From a4447426a3be7aae3fdfcdadd4cdfe7ee15d431e Mon Sep 17 00:00:00 2001
From: OrcaWin <alpha-eng@stably.ai>
Date: Thu, 29 Oct 2026 15:00:20 -0700
Subject: [PATCH] perf(emulator): reuse registered device backend routing
 (#35616)

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>
---
 src/main/emulator/emulator-bridge.test.ts | 27 +++++++++++++++++++++++
 src/main/emulator/emulator-bridge.ts      |  3 ++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/main/emulator/emulator-bridge.test.ts b/src/main/emulator/emulator-bridge.test.ts
index 1bbbd32bbc7..4dc2025f306 100644
--- a/src/main/emulator/emulator-bridge.test.ts
+++ b/src/main/emulator/emulator-bridge.test.ts
@@ -92,6 +92,33 @@ describe('EmulatorBridge helper ownership', () => {
     netFetchMock.mockReset()
   })
 
+  it('routes a registered explicit device without inventory and rediscovers after kill', async () => {
+    const bridge = new EmulatorBridge()
+    bridge.registerActiveEmulator('wt-1', session('device-1'), { managed: true })
+
+    await bridge.tap(0.25, 0.75, { device: 'device-1' })
+    expect(execServeSimCommandMock).toHaveBeenCalledWith(
+      { command: '/serve-sim', env: {} },
+      ['tap', '0.25', '0.75', '-d', 'device-1'],
+      undefined
+    )
+    expect(listSimulatorDevicesMock).not.toHaveBeenCalled()
+
+    await bridge.kill('device-1')
+    expect(bridge.getActiveForWorktree('wt-1')).toBeNull()
+    expect(listSimulatorDevicesMock).not.toHaveBeenCalled()
+    listSimulatorDevicesMock.mockResolvedValue([
+      { udid: 'device-1', name: 'iPhone', state: 'Booted', runtime: 'iOS' }
+    ])
+    await bridge.tap(0.5, 0.5, { device: 'device-1' })
+    expect(listSimulatorDevicesMock).toHaveBeenCalledOnce()
+    expect(execServeSimCommandMock).toHaveBeenLastCalledWith(
+      { command: '/serve-sim', env: {} },
+      ['tap', '0.5', '0.5', '-d', 'device-1'],
+      undefined
+    )
+  })
+
   it('stops the previous Orca-managed helper when a worktree switches devices', async () => {
     const bridge = new EmulatorBridge()
     bridge.registerActiveEmulator('wt-1', session('device-old'), { managed: true })
diff --git a/src/main/emulator/emulator-bridge.ts b/src/main/emulator/emulator-bridge.ts
index f578dec8ee3..00c4b4f10f5 100644
--- a/src/main/emulator/emulator-bridge.ts
+++ b/src/main/emulator/emulator-bridge.ts
@@ -325,8 +325,9 @@ export class EmulatorBridge {
   }
 
   private async backendForDevice(device: string): Promise<EmulatorBackend> {
+    const registered = this.sessionRegistry.getSession(device)
     for (const backend of this.backends) {
-      if (await backend.ownsDevice(device)) {
+      if (registered ? backend.kind === registered.backend : await backend.ownsDevice(device)) {
         return backend
       }
     }