How php handles multithreading

Recommended manual:php complete self-study manual

##PHP processing multi-threading

Notes

1, php5.3 or above, and it is a thread-safe version. The compilers used by apache and php must be consistent.

2. If Thread Safety is enabled through phpinfo(), it is a thread-safe version.

3. You can know the compiler used by viewing the Compiler item through phpinfo(). Mine is: MSVC9 (Visual C 2008).

My usage environment

32-bit windows xp sp3, wampserver2.2d (php5.3.10-vc9 apache2.2.21-vc9).

1. Download pthreads extension

According to my environment, I downloaded pthreads-2.0.8-5.3-ts-vc9-x86.

2.0.8 represents the version of pthreads.

5.3 represents the php version.

ts means that php requires a thread-safe version.

vc9 means that php needs to be compiled with Visual C 2008 compiler.

x86 means 32-bit

2. Install pthreads extension 1. Copy php_pthreads.dll to the directory bin\php\ext\. (My path is D:\wamp\bin\php\php5.3.10\ext)

2. Copy pthreadVC2.dll to the directory bin\php\. (My path is D:\wamp\bin\php\php5.3.10)

3. Copy pthreadVC2.dll to the directory C:\windows\system32.

4. Open the php configuration file php.ini. Add extension=php_pthreads.dll

prompt at the end!

Windows system needs to add the path of pthreadVC2.dll to the PATH environment variable. My Computer--->right mouse button--->Properties--->Advanced--->Environment Variables--->System Variables--->Find the path named Path---> ;Edit--->Add the full path of pthreadVC2.dll at the end of the variable value.

3. Test the pthreads extension

class AsyncOperation extends \Thread {
    public function __construct($arg){
            $this->arg = $arg;
    }
     public function run(){ 
            if($this->arg){ 
            printf("Hello %s\n", $this->arg);
             }    
      }
}
$thread = new AsyncOperation("World");
if($thread->start())    
$thread->join();
?>

Hello World appears when you run the above code, indicating that the pthreads extension is successfully installed!

2. curl_multi_init()

<?php
echo date("Y-m-d H:m:s",time());
echo " ";
echo floor(microtime()*1000);
echo "<br>";
$mtime = explode(" ", microtime());
$mtime = $mtime[1].($mtime[0] * 1000);
$mtime2 = explode(".", $mtime);
$mtime = $mtime2[0];
echo $mtime;
echo "<br>";
$urls = array(
&#39;http://www.webkaka.com&#39;,
&#39;http://www.webkaka.com&#39;,
&#39;http://www.webkaka.com&#39;,
&#39;http://www.webkaka.com&#39;,
&#39;http://www.webkaka.com&#39;);
print_r(async_get_url($urls)); // [0] => example1, [1] => example2
echo "<br>";
echo date("Y-m-d H:m:s",time());
echo " ";
echo floor(microtime()*1000);
echo "<br>";
$mtime_ = explode(" ", microtime());
$mtime_ = $mtime_[1].($mtime_[0] * 1000);
$mtime2_ = explode(".", $mtime_);
$mtime_ = $mtime2_[0];
echo $mtime_;
echo "<br>";
echo $mtime_ - $mtime;
function async_get_url($url_array, $wait_usec = 0)
{
if (!is_array($url_array))
return false;
$wait_usec = intval($wait_usec);
$data = array();
$handle = array();
$running = 0;
$mh = curl_multi_init(); // multi curl handler
$i = 0;
foreach($url_array as $url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // return don&#39;t print
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_USERAGENT, &#39;Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)&#39;);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); // 302 redirect
curl_setopt($ch, CURLOPT_MAXREDIRS, 7);
curl_multi_add_handle($mh, $ch); // 把 curl resource 放进 multi curl handler 里
$handle[$i++] = $ch;
}
/* 执行 */
do {
curl_multi_exec($mh, $running);
if ($wait_usec > 0) /* 每个 connect 要间隔多久 */
usleep($wait_usec); // 250000 = 0.25 sec
} while ($running > 0);
/* 读取资料 */
foreach($handle as $i => $ch) {
$content = curl_multi_getcontent($ch);
$data[$i] = (curl_errno($ch) == 0) ? $content : false;
}
/* 移除 handle*/
foreach($handle as $ch) {
curl_multi_remove_handle($mh, $ch);
}
curl_multi_close($mh);
return $data;
}
?>

About curl_multi_init()

Generally speaking, think of using curl_multi_init() When, the purpose is to request multiple URLs at the same time, rather than requesting them one by one, otherwise curl_init() will be required. However, when using curl_multi, you may encounter phenomena such as excessive CPU consumption and suspended webpages. You can take a look at how to solve the problem of suspended webpages caused by curl_multi.

The steps for using curl_multi are summarized as follows:

Step one: Call curl_multi_init

Step two: Call curl_multi_add_handle in a loop

What you need to pay attention to in this step is , the second parameter of curl_multi_add_handle is the subhandle from curl_init.

Step 3: Continuously call curl_multi_exec

Step 4: Cyclically call curl_multi_getcontent to obtain the results as needed

Step 5: Call curl_multi_remove_handle and call it for each word handle curl_close

Step 6: Call curl_multi_close

Explanation of each function:

curl_multi_init()

Initialize a curl batch handle resource.

curl_multi_add_handle()

Add individual curl handle resources to the curl batch session. The curl_multi_add_handle() function has two parameters. The first parameter represents a curl batch handle resource, and the second parameter represents a separate curl handle resource.

curl_multi_exec()

Parse a curl batch handle. The curl_multi_exec() function has two parameters. The first parameter represents a batch handle resource, and the second parameter The first parameter is a parameter with a reference value, indicating the number of individual curl handle resources remaining that need to be processed.

curl_multi_remove_handle()

Remove a handle resource in the curl batch handle resource. The curl_multi_remove_handle() function has two parameters. The first parameter represents a curl batch handle resource, the second parameter represents a separate curl handle resource.

curl_multi_close()

Close a batch handle resource.

curl_multi_getcontent()

Returns the text stream of the obtained output when CURLOPT_RETURNTRANSFER is set.

curl_multi_info_read()

Get the relevant transmission information of the currently parsed curl.

Recommended related articles:
1.How to implement multi-threading in PHP
2.Three ways to implement multi-threading in PHP
Related video recommendations:
1.Dugu Jiujian (4)_PHP video tutorial

Recommended tutorial: PHP video Tutorial

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