mirror of
https://github.com/golang/go
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72 lines
1.2 KiB
Go
72 lines
1.2 KiB
Go
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// run
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// Copyright 2019 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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// Make sure we use the deferreturn live map instead of
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// the entry live map when handling a segv in a function
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// that defers.
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package main
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import "runtime"
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var finalized bool
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var err string
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type HeapObj [8]int64
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const filler int64 = 0x123456789abcdef0
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func (h *HeapObj) init() {
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for i := 0; i < len(*h); i++ {
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h[i] = filler
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}
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}
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func (h *HeapObj) check() {
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for i := 0; i < len(*h); i++ {
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if h[i] != filler {
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err = "filler overwritten"
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}
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}
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}
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func gc(shouldFinalize bool) {
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runtime.GC()
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runtime.GC()
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runtime.GC()
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if shouldFinalize != finalized {
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err = "heap object finalized at the wrong time"
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}
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}
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func main() {
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h := new(HeapObj)
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h.init()
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runtime.SetFinalizer(h, func(h *HeapObj) {
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finalized = true
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})
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gc(false)
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g(h)
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if err != "" {
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panic(err)
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}
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}
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func g(h *HeapObj) {
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gc(false)
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h.check()
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// h is now unused
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defer func() {
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// h should not be live here. Previously we used to
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// use the function entry point as the place to get
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// the live map when handling a segv.
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gc(true)
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recover()
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}()
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*(*int)(nil) = 0 // trigger a segv
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return
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}
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