初始化Go学习项目

go-sync-practice/rwmutex_cache.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+type Cache struct {
+	mu   sync.RWMutex
+	data map[string]string
+}
+
+func (c *Cache) Get(key string) string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.data[key]
+}
+
+func (c *Cache) Set(key, value string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.data[key] = value
+}
+
+func main() {
+	c := &Cache{data: make(map[string]string)}
+	c.Set("foo", "bar")
+
+	var wg sync.WaitGroup
+
+	// 多个读 goroutine
+	for i := 0; i < 5; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			for j := 0; j < 5; j++ {
+				v := c.Get("foo")
+				fmt.Printf("reader-%d 第 %d 次读到: %s\n", id, j, v)
+				time.Sleep(100 * time.Millisecond)
+			}
+		}(i)
+	}
+
+	// 一个写 goroutine
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		time.Sleep(300 * time.Millisecond)
+		fmt.Println("writer: 更新 foo -> baz")
+		c.Set("foo", "baz")
+	}()
+
+	wg.Wait()
+}