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
|
// 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.
package runtime
import "unsafe"
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//go:nosplit
func sysAlloc(n uintptr, sysStat *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
}
mSysStatInc(sysStat, n)
return v
}
func sysUnused(v unsafe.Pointer, n uintptr) {
// Linux's MADV_DONTNEED is like BSD's MADV_FREE.
madvise(v, n, _MADV_FREE)
}
func sysUsed(v unsafe.Pointer, n uintptr) {
}
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//go:nosplit
func sysFree(v unsafe.Pointer, n uintptr, sysStat *uint64) {
mSysStatDec(sysStat, 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 {
*reserved = true
p := unsafe.Pointer(mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0))
if uintptr(p) < 4096 {
return nil
}
return p
}
const (
_ENOMEM = 12
)
func sysMap(v unsafe.Pointer, n uintptr, reserved bool, sysStat *uint64) {
mSysStatInc(sysStat, n)
p := unsafe.Pointer(mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0))
if uintptr(p) == _ENOMEM {
throw("runtime: out of memory")
}
if p != v {
throw("runtime: cannot map pages in arena address space")
}
}
|
