PHP本身是不是支持多线程的,不过我们可以借助其他的方法来实现多线程,比如 shell 服务,比如 web 服务器,本文我们来讲讲这两个方法如何实现。需要的朋友可以来参考一下。

多线程是java中一个很不错的东西,很多朋友说在php中不可以使用PHP多线程了,其实那是错误的说法PHP多线程实现方法和fsockopen函数有关,下面我们来介绍具体实现程序代码,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:

<"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);
"htmlcode">
<"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";
} 
"htmlcode">
<"htmlcode">
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']}";
     $out .= "Host: {$_SERVER['HTTP_HOST']}rn";
     $out .= "Connection: Closernrn";
     fputs($fp,$out);
     fclose($fp);
    }
   }
  }
 }
}

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