1 |
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/* Copyright (c) 1990 Regents of the University of California */ |
2 |
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|
1 |
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#ifndef lint |
2 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
2 |
> |
static const char RCSid[] = "$Id$"; |
3 |
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#endif |
6 |
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|
4 |
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/* |
5 |
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* Fast malloc for memory hogs and VM environments. |
6 |
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* Performs a minimum of searching through free lists. |
12 |
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* call mscrounge() if sbrk fails. |
13 |
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* mscrounge() returns whatever free memory it can find to satisfy the |
14 |
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* request along with the number of bytes (modified). |
15 |
+ |
* mcompact() takes the same arguments as mscrounge() (and is in fact |
16 |
+ |
* called by mscrounge() under dire circumstances), but it uses |
17 |
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* memory compaction to return a larger block. (MCOMP) |
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* |
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* Greg Ward Lawrence Berkeley Laboratory |
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*/ |
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|
22 |
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#include "copyright.h" |
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|
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#include <errno.h> |
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#include <string.h> |
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|
27 |
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|
28 |
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#ifdef MSTATS |
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#include <stdio.h> |
30 |
+ |
static unsigned b_nsbrked = 0; |
31 |
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static unsigned b_nalloced = 0; |
32 |
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static unsigned b_nfreed = 0; |
33 |
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static unsigned b_nscrounged = 0; |
34 |
+ |
static unsigned b_ncompacted = 0; |
35 |
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static unsigned m_nalloced = 0; |
36 |
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static unsigned m_nfreed = 0; |
37 |
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static unsigned m_nwasted = 0; |
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#define NULL 0 |
40 |
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#endif |
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|
42 |
< |
#ifndef ALIGN |
43 |
< |
#define ALIGN int /* align type */ |
42 |
> |
#ifndef ALIGNT |
43 |
> |
#define ALIGNT int /* align type */ |
44 |
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#endif |
45 |
< |
#define BYTES_WORD sizeof(ALIGN) |
45 |
> |
#define BYTES_WORD sizeof(ALIGNT) |
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|
47 |
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#ifndef MAXINCR |
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#define MAXINCR (1<<16) /* largest sbrk(2) increment */ |
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|
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#ifdef NOVMEM |
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#define getpagesize() 1024 |
49 |
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#endif |
