https://www.cnblogs.com/pandamohist/p/13852197.html
互斥量 std::mutex:解决多个线程对共享数据的访问问题。
条件变量 std::condition_variable:是一种线程间的通讯机制,解决线程的执行问题。
#pragma once
#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <queue>
#include <vector>
std::mutex _mtx;
std::condition_variable _cv_not_full;
std::condition_variable _cv_not_empty;
const int max_queue_size_10 = 10;
enum {
// 总生产数目
cnt_total_10 = 10,
};
template<typename T>
struct repo_ {
// 用作互斥访问缓冲区
std::mutex _mtx_queue;
// 缓冲区最大size
unsigned int _count_max_queue_10 = 10;
// 缓冲区
std::queue<T> _queue;
// 缓冲区没有满,通知生产者继续生产
std::condition_variable _cv_queue_not_full;
// 缓冲区不为空,通知消费者继续消费
std::condition_variable _cv_queue_not_empty;
// 用于生产者之间的竞争
std::mutex _mtx_pro;
// 计算当前已经生产了多少数据了
unsigned int _cnt_cur_pro = 0;
// 用于消费者之间的竞争
std::mutex _mtx_con;
// 计算当前已经消费多少数据了
unsigned int _cnt_cur_con = 0;
repo_(const unsigned int count_max_queue = 10) :_count_max_queue_10(count_max_queue)
, _cnt_cur_con(0)
{
;
}
repo_(const repo_& instance) = delete;
repo_& operator = (const repo_& instance) = delete;
repo_(const repo_&& instance) = delete;
repo_& operator = (const repo_&& instance) = delete;
};
template <typename T>
using repo = repo_<T>;
//----------------------------------------------------------------------------------------
// 生产者生产数据
template <typename T>
void thread_produce_item(const int& thread_index, repo<T>& param_repo, const T& repo_item) {
std::unique_lock<std::mutex> lock(param_repo._mtx_queue);
// 1. 生产者只要发现缓冲区没有满, 就继续生产
param_repo._cv_queue_not_full.wait(lock, [&] { return param_repo._queue.size() < param_repo._count_max_queue_10; });
// 2. 将生产好的商品放入缓冲区
param_repo._queue.push(repo_item);
// log to console
std::cout << "生产者" << thread_index << "生产数据:" << repo_item << "\n";
// 3. 通知消费者可以消费了
//param_repo._cv_queue_not_empty.notify_one();
param_repo._cv_queue_not_empty.notify_one();
}
//----------------------------------------------------------------------------------------
// 消费者消费数据
template <typename T>
T thread_consume_item(const int thread_index, repo<T>& param_repo) {
std::unique_lock<std::mutex> lock(param_repo._mtx_queue);
// 1. 消费者需要等待【缓冲区不为空】的信号
param_repo._cv_queue_not_empty.wait(lock, [&] {return !param_repo._queue.empty(); });
// 2. 拿出数据
T item;
item = param_repo._queue.front();
param_repo._queue.pop();
std::cout << "消费者" << thread_index << "从缓冲区中拿出一组数据:" << item << std::endl;
// 3. 通知生产者,继续生产
param_repo._cv_queue_not_full.notify_one();
return item;
}
//----------------------------------------------------------------------------------------
/**
* @ brief: 生产者线程
* @ thread_index - 线程标识,区分是哪一个线程
* @ count_max_produce - 最大生产次数
* @ param_repo - 缓冲区
* @ return - void
*/
template< typename T >
void thread_pro(const int thread_index, const int count_max_produce, repo<T>* param_repo) {
if (nullptr == param_repo || NULL == param_repo)
return;
while (true) {
bool is_running = true;
{
// 用于生产者之间竞争
std::unique_lock<std::mutex> lock(param_repo->_mtx_pro);
// 缓冲区没有满,继续生产
if (param_repo->_cnt_cur_pro < cnt_total_10) {
thread_produce_item<T>(thread_index, *param_repo, param_repo->_cnt_cur_pro);
++param_repo->_cnt_cur_pro;
} else
is_running = false;
}
std::this_thread::sleep_for(std::chrono::microseconds(16));
if (!is_running)
break;
}
}
/**
* @ brief: 消费者线程
* @ thread_index - 线程标识,区分线程
* @ param_repo - 缓冲区
* @ return - void
*/
template< typename T >
void thread_con(const int thread_index, repo<T>* param_repo) {
if (nullptr == param_repo || NULL == param_repo)
return;
while (true) {
bool is_running = true;
{
std::unique_lock<std::mutex> lock(param_repo->_mtx_con);
// 还没消费到指定的数目,继续消费
if (param_repo->_cnt_cur_con < cnt_total_10) {
thread_consume_item<T>(thread_index, *param_repo);
++param_repo->_cnt_cur_con;
} else
is_running = false;
}
std::this_thread::sleep_for(std::chrono::microseconds(16));
// 结束线程
if ((!is_running))
break;
}
}
// 入口函数
//----------------------------------------------------------------------------------------
int main(int argc, char* argv[], char* env[]) {
// 缓冲区
repo<int> repository;
// 线程池
std::vector<std::thread> vec_thread;
// 生产者
vec_thread.push_back(std::thread(thread_pro<int>, 1, cnt_total_10, &repository));
vec_thread.push_back(std::thread(thread_pro<int>, 2, cnt_total_10, &repository));
// 消费者
vec_thread.push_back(std::thread(thread_con<int>, 1, &repository));
vec_thread.push_back(std::thread(thread_con<int>, 2, &repository));
for (auto& item : vec_thread) {
item.join();
}
return 0;
}
标签:std,queue,cnt,多线程,thread,--,param,repo,转载
From: https://www.cnblogs.com/txtp/p/17170975.html