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
|
// $G $D/$F.go && $L $F.$A && ./$A.out
// Copyright 2009 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.
// Random malloc test.
package main
import (
"flag"
"rand"
"runtime"
"unsafe"
)
var chatty = flag.Bool("v", false, "chatty")
var footprint uint64
var allocated uint64
func bigger() {
if f := runtime.MemStats.Sys; footprint < f {
footprint = f
if *chatty {
println("Footprint", footprint, " for ", allocated)
}
if footprint > 1e9 {
println("too big")
panic("fail")
}
}
}
// Prime the data structures by allocating one of
// each block in order. After this, there should be
// little reason to ask for more memory from the OS.
func prime() {
for i := 0; i < 16; i++ {
b := runtime.Alloc(1 << uint(i))
runtime.Free(b)
}
for i := uintptr(0); i < 256; i++ {
b := runtime.Alloc(i << 12)
runtime.Free(b)
}
}
func memset(b *byte, c byte, n uintptr) {
np := uintptr(n)
for i := uintptr(0); i < np; i++ {
*(*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(b)) + i)) = c
}
}
func main() {
flag.Parse()
// prime()
var blocks [1]struct {
base *byte
siz uintptr
}
for i := 0; i < 1<<10; i++ {
if i%(1<<10) == 0 && *chatty {
println(i)
}
b := rand.Int() % len(blocks)
if blocks[b].base != nil {
// println("Free", blocks[b].siz, blocks[b].base)
runtime.Free(blocks[b].base)
blocks[b].base = nil
allocated -= uint64(blocks[b].siz)
continue
}
siz := uintptr(rand.Int() >> (11 + rand.Uint32()%20))
base := runtime.Alloc(siz)
// ptr := uintptr(syscall.BytePtr(base))+uintptr(siz/2)
// obj, size, ref, ok := allocator.find(ptr)
// if obj != base || *ref != 0 || !ok {
// println("find", siz, obj, ref, ok)
// panic("fail")
// }
blocks[b].base = base
blocks[b].siz = siz
allocated += uint64(siz)
// println("Alloc", siz, base)
memset(base, 0xbb, siz)
bigger()
}
}
|