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/* malloc free lists */ |
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typedef union m_head { |
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union m_head *next; |
53 |
< |
int bucket; |
54 |
< |
ALIGN dummy; |
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> |
struct { |
54 |
> |
short magic; |
55 |
> |
short bucket; |
56 |
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} a; |
57 |
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ALIGNT dummy; |
58 |
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} M_HEAD; |
59 |
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|
60 |
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#define MAGIC 0x1a2 /* magic number for allocated memory */ |
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|
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#define FIRSTBUCKET 3 |
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#define NBUCKETS 30 |
64 |
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|
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static M_HEAD *free_list[NBUCKETS]; |
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|
67 |
< |
static char DUMMYLOC[BYTES_WORD]; |
67 |
> |
static ALIGNT dummy_mem; |
68 |
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|
69 |
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static char *memlim[2]; |
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|
71 |
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#define DUMMYLOC ((char *)&dummy_mem) |
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|
73 |
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#define BADPTR(p) ((p) < memlim[0] | (p) >= memlim[1]) |
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|
75 |
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#ifdef MCOMP /* memory compaction routines */ |
76 |
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static char seedtab[1024]; /* seed for compaction table */ |
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|
78 |
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static struct mblk { |
79 |
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char *ptr; /* pointer to memory block */ |
80 |
+ |
unsigned siz; /* size of memory block */ |
81 |
+ |
} cptab = {seedtab, sizeof(seedtab)}; |
82 |
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|
83 |
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#define mtab(mb) ((struct mblk *)(mb)->ptr) |
84 |
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#define mtablen(mb) ((mb)->siz/sizeof(struct mblk)) |
85 |
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|
86 |
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|
87 |
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static int |
88 |
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mbcmp(m1, m2) /* compare memory block locations */ |
89 |
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register struct mblk *m1, *m2; |
90 |
+ |
{ |
91 |
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/* put empty blocks at end */ |
92 |
+ |
if (m1->siz == 0) |
93 |
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return(m2->siz == 0 ? 0 : 1); |
94 |
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if (m2->siz == 0) |
95 |
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return(-1); |
96 |
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/* otherwise, ascending order */ |
97 |
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return(m1->ptr - m2->ptr); |
98 |
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} |
99 |
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|
100 |
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|
101 |
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int |
102 |
