<?php

/*
?* 同一個PHP進程只運行一次,根據進程名字判斷是否為排重進程,只能運行于linux,高并發條件下是并發平安的.
?*/PHP實例

class SyncProcess {PHP實例

?private $pidFile;PHP實例

?function __construct($pidFile) {
??$this->pidFile = $pidFile;
?}PHP實例

?/**
? * 非阻塞方式返回過程是否正在運行
? */
?function check() {
??if (PHP_OS == 'Linux') {
???$pidFile = $this->pidFile;
???if (!empty($pidFile)) {
????$flag = false;
????$pidDir = dirname($pidFile);
????if (is_dir($pidDir)) {
?????$flag = true;
????}
????if ($flag) {
?????$running = true;
?????clearstatcache(true, $this->pidFile);
?????if (!file_exists($this->pidFile))
??????file_put_contents($this->pidFile, '', LOCK_EX);
?????$f = fopen($this->pidFile, 'r+');
?????if (flock($f, LOCK_EX ^ LOCK_NB)) {
??????$pid = trim(fgets($f));
??????if (!$this->is_process_running($pid)) {
???????$running = false;
??????}
?????}
?????if (!$running) {
??????fseek($f, 0);
??????ftruncate($f, 0);
??????fwrite($f, getmypid());
?????}
?????flock($f, LOCK_UN);
?????fclose($f);
?????return $running;
????} else {
?????debug_print("pid file($pidFile) is invalid", E_USER_WARNING);
????}
???} else {
????debug_print("pid file cant't be empty", E_USER_WARNING);
???}
??} else {
???debug_print(__CLASS__ . ' can only run in Linux', E_USER_WARNING);
???return true;
??}
?}PHP實例

?/**
? * 如果正在運行或者發生未知差錯返回true,如果沒有運行返回false
? * @param mixed $pid
? */
?private function is_process_running($pid) {
??if (is_numeric($pid) && $pid > 0) {
???$output = array();
???$line = exec("ps -o pid --no-headers -p $pid", $output);
???//返回值有空格
???$line = trim($line);
???if ($line == $pid) {
????return true;
???} else {
????if (empty($output)) {
?????return false;
????} else {
?????if (php_sapi_name() == 'cli')
??????$n = "\n";
?????else
??????$n = "<br>";
?????//到這一步的話應該是出什么問題了
?????$output = implode($n, $output);
?????debug_print($output, E_USER_WARNING);
?????return true;
????}
???}
??}else {
???return false;
??}
?}PHP實例

}
PHP實例

$sync = new SyncProcess(APP_PATH . '/data/pid'.implode('', $this->getRoute()));
if ($sync->check()) {
?exit("process is running\n");
}