Offer simulator shutdown when app operations stall

assets/Localizable.xcstrings

@@ -209,6 +209,22 @@
         }
       }
     },
+    "An app operation on %@ hasn’t finished. Keep waiting, or shut down this simulator to stop pending operations. Shutting down closes all of its apps.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "An app operation on %@ hasn’t finished. Keep waiting, or shut down this simulator to stop pending operations. Shutting down closes all of its apps."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "%@ 上的应用操作尚未完成。你可以继续等待，或关闭此模拟器以停止待处理的操作。关机会关闭其中的所有应用。"
+          }
+        }
+      }
+    },
     "App Repository": {
       "localizations": {
         "en": {
@@ -817,6 +833,22 @@
         }
       }
     },
+    "Couldn’t start shutting down %@. Check its current state and try again.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Couldn’t start shutting down %@. Check its current state and try again."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "无法开始关闭 %@。请检查其当前状态后重试。"
+          }
+        }
+      }
+    },
     "Create an iPhone or iPad simulator in %@.\nThen come back to find your next favorite app.": {
       "localizations": {
         "en": {
@@ -1201,6 +1233,22 @@
         }
       }
     },
+    "Keep Waiting": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Keep Waiting"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "继续等待"
+          }
+        }
+      }
+    },
     "License": {
       "localizations": {
         "en": {
@@ -1617,6 +1665,22 @@
         }
       }
     },
+    "Operation Is Taking Longer Than Expected": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Operation Is Taking Longer Than Expected"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "操作耗时较长"
+          }
+        }
+      }
+    },
     "Preparing App…": {
       "localizations": {
         "en": {

src/AppInstallationStore.swift

@@ -15,6 +15,8 @@ final class AppInstallationStore {
   private(set) var openedApp: Key?
   private(set) var uninstalledApp: Key?
   @ObservationIgnored private let installer: AppInstaller
+  @ObservationIgnored private let operationMonitor: SimulatorOperationMonitor?
+  @ObservationIgnored private var monitoredOperations: [Key: UUID] = [:]
   @ObservationIgnored private let didInstall: @MainActor (SimulatorApplication, String) -> Void
   @ObservationIgnored private let didReplace: @MainActor (SimulatorApplication, String) -> Void
   @ObservationIgnored private let didUninstall: @MainActor (String, String) -> Void
@@ -30,14 +32,16 @@ final class AppInstallationStore {
     didInstall: @escaping @MainActor (SimulatorApplication, String) -> Void = { _, _ in },
     didReplace: @escaping @MainActor (SimulatorApplication, String) -> Void = { _, _ in },
     didUninstall: @escaping @MainActor (String, String) -> Void = { _, _ in },
-    didOpen: @escaping @MainActor (String, String) -> Void = { _, _ in }
+    didOpen: @escaping @MainActor (String, String) -> Void = { _, _ in },
+    operationMonitor: SimulatorOperationMonitor? = nil
   ) {
     self.installer = installer
     self.didInstall = didInstall
     self.didReplace = didReplace
     self.didUninstall = didUninstall
     self.showDevice = showDevice
     self.didOpen = didOpen
+    self.operationMonitor = operationMonitor
   }
 
   func phase(appID: String, deviceID: String) -> AppInstallationPhase? {
@@ -87,6 +91,7 @@ final class AppInstallationStore {
             return
           } else {
             phases[key] = phase
+            if phase == .installing { monitor(key, on: device) }
           }
         }
         completion(
@@ -113,6 +118,7 @@ final class AppInstallationStore {
     uninstalledApp = nil
     errors[key] = nil
     phases[key] = .uninstalling
+    monitor(key, on: device)
     jobs[key] = Task {
       defer { finish(key) }
       do {
@@ -150,6 +156,7 @@ final class AppInstallationStore {
     openedApp = nil
     errors[key] = nil
     phases[key] = .opening
+    monitor(key, on: device)
     jobs[key] = Task {
       defer { finish(key) }
       do {
@@ -164,11 +171,19 @@ final class AppInstallationStore {
   }
 
   private func finish(_ key: Key) {
+    if let operation = monitoredOperations.removeValue(forKey: key) {
+      operationMonitor?.end(operation)
+    }
     jobs[key] = nil
     requests[key] = nil
     phases[key] = nil
   }
 
