When we were working on the project, we had some requirements, especially the response processing of data that took a lot of time. We all know that PHP itself does not support multi-threading, so how should we implement multi-threading in PHP?
1. PHP multi-threading under Linux
The following things are derived from the pcntl_fork function of PHP. Because of this The function depends on the implementation of the operating system fork, so the things described in this article only apply to Linux/Unix. So let’s take a look at the usage of this function first. php manual says this:
<?php $pid = pcntl_fork();if ($pid == -1) { die('could not fork'); } else if ($pid) { // we are the parent pcntl_wait($status); / /Protect against Zombie children} else { // we are the child}?>
Create a child process through pcntl_fork, if the return value If it is -1, then it means that the creation of the child process failed. The successfully created process ID will be returned to the parent process, and 0 will be returned to the child process. It is difficult to understand, so it should be written like this:
<?php $pid = pcntl_fork();if($pid == -1){ //创建失败咱就退出呗,没啥好说的 die('could not fork'); }else{ if($pid){ //从这里开始写的代码是父进程的,因为写的是系统程序,记得退出的时候给个返回值 exit(0); } else{ //从这里开始写的代码都是在新的进程里执行的,同样正常退出的话,最好也给一个返回值 exit(0); } }?>
It will be better to change it this way I understand better. If your parent process wants to know that the child process exits normally, you can add the previous pcntl_wait.
2. Through stream_socket_client method
function sendStream() { $english_format_number = number_format($number, 4, '.', ''); echo $english_format_number; exit(); $timeout = 10; $result = array(); $sockets = array(); $convenient_read_block = 8192; $host = "test.local.com"; $sql = "select waybill_id,order_id from xm_waybill where status>40 order by update_time desc limit 1 "; $data = Yii::app()->db->createCommand($sql)->queryAll(); $id = 0; foreach ($data as $k => $v) { if ($k % 2 == 0) { $send_data[$k]['body'] = NoticeOrder::getSendData($v['waybill_id']); } else { $send_data[$k]['body'] = array($v['order_id'] => array('extra' => 16)); } $data = json_encode($send_data[$k]['body']); $s = stream_socket_client($host . ":80", $errno, $errstr, $timeout, STREAM_CLIENT_ASYNC_CONNECT | STREAM_CLIENT_CONNECT); if ($s) { $sockets[$id++] = $s; $http_message = "GET /php/test.php?data=" . $data . " HTTP/1.0\r\nHost:" . $host . "\r\n\r\n"; fwrite($s, $http_message); } else { echo "Stream " . $id . " failed to open correctly."; } } while (count($sockets)) { $read = $sockets; stream_select($read, $w = null, $e = null, $timeout); if (count($read)) { /* stream_select generally shuffles $read, so we need to compute from which socket(s) we're reading. */ foreach ($read as $r) { $id = array_search($r, $sockets); $data = fread($r, $convenient_read_block); if (strlen($data) == 0) { echo "Stream " . $id . " closes at " . date('h:i:s') . ".<br> "; fclose($r); unset($sockets[$id]); } else { $result[$id] = $data; } } } else { /* A time-out means that *all* streams have failed to receive a response. */ echo "Time-out!\n"; break; } } print_r($result); }
3. Through multi-process instead of multi-thread
function daemon($func_name,$args,$number){ while(true){ $pid=pcntl_fork(); if($pid==-1){ echo "fork process fail"; exit(); }elseif($pid){//创建的子进程 static $num=0; $num++; if($num>=$number){ //当进程数量达到一定数量时候,就对子进程进行回收。 pcntl_wait($status); $num--; } }else{ //为0 则代表是子进程创建的,则直接进入工作状态 if(function_exists($func_name)){ while (true) { $ppid=posix_getpid(); var_dump($ppid); call_user_func_array($func_name,$args); sleep(2); } }else{ echo "function is not exists"; } exit(); } } } function worker($args){ //do something } daemon('worker',array(1),2);
Summary:
Multi-threading cannot be used in php. In fact, we all know it. But we can achieve it through many methods. This article introduces the multi-threading implementation method in PHP. Hope this helps!
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