Changed the networking logic to suspend/resume rather than just cancel connections

Session/Calls/Call Management/SessionCallManager.swift

@@ -197,7 +197,7 @@ public final class SessionCallManager: NSObject, CallManagerProtocol {
             
             // Stop all jobs except for message sending and when completed suspend the database
             JobRunner.stopAndClearPendingJobs(exceptForVariant: .messageSend, using: dependencies) {
-                LibSession.closeNetworkConnections()
+                LibSession.suspendNetworkAccess()
                 Storage.suspendDatabaseAccess()
                 Log.flush()
             }

Session/Meta/AppDelegate.swift

@@ -147,6 +147,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
         UNUserNotificationCenter.current().delegate = self
         
         Storage.resumeDatabaseAccess()
+        LibSession.resumeNetworkAccess()
         
         // Reset the 'startTime' (since it would be invalid from the last launch)
         startTime = CACurrentMediaTime()
@@ -211,7 +212,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
         // Stop all jobs except for message sending and when completed suspend the database
         JobRunner.stopAndClearPendingJobs(exceptForVariant: .messageSend, using: dependencies) {
             if !self.hasCallOngoing() {
-                LibSession.closeNetworkConnections()
+                LibSession.suspendNetworkAccess()
                 Storage.suspendDatabaseAccess()
                 Log.info("[AppDelegate] completed network and database shutdowns.")
                 Log.flush()
@@ -281,6 +282,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     
     func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
         Storage.resumeDatabaseAccess()
+        LibSession.resumeNetworkAccess()
         
         // Background tasks only last for a certain amount of time (which can result in a crash and a
         // prompt appearing for the user), we want to avoid this and need to make sure to suspend the
@@ -298,7 +300,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
             BackgroundPoller.isValid = false
             
             if Singleton.hasAppContext && Singleton.appContext.isInBackground {
-                LibSession.closeNetworkConnections()
+                LibSession.suspendNetworkAccess()
                 Storage.suspendDatabaseAccess()
                 Log.flush()
             }
@@ -325,7 +327,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
                 BackgroundPoller.isValid = false
                 
                 if Singleton.hasAppContext && Singleton.appContext.isInBackground {
-                    LibSession.closeNetworkConnections()
+                    LibSession.suspendNetworkAccess()
                     Storage.suspendDatabaseAccess()
                     Log.flush()
                 }

Session/Meta/SessionApp.swift

@@ -114,7 +114,7 @@ public struct SessionApp {
     public static func resetAppData(onReset: (() -> ())? = nil) {
         LibSession.clearMemoryState()
         LibSession.clearSnodeCache()
-        LibSession.closeNetworkConnections()
+        LibSession.suspendNetworkAccess()
         Storage.resetAllStorage()
         ProfileManager.resetProfileStorage()
         Attachment.resetAttachmentStorage()

Session/Notifications/PushRegistrationManager.swift

@@ -287,6 +287,7 @@ public enum PushRegistrationError: Error {
         }
         
         Storage.resumeDatabaseAccess()
+        LibSession.resumeNetworkAccess()
         
         let maybeCall: SessionCall? = Storage.shared.write { db in
             let messageInfo: CallMessage.MessageInfo = CallMessage.MessageInfo(

SessionNotificationServiceExtension/NotificationServiceExtension.swift

@@ -51,6 +51,7 @@ public final class NotificationServiceExtension: UNNotificationServiceExtension
 
         // Perform main setup
         Storage.resumeDatabaseAccess()
+        LibSession.resumeNetworkAccess()
         DispatchQueue.main.sync { self.setUpIfNecessary() { } }
 
         // Handle the push notification
@@ -349,7 +350,7 @@ public final class NotificationServiceExtension: UNNotificationServiceExtension
             .map { NSNumber(value: $0) }
             .defaulting(to: NSNumber(value: 0))
         Log.info("Complete silently.")
-        LibSession.closeNetworkConnections()
+        LibSession.suspendNetworkAccess()
         Storage.suspendDatabaseAccess()
         Log.flush()
         
@@ -416,7 +417,7 @@ public final class NotificationServiceExtension: UNNotificationServiceExtension
 
     private func handleFailure(for content: UNMutableNotificationContent, error: NotificationError) {
         Log.error("Show generic failure message due to error: \(error).")
-        LibSession.closeNetworkConnections()
+        LibSession.suspendNetworkAccess()
         Storage.suspendDatabaseAccess()
         Log.flush()
         

