package main
import (
	"fmt"
	"time"
)
func newTask() {
	for {
		fmt.Println("this is a newTask")
		time.Sleep(time.Second) //延時(shí)1s
	}
}
func main() {
	go newTask() //新建一個(gè)協(xié)程， 新建一個(gè)任務(wù)
	for {
		fmt.Println("this is a main goroutine")
		time.Sleep(time.Second) //延時(shí)1s
	}
}

package main
import (
	"fmt"
	"time"
)
//主協(xié)程退出了，其它子協(xié)程也要跟著退出
func main() {
	go func() {
		i := 0
		for {
			i++
			fmt.Println("子協(xié)程 i = ", i)
			time.Sleep(time.Second)
		}
	}() //別忘了()
	i := 0
	for {
		i++
		fmt.Println("main i = ", i)
		time.Sleep(time.Second)
		if i == 2 {
			break
		}
	}
}

package main
import (
	"fmt"
	"runtime"
)
func main() {
	go func() {
		for i := 0; i < 5; i++ {
			fmt.Println("go")
		}
	}()
	for i := 0; i < 2; i++ {
		//讓出時(shí)間片，先讓別的協(xié)議執(zhí)行，它執(zhí)行完，再回來執(zhí)行此協(xié)程
		runtime.Gosched() 
		fmt.Println("hello")
	}
}


go
go
go
go
go
hello
hello

runtime.Goexit()  //立即結(jié)束當(dāng)前協(xié)程

package main
import (
	"fmt"
	"runtime"
)
func test() {
	defer fmt.Println("ccccccccccccc")
	//return //終止此函數(shù)
	runtime.Goexit() //終止所在的協(xié)程
	fmt.Println("dddddddddddddddddddddd")
}
func main() {
	//創(chuàng)建新建的協(xié)程
	go func() {
		fmt.Println("aaaaaaaaaaaaaaaaaa")

		//調(diào)用了別的函數(shù)
		test()
		fmt.Println("bbbbbbbbbbbbbbbbbbb")
	}() //別忘了()
	//特地寫一個(gè)死循環(huán)，目的不讓主協(xié)程結(jié)束
	for {
	}
}
aaaaaaaaaaaaaaaaaa
ccccccccccccc

runtime.GOMAXPROCS() //設(shè)置并行CPU核數(shù)最大值，并返回之前的值

package main
import (
	"fmt"
	"runtime"
)
func main() {
	//n := runtime.GOMAXPROCS(1) //指定以1核運(yùn)算
	n := runtime.GOMAXPROCS(2) //指定以8核運(yùn)算
	fmt.Println("n = ", n)
	for {
		go fmt.Print(1)
		fmt.Print(0)
	}
}

func main() {
 go test()
 go test()
 go test()
 go test()
 a:=runtime.NumGoroutine()
 fmt.Println(a) // 5
 for  {
 }
}

package main
import (
	"fmt"
	"time"
)
//定義一個(gè)打印機(jī)，參數(shù)為字符串，按每個(gè)字符打印
//打印機(jī)屬于公共資源
func Printer(str string) {
	for _, data := range str {
		fmt.Printf("%c", data)
		time.Sleep(time.Second)
	}
	fmt.Printf("\n")
}
func person1() {
	Printer("hello")
}
func person2() {
	Printer("world")
}
func main() {
	//新建2個(gè)協(xié)程，代表2個(gè)人，2個(gè)人同時(shí)使用打印機(jī)
	go person1()
	go person2()
	//特地不讓主協(xié)程結(jié)束，死循環(huán)
	for {
	}
}

package main
import (
	"fmt"
	"time"
)
//全局變量，創(chuàng)建一個(gè)channel
var ch = make(chan int)
//定義一個(gè)打印機(jī)，參數(shù)為字符串，按每個(gè)字符打印
//打印機(jī)屬于公共資源
func Printer(str string) {
	for _, data := range str {
		fmt.Printf("%c", data)
		time.Sleep(time.Second)
	}
	fmt.Printf("\n")
}
//person1執(zhí)行完后，才能到person2執(zhí)行
func person1() {
	Printer("hello")
	ch <- 666 //給管道寫數(shù)據(jù)，發(fā)送
}
func person2() {
	<-ch //從管道取數(shù)據(jù)，接收，如果通道沒有數(shù)據(jù)他就會(huì)阻塞
	Printer("world")
}
func main() {
	//新建2個(gè)協(xié)程，代表2個(gè)人，2個(gè)人同時(shí)使用打印機(jī)
	go person1()
	go person2()
	//特地不讓主協(xié)程結(jié)束，死循環(huán)
	for {
	}
}

var wg sync.WaitGroup
wg.Add(2)  //任務(wù)數(shù)
wg.Done() //結(jié)束
wg.Wait() //等待
package main
import (
	"fmt"
	"sync"
)
var wg sync.WaitGroup
func main() {
	wg.Add(2)
	out := producer()
	consumer(out)
	defer fmt.Println("主線程結(jié)束")
	wg.Wait()  //等待
}
//此通道只能寫，不能讀
func producer() chan interface{} {
	ch := make(chan interface{})
	go func() {
		for i := 0; i < 5; i++ {
			ch <- fmt.Sprintf("協(xié)程1-%d", i) //寫入字符串
		}
		defer close(ch)
		wg.Done()  //結(jié)束
	}()
	return ch
}
//此channel只能讀，不能寫
func consumer(data chan interface{}) {
	defer fmt.Println("讀取結(jié)束")
	go func() {
		for num := range data {
			fmt.Println(num)
		}
		wg.Done() //結(jié)束
	}()
}