Go HTTP服务器并发性能探究：兼论早期Windows平台特性影响

> ab -n 10000 -c 6 http://localhost:8080/
Concurrency Level:      6
Time taken for tests:   1.678096 seconds
Complete requests:      10000

Percentage of the requests served within a certain time (ms)
  50%      1
  ...
 100%      3 (longest request)

> ab -n 1000 -c 7 http://localhost:8080/
Concurrency Level:      7
Time taken for tests:   10.239586 seconds
Complete requests:      1000

Percentage of the requests served within a certain time (ms)
  50%      1
  ...
  90%    499
  95%    505
  98%    507
  99%    507
 100%    510 (longest request)

package main

import (
    "fmt"
    "io"
    "log"
    "net/http"
    "strconv"
    "time" // 引入 time 包用于模拟耗时操作
)

// fileHandler 模拟一个文件下载或处理的处理器
func fileHandler(w http.ResponseWriter, req *http.Request) {
    // 设置响应头
    w.Header().Set("Content-Type", "text/plain")
    w.Header().Set("Content-Disposition", "inline; filename=example.txt")

    // 模拟耗时操作，例如读取大文件或进行复杂计算
    time.Sleep(100 * time.Millisecond) // 模拟100毫秒的延迟

    // 写入响应内容
    _, err := io.WriteString(w, "This is a sample file content.\n")
    if err != nil {
        log.Printf("Error writing response for fileHandler: %v", err)
    }
    log.Printf("Request to /file completed from %s", req.RemoteAddr)
}

// mainPageHandler 主页处理器
func mainPageHandler(w http.ResponseWriter, req *http.Request) {
    _, err := io.WriteString(w, "Hi, download here: <a href=\"/file\">HERE</a>")
    if err != nil {
        log.Printf("Error writing response for mainPageHandler: %v", err)
    }
    log.Printf("Request to / completed from %s", req.RemoteAddr)
}

func main() {
    var port int
    fmt.Print("Enter port number: ")
    _, err := fmt.Scanf("%d", &port)
    if err != nil {
        log.Fatalf("Invalid port number: %v", err)
    }

    // 注册路由处理器
    http.HandleFunc("/file", fileHandler)
    http.HandleFunc("/", mainPageHandler)

    // 启动HTTP服务器
    addr := "0.0.0.0:" + strconv.Itoa(port)
    fmt.Printf("Starting server on %s...\n", addr)
    // http.ListenAndServe 会阻塞，直到服务器停止或出错
    err = http.ListenAndServe(addr, nil)
    if err != nil {
        log.Fatalf("Server failed to start: %v", err)
    }
}