internal/voice/client.go

@@ -9,15 +9,18 @@
 //
 // The wire is symmetric: a Request from the client is answered by a
 // Response with a matching ID, OR a server-initiated Push frame (no ID)
-// may arrive interleaved. SendRequest loops reading frames, drops Push
-// frames to the harness if a receiver is running (or silently if not),
-// and returns the first Response with the matching ID.
+// may arrive interleaved. One reader goroutine per connection owns the
+// socket. It hands each Response to whichever SendRequest is waiting on
+// that ID and each Push to the handler, so a client may send and listen
+// at the same time on one conn. mavwaked needs exactly that: it speaks
+// utterances and it must hear nudges, and the server routes a nudge to
+// the session that spoke most recently, so a second listening conn would
+// never be picked (V-671).
 package voice
 
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -41,13 +44,22 @@ type PushHandler interface {
 // Client — one connection to the voice.Server.
 type Client struct {
 	addr   string
-	mu     sync.Mutex
-	c      net.Conn
 	nextID atomic.Uint64
 
-	// pushCh fan-out: a reader goroutine (started by RunPushReceiver)
-	// writes Push frames here; SendRequest also drains it when no reader
-	// is running (drops the frame in that case).
+	mu sync.Mutex
+	c  net.Conn
+	// pending holds one channel per in-flight request, keyed by frame id.
+	// The reader goroutine delivers the Response here and deletes the entry.
+	pending map[uint64]chan *Response
+	// dead is closed by the reader goroutine when this conn ends, so a
+	// waiting SendRequest fails at once instead of at its own deadline.
+	dead chan struct{}
+
+	// wmu serialises writes. Frames must not interleave on the wire.
+	wmu sync.Mutex
+
+	// pushH is set by RunPushReceiver and survives a reconnect, because the
+	// client that wants pushes wants them on whatever conn it ends up with.
 	pushMu sync.Mutex
 	pushH  PushHandler
 }
@@ -55,6 +67,15 @@ type Client struct {
 // Dial returns a Client that will connect to addr on first use.
 func Dial(addr string) *Client { return &Client{addr: addr} }
 
+// Connect opens the conn now rather than on the first request. mavwaked calls
+// it at startup: the server registers a session on accept, and a client that
+// has never connected cannot be sent a nudge.
+func (c *Client) Connect(ctx context.Context) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.ensureConnLocked(ctx)
+}
+
 // Close releases the conn. Idempotent.
 func (c *Client) Close() error {
 	c.mu.Lock()
@@ -75,12 +96,14 @@ func (c *Client) PushToTalk(ctx context.Context, a audio.Audio, lang string) (Pu
 	return out, err
 }
 
+// requestTimeout bounds a round-trip with no deadline on its context. It is
+// generous because the far end runs speech-to-text, a router and a voice.
+const requestTimeout = 120 * time.Second
+
 // SendRequest sends one Request frame and waits for the matching Response.
-// Push frames received while waiting are dropped on the floor UNLESS a
-// PushHandler has been wired via RunPushReceiver, in which case the handler
-// is invoked inline (still synchronous with the SendRequest caller's
-// read). For sanity, the reference client runs either one-shot (no
-// receiver) or interactive (RunPushReceiver, no concurrent SendRequest).
+// Push frames arriving meanwhile go to the handler on the reader goroutine,
+// so listening and sending on one Client is supported rather than merely
+// tolerated.
 func (c *Client) SendRequest(ctx context.Context, m Method, params any, out any) error {
 	body, err := marshalParams(params)
 	if err != nil {
@@ -94,58 +117,69 @@ func (c *Client) SendRequest(ctx context.Context, m Method, params any, out any)
 		c.mu.Unlock()
 		return err
 	}
-	conn := c.c
+	conn, dead := c.c, c.dead
+	ch := make(chan *Response, 1)
+	c.pending[id] = ch
 	c.mu.Unlock()
 
