PHP异步协程开发：解决高并发下的验证码生成问题

<?php

use SwooleCoroutine;

// 验证码生成协程函数
function generateCaptcha($width, $height)
{
    $image = imagecreate($width, $height);
    // 省略生成验证码的逻辑

    // 模拟耗时操作
    Coroutine::sleep(1);
    ob_start();
    imagepng($image);
    $data = ob_get_clean();
    imagedestroy($image);
    return $data;
}

// 异步协程回调函数
function coroutineCallback($coroutine, $callback)
{
    $result = Coroutine::getuid();
    $coroutine->send($result);
    $value = $coroutine->current();

    if ($value !== false) {
        // 其他协程操作
        $result = $value;
    }

    if ($callback) {
        $callback($result);
    }
}

// 并发生成验证码
function concurrentGenerate($number, $width, $height)
{
    // 创建协程队列
    $coroutines = [];
    for ($i = 0; $i < $number; $i++) {
        $coroutine = Coroutine::create('generateCaptcha', $width, $height);
        $coroutines[$i] = $coroutine;
    }

    // 结果收集
    $results = [];
    foreach ($coroutines as $coroutine) {
        coroutineCallback($coroutine, function ($result) use (&$results) {
            $results[] = $result;
        });
    }

    return $results;
}

// 测试
$results = concurrentGenerate(10, 100, 50);
print_r($results);