Summary

This PR adds a flushAll() method to:

• Hyperf\Pool\Pool - closes all connections in the pool
• Hyperf\Redis\Pool\PoolFactory - closes all connections in all Redis pools
• Hyperf\DbConnection\Pool\PoolFactory - closes all connections in all database pools

Why is this needed?

Problem: File descriptor exhaustion in test suites

When running large PHPUnit test suites with RunTestsInCoroutine (2000+ tests), each test creates a new application container with new pool instances. The old pools are not explicitly closed - they wait for garbage collection.

PHP's garbage collector does not run immediately. This causes file descriptors (socket connections) to accumulate until the process hits the OS limit (ulimit -n), resulting in errors like:

RedisException: Too many open files

This is a known PHPUnit issue (sebastianbergmann/phpunit#182) where file handles accumulate across tests. With coroutines, the problem is more severe because connection pools hold multiple socket file descriptors.

Solution

With flushAll(), test frameworks can explicitly close all pool connections between tests:

// In test tearDown
$container->get(RedisPoolFactory::class)->flushAll();
$container->get(DbPoolFactory::class)->flushAll();

Other use cases

1. Graceful shutdown - Close all connections when worker exits
2. Resource cleanup - Release connections in long-running processes
3. Connection refresh - Force new connections after configuration change

Implementation

Pool::flushAll() reuses the existing flushOne(true) method:

public function flushAll(): void
{
    while ($this->getConnectionsInChannel() > 0) {
        $this->flushOne(true);
    }
}

PoolFactory::flushAll() calls flushAll() on all managed pools:

public function flushAll(): void
{
    foreach ($this->pools as $pool) {
        $pool->flushAll();
    }
}

Note

The RedisPoolStub test class had its own flushAll() implementation. This PR removes it since the base Pool class now provides this method.

Tests

• Added testPoolFlushAll to PoolTest.php
• Added PoolFactoryTest.php for Redis package
• Added PoolFactoryTest.php for db-connection package

All tests pass with co-phpunit.