Gecko [ 167.86.127.34 ]

Name	Size	Permission
abort.go	449 B	-rw-r--r--
badtraceback.go	1.07 KB	-rw-r--r--
checkptr.go	982 B	-rw-r--r--
crash.go	1.09 KB	-rw-r--r--
deadlock.go	5.93 KB	-rw-r--r--
gc.go	8.62 KB	-rw-r--r--
lockosthread.go	6.53 KB	-rw-r--r--
main.go	651 B	-rw-r--r--
map.go	1.26 KB	-rw-r--r--
memprof.go	884 B	-rw-r--r--
misc.go	306 B	-rw-r--r--
numcpu_freebsd.go	3.24 KB	-rw-r--r--
panicrace.go	414 B	-rw-r--r--
preempt.go	1.42 KB	-rw-r--r--
signal.go	831 B	-rw-r--r--
sleep.go	314 B	-rw-r--r--
stringconcat.go	443 B	-rw-r--r--
syscall_windows.go	1.37 KB	-rw-r--r--
syscalls.go	256 B	-rw-r--r--
syscalls_linux.go	1.27 KB	-rw-r--r--
syscalls_none.go	437 B	-rw-r--r--
timeprof.go	828 B	-rw-r--r--
traceback_ancestors.go	2.13 KB	-rw-r--r--
vdso.go	1019 B	-rw-r--r--

Code Editor : traceback_ancestors.go

// Copyright 2018 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 main

import (
	"bytes"
	"fmt"
	"runtime"
	"strings"
)

func init() {
	register("TracebackAncestors", TracebackAncestors)
}

const numGoroutines = 3
const numFrames = 2

func TracebackAncestors() {
	w := make(chan struct{})
	recurseThenCallGo(w, numGoroutines, numFrames, true)
	<-w
	printStack()
	close(w)
}

var ignoreGoroutines = make(map[string]bool)

func printStack() {
	buf := make([]byte, 1024)
	for {
		n := runtime.Stack(buf, true)
		if n < len(buf) {
			tb := string(buf[:n])

// Delete any ignored goroutines, if present.
			pos := 0
			for pos < len(tb) {
				next := pos + strings.Index(tb[pos:], "\n\n")
				if next < pos {
					next = len(tb)
				} else {
					next += len("\n\n")
				}

if strings.HasPrefix(tb[pos:], "goroutine ") {
					id := tb[pos+len("goroutine "):]
					id = id[:strings.IndexByte(id, ' ')]
					if ignoreGoroutines[id] {
						tb = tb[:pos] + tb[next:]
						next = pos
					}
				}
				pos = next
			}

fmt.Print(tb)
			return
		}
		buf = make([]byte, 2*len(buf))
	}
}

func recurseThenCallGo(w chan struct{}, frames int, goroutines int, main bool) {
	if frames == 0 {
		// Signal to TracebackAncestors that we are done recursing and starting goroutines.
		w <- struct{}{}
		<-w
		return
	}
	if goroutines == 0 {
		// Record which goroutine this is so we can ignore it
		// in the traceback if it hasn't finished exiting by
		// the time we printStack.
		if !main {
			ignoreGoroutines[goroutineID()] = true
		}

// Start the next goroutine now that there are no more recursions left
		// for this current goroutine.
		go recurseThenCallGo(w, frames-1, numFrames, false)
		return
	}
	recurseThenCallGo(w, frames, goroutines-1, main)
}

func goroutineID() string {
	buf := make([]byte, 128)
	runtime.Stack(buf, false)
	const prefix = "goroutine "
	if !bytes.HasPrefix(buf, []byte(prefix)) {
		panic(fmt.Sprintf("expected %q at beginning of traceback:\n%s", prefix, buf))
	}
	buf = buf[len(prefix):]
	n := bytes.IndexByte(buf, ' ')
	return string(buf[:n])
}

${this.title}

Code Editor : traceback_ancestors.go