Wait for socket_write to complete before writing again - php

Question

I need to send some data from a PHP server to a Node server.
Here's a simplified version of what I have so far on the PHP side:
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$result = socket_connect($socket, '127.0.0.1', '3000');
socket_write($socket, "Hello World", 11);
socket_close($socket);
Running this code successfully sends the message to my Node server and outputs this.
However I need to send more than one message back to the socket. I actually need to send several thousand responses. But if I were to call the socket_write() function within a loop like so:
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$result = socket_connect($socket, '127.0.0.1', '3000');
for($i=0;$i<1000;$i++){
socket_write($socket, "Hello World", 11);
}
socket_close($socket);
it seems to append all the data together and send it in one go at the end of the script. I need to send the data back in real time. Is there any way I can do this in PHP?

Answer 1

After looking through many PHP socket libraries, I noticed that nearly all of them just implement a usleep(1000000) after sending a socket. I'm not sure if this is the best method, but maybe it's the only way due to PHP's limitations.
In the end, I decided to store the time that data was last written to a socket. Then, calculate the time elapsed since then and subtract that from 1000000 microseconds. This way, the script will not wait longer than necessary.
public function send(array $payload){
$json = json_encode($payload);
$write = socket_write($this->socket, $json, strlen($json);
$sleep_time = 1000000 - (microtime(true) - $this->last_sent);
if($sleep_time > 0) usleep($sleep_time);
$this->last_sent = microtime(true);
return $write !== false ? true : false;
}