我需要Golang调度器在继续之前运行所有的goroutines,运行时。Gosched()不能解决。
问题是go例程可以运行得如此之快,以至于start()中的“select”在de stopStream()中的“select”之后运行,然后“case <-chanStopStream:”接收方没有准备好发送方“case retChan <- true:”。结果是,当这种情况发生时,结果与stopStream()挂起时的行为相同
运行此代码https://go.dev/play/p/DQ85XqjU2Q_z多次,您将看到这两个响应Expected response when NOT hang:
2009/11/10 23:00:00 Start
2009/11/10 23:00:00 receive chan
2009/11/10 23:00:03 end
挂起时的预期响应,但不是这么快时的响应:
2009/11/10 23:00:00 Start
2009/11/10 23:00:00 default
2009/11/10 23:00:01 TIMER
2009/11/10 23:00:04 end
密码
package main
import (
"log"
"runtime"
"sync"
"time"
)
var wg sync.WaitGroup
func main() {
wg.Add(1)
//run multiples routines on a huge system
go start()
wg.Wait()
}
func start() {
log.Println("Start")
chanStopStream := make(chan bool)
go stopStream(chanStopStream)
select {
case <-chanStopStream:
log.Println("receive chan")
case <-time.After(time.Second): //if stopStream hangs do not wait more than 1 second
log.Println("TIMER")
//call some crash alert
}
time.Sleep(3 * time.Second)
log.Println("end")
wg.Done()
}
func stopStream(retChan chan bool) {
//do some work that can be faster then caller or not
runtime.Gosched()
//time.Sleep(time.Microsecond) //better solution then runtime.Gosched()
//time.Sleep(2 * time.Second) //simulate when this routine hangs more than 1 second
select {
case retChan <- true:
default: //select/default is used because if the caller times out this routine will hangs forever
log.Println("default")
}
}
1条答案
按热度按时间hfyxw5xn1#
在继续执行当前的goroutine之前,没有办法运行所有其他的goroutine。
通过确保goroutine不会在
stopStream
上阻塞来解决这个问题:选项1:将
chanStopStream
更改为buffered channel。这确保了stopStream
可以不阻塞地发送值。https://go.dev/play/p/xWg42TO_fIW
选项二:关闭通道,而不是发送值。发送方始终可以关闭通道。在关闭的通道上接收返回通道的值类型的零值。
https://go.dev/play/p/lNfT6qzrMmO