在Go语言里检测内存泄漏

create database mytest default character set utf8;
use mytest ;

create table users(login_name varchar(20),nickname varchar(20),uid int(8),password char(32),forbidden tinyint(1));

insert into users value ('Alex','Sunday','12345678','827ccb0eea8a706c4c34a16891f84e7b','0');

package main
import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"os"
	"os/signal"
	"runtime"
	"runtime/pprof"
	"strings"
	"time"
)

var (
	pid      int
	progname string
)

func init() {
	pid = os.Getpid()
	paths := strings.Split(os.Args[0], "/")
	paths = strings.Split(paths[len(paths)-1], string(os.PathSeparator))
	progname = paths[len(paths)-1]

	runtime.MemProfileRate = 1
}

func saveHeapProfile() {
	runtime.GC()

	f, err := os.Create(fmt.Sprintf("heap_%s_%d_%s.prof", progname, pid, time.Now().Format("2006_01_02_03_04_05")))
	if err != nil {
		return
	}
	defer f.Close()
	pprof.Lookup("heap").WriteTo(f, 1)
}

func waitForSignal() os.Signal {
	signalChan := make(chan os.Signal, 1)
	defer close(signalChan)

	signal.Notify(signalChan, os.Kill, os.Interrupt)
	s := <-signalChan
	signal.Stop(signalChan)
	return s
}

func connect(source string) *sql.DB {
	db, err := sql.Open("mysql", source)
	if err != nil {
		return nil
	}

	if err := db.Ping(); err != nil {
		return nil
	}

	return db
}

type User struct {
	uid       int
	name      string
	nick      string
	forbidden int
	cid       int
}

func query(db *sql.DB, name string, id int, dataChan chan *User) {
	for {
		time.Sleep(time.Millisecond)

		user := &User{
			cid:  id,
			name: name,
		}

		err := db.QueryRow("SELECT nickname, uid, forbidden FROM users WHERE login_name = ?", name).Scan(&user.nick, &user.uid, &user.forbidden)
		if err != nil {
			continue
		}

		dataChan <- user
	}
}

func main() {
	defer saveHeapProfile()

	db := connect("mytest:mytest@tcp(localhost:3306)/mytest?charset=utf8")
	if db == nil {
		return
	}

	userChan := make(chan *User, 100)
	for i := 0; i < 100; i++ {
		go query(db, "Alex", i+1, userChan)
	}

	allUsers := make([]*User, 1<<12)
	go func() {
		for user := range userChan {
			fmt.Printf("routine[%d] get user %+v
", user.cid, user)
			allUsers = append(allUsers, user)
		}
	}()

	s := waitForSignal()

	fmt.Printf("signal got: %v, all users: %d
", s, len(allUsers))
}

go func(){
    http.ListenAndServe(":6789", nil)
}()