ComponentsScope::setExceptionHandler

Scope::setExceptionHandler ​

(PHP 8.6+, True Async 1.0)

php
public function setExceptionHandler(callable $exceptionHandler): void

Sets an exception handler for exceptions thrown in child coroutines of the scope. When a coroutine finishes with an unhandled exception, instead of the error propagating upward, the specified handler is called.

Parameters ​

exceptionHandler — the exception handling function. Accepts a \Throwable as an argument.

Return Value ​

No value is returned.

Examples ​

Example #1 Handling coroutine errors ​

php
<?php

use Async\Scope;

$scope = new Scope();

$scope->setExceptionHandler(function(\Throwable $e) {
    error_log("Coroutine error: " . $e->getMessage());
});

$scope->spawn(function() {
    throw new \RuntimeException("Something went wrong");
});

$scope->awaitCompletion(Async\timeout(5000));
// Log will contain: "Coroutine error: Something went wrong"

Example #2 Centralized error logging ​

php
<?php

use Async\Scope;

$scope = new Scope();
$errors = [];

$scope->setExceptionHandler(function(\Throwable $e) use (&$errors) {
    $errors[] = $e;
});

$scope->spawn(function() {
    throw new \RuntimeException("Error 1");
});

$scope->spawn(function() {
    throw new \LogicException("Error 2");
});

$scope->awaitCompletion(Async\timeout(5000));

echo "Total errors: " . count($errors) . "\n"; // Total errors: 2

See Also ​