Subscriber of MosquittoClient doesn't show single subscribed message in a interval time period

Question

I'm using Mosquitto/Client php library. I have made connected properly between broker and client. When i execute publisher and subscriber then subscriber displays a number of messages but I want to get a single published message when publisher publish the message. How will i get a single message by subscribing the published message?

Subscriber.php

define('BROKER', '192.168.0.13');
define('PORT', 1883);
define('CLIENT_ID', "pubclient_" + getmypid());
$client = new Mosquitto\Client(CLIENT_ID);
$client->onConnect('connect');
$client->onDisconnect('disconnect');
$client->onSubscribe('subscribe');
$client->onMessage('message');
$client->connect(BROKER, PORT, 60);
$client->subscribe('test/foo/bar', 1);
$client->loopForever();
function connect($r) {
    echo "Received response code {$r}\n";
}
function subscribe() {
    echo "Subscribed to a topic\n";
}
function message($message) {
    printf("Got a message on topic %s with payload:\n%s\n", $message->topic, $message->payload);
}
function disconnect() {
    echo "Disconnected cleanly\n";
}

publisher.php

define('BROKER', '192.168.0.13');
define('PORT', 1883);
define('CLIENT_ID', "pubclient_" + getmypid());
$client = new Mosquitto\Client(CLIENT_ID);
$client->connect(BROKER, PORT, 5);
while ($client->loop() == 0) {
    $message = "Test message at " . date("Y-m-d H:i:s");
    $client->publish('test/foo/bar', $message, 1, false);
    $client->loop();
    sleep(1);
}

I want to publish/subscribe in a specific interval. Publisher.php publishes a topic with a message in a interval time period and subscriber.php get that topic with that message in a interval time period.