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compactfree() /* compact free lists (moving to table) */ |
103 |
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{ |
104 |
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register struct mblk *tp; |
105 |
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register int bucket; |
106 |
+ |
unsigned n, bsiz, ncomp; |
107 |
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/* fill table from free lists */ |
108 |
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tp = mtab(&cptab); n = mtablen(&cptab); |
109 |
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bucket = NBUCKETS-1; bsiz = 1<<(NBUCKETS-1); |
110 |
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ncomp = 0; |
111 |
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for ( ; ; ) { |
112 |
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while (tp->siz) { /* find empty slot */ |
113 |
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if (--n == 0) |
114 |
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goto loopexit; |
115 |
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tp++; |
116 |
+ |
} |
117 |
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while (free_list[bucket] == NULL) { /* find block */ |
118 |
+ |
if (--bucket < FIRSTBUCKET) |
119 |
+ |
goto loopexit; |
120 |
+ |
bsiz >>= 1; |
121 |
+ |
} |
122 |
+ |
tp->ptr = (char *)free_list[bucket]; |
123 |
+ |
ncomp += (tp->siz = bsiz + sizeof(M_HEAD)); |
124 |
+ |
free_list[bucket] = free_list[bucket]->next; |
125 |
+ |
} |
126 |
+ |
loopexit: |
127 |
+ |
if (ncomp == 0) |
128 |
+ |
return(0); /* nothing new to compact */ |
129 |
+ |
#ifdef MSTATS |
130 |
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b_ncompacted += ncomp; |
131 |
+ |
#endif |
132 |
+ |
tp = mtab(&cptab); n = mtablen(&cptab); /* sort table */ |
133 |
+ |
qsort((char *)tp, n, sizeof(struct mblk), mbcmp); |
134 |
+ |
ncomp = 0; /* collect blocks */ |
135 |
+ |
while (--n && tp[1].siz) { |
136 |
+ |
if (tp[0].ptr + tp[0].siz == tp[1].ptr) { |
137 |
+ |
tp[1].ptr = tp[0].ptr; |
138 |
+ |
tp[1].siz += tp[0].siz; |
139 |
+ |
ncomp += tp[0].siz; |
140 |
+ |
tp[0].siz = 0; |
141 |
+ |
} |
142 |
+ |
tp++; |
143 |
+ |
} |
144 |
+ |
return(ncomp); |
145 |
+ |
} |
146 |
+ |
|
147 |
+ |
|
148 |
|
char * |
149 |
+ |
mcompact(np) /* compact free lists to satisfy request */ |
150 |
+ |
unsigned *np; |
151 |
+ |
{ |
152 |
+ |
struct mblk *tab; |
153 |
+ |
unsigned tablen; |
154 |
+ |
register struct mblk *bp, *big; |
155 |
+ |
|
156 |
+ |
for ( ; ; ) { |
157 |
+ |
/* compact free lists */ |
158 |
+ |
while (compactfree()) |
159 |
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; |
160 |
+ |
/* find largest block */ |
161 |
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tab = mtab(&cptab); tablen = mtablen(&cptab); |
162 |
+ |
big = tab; |
163 |
+ |
bp = tab + tablen; |
164 |
+ |
while (--bp > tab) |
165 |
+ |
if (bp->siz > big->siz) |
166 |
+ |
big = bp; |
167 |
+ |
if (big->siz >= *np) { /* big enough? */ |
168 |
+ |
*np = big->siz; |
169 |
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big->siz = 0; /* remove from table */ |
170 |
+ |
return(big->ptr); /* return it */ |
171 |
+ |
} |
172 |
+ |
if (mtablen(big) <= tablen) { |
173 |
+ |
*np = 0; /* cannot grow table */ |
174 |
+ |
return(NULL); /* report failure */ |
175 |
+ |
} |
176 |
+ |
/* enlarge table, free old one */ |
177 |
+ |
mtab(big)[0].ptr = cptab.ptr; |
178 |
+ |
mtab(big)[0].siz = cptab.siz; |
179 |
+ |
cptab.ptr = big->ptr; |
180 |
+ |
cptab.siz = big->siz; |
181 |
+ |
big->siz = 0; /* clear and copy */ |
182 |
+ |
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 |
+ |
} /* next round */ |
187 |
+ |
} |
188 |
+ |
#endif /* MCOMP */ |
189 |
+ |
|
190 |
+ |
|
191 |
+ |
char * |
192 |
