Documentation

Learn how to use TrueAsync for building concurrent PHP applications.

Channel::recvAsync

(PHP 8.6+, True Async 1.0)

public Channel::recvAsync(): Future

Performs a non-blocking receive of a value from the channel and returns a Future object that can be awaited later.

Unlike recv(), this method does not suspend the current coroutine immediately. Instead, a Future is returned that will be resolved when a value becomes available.

Return values

A Future object that will resolve with the received value from the channel.

Examples

Example #1 Non-blocking receive

<?php

use Async\Channel;

$channel = new Channel(3);

spawn(function() use ($channel) {
    $channel->send('data A');
    $channel->send('data B');
    $channel->close();
});

spawn(function() use ($channel) {
    $futureA = $channel->recvAsync();
    $futureB = $channel->recvAsync();

    // Can perform other work while data is not yet needed
    doSomeWork();

    echo await($futureA) . "\n"; // "data A"
    echo await($futureB) . "\n"; // "data B"
});

Example #2 Parallel receive from multiple channels

<?php

use Async\Channel;

$orders = new Channel(10);
$notifications = new Channel(10);

spawn(function() use ($orders, $notifications) {
    $orderFuture = $orders->recvAsync();
    $notifFuture = $notifications->recvAsync();

    // Wait for the first available value from any channel
    [$result, $index] = awaitAnyOf($orderFuture, $notifFuture);

    echo "Received from channel #$index: $result\n";
});

See also