基于C++11的threadpool线程池(简洁且可以带任意多的参数)

#pragma once#ifndef THREAD_POOL_H#define THREAD_POOL_H#include <vector>#include <queue>#include <thread>#include <atomic>#include <condition_variable>#include <future>#include <functional>#include <stdexcept>namespace std{#define MAX_THREAD_NUM 256//线程池,可以提交变参函数或拉姆达表达式的匿名函数执行,可以获取执行返回值//不支持类成员函数, 支持类静态成员函数或全局函数,Opteron()函数等class threadpool{  using Task = std::function<void()>;  // 线程池  std::vector<std::thread> pool;  // 任务队列  std::queue<Task> tasks;  // 同步  std::mutex m_lock;  // 条件阻塞  std::condition_variable cv_task;  // 是否关闭提交  std::atomic<bool> stoped;  //空闲线程数量  std::atomic<int> idlThrNum;public:  inline threadpool(unsigned short size = 4) :stoped{ false }  {    idlThrNum = size < 1 ? 1 : size;    for (size = 0; size < idlThrNum; ++size)    {  //初始化线程数量      pool.emplace_back(        [this]        { // 工作线程函数          while(!this->stoped)          {            std::function<void()> task;            {  // 获取一个待执行的 task              std::unique_lock<std::mutex> lock{ this->m_lock };// unique_lock 相比 lock_guard 的好处是：可以随时 unlock() 和 lock()              this->cv_task.wait(lock,                [this] {                  return this->stoped.load() || !this->tasks.empty();                }              ); // wait 直到有 task              if (this->stoped && this->tasks.empty())                return;              task = std::move(this->tasks.front()); // 取一个 task              this->tasks.pop();            }            idlThrNum--;            task();            idlThrNum++;          }        }      );    }  }  inline ~threadpool()  {    stoped.store(true);    cv_task.notify_all(); // 唤醒所有线程执行    for (std::thread& thread : pool) {      //thread.detach(); // 让线程“自生自灭”      if(thread.joinable())        thread.join(); // 等待任务结束， 前提：线程一定会执行完    }  }public:  // 提交一个任务  // 调用.get()获取返回值会等待任务执行完,获取返回值  // 有两种方法可以实现调用类成员，  // 一种是使用  bind： .commit(std::bind(&Dog::sayHello, &dog));  // 一种是用 mem_fn： .commit(std::mem_fn(&Dog::sayHello), &dog)  template<class F, class... Args>  auto commit(F&& f, Args&&... args) ->std::future<decltype(f(args...))>  {    if (stoped.load())  // stop == true ??      throw std::runtime_error("commit on ThreadPool is stopped.");    using RetType = decltype(f(args...)); // typename std::result_of<F(Args...)>::type, 函数 f 的返回值类型    auto task = std::make_shared<std::packaged_task<RetType()> >(      std::bind(std::forward<F>(f), std::forward<Args>(args)...)      );  // wtf !    std::future<RetType> future = task->get_future();    {  // 添加任务到队列      std::lock_guard<std::mutex> lock{ m_lock };//对当前块的语句加锁 lock_guard 是 mutex 的 stack 封装类，构造的时候 lock()，析构的时候 unlock()      tasks.emplace(        [task]()        { // push(Task{...})          (*task)();        }      );    }    cv_task.notify_one(); // 唤醒一个线程执行    return future;  }  //空闲线程数量  int idlCount() { return idlThrNum; }};}#endif

#include "threadpool.h"#include <iostream>void fun1(int slp){  printf(" hello, fun1 ! %d/n" ,std::this_thread::get_id());  if (slp>0) {    printf(" ======= fun1 sleep %d ========= %d/n",slp, std::this_thread::get_id());    std::this_thread::sleep_for(std::chrono::milliseconds(slp));  }}struct gfun {  int operator()(int n) {    printf("%d hello, gfun ! %d/n" ,n, std::this_thread::get_id() );    return 42;  }};class A { public:  static int Afun(int n = 0) {  //函数必须是 static 的才能直接使用线程池    std::cout << n << " hello, Afun ! " << std::this_thread::get_id() << std::endl;    return n;  }  static std::string Bfun(int n, std::string str, char c) {    std::cout << n << " hello, Bfun ! "<< str.c_str() <<" " << (int)c <<" " << std::this_thread::get_id() << std::endl;    return str;  }};int main()  try {    std::threadpool executor{ 50 };    A a;    std::future<void> ff = executor.commit(fun1,0);    std::future<int> fg = executor.commit(gfun{},0);    std::future<int> gg = executor.commit(a.Afun, 9999); //IDE提示错误,但可以编译运行    std::future<std::string> gh = executor.commit(A::Bfun, 9998,"mult args", 123);    std::future<std::string> fh = executor.commit([]()->std::string { std::cout << "hello, fh ! " << std::this_thread::get_id() << std::endl; return "hello,fh ret !"; });    std::cout << " ======= sleep ========= " << std::this_thread::get_id() << std::endl;    std::this_thread::sleep_for(std::chrono::microseconds(900));    for (int i = 0; i < 50; i++) {      executor.commit(fun1,i*100 );    }    std::cout << " ======= commit all ========= " << std::this_thread::get_id()<< " idlsize="<<executor.idlCount() << std::endl;    std::cout << " ======= sleep ========= " << std::this_thread::get_id() << std::endl;    std::this_thread::sleep_for(std::chrono::seconds(3));    ff.get(); //调用.get()获取返回值会等待线程执行完,获取返回值    std::cout << fg.get() << " " << fh.get().c_str()<< " " << std::this_thread::get_id() << std::endl;    std::cout << " ======= sleep ========= " << std::this_thread::get_id() << std::endl;    std::this_thread::sleep_for(std::chrono::seconds(3));    std::cout << " ======= fun1,55 ========= " << std::this_thread::get_id() << std::endl;    executor.commit(fun1,55).get();  //调用.get()获取返回值会等待线程执行完    std::cout << "end... " << std::this_thread::get_id() << std::endl;    std::threadpool pool(4);    std::vector< std::future<int> > results;    for (int i = 0; i < 8; ++i) {      results.emplace_back(        pool.commit([i] {          std::cout << "hello " << i << std::endl;          std::this_thread::sleep_for(std::chrono::seconds(1));          std::cout << "world " << i << std::endl;          return i*i;        })      );    }    std::cout << " ======= commit all2 ========= " << std::this_thread::get_id() << std::endl;    for (auto && result : results)      std::cout << result.get() << ' ';    std::cout << std::endl;    return 0;  }catch (std::exception& e) {  std::cout << "some unhappy happened... " << std::this_thread::get_id() << e.what() << std::endl;}