+  private func monitor(_ key: Key, on device: SimulatorDevice) {
+    guard monitoredOperations[key] == nil else { return }
+    monitoredOperations[key] = operationMonitor?.begin(on: device)
+  }
+
   func updateBatch(deviceID: String) -> AppUpdateBatch? {
     updateBatches[deviceID]
   }

src/CMakeLists.txt

@@ -13,6 +13,8 @@ add_executable(SimStore MACOSX_BUNDLE
     SimulatorDevicePresentation.swift
     SimulatorSelectionViews.swift
     SimulatorPowerButton.swift
+    SimulatorOperationMonitor.swift
+    SimulatorRecoveryAlert.swift
     ContentView.swift
     LibrarySection.swift
     AppCatalog.swift

src/ContentView.swift

@@ -7,6 +7,7 @@ struct ContentView: View {
   @State private var catalog: CatalogStore
   @State private var installedApps: InstalledAppsStore
   @State private var installations: AppInstallationStore
+  @State private var operationMonitor: SimulatorOperationMonitor
   @State private var launchError: String?
   @State private var librarySection: LibrarySection = .discover
 
@@ -54,9 +55,12 @@ struct ContentView: View {
       }
     #endif
     let simulators = SimulatorStore(discover: discover, shutdown: shutdown, boot: boot)
+    let operationMonitor = SimulatorOperationMonitor()
+    _operationMonitor = State(initialValue: operationMonitor)
     _simulators = State(initialValue: simulators)
     _catalog = State(initialValue: CatalogStore(client: catalogClient))
-    let installedApps = InstalledAppsStore(load: loadInstalledApps)
+    let installedApps = InstalledAppsStore(
+      load: loadInstalledApps, operationMonitor: operationMonitor)
     _installedApps = State(initialValue: installedApps)
     _installations = State(
       initialValue: AppInstallationStore(
@@ -80,7 +84,7 @@ struct ContentView: View {
         },
         didOpen: { bundleID, deviceID in
           installedApps.removeRecentInstallation(bundleID: bundleID, deviceID: deviceID)
-        }))
+        }, operationMonitor: operationMonitor))
   }
 
   private var needsXcode: Bool {
@@ -151,6 +155,9 @@ struct ContentView: View {
     .frame(minWidth: 900, minHeight: 600)
     .task { await simulators.refresh() }
     .onChange(of: librarySection) { _, _ in installedApps.clearRecentInstallations() }
+    .onChange(of: discovery?.devices) { _, devices in
+      operationMonitor.synchronize(with: devices)
+    }
     .task(id: shouldMonitorState) {
       while shouldMonitorState && !Task.isCancelled {
         do {
@@ -197,6 +204,7 @@ struct ContentView: View {
     } message: {
       Text(simulators.shutdownError ?? "")
     }
+    .modifier(SimulatorRecoveryAlert(monitor: operationMonitor, shutdown: shutdownSimulator))
   }
 
   @ViewBuilder
@@ -249,8 +257,15 @@ struct ContentView: View {
   }
 
   private func shutdownSimulator() {
-    guard let id = simulators.selectedDeviceID, simulators.shutdownDevice(id) != nil else { return }
+    guard let id = simulators.selectedDeviceID else { return }
+    _ = shutdownSimulator(id)
+  }
+
+  private func shutdownSimulator(_ id: String) -> Bool {
+    guard simulators.shutdownDevice(id) != nil else { return false }
+    operationMonitor.stop(deviceID: id)
     installations.cancelOperations(deviceID: id)
+    return true
   }
 
