b010f82221
- 实现用户注册、登录、JWT令牌认证功能 - 集成Gin、GORM、Viper、Zap等框架 - 添加密码加密、数据库操作、中间件等完整功能 - 配置多环境支持、日志轮转、CORS处理 - 创建完整的项目结构和配置文件体系
77 lines
1.9 KiB
Go
77 lines
1.9 KiB
Go
package main
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import (
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"fmt"
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"runtime"
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"sync"
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"time"
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)
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func say(s string, id int) {
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for i := 0; i < 3; i++ {
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fmt.Printf("[%d] %s: step %d\n", id, s, i)
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time.Sleep(100 * time.Millisecond) // 模拟工作
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}
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}
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func main() {
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fmt.Println("=== 1. 单线程顺序执行 ===")
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say("Hello", 1)
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say("World", 2)
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fmt.Println("\n=== 2. 使用 Goroutine 并发执行 ===")
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go say("Goroutine-A", 1)
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go say("Goroutine-B", 2)
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// 主 goroutine 等待 1 秒，否则程序会提前退出
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time.Sleep(1 * time.Second)
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fmt.Println("\n=== 3. 使用 sync.WaitGroup 安全等待 ===")
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var wg sync.WaitGroup
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for i := 1; i <= 3; i++ {
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wg.Add(1)
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go func(id int) {
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defer wg.Done()
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fmt.Printf("Worker %d started\n", id)
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time.Sleep(time.Duration(id*200) * time.Millisecond)
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fmt.Printf("Worker %d finished\n", id)
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}(i)
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}
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wg.Wait() // 阻塞直到所有 goroutine 完成
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fmt.Println("All workers done!")
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fmt.Println("\n=== 4. 查看当前 GOMAXPROCS 和 CPU 核心数 ===")
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fmt.Printf("CPU 核心数: %d\n", runtime.NumCPU())
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fmt.Printf("GOMAXPROCS: %d\n", runtime.GOMAXPROCS(0)) // 0 表示不修改，仅查询
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fmt.Println("\n=== 5. 手动设置 GOMAXPROCS（通常不需要）===")
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old := runtime.GOMAXPROCS(2)
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fmt.Printf("旧 GOMAXPROCS: %d, 新设为: 2\n", old)
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runtime.GOMAXPROCS(old) // 恢复原值
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fmt.Println("\n=== 6. 观察 Goroutine 数量变化 ===")
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fmt.Printf("启动前 Goroutine 数: %d\n", runtime.NumGoroutine())
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var wg2 sync.WaitGroup
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for i := 0; i < 5; i++ {
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wg2.Add(1)
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go func(n int) {
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defer wg2.Done()
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time.Sleep(200 * time.Millisecond)
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}(i)
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}
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time.Sleep(50 * time.Millisecond) // 让 goroutine 启动
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fmt.Printf("启动后 Goroutine 数: %d\n", runtime.NumGoroutine())
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wg2.Wait()
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fmt.Printf("全部完成后 Goroutine 数: %d\n", runtime.NumGoroutine())
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// 在程序最后添加
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time.Sleep(1 * time.Second)
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fmt.Printf("延迟后 Goroutine 数: %d\n", runtime.NumGoroutine())
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}
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