5
我使用sync.WaitGroup
, defer wg.Close()
和wg.Wait()
等待我的goroutines完成。Golang应用程序使用sync.WaitGroup&通道永不退出
该程序等待,但它永远不会退出。
这是我的程序(可运行):
package main
import (
"fmt"
"io"
"log"
"net/http"
"os"
"sync"
)
var symbols = []string{
"ASSA-B.ST",
"ELUX-B.ST",
"HM-B.ST",
}
func main() {
fmt.Println("fetching quotes...")
fetchedSymbols := make(chan string)
var wg sync.WaitGroup
wg.Add(len(symbols))
for _, symbol := range symbols {
go fetchSymbol(symbol, &wg, fetchedSymbols)
}
for response := range fetchedSymbols {
fmt.Println("fetched " + response)
}
wg.Wait()
fmt.Println("done")
}
func fetchSymbol(symbol string, wg *sync.WaitGroup, c chan<- string) {
defer wg.Done()
resp, err := http.Get("http://ichart.yahoo.com/table.csv?s=" + symbol + "&a=0&b=1&c=2000")
defer resp.Body.Close()
if err != nil {
log.Fatal(err)
}
out, err := os.Create("./stock-quotes/" + symbol + ".csv")
defer out.Close()
if err != nil {
log.Fatal(err)
}
io.Copy(out, resp.Body)
c <- symbol
}
不应该当所有的报价已经被下载了这个程序退出? (仅供参考:我刚开始学习GO)