SessionShareExtension/ThreadPickerVC.swift

@@ -100,7 +100,7 @@ final class ThreadPickerVC: UIViewController, UITableViewDataSource, UITableView
         
         // When the thread picker disappears it means the user has left the screen (this will be called
         // whether the user has sent the message or cancelled sending)
-        LibSession.closeNetworkConnections()
+        LibSession.suspendNetworkAccess()
         Storage.suspendDatabaseAccess()
         Log.flush()
     }
@@ -229,6 +229,7 @@ final class ThreadPickerVC: UIViewController, UITableViewDataSource, UITableView
         
         ModalActivityIndicatorViewController.present(fromViewController: shareNavController!, canCancel: false, message: "vc_share_sending_message".localized()) { activityIndicator in
             Storage.resumeDatabaseAccess()
+            LibSession.resumeNetworkAccess()
             
             let swarmPublicKey: String = {
                 switch threadVariant {
@@ -314,7 +315,7 @@ final class ThreadPickerVC: UIViewController, UITableViewDataSource, UITableView
                 .receive(on: DispatchQueue.main)
                 .sinkUntilComplete(
                     receiveCompletion: { [weak self] result in
-                        LibSession.closeNetworkConnections()
+                        LibSession.suspendNetworkAccess()
                         Storage.suspendDatabaseAccess()
                         Log.flush()
                         activityIndicator.dismiss { }

SessionSnodeKit/LibSession/LibSession+Networking.swift

@@ -12,6 +12,7 @@ import SessionUtilitiesKit
 public extension LibSession {
     private static var networkCache: Atomic<UnsafeMutablePointer<network_object>?> = Atomic(nil)
     private static var snodeCachePath: String { "\(OWSFileSystem.appSharedDataDirectoryPath())/snodeCache" }
+    private static var isSuspended: Atomic<Bool> = Atomic(false)
     private static var lastPaths: Atomic<[[Snode]]> = Atomic([])
     private static var lastNetworkStatus: Atomic<NetworkStatus> = Atomic(.unknown)
     private static var pathsChangedCallbacks: Atomic<[UUID: ([[Snode]], UUID) -> ()]> = Atomic([:])
@@ -114,12 +115,18 @@ public extension LibSession {
         pathsChangedCallbacks.mutate { $0.removeValue(forKey: callbackId) }
     }
     
-    static func closeNetworkConnections() {
+    static func suspendNetworkAccess() {
+        isSuspended.mutate { $0 = true }
+        
         guard let network: UnsafeMutablePointer<network_object> = networkCache.wrappedValue else { return }
         
         network_close_connections(network)
     }
     
+    static func resumeNetworkAccess() {
+        isSuspended.mutate { $0 = false }
+    }
+    
     static func clearSnodeCache() {
         guard let network: UnsafeMutablePointer<network_object> = networkCache.wrappedValue else { return }
         
@@ -329,6 +336,11 @@ public extension LibSession {
     // MARK: - Internal Functions
     
     private static func getOrCreateNetwork() -> AnyPublisher<UnsafeMutablePointer<network_object>?, Error> {
+        guard !isSuspended.wrappedValue else {
+            Log.warn("[LibSession] Attempted to access suspended network.")
+            return Fail(error: NetworkError.suspended).eraseToAnyPublisher()
+        }
+        
         guard networkCache.wrappedValue == nil else {
             return Just(networkCache.wrappedValue)
                 .setFailureType(to: Error.self)

SessionUtilitiesKit/Networking/NetworkError.swift

@@ -15,6 +15,7 @@ public enum NetworkError: LocalizedError, Equatable {
     case badRequest(error: String, rawData: Data?)
     case requestFailed(error: String, rawData: Data?)
     case timeout
+    case suspended
     case unknown
     
     public var errorDescription: String? {
@@ -27,6 +28,7 @@ public enum NetworkError: LocalizedError, Equatable {
             case .unauthorised: return "Unauthorised (Failed to verify the signature)."
             case .badRequest(let error, _), .requestFailed(let error, _): return error
             case .timeout: return "The request timed out."
+            case .suspended: return "Network requests are suspended."
             case .unknown: return "An unknown error occurred."
         }
     }