ComponentsThreadChannel::isClosed()

ThreadChannel::isClosed ​

(PHP 8.6+, True Async 1.0)

php
public ThreadChannel::isClosed(): bool

Returns true if the channel has been closed via close().

A closed channel does not accept new values through send(), but recv() continues to return any values remaining in the buffer until it is drained.

isClosed() is thread-safe and can be called from any thread without synchronization.

Return values ​

true — the channel is closed. false — the channel is open.

Examples ​

Example #1 Checking channel state from the main thread ​

php
<?php

use Async\ThreadChannel;
use function Async\spawn;
use function Async\spawn_thread;
use function Async\await;

spawn(function() {
    $channel = new ThreadChannel(5);

    echo $channel->isClosed() ? "closed" : "open"; // "open"

    $channel->send('data');
    $channel->close();

    echo $channel->isClosed() ? "closed" : "open"; // "closed"

    // Values buffered before close are still readable
    echo $channel->recv(), "\n"; // "data"
});

Example #2 Consumer loop guarded by isClosed() ​

php
<?php

use Async\ThreadChannel;
use function Async\spawn;
use function Async\spawn_thread;
use function Async\await;

spawn(function() {
    $channel = new ThreadChannel(20);

    $producer = spawn_thread(function() use ($channel) {
        for ($i = 0; $i < 10; $i++) {
            $channel->send($i);
        }
        $channel->close();
    });

    $consumer = spawn_thread(function() use ($channel) {
        // Keep reading until closed AND buffer is empty
        while (!$channel->isClosed() || !$channel->isEmpty()) {
            try {
                echo $channel->recv(), "\n";
            } catch (\Async\ThreadChannelException) {
                break;
            }
        }
    });

    await($producer);
    await($consumer);
});

See also ​