Go语言编程-包+并发编程基础

Windows PowerShell版权所有 (C) Microsoft Corporation。保留所有权利。尝试新的跨平台 PowerShell https://aka.ms/pscore6PS F:\AA-GoProject> go mod init lzy.com/AA-GoProjectgo: creating new go.mod: module lzy.com/AA-GoProjectgo: to add module requirements and sums:        go mod tidyPS F:\AA-GoProject> cd .\service\PS F:\AA-GoProject\service> go buildPS F:\AA-GoProject\service>

customer_service中的代码：package service
import "fmt"
func TestCustomerService() {  fmt.Println("test customer service...")}

package service
import "fmt"
func TestUserService()  {  fmt.Println("test uer service ....")
}

package main
import (  //"fmt"  "net/http")import "github.com/gin-gonic/gin"//import "lzy.com/AA-GoProject/service"
func main() {  //fmt.Println("hello world")  //service.TestUserService()  //service.TestCustomerService()  /*  hello world  test uer service ....  test customer service...   */  r := gin.Default()  r.GET("/ping", func(c *gin.Context) {    c.JSON(http.StatusOK, gin.H{      "message": "pong",    })  })  r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")}

GOROOT=C:\Program Files\Go #gosetupGOPATH=C:\Program Files\Go\bin;C:\Users\Admin\go #gosetup"C:\Program Files\Go\bin\go.exe" build -o C:\Users\Admin\AppData\Local\Temp\GoLand\___go_build_main_go.exe F:\AA-GoProject\main.go #gosetupC:\Users\Admin\AppData\Local\Temp\GoLand\___go_build_main_go.exe #gosetup[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.
[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production. - using env:  export GIN_MODE=release - using code:  gin.SetMode(gin.ReleaseMode)
[GIN-debug] GET    /ping                     --> main.main.func1 (3 handlers)[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default[GIN-debug] Listening and serving HTTP on :8080[GIN] 2022/11/06 - 16:19:23 | 404 |            0s |             ::1 | GET      "/"[GIN] 2022/11/06 - 16:19:23 | 404 |            0s |             ::1 | GET      "/favicon.ico"

package main////import (//  "fmt"//  "math/rand"//  "time"//)////// 创建int类型的通道，只能传入int类型值//var values = make(chan int)////func send() {//  rand.Seed(time.Now().UnixNano())//  value := rand.Intn(10)//  fmt.Printf("send: %v\n", value)//  time.Sleep(time.Second * 5)//  values <- value////}////func main() {//  //从通道接收值//  defer close(values)//  go send()//  fmt.Println("wait...")//  value := <-values//  fmt.Printf("receive %v\n", value)//  fmt.Println("end...")//  /*//  wait...//  send: 4//  receive 4//  end...//   *///}

package main
import "fmt"
var c = make(chan int)
func main() {  go func() {    for i := 0; i < 2; i++ {      c <- i    }    close(c)  }()
  //1.for range 读取c  //for v := range c {  //  fmt.Printf("v:%v\n", v)  //}  /*    v:0    v:1  */  //2.for循环  for i := 0; i < 3; i++ {    r := <-c    fmt.Printf("%v\n", r)  }  /*  0  1  0   */}

package main
// Coshed的使用//func showMes(mes string) {//  for i := 0; i < 2; i++ {//    fmt.Printf("message:%v\n", mes)//  }////}////func main() {//  go showMes("java") // 开启子协程////  for i := 0; i < 2; i++ {//    runtime.Gosched() // 表示现在有权利执行任务了，但是让给子协程去执行//    fmt.Printf("golang\n")//  }//  fmt.Printf("end...")//  /*//    message:java//    message:java//    golang//    golang//    end...//  */////}//-------------------------------go

package main
import (  "fmt"  "runtime"  "time")
//cpu最大核心数
func a() {  for i := 0; i < 10; i++ {    fmt.Printf("A:%v\n", i)    time.Sleep(100 * time.Millisecond)  }
}func b() {  for i := 0; i < 10; i++ {    fmt.Printf("B: %v\n", i)    time.Sleep(100 * time.Millisecond)  }
}func main() {  // 查看现在的PU核心数  fmt.Printf("runtime.NumCPU:%v\n", runtime.NumCPU())  // 将CPU数量修改为1  //runtime.GOMAXPROCS(1)  go a()  go b()  time.Sleep(1 * time.Second)  /*    未修改CPU数量时执行情况,它会占用所有的CPU的核心数    runtime.NumCPU:12    B: 0    B: 1    B: 2    B: 3    B: 4    B: 5    B: 6    B: 7    B: 8    B: 9    A:0    A:1    A:2    A:3    A:4    A:5    A:6    A:7    A:8    A:9  修改CPU的核心为1时，并且每个循环的等待100毫秒时的执行情况交替执行，并发执行  B: 0  A:0  A:1  B: 1  B: 2  A:2  A:3  B: 3  B: 4  A:4  A:5  B: 5  B: 6  A:6  A:7  B: 7  A:8  B: 8  B: 9  A:9  */
}

package main////import (//  "fmt"//  "runtime"//  "time"//)////func showNum() {//  for i := 0; i < 10; i++ {//    fmt.Printf("i:%v\n", i)//    if i >=5 {//      runtime.Goexit() // 协程退出//    }//  }////}////func main() {//  go showNum()//  time.Sleep(1 * time.Second)//  /*//  i:0//  i:1//  i:2//  i:3//  i:4//  i:5//   */////}

package main
import (  "fmt"  "sync"  "time")// golang并发编程Mutex互斥锁
var i int = 100var wg sync.WaitGroupvar lock sync.Mutex
func add() {  defer wg.Done()  //加锁操作  lock.Lock()  i += 1  fmt.Printf("i++:%v\n", i)  time.Sleep(100 * time.Microsecond)  // 解锁  lock.Unlock()
}func sub() {  lock.Lock()  time.Sleep(100 * time.Millisecond)  defer wg.Done()  i -= 1  fmt.Printf("i--:%v\n", i)  lock.Unlock()}
func main() {  // 两个协程 不加锁的话最后的输出结果可能会有变化  for i := 0; i < 100; i++ {    wg.Add(1)    go add()    wg.Add(1)    go sub()    wg.Wait()  }
  fmt.Printf("end i:%v\n", i)  /*    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i++:101    i--:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    i--:99    i++:100    end i:100  */
}

package main
import "fmt"
var c = make(chan int)
func main() {  go func() {    for i := 0; i < 2; i++ {      c <- i    }    close(c)  }()
  //1.for range 读取c  //for v := range c {  //  fmt.Printf("v:%v\n", v)  //}  /*    v:0    v:1  */  //2.for循环  for i := 0; i < 3; i++ {    r := <-c    fmt.Printf("%v\n", r)  }  /*  0  1  0   */}