hw05的作业

main.cpp

@@ -6,6 +6,9 @@
 #include <string>
 #include <thread>
 #include <map>
+#include <mutex>
+#include <shared_mutex>
+#include <chrono>
 
 
 struct User {
@@ -15,26 +18,41 @@ struct User {
 };
 
 std::map<std::string, User> users;
-std::map<std::string, long> has_login;  // 换成 std::chrono::seconds 之类的
+// std::map<std::string, long> has_login;  // 换成 std::chrono::seconds 之类的
+std::map<std::string, std::chrono::steady_clock::time_point> has_login;
+
+std::mutex users_write_mutex;
+std::shared_mutex users_read_mutex;
+std::shared_mutex has_login_read_mutex;
+std::mutex has_login_write_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) {
     User user = {password, school, phone};
-    if (users.emplace(username, user).second)
+    std::shared_lock grd_r(users_read_mutex);
+    if (users.find(username) == users.end()) {
+        std::unique_lock grd_w(users_write_mutex);
+        users.emplace(username, user);
         return "注册成功";
-    else
+    } 
+    else {
         return "用户名已被注册";
+    }     
 }
-
 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
+    std::shared_lock grd_r(has_login_read_mutex);
+    auto t0 = std::chrono::steady_clock::now();
     if (has_login.find(username) != has_login.end()) {
-        int sec = now - has_login.at(username);  // C 语言算时间差
+        // int sec = now - has_login.at(username);  // C 语言算时间差
+        auto dt = t0 - has_login.at(username);
+        int sec = std::chrono::duration_cast<std::chrono::seconds>(dt).count();
         return std::to_string(sec) + "秒内登录过";
     }
-    has_login[username] = now;
+    std::unique_lock grd_w(has_login_write_mutex);
+    has_login[username] = t0;
+    grd_w.unlock();
 
     if (users.find(username) == users.end())
         return "用户名错误";
@@ -44,6 +62,7 @@ std::string do_login(std::string username, std::string password) {
 }
 
 std::string do_queryuser(std::string username) {
+    if(users.find(username) == users.end()) return "没有这样的用户";
     auto &user = users.at(username);
     std::stringstream ss;
     ss << "用户名: " << username << std::endl;
@@ -52,13 +71,19 @@ std::string do_queryuser(std::string username) {
     return ss.str();
 }
 
-
-struct ThreadPool {
+class ThreadPool {
+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);
+        pool.push_back(std::move(thr));
+    }
+    ~ThreadPool() {
+        for(auto& t : pool) {
+            t.join();
+        }
     }
+private:
+    std::vector<std::thread> pool;
 };
 
 ThreadPool tpool;
@@ -72,7 +97,7 @@ std::string phone[] = {"110", "119", "120", "12315"};
 }
 
 int main() {
-    for (int i = 0; i < 262144; i++) {
+    for (int i = 0; i < 1e4; i++) {  // 262144
         tpool.create([&] {
             std::cout << do_register(test::username[rand() % 4], test::password[rand() % 4], test::school[rand() % 4], test::phone[rand() % 4]) << std::endl;
         });
@@ -85,5 +110,6 @@ int main() {
     }
 
     // 作业要求4：等待 tpool 中所有线程都结束后再退出
+    // 在ThreadPool的析构函数中等待线程结束
     return 0;
 }