Timeout Pattern Generator

Creates Timeout pattern infrastructure for execution time limits with fallback support.

When to Use

Scenario	Example
External API calls	HTTP requests to third-party services
Database queries	Long-running or unoptimized queries
Queue consumers	Message processing time limits
File operations	Large file uploads/downloads
Distributed calls	gRPC, SOAP, or REST inter-service calls
Batch processing	Individual item timeout within batch

Component Characteristics

TimeoutConfig

• Immutable value object
• Duration in seconds (float for sub-second precision)
• Optional fallback callable
• Optional shouldRetry flag
• Named presets (fast, standard, slow)

TimeoutInterface

• Domain layer contract
• execute(callable operation, TimeoutConfig config): mixed
• Single responsibility: enforce time limit

TimeoutExecutor

• pcntl_alarm + async signal based for CLI
• Catches SIGALRM to throw TimeoutException
• Restores previous signal handler after execution
• Thread-safe via execution context

StreamTimeoutExecutor

• stream_set_timeout for I/O operations
• Works in both CLI and FPM
• Socket and stream resource support

TimeoutException

• Extends RuntimeException
• Contains elapsed time and operation context
• Machine-readable properties for monitoring

TimeoutMiddleware

• PSR-15 compatible for HTTP clients
• Adds timeout to outgoing requests
• Configurable per-route timeouts

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Generation Process

Step 1: Analyze Request

Determine:

• Target use case (API calls, DB queries, queue consumers)
• Timeout strategy (signal-based, stream-based, or both)
• Fallback behavior (exception, default value, cached result)

Step 2: Generate Core Components

1. Domain Layer (src/Domain/Shared/Timeout/)

   • TimeoutConfig.php — Configuration value object
   • TimeoutInterface.php — Execution contract
   • TimeoutException.php — Timeout exceeded exception

2. Infrastructure Layer (src/Infrastructure/Resilience/Timeout/)

   • SignalTimeoutExecutor.php — pcntl_alarm based implementation
   • StreamTimeoutExecutor.php — stream_set_timeout based
   • NullTimeoutExecutor.php — No-op for testing
   • TimeoutExecutorFactory.php — Environment-aware factory

3. Presentation Layer (src/Presentation/Middleware/)

   • TimeoutMiddleware.php — PSR-15 HTTP middleware

4. Tests

   • TimeoutConfigTest.php
   • SignalTimeoutExecutorTest.php
   • TimeoutExceptionTest.php

---

File Placement

Layer	Path
Domain Types	src/Domain/Shared/Timeout/
Infrastructure	src/Infrastructure/Resilience/Timeout/
Middleware	src/Presentation/Middleware/
Unit Tests	tests/Unit/{Layer}/{Path}/

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Key Principles

Signal-Based Timeout (CLI)

1. Register SIGALRM handler
2. Set pcntl_alarm with timeout duration
3. Execute operation
4. Cancel alarm on completion
5. Restore previous handler
6. If alarm fires → throw TimeoutException

Stream-Based Timeout (FPM/CLI)

1. Set stream_set_timeout on resource
2. Check stream_get_meta_data for timed_out flag
3. Works for network I/O operations

Fallback Strategy

1. On timeout, check if fallback provided
2. Execute fallback within separate timeout (prevent cascading)
3. If no fallback, throw TimeoutException
4. Log timeout event with context

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Naming Conventions

Component	Pattern	Example
Config VO	TimeoutConfig	TimeoutConfig
Interface	TimeoutInterface	TimeoutInterface
Signal Impl	SignalTimeoutExecutor	SignalTimeoutExecutor
Stream Impl	StreamTimeoutExecutor	StreamTimeoutExecutor
Null Impl	NullTimeoutExecutor	NullTimeoutExecutor
Exception	TimeoutException	TimeoutException
Factory	TimeoutExecutorFactory	TimeoutExecutorFactory
Middleware	TimeoutMiddleware	TimeoutMiddleware
Test	{ClassName}Test	SignalTimeoutExecutorTest

---

Quick Template Reference

TimeoutConfig

final readonly class TimeoutConfig
{
    public function __construct(
        public float $durationSeconds,
        public ?callable $fallback = null,
        public bool $shouldRetry = false,
        public string $operationName = 'unknown',
    ) {}

    public static function fast(): self; // 3 seconds
    public static function standard(): self; // 10 seconds
    public static function slow(): self; // 30 seconds
    public static function of(float $seconds): self;
}

TimeoutInterface

interface TimeoutInterface
{
    /**
     * @template T
     * @param callable(): T $operation
     * @return T
     * @throws TimeoutException
     */
    public function execute(callable $operation, TimeoutConfig $config): mixed;
}

TimeoutException

final class TimeoutException extends \RuntimeException
{
    public function __construct(
        public readonly float $elapsedSeconds,
        public readonly float $timeoutSeconds,
        public readonly string $operationName,
        ?\Throwable $previous = null,
    ) {
        parent::__construct(
            sprintf('Operation "%s" timed out after %.2fs (limit: %.2fs)', $operationName, $elapsedSeconds, $timeoutSeconds),
            0,
            $previous,
        );
    }
}

---

Usage Example

$timeout = $timeoutFactory->create();

try {
    $result = $timeout->execute(
        operation: fn() => $httpClient->request('GET', $url),
        config: TimeoutConfig::of(5.0),
    );
} catch (TimeoutException $e) {
    $logger->warning('API call timed out', [
        'operation' => $e->operationName,
        'elapsed' => $e->elapsedSeconds,
        'timeout' => $e->timeoutSeconds,
    ]);
    return $cachedResult;
}

---

Composition with Circuit Breaker

$result = $circuitBreaker->execute(
    operation: fn() => $timeout->execute(
        operation: fn() => $api->call($request),
        config: TimeoutConfig::of(5.0),
    ),
    fallback: fn() => $cache->get($cacheKey),
);

---

Anti-patterns to Avoid

Anti-pattern	Problem	Solution
No timeout	Indefinite blocking	Always set explicit timeout
Too aggressive	Fail on normal slow responses	Tune per-operation
Global timeout	One size doesn't fit all	Per-operation config
No fallback	Hard failure on timeout	Provide degraded response
Ignoring context	Can't debug timeouts	Include operation name
Nested timeouts	Outer timeout kills inner	Coordinate timeout budgets

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References

For complete PHP templates and examples, see:

• references/templates.md — All component templates
• references/examples.md — API call, DB query examples and tests