1 #include <u.h>
2 #include <libc.h>
3 #include <venti.h>
4 
5 enum {
6 	IdealAlignment = 32,
7 	ChunkSize 	= 128*1024,
8 };
9 
10 
11 void
12 vtfree(void *p)
13 {
14 	if(p == 0)
15 		return;
16 	free(p);
17 }
18 
19 void *
20 vtmalloc(int size)
21 {
22 	void *p;
23 
24 	p = malloc(size);
25 	if(p == 0)
26 		sysfatal("vtmalloc: out of memory");
27 	setmalloctag(p, getcallerpc(&size));
28 	return p;
29 }
30 
31 void *
32 vtmallocz(int size)
33 {
34 	void *p = vtmalloc(size);
35 	memset(p, 0, size);
36 	setmalloctag(p, getcallerpc(&size));
37 	return p;
38 }
39 
40 void *
41 vtrealloc(void *p, int size)
42 {
43 	if(p == nil)
44 		return vtmalloc(size);
45 	p = realloc(p, size);
46 	if(p == 0)
47 		sysfatal("vtMemRealloc: out of memory");
48 	setrealloctag(p, getcallerpc(&size));
49 	return p;
50 }
51 
52 void *
53 vtbrk(int n)
54 {
55 	static Lock lk;
56 	static uchar *buf;
57 	static int nbuf;
58 	static int nchunk;
59 	int align, pad;
60 	void *p;
61 
62 	if(n >= IdealAlignment)
63 		align = IdealAlignment;
64 	else if(n > 8)
65 		align = 8;
66 	else	
67 		align = 4;
68 
69 	lock(&lk);
70 	pad = (align - (ulong)buf) & (align-1);
71 	if(n + pad > nbuf) {
72 		buf = vtmallocz(ChunkSize);
73 		nbuf = ChunkSize;
74 		pad = (align - (ulong)buf) & (align-1);
75 		nchunk++;
76 	}
77 
78 	assert(n + pad <= nbuf);	
79 	
80 	p = buf + pad;
81 	buf += pad + n;
82 	nbuf -= pad + n;
83 	unlock(&lk);
84 
85 	return p;
86 }
87