Hướng dẫn is php curl asynchronous?

So what you want to do is asynchronous execution of the cUrl Requests.

So you would need a asynchronous/parallel processing library for php.

Async cURL

The other way is to use the built in asynchronous cURL functions.

So, when using curl_multi_*, your code would look something like:

$username = 'xxxxx'; 
$api_onfleet = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';    
$url_onfleet = "https://onfleet.com/api/v2/tasks";

curl_setopt($curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1_2);
    $request =  $url.'api/mail.send.json';

    // Generate curl request
    $session = curl_init($request);
    // Tell curl to use HTTP POST
    curl_setopt ($session, CURLOPT_POST, true);
    // Tell curl that this is the body of the POST
    curl_setopt ($session, CURLOPT_POSTFIELDS, $params);
    // Tell curl not to return headers, but do return the response
    curl_setopt($session, CURLOPT_HEADER, false);
    curl_setopt($session, CURLOPT_RETURNTRANSFER, true);


     // Post the Pickup task to Onfleet
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url_onfleet);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_USERPWD, $api_onfleet);
    curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_setopt($ch, CURLOPT_ENCODING, "");  
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, '{"destination":{"address":{"unparsed":"'.$pickup_address.'"},"notes":"'.$comments.'"},"recipients":[{"name":"'.$name.'","phone":"+61'.$phone.'","notes":"Number of riders: '.$riders.'"}],"completeBefore":'.$timestamp.',"pickupTask":"yes","autoAssign":{"mode":"distance"}}');
$mh = curl_multi_init();
curl_multi_add_handle($mh,$session);
curl_multi_add_handle($mh,$ch);

$active = null;
//execute the handles
do {
    $mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);

while ($active && $mrc == CURLM_OK) {
    if (curl_multi_select($mh) != -1) {
        do {
            $mrc = curl_multi_exec($mh, $active);
        } while ($mrc == CURLM_CALL_MULTI_PERFORM);
    }
}
//close the handles
curl_multi_remove_handle($mh, $ch2);
curl_multi_remove_handle($mh, $ch2);
curl_multi_close($mh);

Suggested Reading:

1. curl_multi_init()
2. curl_multi_exec()
3. curl_multi_add_handle()
4. curl_multi_remove_handle()

pThreads

One of the prominent threading libraries for php is pthreads

You would need to first get the dll/so file and save it in the php/ext dir, and enable that extension in php.ini.

After That, this code would do your job:

class Request1 extends Thread {
    $username = 'xxxxx'; 
    $api_onfleet = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';    
    $url_onfleet = "https://onfleet.com/api/v2/tasks";
    public function run() {
        curl_setopt($curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1_2);
        $request =  $this->url.'api/mail.send.json';
    
        // Generate curl request
        $session = curl_init($request);
        // Tell curl to use HTTP POST
        curl_setopt ($session, CURLOPT_POST, true);
       // Tell curl that this is the body of the POST
       curl_setopt ($session, CURLOPT_POSTFIELDS, $params);
       // Tell curl not to return headers, but do return the response
       curl_setopt($session, CURLOPT_HEADER, false);
       curl_setopt($session, CURLOPT_RETURNTRANSFER, true);

        // obtain response
        $response = curl_exec($session);
        curl_close($session);
    }
}


class Request2 extends Thread {
    $username = 'xxxxx'; 
    $api_onfleet = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';    
    $url_onfleet = "https://onfleet.com/api/v2/tasks";
    public function run() {
      $ch = curl_init();
      curl_setopt($ch, CURLOPT_URL, $url_onfleet);
      curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
      curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
      curl_setopt($ch, CURLOPT_USERPWD, $this->api_onfleet);
      curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
      curl_setopt($ch, CURLOPT_ENCODING, "");  
      curl_setopt($ch, CURLOPT_POST, true);
      curl_setopt($ch, CURLOPT_POSTFIELDS, '{"destination":{"address":{"unparsed":"'.$pickup_address.'"},"notes":"'.$comments.'"},"recipients":[{"name":"'.$name.'","phone":"+61'.$phone.'","notes":"Number of riders: '.$riders.'"}],"completeBefore":'.$timestamp.',"pickupTask":"yes","autoAssign":{"mode":"distance"}}');

      $result_pickup = curl_exec($ch);
      curl_close($ch);

      // Post the Dropoff task to Onfleet
      $curl = curl_init();
      curl_setopt($curl, CURLOPT_URL, $this->url_onfleet);
      curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
      curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
      curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
      curl_setopt($curl, CURLOPT_USERPWD, $this->api_onfleet);
      curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
      curl_setopt($curl, CURLOPT_ENCODING, "");  
      curl_setopt($curl, CURLOPT_POST, true);
      curl_setopt($curl, CURLOPT_POSTFIELDS, '{"destination":{"address":{"unparsed":"'.$dropoff_address.'"},"notes":"'.$comments.'"},"recipients":[{"name":"'.$name.'","phone":"+61'.$phone.'","notes":"Number of riders: '.$riders.'"}],"autoAssign":{"mode":"distance"}}');

      $result_dropoff = curl_exec($curl);
      curl_close($curl);
    }
}

$req1 = new Request1();
$req1->start();
$req2 = new Request2();
$req2->start();

So, basically you need to create a class which extends the Thread class and everything you want to run asynchronously (rather parallely), would be put in the function run() of the class.

When you want to start the thread just instantiate the class in a variable, and call the start method of the object, like $threadsObject->start() and everything in the run() would be executed on another thread.

Reference:

1. class::Thread
2. Thread::start

That's it.