pocketmine\level\Level::processChunkRequest PHP Method

    private function processChunkRequest()
    {
        if (count($this->chunkSendQueue) > 0) {
            $this->timings->syncChunkSendTimer->startTiming();
            $x = null;
            $z = null;
            foreach ($this->chunkSendQueue as $index => $players) {
                if (isset($this->chunkSendTasks[$index])) {
                    continue;
                }
                Level::getXZ($index, $x, $z);
                $this->chunkSendTasks[$index] = true;
                if (isset($this->chunkCache[$index])) {
                    $this->sendChunkFromCache($x, $z);
                    continue;
                }
                $this->timings->syncChunkSendPrepareTimer->startTiming();
                $task = $this->provider->requestChunkTask($x, $z);
                if ($task !== null) {
                    $this->server->getScheduler()->scheduleAsyncTask($task);
                }
                $this->timings->syncChunkSendPrepareTimer->stopTiming();
            }
            $this->timings->syncChunkSendTimer->stopTiming();
        }
    }