在多线程编程中使用 `std::future` 和 `std::vector＜std::future＜void＞＞`

Using std::future and std::vector<std::future<void>> in Multithreaded Programming

在多线程编程中使用 std::future 和 std::vector<std::future<void>>

Introduction

Multithreading in C++ allows for parallel execution of code. Using std::future and std::vector<std::future<void>>, you can manage asynchronous operations more efficiently.

介绍

C++中的多线程允许代码并行执行。使用std::future和std::vector<std::future<void>>，你可以更有效地管理异步操作。

std::future Basics

std::future provides a mechanism to access the result of asynchronous operations. It’s often used with std::async to run tasks in parallel.

std::future 基础

std::future提供了一种访问异步操作结果的机制。它通常与std::async一起使用，以并行运行任务。

Using std::vector<std::future<void>> for Multiple Tasks

When you have multiple tasks to run in parallel, storing each task’s std::future in a std::vector simplifies task management.

使用std::vector<std::future<void>>处理多个任务

当你有多个任务需要并行运行时，将每个任务的std::future存储在一个std::vector中可以简化任务管理。

Example

This example demonstrates launching multiple tasks asynchronously and waiting for all to complete:

示例

此示例演示了如何异步启动多个任务并等待全部完成：

#include <future>
#include <vector>
#include <iostream>

void doWork(int id) {
    // Simulate some work.
    std::cout << "Task " << id << " completed.\n";
}

int main() {
    std::vector<std::future<void>> futures;

    for (int i = 0; i < 5; ++i) {
        futures.emplace_back(std::async(std::launch::async, doWork, i));
    }

    for (auto& fut : futures) {
        fut.get(); // Wait for each task to complete
    }

    std::cout << "All tasks completed.\n";
    return 0;
}

Suitable Cases

• Parallel Data Processing: Ideal for operations that can be executed concurrently, such as processing multiple files.
• Asynchronous I/O Operations: Useful for non-blocking I/O operations.

适用情况

• 并行数据处理：适用于可以并发执行的操作，如处理多个文件。
• 异步I/O操作：用于非阻塞I/O操作。

Conclusion

std::future and std::vector<std::future<void>> simplify handling asynchronous tasks in C++, making your code more efficient and easier to manage.

结论

std::future和std::vector<std::future<void>>简化了C++中异步任务的处理，使你的代码更高效、更易于管理。