PHP如何实现多进程？
PHP实现多进程并行执行脚本
由于php的进程是不支持多线程的，有些场景为了方便以及提高性能，可以用php实现多进程以弥补这个不足：
#!/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){ //进程创建失败
die('fork child process failure!');
}
else if($pid){ //父进程处理逻辑
pcntl_wait($status,WNOHANG);
}
else{ //子进程处理逻辑
pcntl_exec('/usr/local/bin/php',$cmd);
}
}
PHP 5.3 以上版本，使用pthreads PHP扩展，可以使PHP真正地支持多线程。多线程在处理重复性的循环任务，能够大大缩短程序执行时间。
我之前的文章中说过，大多数网站的性能瓶颈不在PHP服务器上，因为它可以简单地通过横向增加服务器或CPU核数来轻松应对（对于各种云主机，增加 VPS或CPU核数就更方便了，直接以备份镜像增加VPS，连操作系统、环境都不用安装配置），而是在于MySQL数据库。如果用 MySQL 数据库，一条联合查询的SQL，也许就可以处理完业务逻辑，但是，遇到大量并发请求，就歇菜了。如果用 NoSQL 数据库，也许需要十次查询，才能处理完同样地业务逻辑，但每次查询都比 MySQL 要快，十次循环NoSQL查询也许比一次MySQL联合查询更快，应对几万次/秒的查询完全没问题。如果加上PHP多线程，通过十个线程同时查询 NoSQL，返回结果汇总输出，速度就要更快了。我们实际的APP产品中，调用一个通过用户喜好实时推荐商品的PHP接口，PHP需要对BigSea NoSQL数据库发起500~1000次查询，来实时算出用户的个性喜好商品数据，PHP多线程的作用非常明显。
PHP扩展下载：https://github.com/krakjoe/pthreads
PHP手册文档：http://php.net/manual/zh/book.pthreads.php
1、扩展的编译安装(Linux），编辑参数 --enable-maintainer-zts 是必选项：
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、给出一段PHP多线程、与For循环，抓取百度搜索页面的PHP代码示例：
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);
$e = microtime(true);
echo "多线程：".($e-$t)." ";
$t = microtime(true);
foreach ($urls_array as $key => $value)
{
$result_new[$key] = model_http_curl_get($value["url"]);
}
$e = microtime(true);
echo "For循环：".($e-$t)." ";
?>
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);
$e = microtime(true);
echo "多线程：".($e-$t)." ";
$t = microtime(true);
foreach ($urls_array as $key => $value)
{
$result_new[$key] =
model_http_curl_get($value["url"]);
}
$e = microtime(true);
echo "For循环：".($e-$t)." ";
?>
网上看到的，没有看太懂，先转了！
文章来源：刘俊涛的博客
地址：http://www.cnblogs.com/lovebing
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