagesz-1))&~(pagesz-1); |
249 |
|
|
if (thisamnt <= MAXINCR) /* increase amnt */ |
250 |
|
|
amnt = thisamnt; |
251 |
|
|
} else |
252 |
|
|
thisamnt = amnt; |
253 |
|
|
p = sbrk(thisamnt); |
254 |
greg |
1.4 |
if ((int)p == -1) { /* uh-oh, ENOMEM */ |
255 |
greg |
1.3 |
thisamnt = n; /* search free lists */ |
256 |
|
|
p = mscrounge(&thisamnt); |
257 |
|
|
if (p == NULL) /* we're really out */ |
258 |
|
|
return(NULL); |
259 |
|
|
} |
260 |
greg |
1.14 |
#ifdef MSTATS |
261 |
|
|
else b_nsbrked += thisamnt; |
262 |
|
|
#endif |
263 |
greg |
1.3 |
if (p != bpos+nrem) { /* not an increment */ |
264 |
greg |
1.4 |
bfree(bpos, nrem); /* free what we have */ |
265 |
greg |
1.1 |
bpos = p; |
266 |
greg |
1.3 |
nrem = thisamnt; |
267 |
greg |
1.4 |
} else /* otherwise tack on */ |
268 |
greg |
1.3 |
nrem += thisamnt; |
269 |
greg |
1.1 |
} |
270 |
|
|
p = bpos; |
271 |
|
|
bpos += n; /* advance */ |
272 |
|
|
nrem -= n; |
273 |
greg |
1.13 |
#ifdef MSTATS |
274 |
|
|
b_nalloced += n; |
275 |
|
|
#endif |
276 |
greg |
1.1 |
return(p); |
277 |
|
|
} |
278 |
|
|
|
279 |
|
|
|
280 |
|
|
bfree(p, n) /* free n bytes of random memory */ |
281 |
greg |
1.2 |
register char *p; |
282 |
|
|
register unsigned n; |
283 |
greg |
1.1 |
{ |
284 |
|
|
register int bucket; |
285 |
|
|
register unsigned bsiz; |
286 |
greg |
1.9 |
|
287 |
greg |
1.15 |
if (n < 1<<FIRSTBUCKET) |
288 |
|
|
return; |
289 |
greg |
1.9 |
#ifdef MSTATS |
290 |
|
|
b_nfreed += n; |
291 |
|
|
#endif |
292 |
greg |
1.4 |
/* align pointer */ |
293 |
greg |
1.6 |
bsiz = BYTES_WORD - ((unsigned)p&(BYTES_WORD-1)); |
294 |
greg |
1.4 |
if (bsiz < BYTES_WORD) { |
295 |
|
|
p += bsiz; |
296 |
|
|
n -= bsiz; |
297 |
greg |
1.1 |
} |
298 |
greg |
1.4 |
/* fill big buckets first */ |
299 |
|
|
for (bucket = NBUCKETS-1, bsiz = 1<<(NBUCKETS-1); |
300 |
|
|
bucket >= FIRSTBUCKET; bucket--, bsiz >>= 1) |
301 |
|
|
if (n >= bsiz+sizeof(M_HEAD)) { |
302 |
|
|
((M_HEAD *)p)->next = free_list[bucket]; |
303 |
|
|
free_list[bucket] = (M_HEAD *)p; |
304 |
|
|
p += bsiz+sizeof(M_HEAD); |
305 |
|
|
n -= bsiz+sizeof(M_HEAD); |
306 |
|
|
} |
307 |
greg |
1.1 |
} |
308 |
|
|
|
309 |
|
|
|
310 |
|
|
char * |
311 |
|
|
malloc(n) /* allocate n bytes of memory */ |
312 |
|
|
unsigned n; |
313 |
|
|
{ |
314 |
greg |
1.6 |
extern int errno; |
315 |
greg |
1.1 |
register M_HEAD *mp; |
316 |
|
|
register int bucket; |
317 |
|
|
register unsigned bsiz; |
318 |
greg |
1.10 |
/* don't return NULL on 0 request */ |
319 |
|
|
if (n == 0) |
320 |
|
|
return(DUMMYLOC); |
321 |
greg |
1.2 |
/* find first bucket that fits */ |
322 |
greg |
1.6 |
for (bucket = FIRSTBUCKET, bsiz = 1<<FIRSTBUCKET; |
323 |
|
|
bucket < NBUCKETS; bucket++, bsiz <<= 1) |
324 |
|
|
if (bsiz >= n) |
325 |
|
|
break; |
326 |
|
|
if (bucket >= NBUCKETS) { |
327 |
|
|
errno = EINVAL; |
328 |
|
|
return(NULL); |
329 |
|
|
} |
330 |
greg |
1.4 |
if (free_list[bucket] == NULL) { /* need more core */ |
331 |
greg |
1.1 |
mp = (M_HEAD *)bmalloc(bsiz+sizeof(M_HEAD)); |
332 |
|
|
if (mp == NULL) |
333 |
|
|
return(NULL); |
334 |
greg |
1.4 |
} else { /* got it */ |
335 |
greg |
1.1 |
mp = free_list[bucket]; |
336 |
|
|
free_list[bucket] = mp->next; |
337 |
|
|
} |
338 |
greg |
1.13 |
#ifdef MSTATS |
339 |
|
|
m_nalloced += bsiz + sizeof(M_HEAD); |
340 |
|
|
m_nwasted += bsiz + sizeof(M_HEAD) - n; |
