方法阻塞的解决方案之一

1、简单使用

一个h一个cpp文件

cpp 复制代码

#pragma once
#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>

class Person {

public:
    struct dog {
        std::string name;
        int age;
    };

public:
    void a(std::atomic<bool>& running, int param1, double param2, const std::string& param3);

    void startA(int param1, double param2, const std::string& param3);
};

cpp 复制代码

#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>
#include "osg.h"

void Person::a(std::atomic<bool>& running, int param1, double param2, const std::string& param3) {
    std::cout << "Function a started with params " << param1 << ", " << param2 << ", " << param3 << "." << std::endl;
    // 模拟耗时操作
    while (running) {
        // 执行一些操作
    }
    std::cout << "Function a ended." << std::endl;
}

void Person::startA(int param1, double param2, const std::string& param3) {
    std::atomic<bool> running(true);

    // 创建并启动线程
    std::thread thread_a(&Person::a, this, std::ref(running), param1, param2, param3);

    std::this_thread::sleep_for(std::chrono::seconds(10));
    if (running.load()) {
        std::cout << "stop" << std::endl;
        running = false;
    }

    // 等待线程完成执行
    if (thread_a.joinable()) {
        thread_a.join();
    }
}
    int main() {
        Person person;
        person.startA(42, 3.14, "Hello");

        // ... 其他代码 ...
        return 0;
    }

2、方法A中存在引用

错误示例：

将sum执行的数据保存下来

cpp 复制代码

#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>
#include "osg.h"

void Person::a(std::atomic<bool>& running, int& sum, double param2) {
    std::cout << "Function a started with params " << sum << ", " << param2 << std::endl;
    // 模拟耗时操作
    while (running) {
        // 执行一些操作
        for (int i = 0; i < 10000000; i++) {
            sum = i;
        }
    }
    std::cout << "Function a ended." << std::endl;
}

void Person::startA(int param1, double param2, const std::string& param3) {
    for (int i = 0; i < 2; i++) {
        int sum = 0;
        std::atomic<bool> running(true);
        // 创建并启动线程
        std::thread thread_a(&Person::a, this, std::ref(running), sum, param2);

        std::this_thread::sleep_for(std::chrono::seconds(5));
        if (running.load()) {
            std::cout << "stop" << std::endl;
            running = false;
        }

        // 等待线程完成执行
        if (thread_a.joinable()) {
            thread_a.join();
            std::cout << "等待线程完成执行" << std::endl;
        }

        std::cout << "sum: " <<sum<< std::endl;
    }

    std::cout << "任务结束" << std::endl;

}
int main() {
    Person person;
    person.startA(42, 3.14, "Hello");

    // ... 其他代码 ...
    return 0;
}

编译都过不去

正确示例：

只修改一句

cpp 复制代码

        std::thread thread_a(&Person::a, this, std::ref(running), std::ref(sum), param2);

cpp 复制代码

#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>
#include "osg.h"

void Person::a(std::atomic<bool>& running, int& sum, double param2) {
    std::cout << "Function a started with params " << sum << ", " << param2 << std::endl;
    // 模拟耗时操作
    while (running) {
        // 执行一些操作
        for (int i = 0; i < 1000000000; i++) {
            sum = i;
        }
    }
    std::cout << "Function a ended." << std::endl;
}

void Person::startA(int param1, double param2, const std::string& param3) {
    for (int i = 0; i < 2; i++) {
        int sum = 0;
        std::atomic<bool> running(true);
        // 创建并启动线程
        std::thread thread_a(&Person::a, this, std::ref(running), std::ref(sum), param2);

        std::this_thread::sleep_for(std::chrono::seconds(5));
        if (running.load()) {
            std::cout << "stop" << std::endl;
            running = false;
        }

        // 等待线程完成执行
        if (thread_a.joinable()) {
            thread_a.join();
            std::cout << "等待线程完成执行" << std::endl;
        }

        std::cout << "sum: " <<sum<< std::endl;
    }

    std::cout << "任务结束" << std::endl;

}
int main() {
    Person person;
    person.startA(42, 3.14, "Hello");

    // ... 其他代码 ...
    return 0;
}

3、A方法阻塞时间过长，希望停止

如果Person::a 方法卡住了，那么 if (thread_a.joinable()) { thread_a.join(); } 就阻塞了，std::cout << "sum: " <<sum<< std::endl; 值就得不到了，除非a方法完成了

cpp 复制代码

#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>
#include "osg.h"

void Person::a(std::atomic<bool>& running, int& sum, const double &param2) {
    std::cout << "Function a started with params " << sum << ", " << param2 << std::endl;
    // 模拟耗时操作
    for (int i = 0; i < 10; i++) {
        std::this_thread::sleep_for(std::chrono::seconds(1));
        sum = i;
    }
    std::cout << "Function a ended." << std::endl;

}

void Person::startA(int param1, double param2, const std::string& param3) {
    for (int i = 0; i < 2; i++) {
        int sum = 0;
        std::atomic<bool> running(true);
        // 创建并启动线程
        std::thread thread_a(&Person::a, this, std::ref(running), std::ref(sum), param2);

        std::this_thread::sleep_for(std::chrono::seconds(3));
        if (running.load()) {
            std::cout << "stop" << std::endl;
            running = false;
        }

        // 等待线程完成执行
        if (thread_a.joinable()) {
            thread_a.join();
        }

        std::cout << "sum: " <<sum<< std::endl;
    }

    std::cout << "任务结束" << std::endl;

}
int main() {
    Person person;
    person.startA(42, 3.14, "Hello");

    // ... 其他代码 ...
    return 0;
}

修改：

在每次循环、处理小任务、遍历某数据中进行running判断

cpp 复制代码

#include <iostream>
#include <thread>
#include <atomic>
#include <chrono>
#include <string>
#include "osg.h"

void Person::a(std::atomic<bool>& running, int& sum, const double &param2) {
    std::cout << "Function a started with params " << sum << ", " << param2 << std::endl;
        // 模拟耗时操作
    for (int i = 0; i < 10; i++) {
        if (!running) break;
        std::this_thread::sleep_for(std::chrono::seconds(1));
        sum = i;
    }
    std::cout << "Function a ended." << std::endl;

}

void Person::startA(int param1, double param2, const std::string& param3) {
    for (int i = 0; i < 2; i++) {
        int sum = 0;
        std::atomic<bool> running(true);
        // 创建并启动线程
        std::thread thread_a(&Person::a, this, std::ref(running), std::ref(sum), param2);

        std::this_thread::sleep_for(std::chrono::seconds(3));
        if (running.load()) {
            std::cout << "stop" << std::endl;
            running = false;
        }

        // 等待线程完成执行
        if (thread_a.joinable()) {
            thread_a.join();
        }

        std::cout << "sum: " <<sum<< std::endl;
    }

    std::cout << "任务结束" << std::endl;

}
int main() {
    Person person;
    person.startA(42, 3.14, "Hello");

    // ... 其他代码 ...
    return 0;
}