4种PHP异步执行的常用方式

客户端与服务器端是通过HTTP协议进行连接通讯，客户端发起请求，服务器端接收到请求后执行处理，并返回处理结果。 有时服务器需要执行很耗时的操作，这个操作的结果并不需要返回给客户端。但因为php是同步执行的，所以客户端需要等待服务处理完才可以进行下一步。 因此对于耗时的操作适合异步执行，服务器接收到请求后，处理完客户端需要的数据就返回，再异步在服务器执行耗时的操作。 1.使用Ajax 与 img 标记 原理，服务器返回的html中插入Ajax 代码或 img 标记，img的src为需要执行的程序。 优点：实现简单，服务端无需执行任何调用 缺点：在执行期间，浏览器会一直处于loading状态，因此这种方法并不算真正的异步调用。 <div class="line number1 index0 alt2">$.get("doRequest.php", { name: "fdipzone"} );</div><div class="line number2 index1 alt1"><img src="</code"></img>"doRequest.php?name=fdipzone"></div>

• 2）.不能传递大量参数

• 3）.访问量高时会创建很多进程

  3.使用curl 设置curl的超时时间 CURLOPT\_TIMEOUT 为1 （最小为1），因此客户端需要等待1秒

  </div><div><div class="line number1 index0 alt2">`<?php </code?>`</div><div class="line number2 index1 alt1">`$ch` `= curl_init(); `</div><div class="line number3 index2 alt2">`$curl_opt` `= array( `</div><div class="line number4 index3 alt1">`  CURLOPT_URL, '<a href="http://www.example.com/doRequest.php">http://www.example.com/doRequest.php</a>'`</div><div class="line number5 index4 alt2">`  CURLOPT_RETURNTRANSFER,1, </div><div class="line number6 index5 alt1">  CURLOPT_TIMEOUT,1 `</div><div class="line number7 index6 alt2">`); `</div><div class="line number8 index7 alt1">`curl_setopt_array($ch, $curl_opt); `</div><div class="line number9 index8 alt2">`curl_exec($ch); `</div><div class="line number10 index9 alt1">`curl_close($ch); `</div><div class="line number11 index10 alt2">`?>`</div> </div><div class="syntaxhighlighter php"></div><div></div> </div> **4.使用fsockopen** fsockopen是最好的，缺点是需要自己拼接header部分。 <div class="jb51code"><div class="syntaxhighlighter php" id="highlighter_378781"><div class="toolbar"></div>

  <?php </code?>

     

  $url = `'http://www.example.com/doRequest.php'; `</div><div class="line number4 index3 alt1">`$param` `= array( `</div><div class="line number5 index4 alt2">`  'name'=>'fdipzone', `</div><div class="line number6 index5 alt1">`  'gender'=>'male', `</div><div class="line number7 index6 alt2">`  'age'=>30 `</div><div class="line number8 index7 alt1">`); `</div><div class="line number9 index8 alt2">`   `</div><div class="line number10 index9 alt1">`doRequest($url, $param); `</div><div class="line number11 index10 alt2">`   `</div><div class="line number12 index11 alt1">`function` `doRequest($url, $param=array()){ `</div><div class="line number13 index12 alt2">`   `</div><div class="line number14 index13 alt1">`  $urlinfo = parse_url($url); </div><div class="line number15 index14 alt2">   </div><div class="line number16 index15 alt1">  $host` `= $urlinfo['host']; `</div><div class="line number17 index16 alt2">`  $path = $urlinfo['path']; </div><div class="line number18 index17 alt1">  $query` `= isset($param)? http_build_query($param) : ''; `</div><div class="line number19 index18 alt2">`   `</div><div class="line number20 index19 alt1">`  $port = 80; </div><div class="line number21 index20 alt2">  $errno` `= 0; `</div><div class="line number22 index21 alt1">`  $errstr = ''; </div><div class="line number23 index22 alt2">  $timeout` `= 10; `</div><div class="line number24 index23 alt1">`   `</div><div class="line number25 index24 alt2">`  $fp = fsockopen($host, $port, $errno, $errstr, $timeout); </div><div class="line number26 index25 alt1">   </div><div class="line number27 index26 alt2">  $out` `= "POST ".$path." HTTP/1.1\r\n"; `</div><div class="line number28 index27 alt1">`  $out .= "host:".$host."\r\n"; </div><div class="line number29 index28 alt2">  $out` `.= "content-length:".strlen($query)."\r\n"; `</div><div class="line number30 index29 alt1">`  $out .= "content-type:application/x-www-form-urlencoded\r\n"; </div><div class="line number31 index30 alt2">  $out` `.= "connection:close\r\n\r\n"; `</div><div class="line number32 index31 alt1">`  $out .= $query; </div><div class="line number33 index32 alt2">   </div><div class="line number34 index33 alt1">  fputs($fp, $out); </div><div class="line number35 index34 alt2">  fclose($fp); `</div><div class="line number36 index35 alt1">`} `</div><div class="line number37 index36 alt2">`   `</div><div class="line number38 index37 alt1">`?>`</div> </div><div class="syntaxhighlighter php"></div> </div> 注意：当执行过程中，客户端连接断开或连接超时，都会有可能造成执行不完整，因此需要加上 <div class="jb51code"><div class="syntaxhighlighter php" id="highlighter_512299"><div class="toolbar"></div>

  ignore_user_abort(true); `// 忽略客户端断开 </div><div class="line number2 index1 alt1">set_time_limit(0);    `// 设置执行不超时