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
|
// 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.
// +build dragonfly freebsd nacl netbsd openbsd solaris
package runtime
import "unsafe"
//go:nosplit
func sysAlloc(n uintptr, stat *uint64) unsafe.Pointer {
v := unsafe.Pointer(mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0))
if uintptr(v) < 4096 {
return nil
}
xadd64(stat, int64(n))
return v
}
func sysUnused(v unsafe.Pointer, n uintptr) {
madvise(v, n, _MADV_FREE)
}
func sysUsed(v unsafe.Pointer, n uintptr) {
}
func sysFree(v unsafe.Pointer, n uintptr, stat *uint64) {
xadd64(stat, -int64(n))
munmap(v, n)
}
func sysFault(v unsafe.Pointer, n uintptr) {
mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
}
func sysReserve(v unsafe.Pointer, n uintptr, reserved *bool) unsafe.Pointer {
// On 64-bit, people with ulimit -v set complain if we reserve too
// much address space. Instead, assume that the reservation is okay
// and check the assumption in SysMap.
if ptrSize == 8 && uint64(n) > 1<<32 || goos_nacl != 0 {
*reserved = false
return v
}
p := unsafe.Pointer(mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0))
if uintptr(p) < 4096 {
return nil
}
*reserved = true
return p
}
func sysMap(v unsafe.Pointer, n uintptr, reserved bool, stat *uint64) {
const _ENOMEM = 12
xadd64(stat, int64(n))
// On 64-bit, we don't actually have v reserved, so tread carefully.
if !reserved {
flags := int32(_MAP_ANON | _MAP_PRIVATE)
if GOOS == "dragonfly" {
// TODO(jsing): For some reason DragonFly seems to return
// memory at a different address than we requested, even when
// there should be no reason for it to do so. This can be
// avoided by using MAP_FIXED, but I'm not sure we should need
// to do this - we do not on other platforms.
flags |= _MAP_FIXED
}
p := mmap(v, n, _PROT_READ|_PROT_WRITE, flags, -1, 0)
if uintptr(p) == _ENOMEM {
gothrow("runtime: out of memory")
}
if p != v {
print("runtime: address space conflict: map(", v, ") = ", p, "\n")
gothrow("runtime: address space conflict")
}
return
}
p := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
if uintptr(p) == _ENOMEM {
gothrow("runtime: out of memory")
}
if p != v {
gothrow("runtime: cannot map pages in arena address space")
}
}
|
