fix: simplify pool synchronization by replacing RWMutex with Mutex

Replaced RWMutex with Mutex to streamline lock handling and simplify the synchronization logic in the connection pool implementation.

The change eliminates redundant lock/unlock calls, ensuring thread safety while reducing complexity.

Author: kop

pkg/clients/database/pool.go

@@ -63,7 +63,7 @@ func NewPoolWithConnectionFactory(
 }
 
 type poolImpl struct {
-	sync.RWMutex
+	sync.Mutex
 	isClosed          bool
 	logger            *slog.Logger
 	closers           []func()
@@ -75,6 +75,9 @@ type poolImpl struct {
 
 func (p *poolImpl) GetConnection(params PoolParams) (Connection, error) {
 
+	p.Lock()
+	defer p.Unlock()
+
 	connectionParams := ConnectionParams{
 		ClientID:     p.clientID,
 		ClientSecret: p.clientSecret,
@@ -84,29 +87,23 @@ func (p *poolImpl) GetConnection(params PoolParams) (Connection, error) {
 	}
 	hash := connectionParams.Hash()
 
-	// First, try to get an existing connection with a read lock
-	p.RLock()
+	// First, try to get an existing connection
 	if p.isClosed {
-		p.RUnlock()
 		return nil, ErrPoolClosed
 	}
 	if conn, ok := p.connections[hash]; ok {
-		p.RUnlock()
 		return conn, nil
 	}
-	p.RUnlock()
 
 	// Create a new connection if one doesn't exist
 	conn, closer, err := p.newConnectionFunc(p.logger, connectionParams)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create connection: %w", err)
 	}
 
-	// Store the new connection in the pool with a write lock
-	p.Lock()
+	// Store the new connection in the pool
 	p.connections[hash] = conn
 	p.closers = append(p.closers, closer)
-	p.Unlock()
 
 	return conn, nil
 }