The parallel\Events class

<?php
/**
Example showing the usage of events.
The documentation still is very thin, so I'm not sure, the example is the best solution. But it works.
*/
use parallel\{Channel,Runtime,Events,Events\Event};
$myThread = function(Channel $channel) {
 $events = new Events();
 $events->addChannel($channel);
 //$events->setBlocking(false); //Uncomment to don't block on Events::poll()
 $events->setTimeout(1000000); //Comment when not blocking
 while(true)
 {
 /*
 ...
 Your code.
 ...
 */
 //Read all available events
 try
 {
 $event = NULL;
 do
 {
 $event = $events->poll(); //Returns non-null if there is an event
 if($event && $event->source == 'myChannel')
 {
 //It seems, the target gets deleted after returning an event,
 //so add it again.
 $events->addChannel($channel);
 if($event->type == Event\Type::Read)
 {
 if(is_array($event->value) && count($event->value) > 0)
 {
 if($event->value['name'] == 'stop')
 {
 echo 'Stopping thread';
 return; //Stop
 }
 else
 {
 echo 'Event: '.$event->value['name'].' => '.$event->value['value'].PHP_EOL;
 }
 }
 }
 else if($event->type == Event\Type::Close) return; //Stop
 }
 }
 while($event);
 }
 catch(Events\Error\Timeout $ex)
 {
 //Timeout
 echo 'Timeout'.PHP_EOL;
 }
 }
};
class MyClass {
 private $runtime;
 private $future;
 private $channel;
 public function start() {
 //Create runtime
 $this->runtime = new Runtime();
 //Create buffered channel.
 //Buffered channels don't block on Channel::send().
 //Note that target names need to be unique within the process.
 $this->channel = Channel::make('myChannel', Channel::Infinite);
 global $myThread;
 $this->future = $this->runtime->run($myThread, [$this->channel]);
 }
 public function stop() {
 $this->channel->send(['name' => 'stop', 'value' => true]);
 $this->future->value(); //Wait for thread to finish
 $this->channel->close();
 }
 public function emit(string $name, $value)
 {
 $this->channel->send(['name' => $name, 'value' => $value]);
 }
}
$a = new MyClass();
$a->start();
for($i = 0; $i < 5; $i++)
{
 $a->emit('test', $i);
 sleep(0.5);
}
sleep(2);
for($i = 5; $i < 10; $i++)
{
 $a->emit('test', $i);
 sleep(0.5);
}
$a->stop();
?>

<?php
// this example shows how Events handle Future events
use parallel\{Events, Events\Event, Runtime};
$events = new Events();
$runtime = new Runtime();
//Read (type: 1)
$future = $runtime->run(
 static function (string $name) {
 return "Future#$name result";
 },
 ['Read']
);
$events->addFuture("Future#Read", $future);
//Cancel (type: 4)
$future = $runtime->run(
 static function (string $name) {
 throw new \Exception("Exception#$name");
 },
 ['Cancel']
);
$events->addFuture("Future#Cancel", $future);
//Kill (type: 5)
$future = $runtime->run(
 static function () {
 sleep(100000);
 },
 []
);
$events->addFuture("Future#Kill", $future);
$future->cancel(); //kill it
//Error (type: 6)
$future = $runtime->run(
 static function () {
 $memoryEater = [];
 $i = 0;
 while (++$i) {
 $memoryEater[] = $i;
 }
 }
);
$events->addFuture("Future#Error", $future);
// reading events
/** @var Event $event */
foreach ($events as $i => $event) {
 echo str_pad('', 50, '=') . " EVENT_$i\n";
 var_dump($event);
 echo "\n";
}

<?php
// example below shows how to stop child thread from main thread
use parallel\{Channel, Events, Events\Event\Type, Runtime};
$fnThread = static function (Channel $channel) {
 $events = new Events();
 $events->addChannel($channel);
 $events->setBlocking(false); // don't block on Events::poll()
 while (true) {
 if ($event = $events->poll()) {
 //It seems, the target gets deleted after returning an event, so add it again.
 $events->addChannel($channel);
 if (Type::Read === $event->type) {
 echo "- received value: ".$event->value.PHP_EOL;
 } elseif (Type::Close === $event->type) {
 echo "- receiving close event".PHP_EOL;
 return "i'm done";
 }
 }
 echo "-\n";
 usleep(500_000);
 }
};
// main thread
$runtime = new Runtime();
$channel = new Channel();
$future = $runtime->run($fnThread, [$channel]);
$channel->send('message1');
sleep(2);
$channel->send('message2');
sleep(2);
echo "closing channel\n";
$channel->close();
echo "future said: ".$future->value();
echo PHP_EOL;