golang coredump

golang生成coredump文件
refer:
    https://blog.csdn.net/xmcy001122/article/details/105665732
    http://t.zoukankan.com/lit10050528-p-4811833.html

1.设置coredump文件
1).临时设置
    echo "/tmp/core-%e-%p-%s-%t" > /proc/sys/kernel/core_pattern
    echo 1 > /proc/sys/kernel/core_pid
2).永久设置
    echo -e "\nkernel.core_pattern=/tmp/core-%e-%p-%s-%t" >> /etc/sysctl.conf
    echo -e "\nkernel.core_uses_pid = 1" >> /etc/sysctl.conf
    sysctl -p /etc/sysctl.conf


2.设置环境变量
echo "GOTRACEBACK=crash" >> ~/.bashrc

3.执行程序
go build -o meng.out meng.go
./meng.out
或者2，3步骤合并：
    GOTRACEBACK=crash ./meng.out
    
4.调试coredump
gdb ./meng.out /tmp/core-meng-399155-6-1669296379    
或
dlv ./meng.out /tmp/core-meng-399155-6-1669296379    
>>
>>bt
 0  0x000000000045cf41 in runtime.raise
    at /usr/local/src/go/src/runtime/sys_linux_amd64.s:165
 1  0x0000000000443a25 in runtime.dieFromSignal
    at /usr/local/src/go/src/runtime/signal_unix.go:769
 。。。。。。
10  0x000000000048ae1f in main.doCommitTask.func1
    at ./meng.go:27
>>frame 10(报错所在栈)
>>list

5.附：meng.go

package main

import (
    "errors"
    "fmt"

    "time"
    "runtime"
    "path"
)

func main() {
    fmt.Printf("Hello world!\n")    
    taskIds := make([]int32, 0)
    go doCommitTask(&taskIds)
    time.Sleep(10*time.Second)
    fmt.Printf("taskIds=%v\n", taskIds)
}

func doCommitTask(taskIds *[]int32) {
    defer func() {
        err := recover()
        if err != nil {
            fmt.Printf("error: err=%v\n", err)
        }
        fmt.Printf("defer: now=%v\n", time.Now())
        panic("now")
    }()
    fmt.Printf("doCommitTask: start2\n")
    panic("jack at home2")
    for i := int32(0); i < 100; i += 1 {
        *taskIds = append(*taskIds, i)
    }
}


func play() {
    defer func() {
        if err := recover(); err != nil {
            fmt.Errorf("panic in safeGo: %v", err)
        }
    }()
    fmt.Printf("player: hello\n")
    err := errors.New("player stop")
    panic(err)
    fmt.Printf("player: world\n\n")
}

func SafeGo(fun func()) {
    defer func() {
        if err := recover(); err != nil {
            fmt.Errorf("panic in safeGo: %v", err)
        }
    }()
    fun()
}

func getRootPath(skip int) string {
    pc, fileName, line, ok := runtime.Caller(skip)
    if !ok {
        fmt.Printf("StartUp: runtime.Caller is error.\n")
        return ""
    }
    funcName := runtime.FuncForPC(pc).Name()
    rootPath := path.Dir(fileName)
    fmt.Printf("getRootPath: skip=%d, funcName=%s, rootPath=%s, fileName=%s, line=%d.\n", skip, funcName, rootPath, fileName, line)
    GetNextZeroTime()
    return rootPath
}

//当地时间下一次0点
func GetNextZeroTime() int64 {
    nowTime := time.Now()
    now := nowTime.Unix()
    _, offsetSeconds := nowTime.Zone()          //相对于utc时区偏移秒数
    sec := (now + int64(offsetSeconds)) % 86400 //相对于当前时区0点偏移秒数
    return now - sec + 86400
}

func PrintLatestStack(playerId int32, skip int) {
    fmt.Printf("PrintLatestStack: playerId=%d, traces:\n", playerId)
    pcs := make([]uintptr, 10)
    n := runtime.Callers(skip+2, pcs)
    for i := 0; i < n; i += 1 {
        pc := pcs[i]
        runFunc := runtime.FuncForPC(pc)
        fileName, line := runFunc.FileLine(pc)
        fmt.Printf("funcName=%s, fileName=%s, line=%d.\n", runFunc.Name(), fileName, line)
    }
}