-	if dl, ok := ctx.Deadline(); ok {
-		_ = conn.SetDeadline(dl)
-	} else {
-		_ = conn.SetDeadline(time.Now().Add(120 * time.Second))
-	}
-	defer conn.SetDeadline(time.Time{})
-
-	if err := writeFrame(conn, &req); err != nil {
-		c.teardown()
+	c.wmu.Lock()
+	err = writeFrame(conn, &req)
+	c.wmu.Unlock()
+	if err != nil {
+		c.forget(id)
+		c.teardownConn(conn)
 		return err
 	}
-	for {
-		resp, push, err := readOneFrame(conn)
-		if err != nil {
-			c.teardown()
-			return err
-		}
-		if push != nil {
-			c.deliverPush(*push)
-			continue
-		}
-		if resp.ID != id {
-			continue // not ours; ignore (singleplex ⇒ shouldn't happen)
-		}
-		if resp.Error != nil {
-			return hydrate(resp.Error)
-		}
-		if out != nil {
-			if err := json.Unmarshal(resp.Result, out); err != nil {
-				return fmt.Errorf("voice: unmarshal result: %w", err)
-			}
-		}
-		return nil
+
+	timer := time.NewTimer(requestTimeout)
+	defer timer.Stop()
+
+	var resp *Response
+	select {
+	case resp = <-ch:
+	case <-dead:
+		c.forget(id)
+		return fmt.Errorf("voice: connection closed before reply")
+	case <-ctx.Done():
+		c.forget(id)
+		return ctx.Err()
+	case <-timer.C:
+		c.forget(id)
+		c.teardownConn(conn)
+		return fmt.Errorf("voice: no reply within %s", requestTimeout)
 	}
+
+	if resp.Error != nil {
+		return hydrate(resp.Error)
+	}
+	if out != nil {
+		if err := json.Unmarshal(resp.Result, out); err != nil {
+			return fmt.Errorf("voice: unmarshal result: %w", err)
+		}
+	}
+	return nil
 }
 
-// RunPushReceiver spawns a reader goroutine that delivers Push frames to h
-// until the conn closes or Close is called. Today's reference client uses
-// this in -listen mode (proactive voice playback). SendRequest and
-// RunPushReceiver SHOULD NOT be used concurrently on the same Client — the
-// wire is singleplex at the reference client's scale; production picks one
-// mode per conn. Returns when the goroutine ends (ctx cancel or conn close).
+// forget drops an abandoned request so a late Response is discarded rather
+// than delivered to nobody.
+func (c *Client) forget(id uint64) {
+	c.mu.Lock()
+	delete(c.pending, id)
+	c.mu.Unlock()
+}
+
+// RunPushReceiver wires h and blocks until the conn ends or ctx is
+// cancelled. Frames are read by the per-conn reader goroutine, so a client
+// may call SendRequest on the same Client while this is running. Returns nil
+// when the conn ended, so a caller that wants to stay reachable reconnects
+// and calls it again.
 func (c *Client) RunPushReceiver(ctx context.Context, h PushHandler) error {
 	c.mu.Lock()
 	if err := c.ensureConnLocked(ctx); err != nil {
 		c.mu.Unlock()
 		return err
 	}
-	conn := c.c
+	dead := c.dead
 	c.mu.Unlock()
 
 	c.pushMu.Lock()
@@ -158,21 +192,34 @@ func (c *Client) RunPushReceiver(ctx context.Context, h PushHandler) error {
 		c.pushMu.Unlock()
 	}()
 
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-dead:
+		return nil
+	}
+}
+
+// readLoop owns conn for its whole life. It ends on any read error, which is
+// how a closed conn, a killed server and a cancelled dial all arrive here.
+func (c *Client) readLoop(conn net.Conn, dead chan struct{}) {
+	defer close(dead)
 	for {
-		select {
-		case <-ctx.Done():
-			return ctx.Err()
-		default:
-		}
-		_, push, err := readOneFrame(conn)
+		resp, push, err := readOneFrame(conn)
 		if err != nil {
-			if errors.Is(err, io.EOF) || errors.Is(err, net.ErrClosed) {
-				return nil
-			}
-			return err
+			c.teardownConn(conn)
+			return
 		}
 		if push != nil {
 			c.deliverPush(*push)
+			continue
+		}
+		c.mu.Lock()
+		ch := c.pending[resp.ID]
+		delete(c.pending, resp.ID)
+		c.mu.Unlock()
+		if ch != nil {
+			ch <- resp
 		}
 	}
 }
@@ -196,13 +243,19 @@ func (c *Client) ensureConnLocked(ctx context.Context) error {
 		return fmt.Errorf("voice: dial %s: %w", c.addr, err)
 	}
 	c.c = conn
+	c.pending = make(map[uint64]chan *Response)
+	c.dead = make(chan struct{})
+	go c.readLoop(conn, c.dead)
 	return nil
 }
 
