package main

import "fmt"

func main() {

	// 使用go關(guān)鍵字使用goroutine調(diào)用hello函數(shù)
	go hello()
	for i := 0; i < 150000; i++ {
		//fmt.Println("main-", i)
	}
}

func hello() {
	for i := 0; i < 10; i++ {
		fmt.Println("hello-----------", i)
	}
}

/*
    此處代碼可設(shè)置main協(xié)程for循環(huán)次數(shù)的大小觀測go協(xié)程調(diào)用hello情況
*/

package main

import (
	"fmt"
	"runtime"
)

func main() {

	//獲取系統(tǒng)信息
	fmt.Println("獲取GOROOT目錄", runtime.GOROOT())
	fmt.Println("獲取操作系統(tǒng)", runtime.GOOS)
	fmt.Println("獲取CPU", runtime.NumCPU())

	//Goroutine 調(diào)度
	go func() {
		for i := 0; i < 100; i++ {
			fmt.Println("Goroutine---", i)
		}
	}()

	for i := 0; i < 100; i++ {
		//讓出時間片，讓別的Goroutine先執(zhí)行，不一定可以讓成功
		runtime.Gosched()
		fmt.Println("main---", i)
	}
}

package main

import (
	"fmt"
	"runtime"
	"time"
)

func main() {
	/*
		因為goroutine2延時了一定時間，如果goroutine1不讓出CPU時間片那么必先執(zhí)行完成
	*/
	go func() {
		for i := 0; i < 5; i++ {
			runtime.Gosched() // 讓出 CPU 時間片
			fmt.Println("Goroutine 1:", i)
		}
	}()

	go func() {
		for i := 0; i < 5; i++ {
			time.Sleep(100 * time.Millisecond)
			fmt.Println("Goroutine 2:", i)
		}
	}()

	time.Sleep(3 * time.Second) // 等待兩個 goroutine 執(zhí)行完畢
}

package main

import (
	"fmt"
	"runtime"
	"sync"
)

func main() {
	var wg sync.WaitGroup //創(chuàng)建并發(fā)組
	fmt.Printf("當(dāng)前運行的goroutine數(shù)量: %d\n", runtime.NumGoroutine())
	//創(chuàng)建10個協(xié)程
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()
			fmt.Printf("第 %d 個協(xié)程在 running\n", id)
		}(i)
	}
	fmt.Printf("當(dāng)前運行的goroutine數(shù)量: %d\n", runtime.NumGoroutine())
	wg.Wait()

	fmt.Printf("CPU核心數(shù): %d\n", runtime.NumCPU())
}

package main

import (
	"fmt"
	"sync"
	"time"
)

// 定義全局變量 票庫存為10張
var tickets int = 10

// 創(chuàng)建鎖
var mutexs sync.Mutex

func main() {
	//三個窗口同時售票
	go saleTicket("售票口1")
	go saleTicket("售票口2")
	go saleTicket("售票口3")
	time.Sleep(time.Second * 15) //等待售票完

}

// 售票函數(shù)
func saleTicket(name string) {
	for {
		// 在檢查之前上鎖
		mutexs.Lock()
		if tickets > 0 {
			time.Sleep(time.Second)
			fmt.Printf("%s剩余的票數(shù)為：%d\n", name, tickets)
			tickets--
		} else {
			fmt.Println("票已售完")
			break
		}
		//操作結(jié)束后解鎖
		mutexs.Unlock()
	}
}

package main

import (
	"fmt"
	"sync"
	"time"
)

var w sync.WaitGroup

func main() {
	// 公司最后關(guān)門的人   0
	// wg.Add(2) 判斷還有幾個線程、計數(shù)  num=2
	// wg.Done() 我告知我已經(jīng)結(jié)束了  -1
	w.Add(2)

	go test11()
	go test22()

	fmt.Println("main等待ing")
	w.Wait() // 等待 wg 歸零，才會繼續(xù)向下執(zhí)行
	fmt.Println("end")

	// 理想狀態(tài)：所有協(xié)程執(zhí)行完畢之后，自動停止。
	//time.Sleep(3 * time.Second)

}
func test11() {
	for i := 0; i < 5; i++ {
		time.Sleep(1 * time.Second)
		fmt.Println("test1--", i)
	}
	w.Done()
}
func test22() {
	defer w.Done()
	for i := 0; i < 5; i++ {
		fmt.Println("test2--", i)
	}
}

close(ch)

v,ok := <- ch

package main

import (
	"fmt"
	"strconv"
	"time"
)

func main() {
	//定義通道可以寫10個數(shù)據(jù)
	ch := make(chan string, 10)
	go test3(ch)

	for v := range ch {
		fmt.Println(v)
	}
}

func test3(ch chan string) {
	for i := 0; i < 5; i++ {
		time.Sleep(time.Second)
		fmt.Println("通道內(nèi)寫入數(shù)據(jù)", "tset--"+strconv.Itoa(i))
		ch <- "tset--" + strconv.Itoa(i)
	}
	close(ch)//如果不關(guān)閉協(xié)程，主協(xié)程的for循環(huán)一值阻塞，知道報錯“fatal error: all goroutines are asleep - deadlock!”
}

package main

import (
	"fmt"
	"time"
)

func main() {
	ch := make(chan int)
	go writerOnly(ch)
	go readOnly(ch)

	time.Sleep(time.Second * 2)
}

// 只讀，指只允許管道讀入/寫出數(shù)據(jù)
func writerOnly(ch chan<- int) {
	ch <- 10
}

// 只寫，指指只允許管道讀出/寫入數(shù)據(jù)
func readOnly(ch <-chan int) {
	temp := <-ch
	fmt.Println(temp)
}

package main

import (
	"fmt"
	"time"
)

func main() {

	ch1 := make(chan int)
	ch2 := make(chan int)

	go func() {
		time.Sleep(time.Second * 2)
		ch1 <- 100
	}()

	go func() {
		time.Sleep(time.Second * 2)
		ch2 <- 200
	}()

	select {
	case num1 := <-ch1:
		fmt.Println("ch1--", num1)
	case num2 := <-ch2:
		fmt.Println("ch2--", num2)
	}
    //沒有default，則等待通道(阻塞),因為select{}本身是阻塞的
}

package main

import (
	"fmt"
	"sync"
	"time"
)

// 定義全局chan，存儲票總數(shù)
var totalTickets chan int
var wg sync.WaitGroup

func main() {

	// 初始化票數(shù)量：總票數(shù)10張
	totalTickets = make(chan int, 2)
	totalTickets <- 10

	wg.Add(3)

	go sell("售票口1")
	go sell("售票口2")
	go sell("售票口3")

	wg.Wait()

	fmt.Println("買完了，下班")

}

func sell(name string) {
	defer wg.Done()

	for { //for循環(huán)表示一直在賣，一直在營業(yè)
		residue, ok := <-totalTickets
		if !ok {
			fmt.Printf("%s: 關(guān)閉\n", name)
			break
		}
		if residue > 0 {
			time.Sleep(time.Second * 1)
			totalTickets <- residue - 1 //
			fmt.Println(name, "售出1張票，余票：", residue)
		} else {
			//進入此處時票已經(jīng)買完了，因為for循環(huán)一進來售票窗口就檢查是否還有票，假如最后賣完的是售票口3，那么銷售窗口1跟2就會判斷還有沒有
			fmt.Printf("%s: 關(guān)閉\n", name)
			close(totalTickets)
			break
		}
	}
}