添加线程池

README.md

@@ -19,4 +19,9 @@
 参考内容        
 * CoverEars(迅雷不及掩耳，Qt版多线程下载器) https://github.com/xj361685640/CoverEars-Qt 
 
-![](./MultiplethreadDownload/screenshot.png)
+![](./MultiplethreadDownload/screenshot.png)
+
+# C++ 相关DEMO
+用来测试练习C++技术的。 
+
+C++实现的线程池，有些问题 [点击查看](./ThreadPool)

ThreadPool/HeapQueue.hpp

@@ -0,0 +1,79 @@
+#pragma once
+#include <vector>
+#include <functional>
+
+template<
+    typename T, 
+    typename Array=std::vector<T>,
+    typename compare_T=std::less<T>
+>
+class HeapQueue
+{
+public:
+    HeapQueue() { elements.clear(); }
+
+    bool empty() { return elements.size() == 0; }
+
+    T front() { return elements[0]; }
+
+    /**
+     * 入列，并向上调整
+     */ 
+    void push(const T &val) 
+    {
+        elements.push_back(val);    
+        up_update();
+    }
+
+    /**
+     * 出列，弹出栈顶元素
+     */ 
+    void pop() {
+        if (empty())
+            return ; 
+        int n = elements.size();
+        std::swap(elements[n-1], elements[0]);
+        elements.pop_back();
+        down_update();
+        return ;
+    }
+
+private:
+    /**
+     * 向上调整
+     */ 
+    void up_update() 
+    {
+        int ind = elements.size();
+        while (ind > 1 && compare(elements[ind / 2 - 1], elements[ind - 1]))
+        {
+            std::swap(elements[ind / 2 - 1], elements[ind - 1]);
+            ind /= 2;
+        }
+    }
+
+    /**
+     * 向下调整
+     */ 
+    void down_update() 
+    {
+        int ind = 0, n = elements.size(); 
+        while (ind * 2 + 1 < n)
+        {
+            int tind = ind;    
+            if (compare(elements[tind], elements[ind * 2 + 1]))
+                tind = ind * 2 + 1;
+
+            if (ind * 2 + 2 < n && compare(elements[tind], elements[ind * 2 + 2]))
+                tind = ind * 2 + 2;
+
+            if (ind == tind) 
+                break;
+            std::swap(elements[ind], elements[tind]);
+            ind = tind;
+        }
+    }
+
+    Array elements;
+    compare_T compare;
+};

ThreadPool/ThreadPool.hpp

@@ -0,0 +1,115 @@
+#pragma once
+#include <cstdlib>
+#include <thread>
+#include <vector>
+#include <queue>
+#include <mutex>
+#include <condition_variable>
+#include <iostream>
+#include <functional>
+
+class Task
+{
+public:
+    template<typename Func, typename ...Args>
+    Task(Func&& f, Args&& ...args)
+    {
+        func = std::bind(std::forward<Func>(f), std::forward<Args>(args)...);
+    }
+
+    void run()
+    {
+        std::cout << "开始运行任务函数！" << std::endl;
+        func();    
+        return;
+    }
+
+private:
+    std::function<void()> func;
+};
+
+/**
+ * 将线程池改成模板类，让任务队列可配置
+ */ 
+template<typename QueueType = std::queue<Task*>>
+class ThreadPool
+{
+public:
+    ThreadPool(size_t n)
+    {
+
+        for (int i = 0; i < n; i++) {
+            threads.push_back(new std::thread(
+                &ThreadPool::thread_worker, this
+            ));
+        }
+    }
+    ~ThreadPool()
+    {
+    {
+        std::unique_lock<std::mutex> lock(m_mutex);
+        is_running = false; // 线程池即将要销毁停止工作了
+    }
+        m_cond.notify_all();
+        for(auto &worker : threads) {
+            worker->join();
+            delete worker;
+            worker = nullptr;
+        }
+    }
+    
+    /**
+     * 工作线程入口函数，在取任务和执行任务之间做循环，
+     * 直到整个线程池停止工作、被销毁为止   
+     */
+    void thread_worker()
+    {
+        while (is_running) {
+            Task *t = getOneTask();
+            if (t == nullptr) {
+                std::cout << "获取任务失败 调用了个寂寞" << std::endl;
+                return;
+            } else {
+                std::cout << "拿到了任务，耶耶耶" << std::endl;
+            }
+            t->run();
+        }
+    }
+    
+    Task *getOneTask()
+    {
+        {
+            // 进入线程临界区时加锁
+            std::unique_lock<std::mutex> lock(m_mutex); 
+            // 等待任务
+            m_cond.wait(lock, [this](){
+                return is_running && tasks.empty();
+            });
+            Task *t = nullptr; 
+            if (is_running) {
+                t = tasks.front();
+                tasks.pop();
+            }
+            return t;
+        }
+    }
+    
+    void addOneTask(Task *t)
+    {
+        std::unique_lock<std::mutex> lock(m_mutex); 
+        // 线程池停止，不允许再添加新的任务
+        if (!is_running) { 
+            return;
+        }
+        tasks.push(t);
+        std::cout << "添加任务成功！";
+        m_cond.notify_one();
+    }
+
+private:
+    std::vector<std::thread *> threads;
+    bool is_running = true;
+    QueueType tasks;
+    std::mutex  m_mutex;
+    std::condition_variable m_cond;
+};

ThreadPool/main.cpp

@@ -0,0 +1,24 @@
+#include "ThreadPool.hpp"
+#include <iostream>
+
+void func(int a, int b)
+{
+    std::cout << a << "+" << b << "=" << a + b << std::endl; 
+    return;
+}
+
+/**
+ * 这个运行还是有点问题的，会卡顿，应该是线程退出的问题
+ * 不像另外一个线程池，能够很快地运行   
+ */ 
+int main(int argc, char const *argv[])
+{
+    std::cout << "测试输出！" << std::endl;
+    ThreadPool<> pool(5);
+    Task t1(func, 3, 4), t2(func, 5, 6);
+    
+    pool.addOneTask(&t1);
+    pool.addOneTask(&t2);
+
+    return 0;
+}