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https://github.com/golang/go
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4f61fc96b2
The ken directory is untouched so we have some examples with explicit semis. R=gri CC=golang-dev https://golang.org/cl/2157041
92 lines
1.9 KiB
Go
92 lines
1.9 KiB
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Random malloc test.
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package main
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import (
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"flag"
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"rand"
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"runtime"
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"unsafe"
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)
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var chatty = flag.Bool("v", false, "chatty")
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var footprint uint64
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var allocated uint64
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func bigger() {
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if f := runtime.MemStats.Sys; footprint < f {
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footprint = f
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if *chatty {
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println("Footprint", footprint, " for ", allocated)
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}
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if footprint > 1e9 {
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println("too big")
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panic("fail")
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}
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}
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}
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// Prime the data structures by allocating one of
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// each block in order. After this, there should be
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// little reason to ask for more memory from the OS.
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func prime() {
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for i := 0; i < 16; i++ {
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b := runtime.Alloc(1 << uint(i))
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runtime.Free(b)
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}
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for i := uintptr(0); i < 256; i++ {
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b := runtime.Alloc(i << 12)
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runtime.Free(b)
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}
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}
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func memset(b *byte, c byte, n uintptr) {
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np := uintptr(n)
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for i := uintptr(0); i < np; i++ {
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*(*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(b)) + i)) = c
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}
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}
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func main() {
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flag.Parse()
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// prime()
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var blocks [1]struct {
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base *byte
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siz uintptr
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}
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for i := 0; i < 1<<10; i++ {
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if i%(1<<10) == 0 && *chatty {
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println(i)
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}
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b := rand.Int() % len(blocks)
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if blocks[b].base != nil {
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// println("Free", blocks[b].siz, blocks[b].base)
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runtime.Free(blocks[b].base)
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blocks[b].base = nil
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allocated -= uint64(blocks[b].siz)
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continue
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}
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siz := uintptr(rand.Int() >> (11 + rand.Uint32()%20))
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base := runtime.Alloc(siz)
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// ptr := uintptr(syscall.BytePtr(base))+uintptr(siz/2)
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// obj, size, ref, ok := allocator.find(ptr)
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// if obj != base || *ref != 0 || !ok {
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// println("find", siz, obj, ref, ok)
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// panic("fail")
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// }
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blocks[b].base = base
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blocks[b].siz = siz
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allocated += uint64(siz)
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// println("Alloc", siz, base)
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memset(base, 0xbb, siz)
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bigger()
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}
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}
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