1 #include "c.h"
2 struct block {
3 struct block *next;
4 char *limit;
5 char *avail;
6 };
7 union align {
8 long l;
9 char *p;
10 double d;
11 int (*f)(void);
12 };
13 union header {
14 struct block b;
15 union align a;
16 };
17 #ifdef PURIFY
18 union header *arena[3];
19
allocate(unsigned long n,unsigned a)20 void *allocate(unsigned long n, unsigned a) {
21 union header *new = malloc(sizeof *new + n);
22
23 assert(a < NELEMS(arena));
24 if (new == NULL) {
25 error("insufficient memory\n");
26 exit(1);
27 }
28 new->b.next = (void *)arena[a];
29 arena[a] = new;
30 return new + 1;
31 }
32
deallocate(unsigned a)33 void deallocate(unsigned a) {
34 union header *p, *q;
35
36 assert(a < NELEMS(arena));
37 for (p = arena[a]; p; p = q) {
38 q = (void *)p->b.next;
39 free(p);
40 }
41 arena[a] = NULL;
42 }
43
newarray(unsigned long m,unsigned long n,unsigned a)44 void *newarray(unsigned long m, unsigned long n, unsigned a) {
45 return allocate(m*n, a);
46 }
47 #else
48 static struct block
49 first[] = { { NULL }, { NULL }, { NULL } },
50 *arena[] = { &first[0], &first[1], &first[2] };
51 static struct block *freeblocks;
52
allocate(unsigned long n,unsigned a)53 void *allocate(unsigned long n, unsigned a) {
54 struct block *ap;
55
56 assert(a < NELEMS(arena));
57 assert(n > 0);
58 ap = arena[a];
59 n = roundup(n, sizeof (union align));
60 while (n > ap->limit - ap->avail) {
61 if ((ap->next = freeblocks) != NULL) {
62 freeblocks = freeblocks->next;
63 ap = ap->next;
64 } else
65 {
66 unsigned m = sizeof (union header) + n + roundup(10*1024, sizeof (union align));
67 ap->next = malloc(m);
68 ap = ap->next;
69 if (ap == NULL) {
70 error("insufficient memory\n");
71 exit(1);
72 }
73 ap->limit = (char *)ap + m;
74 }
75 ap->avail = (char *)((union header *)ap + 1);
76 ap->next = NULL;
77 arena[a] = ap;
78
79 }
80 ap->avail += n;
81 return ap->avail - n;
82 }
83
newarray(unsigned long m,unsigned long n,unsigned a)84 void *newarray(unsigned long m, unsigned long n, unsigned a) {
85 return allocate(m*n, a);
86 }
deallocate(unsigned a)87 void deallocate(unsigned a) {
88 assert(a < NELEMS(arena));
89 arena[a]->next = freeblocks;
90 freeblocks = first[a].next;
91 first[a].next = NULL;
92 arena[a] = &first[a];
93 }
94 #endif
95