php swoole多进程/多线程例子

swoole的多线程其实就是多进程，进程创建太多切换的开销很大，如果能用上pthreads建议用pthreads，因为我用的是php7nts版本没办法用pthreads

swoole实例如下：

useQueue(0, 2);
    $pid = $process->start();

    // 管道写入内容
    $process->write('index:'.$i);

    $process->push('进程的消息队列内容');
    // 将每一个进程的句柄存起来
    $workers[$pid] = $process;
}


/**
 * 子进程回调
 * @param  swoole_process $worker [description]
 * @return [type]                 [description]
 */
function callback_function(swoole_process $worker)
{
    $recv = $worker->pop();
    echo "子输出主内容: {$recv}".PHP_EOL;
    //get guandao content
    $recv = $worker->read();
    $result = doTask();
    
    echo PHP_EOL.$result.'==='.$worker->pid.'==='.$recv;

    $worker->exit(0);
}


/**
 * 监控/回收子进程
 */
while(1){
    $ret = swoole_process::wait();
    if ($ret){// $ret 是个数组 code是进程退出状态码，
        $pid = $ret['pid'];
        echo PHP_EOL."Worker Exit, PID=" . $pid . PHP_EOL;
    }else{
        break;
    }
}


/**
 * doTask
 * @return [type] [description]
 */
function doTask()
{
    sleep(2);
    return true;
}