1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "runtime.h"
#include "defs_GOOS_GOARCH.h"
#include "arch_GOARCH.h"
#include "malloc.h"
#include "os_GOOS.h"
#include "textflag.h"
extern byte runtime·end[];
#pragma dataflag NOPTR
static byte *bloc = { runtime·end };
static Mutex memlock;
enum
{
Round = PAGESIZE-1
};
static void*
brk(uintptr nbytes)
{
uintptr bl;
runtime·lock(&memlock);
// Plan 9 sbrk from /sys/src/libc/9sys/sbrk.c
bl = ((uintptr)bloc + Round) & ~Round;
if(runtime·brk_((void*)(bl + nbytes)) < 0) {
runtime·unlock(&memlock);
return nil;
}
bloc = (byte*)bl + nbytes;
runtime·unlock(&memlock);
return (void*)bl;
}
static void
sysalloc(void)
{
uintptr nbytes;
uint64 *stat;
void *p;
nbytes = g->m->scalararg[0];
stat = g->m->ptrarg[0];
g->m->scalararg[0] = 0;
g->m->ptrarg[0] = nil;
p = brk(nbytes);
if(p != nil)
runtime·xadd64(stat, nbytes);
g->m->ptrarg[0] = p;
}
#pragma textflag NOSPLIT
void*
runtime·sysAlloc(uintptr nbytes, uint64 *stat)
{
void (*fn)(void);
void *p;
g->m->scalararg[0] = nbytes;
g->m->ptrarg[0] = stat;
fn = sysalloc;
runtime·onM(&fn);
p = g->m->ptrarg[0];
g->m->ptrarg[0] = nil;
return p;
}
void
runtime·SysFree(void *v, uintptr nbytes, uint64 *stat)
{
runtime·xadd64(stat, -(uint64)nbytes);
runtime·lock(&memlock);
// from tiny/mem.c
// Push pointer back if this is a free
// of the most recent sysAlloc.
nbytes += (nbytes + Round) & ~Round;
if(bloc == (byte*)v+nbytes)
bloc -= nbytes;
runtime·unlock(&memlock);
}
void
runtime·SysUnused(void *v, uintptr nbytes)
{
USED(v, nbytes);
}
void
runtime·SysUsed(void *v, uintptr nbytes)
{
USED(v, nbytes);
}
void
runtime·SysMap(void *v, uintptr nbytes, bool reserved, uint64 *stat)
{
// SysReserve has already allocated all heap memory,
// but has not adjusted stats.
USED(v, reserved);
runtime·xadd64(stat, nbytes);
}
void
runtime·SysFault(void *v, uintptr nbytes)
{
USED(v, nbytes);
}
void*
runtime·SysReserve(void *v, uintptr nbytes, bool *reserved)
{
USED(v);
*reserved = true;
return brk(nbytes);
}
|
