52 lines
883 B
Go
52 lines
883 B
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 151.
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// Defer2 demonstrates a deferred call to runtime.Stack during a panic.
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package main
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import (
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"fmt"
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"os"
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"runtime"
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)
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//!+
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func main() {
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defer printStack()
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f(3)
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}
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func printStack() {
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var buf [4096]byte
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n := runtime.Stack(buf[:], false)
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os.Stdout.Write(buf[:n])
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}
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//!-
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func f(x int) {
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fmt.Printf("f(%d)\n", x+0/x) // panics if x == 0
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defer fmt.Printf("defer %d\n", x)
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f(x - 1)
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}
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/*
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//!+printstack
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goroutine 1 [running]:
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main.printStack()
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src/gopl.io/ch5/defer2/defer.go:20
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main.f(0)
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src/gopl.io/ch5/defer2/defer.go:27
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main.f(1)
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src/gopl.io/ch5/defer2/defer.go:29
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main.f(2)
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src/gopl.io/ch5/defer2/defer.go:29
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main.f(3)
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src/gopl.io/ch5/defer2/defer.go:29
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main.main()
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src/gopl.io/ch5/defer2/defer.go:15
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//!-printstack
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*/
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