From 7ae18356023d5f4c54222b9bdfe824b12a1cedd8 Mon Sep 17 00:00:00 2001
From: yanmulin <yans1996@outlook.com>
Date: Tue, 18 Jan 2022 21:16:17 +0000
Subject: [PATCH] finish hw05

---
 main.cpp | 36 +++++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/main.cpp b/main.cpp
index f4ecab8..4256f9f 100644
--- a/main.cpp
+++ b/main.cpp
@@ -6,6 +6,9 @@
 #include <string>
 #include <thread>
 #include <map>
+#include <shared_mutex>
+#include <vector>
+#include <future>
 
 
 struct User {
@@ -14,13 +17,16 @@ struct User {
     std::string phone;
 };
 
+std::shared_mutex users_mtx;
 std::map<std::string, User> users;
-std::map<std::string, long> has_login;  // 换成 std::chrono::seconds 之类的
+std::mutex has_login_mtx;
+std::map<std::string, std::chrono::time_point<std::chrono::steady_clock>> has_login;  // 换成 std::chrono::seconds 之类的
 
 // 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};
+    std::lock_guard<std::shared_mutex> lock(users_mtx);
     if (users.emplace(username, user).second)
         return "注册成功";
     else
@@ -29,13 +35,19 @@ 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
-    if (has_login.find(username) != has_login.end()) {
-        int sec = now - has_login.at(username);  // C 语言算时间差
-        return std::to_string(sec) + "秒内登录过";
+    auto now = std::chrono::steady_clock::now();
+
+    {
+        std::lock_guard<std::mutex> lock(has_login_mtx);
+        if (has_login.find(username) != has_login.end()) {
+            auto dt = now - has_login.at(username);
+            int64_t sec = std::chrono::duration_cast<std::chrono::seconds>(dt).count();
+            return std::to_string(sec) + "秒内登录过";
+        }
+        has_login[username] = now;
     }
-    has_login[username] = now;
 
+    std::shared_lock<std::shared_mutex> lock(users_mtx);
     if (users.find(username) == users.end())
         return "用户名错误";
     if (users.at(username).password != password)
@@ -44,6 +56,7 @@ std::string do_login(std::string username, std::string password) {
 }
 
 std::string do_queryuser(std::string username) {
+    std::shared_lock<std::shared_mutex> lock(users_mtx);
     auto &user = users.at(username);
     std::stringstream ss;
     ss << "用户名: " << username << std::endl;
@@ -54,11 +67,20 @@ std::string do_queryuser(std::string username) {
 
 
 struct ThreadPool {
+    
     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);
+        _futures.push_back(std::async(start));
+    }
+
+    ~ThreadPool() {
+        for (auto &fut: futures_) {
+            fut.wait();
+        }
     }
+private:
+    std::vector<std::future<void>> _futures;
 };
 
 ThreadPool tpool;