raspisms/daemons/AbstractDaemon.php

132 lines
2.9 KiB
PHP

<?php
namespace daemons;
/**
* Class defining the global structur of a Linux Daemon
*/
abstract class AbstractDaemon
{
protected $name;
private $is_running = true;
private $signals = array (
SIGTERM,
SIGINT,
SIGCHLD,
SIGHUP
);
/**
* Class used to handle POSIX signals and fork from the current process
*
* @param string $name : The name of the class
* @param array $signals :An array containing additional POSIX signals to handle [optionel]
*/
protected function __construct (string $name, array $signals = [])
{
$this->name = $name;
$this->signals = array_merge($this->signals, $signals);
//Allow script to run indefinitly
set_time_limit(0);
//Register signals
$this->register_signals();
}
/**
* Used to register POSIX signals
*/
private function register_signals()
{
//Enable a tick at every 1 instruction, allowing us to run a function frequently, for exemple looking at signal status
declare(ticks = 1);
foreach ($this->signals as $signal)
{
//For each signal define the method handle_signal of the current class as the way to handle it
@pcntl_signal($signal, [
'self',
'handle_signal'
]);
}
}
/**
* Used to handle properly SIGINT, SIGTERM, SIGCHLD and SIGHUP
*
* @param int $signal
* @param mixed $signinfo
*/
protected function handle_signal(int $signal, $signinfo)
{
if ($signal == SIGTERM || $signal == SIGINT) //Stop the daemon
{
$this->is_running = false;
}
else if ($signal == SIGHUP) //Restart the daemon
{
$this->on_stop();
$this->on_start();
}
else if ($signal == SIGCHLD) //On daemon child stopping
{
pcntl_waitpid(-1, $status, WNOHANG);
}
else //All the other signals
{
$this->handle_other_signals($signal);
}
}
/**
* Launch the infinite loop executing the "run" abstract method
*/
protected function start ()
{
$this->on_start();
while ($this->is_running)
{
pcntl_signal_dispatch(); //Call dispatcher for signals
$this->run();
}
$this->on_stop();
}
/**
* True if the daemon is running
*/
public function is_running()
{
return $this->is_running;
}
/**
* Override to implement the code that run infinetly (actually, it run one time but repeat the operation infinetly
*/
protected abstract function run();
/**
* Override to execute code before the ''run'' method on daemon start
*/
protected abstract function on_start();
/**
* Override to execute code after the ''run'' method on daemon shutdown
*/
protected abstract function on_stop();
/**
* Override to handle additional POSIX signals
*
* @param int $signal : Signal sent by interrupt
*/
protected abstract function handle_other_signals(int $signal);
}