本节讲解几个多进程的实例。
多进程实例
Master-Worker结构
下面例子实现了简单的多进程管理：
-
支持设置最大子进程数
-
Master-Worker结构：Worker挂掉，Master进程会重新创建一个
<?php
$pids = []; //存储子进程pid
$MAX_PROCESS = 3;//最大进程数
$pid = pcntl_fork();
if($pid <0){
exit("fork fail\n");
}elseif($pid > 0){
exit;//父进程退出
}else{
// 从当前终端分离
if (posix_setsid() == -1) {
die("could not detach from terminal");
}
$id = getmypid();
echo time()." Master process, pid {$id}\n";
for($i=0; $i<$MAX_PROCESS;$i++){
start_worker_process();
}
//Master进程等待子进程退出，必须是死循环
while(1){
foreach($pids as $pid){
if($pid){
$res = pcntl_waitpid($pid, $status, WNOHANG);
if ( $res == -1 || $res > 0 ){
echo time()." Worker process $pid exit, will start new... \n";
start_worker_process();
unset($pids[$pid]);
}
}
}
}
}
/**
* 创建worker进程
*/
function start_worker_process(){
global $pids;
$pid = pcntl_fork();
if($pid <0){
exit("fork fail\n");
}elseif($pid > 0){
$pids[$pid] = $pid;
// exit; //此处不可退出，否则Master进程就退出了
}else{
//实际代码
$id = getmypid();
$rand = rand(1,3);
echo time()." Worker process, pid {$id}. run $rand s\n";
while(1){
sleep($rand);
}
}
}
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多进程Server
下面我们使用多进程实现一个tcp服务器，支持：
-
多进程处理客户端连接
-
子进程退出，Master进程会重新创建一个
-
支持事件回调
<?php
class TcpServer{
const MAX_PROCESS = 3;//最大进程数
private $pids = []; //存储子进程pid
private $socket;
public function __construct(){
$pid = pcntl_fork();
if($pid <0){
exit("fork fail\n");
}elseif($pid > 0){
exit;//父进程退出
} else{
// 从当前终端分离
if (posix_setsid() == -1) {
die("could not detach from terminal");
}
umask(0);
$id = getmypid();
echo time()." Master process, pid {$id}\n";
//创建tcp server
$this->socket = stream_socket_server("tcp://0.0.0.0:9201", $errno, $errstr);
if(!$this->socket) exit("start server err: $errstr --- $errno");
}
}
public function run(){
for($i=0; $i<self::MAX_PROCESS;$i++){
$this->start_worker_process();
}
echo "waiting client...\n";
//Master进程等待子进程退出，必须是死循环
while(1){
foreach($this->pids as $k=>$pid){
if($pid){
$res = pcntl_waitpid($pid, $status, WNOHANG);
if ( $res == -1 || $res > 0 ){
echo time()." Worker process $pid exit, will start new... \n";
$this->start_worker_process();
unset($this->pids[$k]);
}
}
}
sleep(1);//让出1s时间给CPU
}
}
/**
* 创建worker进程，接受客户端连接
*/
private function start_worker_process(){
$pid = pcntl_fork();
if($pid <0){
exit("fork fail\n");
}elseif($pid > 0){
$this->pids[] = $pid;
// exit; //此处不可退出，否则Master进程就退出了
}else{
$this->acceptClient();
}
}
private function acceptClient()
{
//子进程一直等待客户端连接，不能退出
while(1){
$conn = stream_socket_accept($this->socket, -1);
if($this->onConnect) call_user_func($this->onConnect, $conn); //回调连接事件
//开始循环读取消息
$recv = ''; //实际收到消息
$buffer = ''; //缓冲消息
while(1){
$buffer = fread($conn, 20);
//没有收到正常消息
if($buffer === false || $buffer === ''){
if($this->onClose) call_user_func($this->onClose, $conn); //回调断开连接事件
break;//结束读取消息，等待下一个客户端连接
}
$pos = strpos($buffer, "\n"); //消息结束符
if($pos === false){
$recv .= $buffer;
}else{
$recv .= trim(substr($buffer, 0, $pos+1));
if($this->onMessage) call_user_func($this->onMessage, $conn, $recv); //回调收到消息事件
//客户端强制关闭连接
if($recv == "quit"){
echo "client close conn\n";
fclose($conn);
break;
}
$recv = ''; //清空消息，准备下一次接收
}
}
}
}
function __destruct() {
@fclose($this->socket);
}
}
$server = new TcpServer();
$server->onConnect = function($conn){
echo "onConnect -- accepted " . stream_socket_get_name($conn,true) . "\n";
fwrite($conn,"conn success\n");
};
$server->onMessage = function($conn,$msg){
echo "onMessage --" . $msg . "\n";
fwrite($conn,"received ".$msg."\n");
};
$server->onClose = function($conn){
echo "onClose --" . stream_socket_get_name($conn,true) . "\n";
fwrite($conn,"onClose "."\n");
};
$server->run();
运行：
$ php process_multi.server.php
1528734803 Master process, pid 9110
waiting client...
此时服务端已经变成守护进程了。新开终端，我们使用ps命令查看进程：
$ ps -ef | grep php
yjc 9110 1 0 00:33 ? 00:00:00 php process_multi.server.php
yjc 9111 9110 0 00:33 ? 00:00:00 php process_multi.server.php
yjc 9112 9110 0 00:33 ? 00:00:00 php process_multi.server.php
yjc 9113 9110 0 00:33 ? 00:00:00 php process_multi.server.php
yjc 9134 8589 0 00:35 pts/1 00:00:00 grep php
可以看到4个进程：1个主进程，3个子进程。使用kill命令结束子进程，主进程会重新拉起一个新的子进程。
然后我们使用telnet测试连接：
$ telnet 127.0.0.1 9201
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
conn success
hello server!
received hello server!
quit
received quit
Connection closed by foreign host.
