Create goroutine.md

Author: CompetitiveLin

Multi-Thread/goroutine.md

@@ -0,0 +1,130 @@
+# Goroutine
+
+1. 两个协程轮流打印 `1, 2`
+
+```go
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+var wg sync.WaitGroup
+
+func main() {
+	wg.Add(2)
+	ch1 := make(chan int)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 10; i++ {
+			ch1 <- i
+			if i%2 == 0 {
+				fmt.Println("1: ", i)
+			}
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 10; i++ {
+			<-ch1
+			if i%2 == 1 {
+				fmt.Println("2: ", i)
+			}
+		}
+	}()
+	wg.Wait()
+}
+```
+
+2. 三个协程轮流打印 `1, 2, 3`
+
+```go
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+func main() {
+	var wg sync.WaitGroup
+	wg.Add(2)
+	ch1 := make(chan int)
+	ch2 := make(chan int)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 100; i++ {
+			<-ch1
+			<-ch2
+			if i%3 == 0 {
+				fmt.Println(1, ": ", i)
+			}
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 100; i++ {
+			ch1 <- 1
+			if i%3 == 1 {
+				fmt.Println(2, ": ", i)
+			}
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 100; i++ {
+			ch2 <- 1
+			if i%3 == 2 {
+				fmt.Println(3, ": ", i)
+			}
+		}
+	}()
+	wg.Wait()
+}
+```
+
+3. 生产者消费者模型
+
+```go
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+var wg sync.WaitGroup
+var lock sync.Mutex
+
+func main() {
+	ch := make(chan int, 100)
+	producer(ch)
+	cnt := 3
+	wg.Add(cnt)
+	for i := 0; i < cnt; i++ {
+		go consumer(i, ch)
+	}
+	wg.Wait()
+}
+
+func producer(ch chan int) {
+	defer close(ch)
+	for i := 0; i < 10; i++ {
+		fmt.Println("producer: ", i)
+		ch <- i
+	}
+}
+
+func consumer(i int, ch chan int) {
+	for {
+		if v, ok := <-ch; ok {
+			fmt.Println("consumer ", i, ":", v)
+		} else {
+			break
+		}
+	}
+	wg.Done()
+}
+```
+