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mscrounge(np) /* search free lists to satisfy request */ |
193 |
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register unsigned *np; |
194 |
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{ |
207 |
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#endif |
208 |
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return(p); |
209 |
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} |
210 |
+ |
#ifdef MCOMP |
211 |
+ |
return(mcompact(np)); /* try compaction */ |
212 |
+ |
#else |
213 |
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*np = 0; |
214 |
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return(NULL); |
215 |
+ |
#endif |
216 |
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} |
217 |
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|
218 |
|
|
228 |
|
unsigned thisamnt; |
229 |
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register char *p; |
230 |
|
|
97 |
– |
#ifdef MSTATS |
98 |
– |
b_nalloced += n; |
99 |
– |
#endif |
231 |
|
if (pagesz == 0) { /* initialize */ |
232 |
|
pagesz = amnt = getpagesize(); |
233 |
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nrem = (int)sbrk(0); /* page align break */ |
234 |
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nrem = pagesz - (nrem&(pagesz-1)); |
235 |
< |
bpos = sbrk(nrem); /* word aligned! */ |
235 |
> |
bpos = sbrk(nrem); |
236 |
|
if ((int)bpos == -1) |
237 |
|
return(NULL); |
238 |
+ |
#ifdef MSTATS |
239 |
+ |
b_nsbrked += nrem; |
240 |
+ |
#endif |
241 |
+ |
bpos += nrem & (BYTES_WORD-1); /* align pointer */ |
242 |
+ |
nrem &= ~(BYTES_WORD-1); |
243 |
+ |
memlim[0] = bpos; |
244 |
+ |
memlim[1] = bpos + nrem; |
245 |
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} |
246 |
|
|
247 |
|
n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align rqst. */ |
248 |
|
|
249 |
|
if (n > nrem) { /* need more core */ |
250 |
+ |
tryagain: |
251 |
|
if (n > amnt) { /* big chunk */ |
252 |
|
thisamnt = (n+(pagesz-1))&~(pagesz-1); |
253 |
|
if (thisamnt <= MAXINCR) /* increase amnt */ |
256 |
|
thisamnt = amnt; |
257 |
|
p = sbrk(thisamnt); |
258 |
|
if ((int)p == -1) { /* uh-oh, ENOMEM */ |
259 |
< |
thisamnt = n; /* search free lists */ |
260 |
< |
p = mscrounge(&thisamnt); |
261 |
< |
if (p == NULL) /* we're really out */ |
259 |
> |
errno = 0; /* call cavalry */ |
260 |
> |
if (thisamnt >= n+pagesz) { |
261 |
> |
amnt = pagesz; /* minimize request */ |
262 |
> |
goto tryagain; |
263 |
> |
} |
264 |
> |
thisamnt = n; |
265 |
> |
p = mscrounge(&thisamnt); /* search free lists */ |
266 |
> |
if (p == NULL) { /* we're really out */ |
267 |
> |
errno = ENOMEM; |
268 |
|
return(NULL); |
269 |
+ |
} |
270 |
|
} |
271 |
+ |
#ifdef MSTATS |
272 |
+ |
else b_nsbrked += thisamnt; |
273 |
+ |
#endif |
274 |
|
if (p != bpos+nrem) { /* not an increment */ |
275 |
|
bfree(bpos, nrem); /* free what we have */ |
276 |
|
bpos = p; |
277 |
|
nrem = thisamnt; |
278 |
|
} else /* otherwise tack on */ |
279 |
|
nrem += thisamnt; |
280 |
+ |
if (bpos < memlim[0]) |
281 |
+ |
memlim[0] = bpos; |
282 |
+ |
if (bpos + nrem > memlim[1]) |
283 |
+ |
memlim[1] = bpos + nrem; |
284 |
|
} |
285 |
|
p = bpos; |
286 |
|
bpos += n; /* advance */ |
287 |
|
nrem -= n; |
288 |
+ |
#ifdef MSTATS |
289 |
+ |
b_nalloced += n; |
290 |
+ |
#endif |
291 |
|
return(p); |
292 |
|
} |
293 |
|
|
299 |
|
register int bucket; |
300 |
|
register unsigned bsiz; |
301 |
|
|
302 |
+ |
if (n < 1<<FIRSTBUCKET || p == NULL) |
303 |
+ |
return; |
304 |
|
#ifdef MSTATS |
305 |
|
b_nfreed += n; |
306 |
|
#endif |
310 |
|
p += bsiz; |
311 |
|
n -= bsiz; |
312 |
|
} |
313 |
+ |
if (p < memlim[0]) |
314 |
+ |
memlim[0] = p; |
315 |
+ |
if (p + n > memlim[1]) |
316 |
+ |
memlim[1] = p + n; |
317 |
|
/* fill big buckets first */ |
318 |
|
for (bucket = NBUCKETS-1, bsiz = 1<<(NBUCKETS-1); |
319 |
|
