pocketmine/snooze

Thread notification management library for code using the pthreads extension

0.1.5 2021-02-22 16:16 UTC

This package is auto-updated.

Last update: 2021-03-29 16:53:25 UTC


README

Event-driven thread notification management library for code using the pthreads extension

Use cases

ext-pthreads currently doesn't make it conveniently possible to wait() for notifications from multiple threads simultaneously. This library allows you to do that using a SleeperHandler.

Every thread must receive its own SleeperNotifier (since they are thread-safe, you can share notifiers between threads, but it's recommended not to). The thread should call wakeupSleeper() on its SleeperNotifier, which will cause the thread waiting on SleeperHandler to wake up and process whatever notification was delivered.

It's similar to using the select() system call on an array of sockets or file descriptors, but with threads instead.

Example

class SleepyThread extends \Thread{
	/** @var \pocketmine\snooze\SleeperNotifier */
	private $notifier;
	/** @var \Threaded */
	private $buffer;

	public function __construct(\pocketmine\snooze\SleeperNotifier $notifier){
		$this->notifier = $notifier;
		$this->buffer = new \Threaded();
	}

	public function run() : void{
		$stdin = fopen('php://stdin', 'r');
		while(true){
			echo "Type something and press ENTER:\n";
			//do whatever you're doing
			$line = fgets($stdin); //blocks until the user enters something

			//add the line to the buffer
			$this->buffer[] = $line;

			//send a notification to the main thread to tell it that we read a line
			//the parent thread doesn't have to be sleeping to receive this, it'll process it next time it tries to go
			//back to sleep
			//if the parent thread is sleeping, it'll be woken up to process notifications immediately.
			$this->notifier->wakeupSleeper();
		}
	}

	public function getLineFromBuffer() : ?string{
		return $this->buffer->shift();
	}
}

$sleeper = new \pocketmine\snooze\SleeperHandler();

$notifier = new \pocketmine\snooze\SleeperNotifier();
$thread = new SleepyThread($notifier);
$sleeper->addNotifier($notifier, function() use($thread) : void{
	//do some things when this notifier sends a notification
	echo "Main thread got line: " . $thread->getLineFromBuffer();
});

//don't start the thread until we add the notifier, otherwise we could get unexpected behaviour (race conditions)
$thread->start();

while(true){
	$start = microtime(true);
	//do some work that you do every tick

	//process any pending notifications, then try to sleep 50ms until the next tick
	//this may wakeup at any time to process received notifications
	//if it wakes up and there is still time left to sleep before the specified time, it will go back to sleep again
	//until that time, guaranteeing a delay of at least this amount
	//if there are notifications waiting when this is called, they'll be processed before going to sleep
	$sleeper->sleepUntil($start + 0.05);
}

while(true){
	//alternatively, if you want to only wait for notifications and not tick:
	//but from the pthreads rulebook, only ever wait FOR something!
	//this will wait indefinitely until something wakes it up, and then return immediately
	$sleeper->sleepUntilNotification();
}