PHP编程中尝试程序并发的几种方式总结

本文大约总结了PHP编程中的五种并发方式：
1.curl_multi_init
文档中说的是 Allows the processing of multiple cURL handles asynchronously. 确实是异步。这里需要理解的是select这个方法，文档中是这么解释的Blocks until there is activity on any of the curl_multi connections.。了解一下常见的异步模型就应该能理解，select, epoll，都很有名

<?php// build the individual requests as above, but do not execute them$ch_1 = curl_init('//www.Vevb.com/');$ch_2 = curl_init('//www.Vevb.com/');curl_setopt($ch_1, CURLOPT_RETURNTRANSFER, true);curl_setopt($ch_2, CURLOPT_RETURNTRANSFER, true);// build the multi-curl handle, adding both $ch$mh = curl_multi_init();curl_multi_add_handle($mh, $ch_1);curl_multi_add_handle($mh, $ch_2);// execute all queries simultaneously, and continue when all are complete$running = null;do {  curl_multi_exec($mh, $running);  $ch = curl_multi_select($mh);  if($ch !== 0){    $info = curl_multi_info_read($mh);    if($info){      var_dump($info);      $response_1 = curl_multi_getcontent($info['handle']);      echo "$response_1 /n";      break;    }  }} while ($running > 0);//close the handlescurl_multi_remove_handle($mh, $ch_1);curl_multi_remove_handle($mh, $ch_2);curl_multi_close($mh);

这里我设置的是，select得到结果，就退出循环，并且删除 curl resource, 从而达到取消http请求的目的。

2.swoole_client
swoole_client提供了异步模式，我竟然把这个忘了。这里的sleep方法需要swoole版本大于等于1.7.21, 我还没升到这个版本，所以直接exit也可以。

<?php$client = new swoole_client(SWOOLE_SOCK_TCP, SWOOLE_SOCK_ASYNC);//设置事件回调函数$client->on("connect", function($cli) {  $req = "GET / HTTP/1.1/r/n  Host: www.Vevb.com/r/n  Connection: keep-alive/r/n  Cache-Control: no-cache/r/n  Pragma: no-cache/r/n/r/n";  for ($i=0; $i < 3; $i++) {    $cli->send($req);  }});$client->on("receive", function($cli, $data){  echo "Received: ".$data."/n";  exit(0);  $cli->sleep(); // swoole >= 1.7.21});$client->on("error", function($cli){  echo "Connect failed/n";});$client->on("close", function($cli){  echo "Connection close/n";});//发起网络连接$client->connect('183.207.95.145', 80, 1);

3.process
哎，竟然差点忘了 swoole_process, 这里就不用 pcntl 模块了。但是写完发现，这其实也不算是中断请求，而是哪个先到读哪个，忽视后面的返回值。

<?php$workers = [];$worker_num = 3;//创建的进程数$finished = false;$lock = new swoole_lock(SWOOLE_MUTEX);for($i=0;$i<$worker_num ; $i++){  $process = new swoole_process('process');  //$process->useQueue();  $pid = $process->start();  $workers[$pid] = $process;}foreach($workers as $pid => $process){  //子进程也会包含此事件  swoole_event_add($process->pipe, function ($pipe) use($process, $lock, &$finished) {    $lock->lock();    if(!$finished){      $finished = true;      $data = $process->read();      echo "RECV: " . $data.PHP_EOL;    }    $lock->unlock();  });}function process(swoole_process $process){  $response = 'http response';  $process->write($response);  echo $process->pid,"/t",$process->callback .PHP_EOL;}for($i = 0; $i < $worker_num; $i++) {  $ret = swoole_process::wait();  $pid = $ret['pid'];  echo "Worker Exit, PID=".$pid.PHP_EOL;}