bucket >= FIRSTBUCKET; bucket--, bsiz >>= 1) |
330 |
|
malloc(n) /* allocate n bytes of memory */ |
331 |
|
unsigned n; |
332 |
|
{ |
171 |
– |
extern int errno; |
333 |
|
register M_HEAD *mp; |
334 |
|
register int bucket; |
335 |
|
register unsigned bsiz; |
345 |
|
errno = EINVAL; |
346 |
|
return(NULL); |
347 |
|
} |
187 |
– |
#ifdef MSTATS |
188 |
– |
m_nalloced += bsiz + sizeof(M_HEAD); |
189 |
– |
m_nwasted += bsiz + sizeof(M_HEAD) - n; |
190 |
– |
#endif |
348 |
|
if (free_list[bucket] == NULL) { /* need more core */ |
349 |
|
mp = (M_HEAD *)bmalloc(bsiz+sizeof(M_HEAD)); |
350 |
|
if (mp == NULL) |
353 |
|
mp = free_list[bucket]; |
354 |
|
free_list[bucket] = mp->next; |
355 |
|
} |
356 |
< |
mp->bucket = bucket; /* tag block */ |
356 |
> |
#ifdef MSTATS |
357 |
> |
m_nalloced += bsiz + sizeof(M_HEAD); |
358 |
> |
m_nwasted += bsiz + sizeof(M_HEAD) - n; |
359 |
> |
#endif |
360 |
> |
mp->a.magic = MAGIC; /* tag block */ |
361 |
> |
mp->a.bucket = bucket; |
362 |
|
return((char *)(mp+1)); |
363 |
|
} |
364 |
|
|
371 |
|
char *p; |
372 |
|
register unsigned on; |
373 |
|
/* get old size */ |
374 |
< |
if (op != NULL && op != DUMMYLOC) |
375 |
< |
on = 1 << ((M_HEAD *)op-1)->bucket; |
374 |
> |
if (op != DUMMYLOC && !BADPTR(op) && |
375 |
> |
((M_HEAD *)op-1)->a.magic == MAGIC) |
376 |
> |
on = 1 << ((M_HEAD *)op-1)->a.bucket; |
377 |
|
else |
378 |
|
on = 0; |
379 |
|
if (n <= on && (n > on>>1 || on == 1<<FIRSTBUCKET)) |
380 |
|
return(op); /* same bucket */ |
381 |
< |
p = malloc(n); |
382 |
< |
if (p != NULL) |
383 |
< |
#ifdef BSD |
384 |
< |
bcopy(op, p, n>on ? on : n); |
385 |
< |
#else |
386 |
< |
(void)memcpy(p, op, n>on ? on : n); |
224 |
< |
#endif |
225 |
< |
free(op); |
381 |
> |
if ((p = malloc(n)) == NULL) |
382 |
> |
return(n<=on ? op : NULL); |
383 |
> |
if (on) { |
384 |
> |
memcpy(p, op, n>on ? on : n); |
385 |
> |
free(op); |
386 |
> |
} |
387 |
|
return(p); |
388 |
|
} |
389 |
|
|
394 |
|
register M_HEAD *mp; |
395 |
|
register int bucket; |
396 |
|
|
397 |
< |
if (p == NULL || p == DUMMYLOC) |
398 |
< |
return; |
397 |
> |
if (p == DUMMYLOC) |
398 |
> |
return(1); |
399 |
> |
if (BADPTR(p)) |
400 |
> |
goto invalid; |
401 |
|
mp = (M_HEAD *)p - 1; |
402 |
< |
bucket = mp->bucket; |
402 |
> |
if (mp->a.magic != MAGIC) /* sanity check */ |
403 |
> |
goto invalid; |
404 |
> |
bucket = mp->a.bucket; |
405 |
> |
if (bucket < FIRSTBUCKET | bucket >= NBUCKETS) |
406 |
> |
goto invalid; |
407 |
|
mp->next = free_list[bucket]; |
408 |
|
free_list[bucket] = mp; |
409 |
|
#ifdef MSTATS |
410 |
|
m_nfreed += (1 << bucket) + sizeof(M_HEAD); |
411 |
|
#endif |
412 |
+ |
return(1); |
413 |
+ |
invalid: |
414 |
+ |
errno = EINVAL; |
415 |
+ |
return(0); |
416 |
|
} |
417 |
|
|
418 |
|
|
248 |
– |
#ifndef NOVMEM |
249 |
– |
#ifndef BSD |
250 |
– |
#include <sys/var.h> |
251 |
– |
int |
252 |
– |
getpagesize() /* use SYSV var structure to get page size */ |
253 |
– |
{ |
254 |
– |
struct var v; |
255 |
– |
|
256 |
– |
uvar(&v); |
257 |
– |
return(1 << v.v_pageshift); |
258 |
– |
} |
259 |
– |
#endif |
260 |
– |
#endif |
261 |
– |
|
262 |
– |
|
419 |
|
#ifdef MSTATS |
420 |
|
printmemstats(fp) /* print memory statistics to stream */ |
421 |
|
FILE *fp; |
426 |
|
unsigned int total = 0; |
427 |
|
|
428 |
|
fprintf(fp, "Memory statistics:\n"); |
429 |
+ |
fprintf(fp, "\tbmalloc: %d bytes from sbrk\n", b_nsbrked); |
430 |
|
fprintf(fp, "\tbmalloc: %d bytes allocated\n", b_nalloced); |
431 |
|
fprintf(fp, "\tbmalloc: %d bytes freed\n", b_nfreed); |
432 |
|
fprintf(fp, "\tbmalloc: %d bytes scrounged\n", b_nscrounged); |
433 |
+ |
fprintf(fp, "\tbmalloc: %d bytes compacted\n", b_ncompacted); |
434 |
|
fprintf(fp, "\tmalloc: %d bytes allocated\n", m_nalloced); |
435 |
|
fprintf(fp, "\tmalloc: %d bytes wasted (%.1f%%)\n", m_nwasted, |
436 |
|
100.0*m_nwasted/m_nalloced); |