守护进程

#ps -efj

<?php
class DaemonCommand
{
    private $info_dir = "/tmp";
    private $pid_file = "";
    private $terminate = false; //是否中断
    private $workers_count = 0;
    private $gc_enabled = null;
    private $workers_max = 8; //最多运行8个进程
    public function __construct($is_sington = false, $user = 'nobody', $output = "/dev/null")
    {
        $this->is_sington = $is_sington; //是否单例运行，单例运行会在tmp目录下建立一个唯一的PID
        $this->user = $user;//设置运行的用户 默认情况下nobody
        $this->output = $output; //设置输出的地方
        $this->checkPcntl();
    }
    //检查环境是否支持pcntl支持
    public function checkPcntl()
    {
        if (!function_exists('pcntl_signal_dispatch')) {
            // PHP < 5.3 uses ticks to handle signals instead of pcntl_signal_dispatch
            // call sighandler only every 10 ticks
            declare(ticks=10);
        }
        // Make sure PHP has support for pcntl
        if (!function_exists('pcntl_signal')) {
            $message = 'PHP does not appear to be compiled with the PCNTL extension. This is neccesary for daemonization';
            $this->_log($message);
            throw new Exception($message);
        }
        //信号处理
        pcntl_signal(SIGTERM, array(__CLASS__, "signalHandler"), false);
        pcntl_signal(SIGINT, array(__CLASS__, "signalHandler"), false);
        pcntl_signal(SIGQUIT, array(__CLASS__, "signalHandler"), false);
        // Enable PHP 5.3 garbage collection
        if (function_exists('gc_enable')) {
            gc_enable();
            $this->gc_enabled = gc_enabled();
        }
    }
    // daemon化程序
    public function daemonize()
    {
        global $stdin, $stdout, $stderr;
        global $argv;
        set_time_limit(0);
        // 只允许在cli下面运行
        if (php_sapi_name() != "cli") {
            die("only run in command line mode\n");
        }
        // 只能单例运行
        if ($this->is_sington == true) {
            $this->pid_file = $this->info_dir . "/" . __CLASS__ . "_" . substr(basename($argv[0]), 0, -4) . ".pid";
            $this->checkPidfile();
        }
        umask(0); //把文件掩码清0
        if (pcntl_fork() != 0) { //是父进程，父进程退出
            exit();
        }
        posix_setsid();//设置新会话组长，脱离终端
        if (pcntl_fork() != 0) { //是第一子进程，结束第一子进程
            exit();
        }
        chdir("/"); //改变工作目录
        $this->setUser($this->user) or die("cannot change owner");
        //关闭打开的文件描述符
        fclose(STDIN);
        fclose(STDOUT);
        fclose(STDERR);
        $stdin = fopen($this->output, 'r');
        $stdout = fopen($this->output, 'a');
        $stderr = fopen($this->output, 'a');
        if ($this->is_sington == true) {
            $this->createPidfile();
        }
    }
//--检测pid是否已经存在
    public function checkPidfile()
    {
        if (!file_exists($this->pid_file)) {
            return true;
        }
        $pid = file_get_contents($this->pid_file);
        $pid = intval($pid);
        if ($pid > 0 && posix_kill($pid, 0)) {
            $this->_log("the daemon process is already started");
        } else {
            $this->_log("the daemon proces end abnormally, please check pidfile " . $this->pid_file);
        }
        exit(1);
    }
//----创建pid
    public function createPidfile()
    {
        if (!is_dir($this->info_dir)) {
            mkdir($this->info_dir);
        }
        $fp = fopen($this->pid_file, 'w') or die("cannot create pid file");
        fwrite($fp, posix_getpid());
        fclose($fp);
        $this->_log("create pid file " . $this->pid_file);
    }
//设置运行的用户
    public function setUser($name)
    {
        $result = false;
        if (empty($name)) {
            return true;
        }
        $user = posix_getpwnam($name);
        if ($user) {
            $uid = $user['uid'];
            $gid = $user['gid'];
            $result = posix_setuid($uid);
            posix_setgid($gid);
        }
        return $result;
    }
//信号处理函数
    public function signalHandler($signo)
    {
        switch ($signo) {
            //用户自定义信号
            case SIGUSR1: //busy
                if ($this->workers_count < $this->workers_max) {
                    $pid = pcntl_fork();
                    if ($pid > 0) {
                        $this->workers_count++;
                    }
                }
                break;
            //子进程结束信号
            case SIGCHLD:
                while (($pid = pcntl_waitpid(-1, $status, WNOHANG)) > 0) {
                    $this->workers_count--;
                }
                break;
            //中断进程
            case SIGTERM:
            case SIGHUP:
            case SIGQUIT:
                $this->terminate = true;
                break;
            default:
                return false;
        }
    }
    /**
     *开始开启进程
     *$count 准备开启的进程数
     */
    public function start($count = 1)
    {
        $this->_log("daemon process is running now");
        pcntl_signal(SIGCHLD, array(__CLASS__, "signalHandler"), false); // if worker die, minus children num
        while (true) {
            if (function_exists('pcntl_signal_dispatch')) {
                pcntl_signal_dispatch();
            }
            if ($this->terminate) {
                break;
            }
            $pid = -1;
            if ($this->workers_count < $count) {
                $pid = pcntl_fork();
            }
            if ($pid > 0) {
                $this->workers_count++;
            } elseif ($pid == 0) {
                // 这个符号表示恢复系统对信号的默认处理
                pcntl_signal(SIGTERM, SIG_DFL);
                pcntl_signal(SIGCHLD, SIG_DFL);
                if (!empty($this->jobs)) {
                    while ($this->jobs['runtime']) {
                        if (empty($this->jobs['argv'])) {
                            call_user_func($this->jobs['function'], $this->jobs['argv']);
                        } else {
                            call_user_func($this->jobs['function']);
                        }
                        $this->jobs['runtime']--;
                        sleep(2);
                    }
                    exit();
                }
                return;
            } else {
                sleep(2);
            }
        }
        $this->mainQuit();
        exit(0);
    }
//整个进程退出
    public function mainQuit()
    {
        if (file_exists($this->pid_file)) {
            unlink($this->pid_file);
            $this->_log("delete pid file " . $this->pid_file);
        }
        $this->_log("daemon process exit now");
        posix_kill(0, SIGKILL);
        exit(0);
    }
// 添加工作实例，目前只支持单个job工作
    public function setJobs($jobs = array())
    {
        if (!isset($jobs['argv']) || empty($jobs['argv'])) {
            $jobs['argv'] = "";
        }
        if (!isset($jobs['runtime']) || empty($jobs['runtime'])) {
            $jobs['runtime'] = 1;
        }
        if (!isset($jobs['function']) || empty($jobs['function'])) {
            $this->log("你必须添加运行的函数！");
        }
        $this->jobs = $jobs;
    }
//日志处理
    private function _log($message)
    {
        printf("%s\t%d\t%d\t%s\n", date("c"), posix_getpid(), posix_getppid(), $message);
    }
}
//调用方法1
$daemon = new DaemonCommand(true);
$daemon->daemonize();
$daemon->start(2);//开启2个子进程工作
work();
//调用方法2
$daemon = new DaemonCommand(true);
$daemon->daemonize();
$daemon->addJobs(array('function' => 'work', 'argv' => '', 'runtime' => 1000));//function 要运行的函数,argv运行函数的参数，runtime运行的次数
$daemon->start(2);//开启2个子进程工作
//具体功能的实现
function work()
{
    echo "测试1";
}
?>