341 |
|
|
#endif |
342 |
greg |
1.12 |
mp->a.magic = MAGIC; /* tag block */ |
343 |
|
|
mp->a.bucket = bucket; |
344 |
greg |
1.1 |
return((char *)(mp+1)); |
345 |
|
|
} |
346 |
|
|
|
347 |
|
|
|
348 |
|
|
char * |
349 |
|
|
realloc(op, n) /* reallocate memory using malloc() */ |
350 |
greg |
1.6 |
register char *op; |
351 |
greg |
1.1 |
unsigned n; |
352 |
|
|
{ |
353 |
greg |
1.6 |
char *p; |
354 |
greg |
1.1 |
register unsigned on; |
355 |
greg |
1.6 |
/* get old size */ |
356 |
greg |
1.12 |
if (op != NULL && op != DUMMYLOC && ((M_HEAD *)op-1)->a.magic == MAGIC) |
357 |
|
|
on = 1 << ((M_HEAD *)op-1)->a.bucket; |
358 |
greg |
1.5 |
else |
359 |
|
|
on = 0; |
360 |
greg |
1.6 |
if (n <= on && (n > on>>1 || on == 1<<FIRSTBUCKET)) |
361 |
greg |
1.5 |
return(op); /* same bucket */ |
362 |
greg |
1.13 |
if ((p = malloc(n)) == NULL) |
363 |
|
|
return(NULL); |
364 |
|
|
if (on) { |
365 |
greg |
1.1 |
#ifdef BSD |
366 |
greg |
1.2 |
bcopy(op, p, n>on ? on : n); |
367 |
greg |
1.1 |
#else |
368 |
greg |
1.2 |
(void)memcpy(p, op, n>on ? on : n); |
369 |
greg |
1.1 |
#endif |
370 |
greg |
1.13 |
free(op); |
371 |
|
|
} |
372 |
greg |
1.1 |
return(p); |
373 |
|
|
} |
374 |
|
|
|
375 |
|
|
|
376 |
|
|
free(p) /* free memory allocated by malloc */ |
377 |
|
|
char *p; |
378 |
|
|
{ |
379 |
|
|
register M_HEAD *mp; |
380 |
|
|
register int bucket; |
381 |
|
|
|
382 |
greg |
1.10 |
if (p == NULL || p == DUMMYLOC) |
383 |
greg |
1.13 |
return(1); |
384 |
greg |
1.1 |
mp = (M_HEAD *)p - 1; |
385 |
greg |
1.12 |
if (mp->a.magic != MAGIC) /* sanity check */ |
386 |
greg |
1.13 |
return(0); |
387 |
greg |
1.12 |
bucket = mp->a.bucket; |
388 |
greg |
1.1 |
mp->next = free_list[bucket]; |
389 |
|
|
free_list[bucket] = mp; |
390 |
greg |
1.9 |
#ifdef MSTATS |
391 |
|
|
m_nfreed += (1 << bucket) + sizeof(M_HEAD); |
392 |
|
|
#endif |
393 |
greg |
1.13 |
return(1); |
394 |
greg |
1.1 |
} |
395 |
greg |
1.9 |
|
396 |
|
|
|
397 |
|
|
#ifdef MSTATS |
398 |
|
|
printmemstats(fp) /* print memory statistics to stream */ |
399 |
|
|
FILE *fp; |
400 |
|
|
{ |
401 |
|
|
register int i; |
402 |
|
|
int n; |
403 |
|
|
register M_HEAD *mp; |
404 |
|
|
unsigned int total = 0; |
405 |
|
|
|
406 |
|
|
fprintf(fp, "Memory statistics:\n"); |
407 |
greg |
1.14 |
fprintf(fp, "\tbmalloc: %d bytes from sbrk\n", b_nsbrked); |
408 |
greg |
1.9 |
fprintf(fp, "\tbmalloc: %d bytes allocated\n", b_nalloced); |
409 |
|
|
fprintf(fp, "\tbmalloc: %d bytes freed\n", b_nfreed); |
410 |
|
|
fprintf(fp, "\tbmalloc: %d bytes scrounged\n", b_nscrounged); |
411 |
greg |
1.14 |
fprintf(fp, "\tbmalloc: %d bytes compacted\n", b_ncompacted); |
412 |
greg |
1.9 |
fprintf(fp, "\tmalloc: %d bytes allocated\n", m_nalloced); |
413 |
|
|
fprintf(fp, "\tmalloc: %d bytes wasted (%.1f%%)\n", m_nwasted, |
414 |
|
|
100.0*m_nwasted/m_nalloced); |
415 |
|
|
fprintf(fp, "\tmalloc: %d bytes freed\n", m_nfreed); |
416 |
|
|
for (i = NBUCKETS-1; i >= FIRSTBUCKET; i--) { |
417 |
|
|
n = 0; |
418 |
|
|
for (mp = free_list[i]; mp != NULL; mp = mp->next) |
419 |
|
|
n++; |
420 |
|
|
if (n) { |
421 |
|
|
fprintf(fp, "\t%d * %u\n", n, 1<<i); |
422 |
|
|
total += n * ((1<<i) + sizeof(M_HEAD)); |
423 |
|
|
} |
424 |
|
|
} |
425 |
|
|
fprintf(fp, "\t %u total bytes in free list\n", total); |
426 |
|
|
} |
427 |
greg |
1.1 |
#endif |