   private var shouldMonitorState: Bool {

src/InstalledAppsStore.swift

@@ -15,6 +15,8 @@ final class InstalledAppsStore {
   @ObservationIgnored
   private let load: @Sendable (SimulatorDevice) async throws -> [SimulatorApplication]
   @ObservationIgnored
+  private let operationMonitor: SimulatorOperationMonitor?
+  @ObservationIgnored
   private var selectedDevice: SimulatorDevice?
   @ObservationIgnored
   private var request: Request?
@@ -26,9 +28,10 @@ final class InstalledAppsStore {
   init(
     load: @escaping @Sendable (SimulatorDevice) async throws -> [SimulatorApplication] = {
       try await SimulatorApplications.installedApps(on: $0)
-    }
+    }, operationMonitor: SimulatorOperationMonitor? = nil
   ) {
     self.load = load
+    self.operationMonitor = operationMonitor
   }
 
   func installedApps(in catalog: AppCatalog, for deviceID: String) -> [CatalogApp]? {
@@ -136,7 +139,9 @@ final class InstalledAppsStore {
     applications = nil
     error = nil
     isLoading = true
+    let operation = operationMonitor?.begin(on: device)
     defer {
+      if let operation { operationMonitor?.end(operation) }
       if request === pending {
         request = nil
         isLoading = false

src/SimulatorOperationMonitor.swift

@@ -0,0 +1,71 @@
+import Foundation
+import Observation
+
+@MainActor
+@Observable
+final class SimulatorOperationMonitor {
+  struct Prompt: Identifiable, Equatable {
+    let id: UUID
+    let device: SimulatorDevice
+  }
+
+  typealias Wait = @Sendable () async throws -> Void
+
+  private var stalled: [Prompt] = []
+  var prompt: Prompt? { stalled.first }
+
+  @ObservationIgnored private let wait: Wait
+  @ObservationIgnored private var active:
+    [UUID: (device: SimulatorDevice, task: Task<Void, Never>)] = [:]
+  @ObservationIgnored private var mutedDevices: Set<String> = []
+
+  init(wait: @escaping Wait = { try await Task.sleep(for: .seconds(30)) }) {
+    self.wait = wait
+  }
+
+  func begin(on device: SimulatorDevice) -> UUID {
+    let id = UUID()
+    guard device.state == "Booted" else { return id }
+    let wait = wait
+    let task = Task { [weak self] in
+      do {
+        try await wait()
+        try Task.checkCancellation()
+      } catch { return }
+      guard let self, active[id] != nil, !mutedDevices.contains(device.id) else { return }
+      stalled.append(Prompt(id: id, device: device))
+    }
+    active[id] = (device, task)
+    return id
+  }
+
+  func end(_ id: UUID) {
+    guard let operation = active.removeValue(forKey: id) else { return }
+    operation.task.cancel()
+    stalled.removeAll { $0.id == id }
+    if !active.values.contains(where: { $0.device.id == operation.device.id }) {
+      mutedDevices.remove(operation.device.id)
+    }
+  }
+
+  func keepWaiting(_ prompt: Prompt) {
+    guard stalled.contains(where: { $0.id == prompt.id }) else { return }
+    mutedDevices.insert(prompt.device.id)
+    stalled.removeAll { $0.device.id == prompt.device.id }
+  }
+
+  func stop(deviceID: String) {
+    for id in active.keys.filter({ active[$0]?.device.id == deviceID }) {
+      end(id)
+    }
+  }
+
+  func synchronize(with devices: [SimulatorDevice]?) {
+    // A failed scan does not confirm that any device has stopped or disappeared.
+    guard let devices else { return }
+    let booted = Set(devices.filter { $0.state == "Booted" }.map(\.id))
+    for deviceID in Set(active.values.map { $0.device.id }).subtracting(booted) {
+      stop(deviceID: deviceID)
+    }
+  }
+}