fix(talk): handle reentrant Google activation cancellation

ui/src/pages/chat/realtime-talk-google-live-lifecycle.ts

@@ -32,7 +32,7 @@ export function buildGoogleLiveUrl(session: RealtimeTalkJsonPcmWebSocketSessionR
   return url.toString();
 }
 
-export type GoogleLiveConnectionState =
+type GoogleLiveConnectionState =
   | "idle"
   | "connecting"
   | "ready"

ui/src/pages/chat/realtime-talk-google-live-timeout.test.ts

@@ -67,6 +67,15 @@ class FakeAudioContext {
   createGain() {
     return { connect() {}, disconnect() {}, gain: { value: 1 } };
   }
+
+  createAnalyser() {
+    return {
+      fftSize: 0,
+      smoothingTimeConstant: 0,
+      disconnect() {},
+      getFloatTimeDomainData: (samples: Float32Array) => samples.fill(0.25),
+    };
+  }
 }
 
 function createSession(): RealtimeTalkJsonPcmWebSocketSessionResult {
@@ -247,6 +256,23 @@ describe("Google Live setup timeout", () => {
     expect(audioContexts.every((context) => context.close.mock.calls.length === 1)).toBe(true);
   });
 
+  it("reclaims the meter when an input-level callback cancels activation", async () => {
+    let stopDuringActivation = () => undefined;
+    const onInputLevel = vi.fn(() => stopDuringActivation());
+    const transport = createTransport({ onInputLevel });
+    stopDuringActivation = () => transport.stop({ emitClosed: false });
+    const { start, socket } = await beginTransport(transport);
+    socket.emitOpen();
+    socket.emitMessage({ setupComplete: {} });
+    await expect(start).resolves.toBe("ready");
+
+    expect(() => transport.activate()).toThrow("Google Live transport activation cancelled");
+    expect(vi.getTimerCount()).toBe(0);
+    expect(stopInputTrack).toHaveBeenCalledOnce();
+    expect(socket.readyState).toBe(3);
+    expect(audioContexts.every((context) => context.close.mock.calls.length === 1)).toBe(true);
+  });
+
   it("clears the deadline after Google setup completes", async () => {
     const onStatus = vi.fn();
     const transport = createTransport({ onStatus });

ui/src/pages/chat/realtime-talk-google-live.ts

@@ -209,28 +209,26 @@ export class GoogleLiveRealtimeTalkTransport implements RealtimeTalkTransport {
     }
     try {
       this.ctx.callbacks.onStatus?.("listening");
-      if (this.closed) {
-        return;
-      }
+      this.assertActivationCurrent();
       this.emitTalkEvent({ type: "session.ready" });
-      if (this.closed) {
-        return;
-      }
+      this.assertActivationCurrent();
       if (this.ctx.callbacks.onInputLevel && this.media && this.inputContext) {
-        this.inputMeter = new RealtimeTalkMediaStreamMeter(this.ctx.callbacks.onInputLevel);
-        this.inputMeter.start(this.media, this.inputContext);
-      }
-      if (this.closed) {
-        return;
+        const inputMeter = new RealtimeTalkMediaStreamMeter(this.ctx.callbacks.onInputLevel);
+        this.inputMeter = inputMeter;
+        inputMeter.start(this.media, this.inputContext);
+        if (this.closed || !this.lifecycle.isActive || this.inputMeter !== inputMeter) {
+          // start() publishes synchronously before installing its interval. A
+          // reentrant stop must reclaim the interval that start() installs next.
+          inputMeter.stop(false);
+        }
+        this.assertActivationCurrent();
       }
       this.startMicrophonePump();
       if (this.camera.stream && !this.cameraPublished) {
         this.cameraPublished = true;
         this.ctx.callbacks.onVideoStream?.(this.camera.stream);
       }
-      if (this.closed) {
-        return;
-      }
+      this.assertActivationCurrent();
       this.startVideoFrames();
     } catch (error) {
       try {
@@ -242,6 +240,12 @@ export class GoogleLiveRealtimeTalkTransport implements RealtimeTalkTransport {
     }
   }
 
+  private assertActivationCurrent(): void {
+    if (this.closed || !this.lifecycle.isActive) {
+      throw new Error("Google Live transport activation cancelled");
+    }
+  }
+
   async setVideoEnabled(enabled: boolean): Promise<void> {
     await this.camera.setEnabled(enabled);
   }