PHP如何實現多進程？
PHP實現多進程並行執行腳本
由於php的進程是不支持多線程的，有些場景為了方便以及提高性能，可以用php實現多進程以彌補這個不足：
#!/usr/bin/env php
<?php
$cmds=array(
array('/apps/bin/launcher.php','charge/promotion_props_stat.php','mobile',1),
array('/apps/bin/launcher.php','charge/promotion_props_stat.php','mobile',2),
array('/apps/bin/launcher.php','charge/promotion_props_stat.php','click',1),
array('/apps/bin/launcher.php','charge/promotion_props_stat.php','click',2),
array('/apps/bin/launcher.php','charge/promotion_props_stat.php',1),
array('/apps/bin/launcher.php','charge/promotion_props_stat.php',2)
);
foreach($cmds as $cmd){
$pid=pcntl_fork();
if($pid==-1){ //進程創建失敗
die('fork child process failure!');
}
else if($pid){ //父進程處理邏輯
pcntl_wait($status,WNOHANG);
}
else{ //子進程處理邏輯
pcntl_exec('/usr/local/bin/php',$cmd);
}
}
PHP 5.3 以上版本，使用pthreads PHP擴展，可以使PHP真正地支持多線程。多線程在處理重復性的循環任務，能夠大大縮短程序執行時間。
我之前的文章中說過，大多數網站的性能瓶頸不在PHP服務器上，因為它可以簡單地通過橫向增加服務器或CPU核數來輕松應對（對於各種雲主機，增加 VPS或CPU核數就更方便了，直接以備份鏡像增加VPS，連操作系統、環境都不用安裝配置），而是在於MySQL數據庫。如果用 MySQL 數據庫，一條聯合查詢的SQL，也許就可以處理完業務邏輯，但是，遇到大量並發請求，就歇菜了。如果用 NoSQL 數據庫，也許需要十次查詢，才能處理完同樣地業務邏輯，但每次查詢都比 MySQL 要快，十次循環NoSQL查詢也許比一次MySQL聯合查詢更快，應對幾萬次/秒的查詢完全沒問題。如果加上PHP多線程，通過十個線程同時查詢 NoSQL，返回結果匯總輸出，速度就要更快了。我們實際的APP產品中，調用一個通過用戶喜好實時推薦商品的PHP接口，PHP需要對BigSea NoSQL數據庫發起500~1000次查詢，來實時算出用戶的個性喜好商品數據，PHP多線程的作用非常明顯。
PHP擴展下載：https://github.com/krakjoe/pthreads
PHP手冊文檔：http://php.net/manual/zh/book.pthreads.php
1、擴展的編譯安裝(Linux），編輯參數 --enable-maintainer-zts 是必選項：
cd /Data/tgz/php-5.5.1
./configure --prefix=/Data/apps/php --with-config-file-path=/Data/apps/php/etc --with-mysql=/Data/apps/mysql --with-mysqli=/Data/apps/mysql/bin/mysql_config --with-iconv-dir --with-freetype-dir=/Data/apps/libs --with-jpeg-dir=/Data/apps/libs --with-png-dir=/Data/apps/libs --with-zlib --with-libxml-dir=/usr --enable-xml --disable-rpath --enable-bcmath --enable-shmop --enable-sysvsem --enable-inline-optimization --with-curl --enable-mbregex --enable-fpm --enable-mbstring --with-mcrypt=/Data/apps/libs --with-gd --enable-gd-native-ttf --with-openssl --with-mhash --enable-pcntl --enable-sockets --with-xmlrpc --enable-zip --enable-soap --enable-opcache --with-pdo-mysql --enable-maintainer-zts
make clean
make
make install
unzip pthreads-master.zip
cd pthreads-master
/Data/apps/php/bin/phpize
./configure --with-php-config=/Data/apps/php/bin/php-config
make
make install
vi /Data/apps/php/etc/php.ini
添加：
extension = "pthreads.so"
2、給出一段PHP多線程、與For循環，抓取百度搜索頁面的PHP代碼示例：
文件1
<?php
class test_thread_run extends Thread
{
public $url;
public $data;
public function __construct($url)
{
$this->url = $url;
}
public function run()
{
if(($url = $this->url))
{
$this->data = model_http_curl_get($url);
}
}
}
function model_thread_result_get($urls_array)
{
foreach ($urls_array as $key => $value)
{
$thread_array[$key] = new test_thread_run($value["url"]);
$thread_array[$key]->start();
}
foreach ($thread_array as $thread_array_key => $thread_array_value)
{
while($thread_array[$thread_array_key]->isRunning())
{
usleep(10);
}
if($thread_array[$thread_array_key]->join())
{
$variable_data[$thread_array_key] = $thread_array[$thread_array_key]->data;
}
}
return $variable_data;
}
function model_http_curl_get($url,$userAgent="")
{
$userAgent = $userAgent ? $userAgent : 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2)';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_TIMEOUT, 5);
curl_setopt($curl, CURLOPT_USERAGENT, $userAgent);
$result = curl_exec($curl);
curl_close($curl);
return $result;
}
for ($i=0; $i < 100; $i++)
{
$urls_array[] = array("name" => "baidu", "url" => "http://www.baidu.com/s?wd=".mt_rand(10000,20000));
}
$t = microtime(true);
$result = model_thread_result_get($urls_array);
$e = microtime(true);
echo "多線程：".($e-$t)."\n";
$t = microtime(true);
foreach ($urls_array as $key => $value)
{
$result_new[$key] = model_http_curl_get($value["url"]);
}
$e = microtime(true);
echo "For循環：".($e-$t)."\n";
?>
文件2
<?php
class
test_thread_run extends Thread
{
public $url;
public $data;
public function __construct($url)
{
$this->url
= $url;
}
public function run()
{
if(($url =
$this->url))
{
$this->data
= model_http_curl_get($url);
}
}
}
function model_thread_result_get($urls_array)
{
foreach ($urls_array as $key =>
$value)
{
$thread_array[$key]
= new test_thread_run($value["url"]);
$thread_array[$key]->start();
}
foreach
($thread_array as $thread_array_key => $thread_array_value)
{
while($thread_array[$thread_array_key]->isRunning())
{
usleep(10);
}
if($thread_array[$thread_array_key]->join())
{
$variable_data[$thread_array_key]
= $thread_array[$thread_array_key]->data;
}
}
return $variable_data;
}
function model_http_curl_get($url,$userAgent="")
{
$userAgent = $userAgent ? $userAgent
: 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2)';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL,
$url);
curl_setopt($curl,
CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_TIMEOUT,
5);
curl_setopt($curl,
CURLOPT_USERAGENT, $userAgent);
$result = curl_exec($curl);
curl_close($curl);
return $result;
}
for ($i=0; $i < 100; $i++)
{
$urls_array[] = array("name" =>
"baidu", "url" => "http://www.baidu.com/s?wd=".mt_rand(10000,20000));
}
$t = microtime(true);
$result = model_thread_result_get($urls_array);
$e = microtime(true);
echo "多線程：".($e-$t)."\n";
$t = microtime(true);
foreach ($urls_array as $key => $value)
{
$result_new[$key] =
model_http_curl_get($value["url"]);
}
$e = microtime(true);
echo "For循環：".($e-$t)."\n";
?>
網上看到的，沒有看太懂，先轉了！
文章來源：劉俊濤的博客
地址：http://www.cnblogs.com/lovebing
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