让main方法等待所有协程执行完毕再退出。可能一般思路是设置一个共有变量，然后通过修改这个变量的状态。这是通过共享变量来通信的方式，而go要做的是，通过通信来共享内存。
1. 按顺序执行
每次通信进行成对通信，当main向协程发送一个写channel时，同时也等待协程返回一个读channel。
这两个channel一定是成对的，所以构造一个结构体
type worker struct {
in chan int
done chan bool
}
func chanDemo1(){
var workers [10]worker
for i := 0; i < 10; i++ {
workers[i] = createWorker1(i)
}
for i := 0; i < 10; i++ {
workers[i].in <- 'a' + i
<- workers[i].done
}
for i := 0; i < 10; i++ {
workers[i].in <- 'A' + i
<- workers[i].done
}
}
func createWorker1(id int) worker {
work := worker{
in: make(chan int),
done: make(chan bool),
}
go func() {
for {
fmt.Printf("Work %d receiverd %c\n", id, <- work.in)
work.done <- true
}
}()
return work
}
func main(){
chanDemo1()
fmt.Println("over")
}
- 这个执行结果完全是按照0-9，先小写再大写的顺序
- 如果这样顺序执行，还要协程干啥
2. 批量处理
type worker struct {
in chan int
done chan bool
}
func chanDemo1(){
var workers [10]worker
for i := 0; i < 10; i++ {
workers[i] = createWorker1(i)
}
for i := 0; i < 10; i++ {
workers[i].in <- 'a' + i
}
for _, worker := range workers {
<- worker.done
}
for i := 0; i < 10; i++ {
workers[i].in <- 'A' + i
}
for _, worker := range workers {
<- worker.done
}
}
func createWorker1(id int) worker {
work := worker{
in: make(chan int),
done: make(chan bool),
}
go func() {
for {
fmt.Printf("Work %d receiverd %c\n", id, <- work.in)
work.done <- true
}
}()
return work
}
这样的话，先打印小写，再打印大写，但是大小写时顺序不固定
3. 完全随机
func chanDemo1(){
var workers [10]worker
for i := 0; i < 10; i++ {
workers[i] = createWorker1(i)
}
for i := 0; i < 10; i++ {
workers[i].in <- 'a' + i
}
for i := 0; i < 10; i++ {
workers[i].in <- 'A' + i
}
for _, worker := range workers {
<- worker.done
<- worker.done
}
}
func createWorker1(id int) worker {
work := worker{
in: make(chan int),
done: make(chan bool),
}
go func() {
for {
fmt.Printf("Work %d receiverd %c\n", id, <- work.in)
// 再开一个协程
go func() { work.done <- true}()
}
}()
return work
}
这种方式就是完全随机了
使用channel进行树的遍历
func (node *Node) TraverseFunc(f func(*Node)){
if node == nil{
return
}
node.Left.TraverseFunc(f)
f(node)
node.Right.TraverseFunc(f)
}
func (node *Node) TraverseWithChannel() chan *Node{
out := make(chan *Node)
go func() {
node.TraverseFunc(func(node *Node) {
out <- node
})
close(out)
}()
return out
}
func main(){
var root Node
root = Node{Value:3}
root.Left = &Node{}
root.Right = &Node{5,nil,nil}
root.Right.Left = new(Node)
root.Left.Right =&Node{6,nil,nil}
root.Traverse()
c:=root.TraverseWithChannel()
maxNode := 0
for node := range c{
if node.Value > maxNode{
maxNode = node.Value
}
}
fmt.Println("max node value:", maxNode)