REQ/REP seems not working

[Nek-]

Hello,

I'm trying to use REQ/REP with reactphp-zmq. While it works properly with the PHP extension, it seems to have some issues.

$loop = React\EventLoop\Factory::create();

$context = new React\ZMQ\Context($loop);

$requester = $context->getSocket(ZMQ::SOCKET_REQ);
$requester->connect('tcp://127.0.0.1:5555');

$i = 0;
$loop->addPeriodicTimer(1, function () use (&$i, $requester) {
    $i++;
    echo "(out) -> $i\n";
    $requester->send($i);
    $reply = $requester->recv();
    echo "(in) <- $reply\n";
});

$loop->run();

Here is the output:

$ php test.php
-> 1
PHP Fatal error:  Uncaught ZMQSocketException: Failed to receive message: Operation cannot be accomplished in current state in /var/www/apps/cadi-back/vendor/react/zmq/src/SocketWrapper.php:171
Stack trace:
#0 [internal function]: ZMQSocket->recv()
#1 /var/www/apps/cadi-back/vendor/react/zmq/src/SocketWrapper.php(171): call_user_func_array(Array, Array)
#2 /var/www/apps/cadi-back/test.php(19): React\ZMQ\SocketWrapper->__call('recv', Array)
#3 /var/www/apps/cadi-back/vendor/react/event-loop/src/Timer/Timers.php(96): {closure}(Object(React\EventLoop\Timer\Timer))
#4 /var/www/apps/cadi-back/vendor/react/event-loop/src/StreamSelectLoop.php(183): React\EventLoop\Timer\Timers->tick()
#5 /var/www/apps/cadi-back/test.php(23): React\EventLoop\StreamSelectLoop->run()
#6 {main}
  thrown in /var/www/apps/cadi-back/vendor/react/zmq/src/SocketWrapper.php on line 171

I understand that this code is not optimal considering I send each second no matter if the reply occured (while it must be according to zmq protocol). But here the issue is about ->recv() not working in "current state" (which should be the good one).

[edit] this is probably due to the buffer that delays the send to "later" while the recv is not delayed. Not a trivial problem.