雨蒼的<Go學習筆記,3e>，關於Goroutines的練習程式。

practice_goroutines.go

// 練習Goroutine

package main

import (
	"math"
	"sync"
)

func sum(id int) {
	var x int64
	for i := int64(0); i < math.MaxUint32; i++ {
		x += i
	}
	println(id, x)
}

func main() {
	wg := new(sync.WaitGroup)
	wg.Add(2)

	for i := 0; i < 2; i++ {
		go func(id int) {
			defer wg.Done()
			sum(id)
		}(i)
	}
	wg.Wait()

}

practice_gosched.go

// 練習Gosched機制： Gosched很像yield，會暫停目前goroutine，讓給Thread給別人。

package main

import (
	"runtime"
	"sync"
)

type HandleFunc func(int)

func Handler(id int, handleFnc HandleFunc, wg *sync.WaitGroup) {
	defer wg.Done()
	handleFnc(id)
}

func HasGoSched(id int) {
	for i := 0; i < 10; i++ {
		println(id, i)
		if i == 3 || i == 8 {
			runtime.Gosched()
		}
	}
}

func SayHello(id int) {
	println(id, "Hello World!")
}

func OtherProc(id int) {
	for i := 0; i < 10; i++ {
		println(id, i)
		if i == 5 {
			runtime.Gosched()
		}
	}
}

func main() {
	wg := new(sync.WaitGroup)

	wg.Add(3)

	go Handler(0, HasGoSched, wg)
	go Handler(1, SayHello, wg)
	go Handler(2, OtherProc, wg)

	wg.Wait()
}