diff --git a/main.cpp b/main.cpp
index f4ecab8..5691ba6 100644
--- a/main.cpp
+++ b/main.cpp
@@ -6,6 +6,11 @@
 #include <string>
 #include <thread>
 #include <map>
+#include <chrono>
+#include <mutex>
+#include <shared_mutex>
+#include <atomic>
+#include "MTQueue.h"
 
 
 struct User {
@@ -15,11 +20,14 @@ struct User {
 };
 
 std::map<std::string, User> users;
-std::map<std::string, long> has_login;  // 换成 std::chrono::seconds 之类的
+std::shared_mutex users_mutex;
+std::map<std::string, std::chrono::steady_clock::time_point> has_login;  // 换成 std::chrono::seconds 之类的
+std::shared_mutex login_mutex;
 
 // 作业要求1：把这些函数变成多线程安全的
 // 提示：能正确利用 shared_mutex 加分，用 lock_guard 系列加分
 std::string do_register(std::string username, std::string password, std::string school, std::string phone) {
+    std::unique_lock grd(users_mutex);
     User user = {password, school, phone};
     if (users.emplace(username, user).second)
         return "注册成功";
@@ -29,13 +37,16 @@ std::string do_register(std::string username, std::string password, std::string
 
 std::string do_login(std::string username, std::string password) {
     // 作业要求2：把这个登录计时器改成基于 chrono 的
-    long now = time(NULL);   // C 语言当前时间
+    auto now = std::chrono::steady_clock::now();   // C 语言当前时间
+    std::unique_lock grd1(login_mutex);
     if (has_login.find(username) != has_login.end()) {
-        int sec = now - has_login.at(username);  // C 语言算时间差
+        int64_t sec = std::chrono::duration_cast<std::chrono::seconds>(now - has_login.at(username)).count();  // C 语言算时间差
         return std::to_string(sec) + "秒内登录过";
     }
     has_login[username] = now;
+    grd1.unlock();
 
+    std::shared_lock grd2(users_mutex);
     if (users.find(username) == users.end())
         return "用户名错误";
     if (users.at(username).password != password)
@@ -44,7 +55,11 @@ std::string do_login(std::string username, std::string password) {
 }
 
 std::string do_queryuser(std::string username) {
-    auto &user = users.at(username);
+    std::shared_lock grd(users_mutex);
+    if (users.find(username) == users.end())
+        return "";
+    auto user = users.at(username);
+    grd.unlock();
     std::stringstream ss;
     ss << "用户名: " << username << std::endl;
     ss << "学校:" << user.school << std::endl;
@@ -52,16 +67,21 @@ std::string do_queryuser(std::string username) {
     return ss.str();
 }
 
-
 struct ThreadPool {
+private:
+    std::vector<std::thread> m_pool;
+public:
     void create(std::function<void()> start) {
-        // 作业要求3：如何让这个线程保持在后台执行不要退出？
-        // 提示：改成 async 和 future 且用法正确也可以加分
         std::thread thr(start);
+        m_pool.push_back(std::move(thr));
+    }
+    ~ThreadPool() {
+        for (auto &thr: m_pool)
+            thr.join();
     }
 };
 
-ThreadPool tpool;
+ThreadPool tpool{};
 
 
 namespace test {  // 测试用例？出水用力！
@@ -74,16 +94,20 @@ std::string phone[] = {"110", "119", "120", "12315"};
 int main() {
     for (int i = 0; i < 262144; i++) {
         tpool.create([&] {
-            std::cout << do_register(test::username[rand() % 4], test::password[rand() % 4], test::school[rand() % 4], test::phone[rand() % 4]) << std::endl;
+            do_register(test::username[rand() % 4], test::password[rand() % 4], test::school[rand() % 4], test::phone[rand() % 4]);
+            // std::cout << do_register(test::username[rand() % 4], test::password[rand() % 4], test::school[rand() % 4], test::phone[rand() % 4]) << std::endl;
         });
         tpool.create([&] {
-            std::cout << do_login(test::username[rand() % 4], test::password[rand() % 4]) << std::endl;
+            do_login(test::username[rand() % 4], test::password[rand() % 4]);
+            // std::cout << do_login(test::username[rand() % 4], test::password[rand() % 4]) << std::endl;
         });
         tpool.create([&] {
-            std::cout << do_queryuser(test::username[rand() % 4]) << std::endl;
+            do_queryuser(test::username[rand() % 4]);
+            // std::cout << do_queryuser(test::username[rand() % 4]) << std::endl;
         });
     }
 
     // 作业要求4：等待 tpool 中所有线程都结束后再退出
+    std::cout << "ALL DONE" << std::endl;
     return 0;
 }