php多线程实现方法及用法实例详解
author:一佰互联 2019-04-27   click:150

下面我们来介绍具体php多线程实现程序代码,有需要了解的同学可参考。当有人想要实现并发功能时,他们通常会想到用fork或者spawn threads,但是当他们发现php不支持多线程的时候,大概会转换思路去用一些不够好的语言,比如perl。其实的是大多数情况下,你大可不必使用fork 或者线程,并且你会得到比用fork 或thread 更好的性能。假设你要建立一个服务来检查正在运行的n台服务器,以确定他们还在正常运转。你可能会写下面这样的代码:代码如下 

<?php$hosts = array("host1.sample.com", "host2.sample.com", "host3.sample.com");$timeout = 15;$status = array();foreach ($hosts as $host) { $errno = 0; $errstr = ""; $s = fsockopen($host, 80, $errno, $errstr, $timeout); if ($s) { $status[$host] = "Connectedn"; fwrite($s, "HEAD / HTTP/1.0rnHost: $hostrnrn"); do {  $data = fread($s, 8192);  if (strlen($data) == 0) {  break;  }  $status[$host] .= $data; } while (true); fclose($s); } else { $status[$host] = "Connection failed: $errno $errstrn"; }}print_r($status);?> 

它运行的很好,但是在fsockopen()分析完hostname并且建立一个成功的连接(或者延时$timeout秒)之前,扩充这段代码来管理大量服务器将耗费很长时间。因此我们必须放弃这段代码;我们可以建立异步连接-不需要等待fsockopen返回连接状态。PHP仍然需要解析hostname(所以直接使用ip更加明智),不过将在打开一个连接之后立刻返回,继而我们就可以连接下一台服务器。有两种方法可以实现:PHP5中可以使用新增的stream_socket_client()函数直接替换掉fsocketopen()。PHP5之前的版本,你需要自己动手,用sockets扩展解决问题。下面是PHP5中的解决方法:代码如下

<?php$hosts = array("host1.sample.com", "host2.sample.com", "host3.sample.com");$timeout = 15;$status = array();$sockets = array();/* Initiate connections to all the hosts simultaneously */foreach ($hosts as $id => $host) { $s = stream_socket_client("$$host:80", $errno, $errstr, $timeout, STREAM_CLIENT_ASYNC_CONNECT|STREAM_CLIENT_CONNECT); if ($s) { $sockets[$id] = $s; $status[$id] = "in progress"; } else { $status[$id] = "failed, $errno $errstr"; }}/* Now, wait for the results to come back in */while (count($sockets)) { $read = $write = $sockets; /* This is the magic function - explained below */ $n = stream_select($read, $write, $e = null, $timeout); if ($n > 0) { /* readable sockets either have data for us, or are failed  * connection attempts */ foreach ($read as $r) {   $id = array_search($r, $sockets);   $data = fread($r, 8192);   if (strlen($data) == 0) {  if ($status[$id] == "in progress") {  $status[$id] = "failed to connect";  }  fclose($r);  unset($sockets[$id]);   } else {  $status[$id] .= $data;   } } /* writeable sockets can accept an HTTP request */ foreach ($write as $w) {  $id = array_search($w, $sockets);  fwrite($w, "HEAD / HTTP/1.0rnHost: "  . $hosts[$id] . "rnrn");  $status[$id] = "waiting for response"; } } else { /* timed out waiting; assume that all hosts associated  * with $sockets are faulty */ foreach ($sockets as $id => $s) {  $status[$id] = "timed out " . $status[$id]; } break; }}foreach ($hosts as $id => $host) { echo "Host: $hostn"; echo "Status: " . $status[$id] . "nn";} ?> 

我们用stream_select()等待sockets打开的连接事件。stream_select()调用系统的select(2)函数来工作:前面三个参数是你要使用的streams的数组;你可以对其读取,写入和获取异常(分别针对三个参数)。stream_select()可以通过设置$timeout(秒)参数来等待事件发生-事件发生时,相应的sockets数据将写入你传入的参数。下面是PHP4.1.0之后版本的实现,如果你已经在编译PHP时包含了sockets(ext/sockets)支持,你可以使用根上面类似的代码,只是需要将上面的streams/filesystem函数的功能用ext/sockets函数实现。主要的不同在于我们用下面的函数代替stream_socket_client()来建立连接:代码如下 

<?php// This value is correct for Linux, other systems have other valuesdefine("EINPROGRESS", 115);function non_blocking_connect($host, $port, &$errno, &$errstr, $timeout) { $ip = gethostbyname($host); $s = socket_create(AF_INET, SOCK_STREAM, 0); if (socket_set_nonblock($s)) { $r = @socket_connect($s, $ip, $port); if ($r || socket_last_error() == EINPROGRESS) {  $errno = EINPROGRESS;  return $s; } } $errno = socket_last_error($s); $errstr = socket_strerror($errno); socket_close($s); return false;}?> 

现在用socket_select()替换掉stream_select(),用socket_read()替换掉fread(),用socket_write()替换掉fwrite(),用socket_close()替换掉fclose()就可以执行脚本了!PHP5的先进之处在于,你可以用stream_select()处理几乎所有的stream-例如你可以通过include STDIN用它接收键盘输入并保存进数组,你还可以接收通过proc_open()打开的管道中的数据。下面来分享一个PHP多线程类代码如下

* @title:   PHP多线程类(Thread) * @version:  1.0 *  * PHP多线程应用示例: * require_once "thread.class.php"; * $thread = new thread(); * $thread->addthread("action_log","a"); * $thread->addthread("action_log","b"); * $thread->addthread("action_log","c"); * $thread->runthread(); *  * function action_log($info) { *   $log = "log/" . microtime() . ".log"; *   $txt = $info . "rnrn" . "Set in " . Date("h:i:s", time()) . (double)microtime() . "rn"; *   $fp = fopen($log, "w"); *   fwrite($fp, $txt); *   fclose($fp); * } */class thread {   var $hooks = array();  var $args = array();   function thread() {  }   function addthread($func)  {    $args = array_slice(func_get_args(), 1);    $this->hooks[] = $func;    $this->args[] = $args;    return true;  }   function runthread()  {    if(isset($_GET["flag"]))    {      $flag = intval($_GET["flag"]);    }    if($flag || $flag === 0)    {      call_user_func_array($this->hooks[$flag], $this->args[$flag]);    }    else    {      for($i = 0, $size = count($this->hooks); $i < $size; $i++)      {        $fp=fsockopen($_SERVER["HTTP_HOST"],$_SERVER["SERVER_PORT"]);        if($fp)        {          $out = "GET {$_SERVER["PHP_SELF"]}?flag=$i HTTP/1.1rn";          $out .= "Host: {$_SERVER["HTTP_HOST"]}rn";          $out .= "Connection: Closernrn";          fputs($fp,$out);          fclose($fp);        }      }    }  }}

希望本文所述对大家的PHP程序设计有所帮助。