Coroutine::getException

Get the exception that occurred in a coroutine.

Coroutine::getException ​

(PHP 8.6+, True Async 1.0)

php
public Coroutine::getException(): mixed

Returns the exception that occurred in the coroutine. If the coroutine completed successfully or has not yet completed, returns null. If the coroutine was cancelled, returns an AsyncCancellation object.

Return Value ​

mixed -- the exception or null.

  • null -- if the coroutine has not completed or completed successfully
  • Throwable -- if the coroutine completed with an error
  • AsyncCancellation -- if the coroutine was cancelled

Errors ​

Throws RuntimeException if the coroutine is currently running.

Examples ​

Example #1 Successful completion ​

php
<?php

use function Async\spawn;
use function Async\await;

$coroutine = spawn(function() {
    return "success";
});

await($coroutine);
var_dump($coroutine->getException()); // NULL

Example #2 Completion with error ​

php
<?php

use function Async\spawn;
use function Async\await;

$coroutine = spawn(function() {
    throw new RuntimeException("test error");
});

try {
    await($coroutine);
} catch (RuntimeException $e) {
    // Caught during await
}

$exception = $coroutine->getException();
var_dump($exception instanceof RuntimeException); // bool(true)
var_dump($exception->getMessage());                // string(10) "test error"

Example #3 Cancelled coroutine ​

php
<?php

use function Async\spawn;
use function Async\suspend;

$coroutine = spawn(function() {
    Async\delay(10000);
});

suspend();
$coroutine->cancel();
suspend();

$exception = $coroutine->getException();
var_dump($exception instanceof \Async\AsyncCancellation); // bool(true)

See Also ​