douxiong1994 2016-10-06 00:15
浏览 13
已采纳

go中奇怪的频道行为

package main
import (
    "encoding/json"
    "fmt"
    "/something/models"
    "os"
    "path/filepath"
    "runtime"
)

func WriteDeviceToFile(d chan *models.Device, fileName string) {

_, b, _, _ := runtime.Caller(0)
basepath := filepath.Dir(b)
filePath := basepath + "/dataFile/" + fileName

var f *os.File
var err error


f, _ = os.OpenFile(filePath, os.O_APPEND|os.O_WRONLY, 0600)

defer f.Close()


for device := range d {
    deviceB, err := json.Marshal(device)
    fmt.Println(string(deviceB))
    if err == nil {
        if _, err = f.WriteString(string(deviceB)); err != nil {
            panic(err)
        }
    } else {
        panic(err)
    }
}

}

func main() {
deviceChan := make(chan *models.Device)
go WriteDeviceToFile(deviceChan, "notalive.txt")
d := models.NewDevice("12346", "")
deviceChan <- d
d = models.NewDevice("abcd", "")
deviceChan <- d
close(deviceChan)
}

This only works with at least two devices sent to channel. With only one device in deviceChan, the function does not receive anything. Is the channel gone before the WriteDeviceToFile gets to it?

  • 写回答

1条回答 默认 最新

  • dtdt0454 2016-10-06 00:20
    关注

    The program exits when main returns. Nothing prevents main from exiting before the files are written

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥20 iOS绕地区网络检测
  • ¥15 python验证码滑块图像识别
  • ¥15 根据背景及设计要求撰写设计报告
  • ¥15 QT6颜色选择对话框显示不完整
  • ¥20 能提供一下思路或者代码吗
  • ¥15 用twincat控制!
  • ¥15 请问一下这个运行结果是怎么来的
  • ¥15 单通道放大电路的工作原理
  • ¥30 YOLO检测微调结果p为1
  • ¥15 DS18B20内部ADC模数转换器