go-meta-listener/listener.go

package meta

import (
	"fmt"
	"net"
)

// Accept implements the net.Listener Accept method.
// It returns the next connection from any of the managed listeners.
func (ml *MetaListener) Accept() (net.Conn, error) {
	// Check if already closed before entering the select loop
	ml.mu.RLock()
	if ml.isClosed {
		ml.mu.RUnlock()
		return nil, ErrListenerClosed
	}
	ml.mu.RUnlock()

	for {
		select {
		case result, ok := <-ml.connCh:
			if !ok {
				return nil, ErrListenerClosed
			}
			// Access RemoteAddr() directly on the connection
			return result, nil
		case <-ml.closeCh:
			// Double-check the closed state under lock to ensure consistency
			closed := ml.isClosed
			if closed {
				return nil, ErrListenerClosed
			}
			continue
		}
	}
}

// Close implements the net.Listener Close method.
// It closes all managed listeners and releases resources.
func (ml *MetaListener) Close() error {
	ml.mu.Lock()

	if ml.isClosed {
		ml.mu.Unlock()
		return nil
	}

	log.Printf("Closing MetaListener with %d listeners", len(ml.listeners))
	ml.isClosed = true

	// Signal all goroutines to stop
	close(ml.closeCh)

	// Close all listeners
	var errs []error
	for id, listener := range ml.listeners {
		if err := listener.Close(); err != nil {
			log.Printf("Error closing %s listener: %v", id, err)
			errs = append(errs, err)
		}
	}

	ml.mu.Unlock()

	// Wait for all listener goroutines to exit
	ml.listenerWg.Wait()
	log.Printf("All listener goroutines have exited")

	// Return combined errors if any
	if len(errs) > 0 {
		return fmt.Errorf("errors closing listeners: %v", errs)
	}

	return nil
}

// Addr implements the net.Listener Addr method.
// It returns a MetaAddr representing all managed listeners.
func (ml *MetaListener) Addr() net.Addr {
	ml.mu.RLock()
	defer ml.mu.RUnlock()

	addresses := make([]net.Addr, 0, len(ml.listeners))
	for _, listener := range ml.listeners {
		addresses = append(addresses, listener.Addr())
	}

	return &MetaAddr{addresses: addresses}
}