使用PHP脚本来写Daemon程序(3)

5、为Worker编写信号控制，接受重启指令，类似于http restart graceful 指令。

最后，结合4和5两种方法，可以实现这样一个Daemon，如果配置文件发生了变化，他就会自动重启；如果接受到了用户的kill  -1 pid 信号，也会重新启动。

代码如下：

<?php

declare( ticks = 1 );

// This case will check the config file regularly, if the config file changed, it will restart it self

// If you want to restart the daemon gracefully, give it a HUP signal

// by shiqiang<cocowool@gmail.com> at 2011-12-04

$init_md5 = md5_file( 'config.php');

// register signal handler

pcntl_signal( SIGALRM, "signal_handler", true );

pcntl_signal( SIGHUP, 'signal_handler', TRUE );

$job_flag = FALSE;    //Job status flag, to justify if the job has been finished

$signal_flag = FALSE;    //Signal status flag, to justify whether we received the kill -1 signal

while( 1 ){

    $job_flag = FALSE;    //Job status flag

    print "Worker start running ... \n";

    sleep(5);

    print "Worker's task done ... \n";

    $flag = TRUE;    //Job status flag

    AutoStart( $signal_flag );

}

function signal_handler( $signal ) {

    global $job_flag;

    global $signal_flag;

    switch( $signal ){

        case SIGQUIT:

            print date('y-m-d H:i:s', time() ) . " Caught Signal : SIGQUIT - No : $signal \n";

            exit(0);

            break;

        case SIGSTOP:

            print date('y-m-d H:i:s', time() ) . " Caught Signal : SIGSTOP - No : $signal \n";

            break;

        case SIGHUP:

            print date('y-m-d H:i:s', time() ) . " Caught Signal : SIGHUP - No : $signal \n";

            if( $flag === TRUE ){

                AutoStart( TRUE );

            }else{