-func (c *Client) teardown() {
+// teardownConn closes conn and forgets it, but only if it is still the live
+// one. A reconnect may already have replaced it, and closing the new conn
+// because the old one died takes the client down on every hiccup.
+func (c *Client) teardownConn(conn net.Conn) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	if c.c != nil {
+	if c.c != nil && c.c == conn {
 		_ = c.c.Close()
 		c.c = nil
 	}

internal/voice/voice_test.go

@@ -221,3 +221,113 @@ func TestClientListenModeReceivesPush(t *testing.T) {
 type pushHandlerFunc func(Push)
 
 func (f pushHandlerFunc) OnPush(p Push) { f(p) }
+
+// The whole point of the per-conn reader (V-671): mavwaked speaks utterances
+// and must hear nudges, and the server routes a nudge to the session that
+// spoke most recently. A second listening conn would never be picked, so both
+// directions have to share one conn.
+func TestClientSendsAndListensOnOneConn(t *testing.T) {
+	l := newTestListener(t)
+	sess := NewSessions()
+	h := &stubHandler{}
+	srv := NewServer(l.Addr().String(), h, sess)
+	if err := srv.Listen(); err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	defer func() {
+		_ = srv.Close()
+		waitPort()
+	}()
+	go func() { _ = srv.Serve() }()
+
+	c := Dial(l.Addr().String())
+	defer c.Close()
+
+	got := make(chan audio.Audio, 4)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go func() {
+		_ = c.RunPushReceiver(ctx, pushHandlerFunc(func(p Push) {
+			var ap AudioNudgePush
+			if err := json.Unmarshal(p.Params, &ap); err == nil {
+				got <- ap.Audio
+			}
+		}))
+	}()
+
+	for i := 0; i < 100 && sess.Active() < 1; i++ {
+		time.Sleep(10 * time.Millisecond)
+	}
+	if sess.Active() != 1 {
+		t.Fatalf("active sessions = %d, want exactly 1", sess.Active())
+	}
+
+	// A round-trip while the receiver is running. Before the reader owned the
+	// conn, this and the receiver raced for every frame.
+	resp, err := c.PushToTalk(context.Background(), audio.Audio{Format: audio.PCM16kMono, Bytes: []byte("hello")}, "ru")
+	if err != nil {
+		t.Fatalf("PushToTalk with a receiver running: %v", err)
+	}
+	if resp.ReplyText != "got it" {
+		t.Fatalf("ReplyText = %q, want %q", resp.ReplyText, "got it")
+	}
+
+	// And the nudge still arrives, on the session that just spoke.
+	err = sess.PushToMostRecent(context.Background(), AudioNudgePush{
+		RuleName: "after-speaking",
+		Audio:    audio.Audio{Format: audio.PCM16kMono, Bytes: []byte("proactive")},
+	})
+	if err != nil {
+		t.Fatalf("PushToMostRecent: %v", err)
+	}
+	select {
+	case a := <-got:
+		if string(a.Bytes) != "proactive" {
+			t.Fatalf("received %q, want the nudge audio", string(a.Bytes))
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("nudge never reached the handler after the client had spoken")
+	}
+}
+
+// A request abandoned by its context must not leave its slot behind, or a
+// long-running client leaks one channel per timeout.
+func TestClientForgetsAbandonedRequests(t *testing.T) {
+	l := newTestListener(t)
+	sess := NewSessions()
+	srv := NewServer(l.Addr().String(), &blockingHandler{}, sess)
+	if err := srv.Listen(); err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	defer func() {
+		_ = srv.Close()
+		waitPort()
+	}()
+	go func() { _ = srv.Serve() }()
+
+	c := Dial(l.Addr().String())
+	defer c.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+	_, err := c.PushToTalk(ctx, audio.Audio{Format: audio.PCM16kMono, Bytes: []byte("x")}, "ru")
+	if err == nil {
+		t.Fatal("expected the round-trip to fail on its context")
+	}
+
+	c.mu.Lock()
+	n := len(c.pending)
+	c.mu.Unlock()
+	if n != 0 {
+		t.Fatalf("pending = %d after an abandoned request, want 0", n)
+	}
+}
+
+// blockingHandler never answers, so the client's context is what ends the
+// round-trip.
+type blockingHandler struct{}
+
+func (blockingHandler) HandlePushToTalk(ctx context.Context, _ PushToTalkReq, _ uint64) (PushToTalkResp, error) {
+	<-ctx.Done()
+	return PushToTalkResp{}, ctx.Err()
+}