go_dead_lock

go_dead_lock.go

package main

import (
    "fmt"
    "os"
    "bufio"
    "sync"
)

// Load data into channel
func laodData(arr []string,channel chan string,wg sync.WaitGroup) {
    for _,path := range arr {
        file,err := os.Open(path)
        fmt.Println("begin to laodData ", path)
        if err != nil {
            fmt.Println(err)
            os.Exit(-1)
        }
        defer file.Close()
        reader := bufio.NewReaderSize(file, 32*10*1024)
        i := 0
        for {
            line,err := reader.ReadString('\n')
            channel <- line
            if err != nil {
                break
            }
            i++
            if i%200 == 0 {
                fmt.Println(i," lines parsed")
            }
        }
        fmt.Println("finish laodData ", path)
    }
    wg.Done()
}

// dispatch data lines into different mappers
func dispatcher(channel chan string,wg sync.WaitGroup){
    fmt.Println("pull data 11")
    line,ok := <- channel
    fmt.Println(ok)
    for ok {
        fmt.Println(line)
        line,ok = <- channel
    }
    fmt.Println("pull data 22")
    wg.Done()
}

func main() {
    path := os.Args
    if len(path) < 2 {
        fmt.Println("Need Input Files")
        os.Exit(0)
    }
    var wg sync.WaitGroup
    wg.Add(2)

    channel := make(chan string)
    defer close(channel)
    
    fmt.Println("before dispatcher")
    go laodData(path[1:],channel,wg)
    go dispatcher(channel,wg)
    wg.Wait()

    fmt.Println("after dispatcher")
}