Fix crash

SignalServiceKit/src/Loki/API/LokiAPI+SwarmAPI.swift

@@ -41,7 +41,7 @@ public extension LokiAPI {
             ]
             print("[Loki] Populating snode pool using: \(target).")
             let (promise, seal) = Promise<LokiAPITarget>.pending()
-            attempt(maxRetryCount: 4) {
+            attempt(maxRetryCount: 4, recoveringOn: LokiAPI.workQueue) {
                 HTTP.execute(.post, url, parameters: parameters).map2 { json -> LokiAPITarget in
                     guard let intermediate = json["result"] as? JSON, let rawTargets = intermediate["service_node_states"] as? [JSON] else { throw LokiAPIError.randomSnodePoolUpdatingFailed }
                     snodePool = try Set(rawTargets.flatMap { rawTarget in

SignalServiceKit/src/Loki/API/LokiAPI.swift

@@ -61,7 +61,7 @@ public final class LokiAPI : NSObject {
     
     // MARK: Public API
     public static func getMessages() -> Promise<Set<MessageListPromise>> {
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getTargetSnodes(for: getUserHexEncodedPublicKey()).mapValues2 { targetSnode in
                 getRawMessages(from: targetSnode, usingLongPolling: false).map2 { parseRawMessagesResponse($0, from: targetSnode) }
             }.map2 { Set($0) }
@@ -89,7 +89,7 @@ public final class LokiAPI : NSObject {
                 let parameters = lokiMessageWithPoW.toJSON()
                 return Set(snodes.map { snode in
                     // Send the message to the target snode
-                    return attempt(maxRetryCount: maxRetryCount) {
+                    return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
                         invoke(.sendMessage, on: snode, associatedWith: destination, parameters: parameters)
                     }.map2 { rawResponse in
                         if let json = rawResponse as? JSON, let powDifficulty = json["difficulty"] as? Int {

SignalServiceKit/src/Loki/API/LokiFileServerAPI.swift

@@ -98,7 +98,7 @@ public final class LokiFileServerAPI : LokiDotNetAPI {
             let url = URL(string: "\(server)/users/me")!
             let request = TSRequest(url: url, method: "PATCH", parameters: parameters)
             request.allHTTPHeaderFields = [ "Content-Type" : "application/json", "Authorization" : "Bearer \(token)" ]
-            return attempt(maxRetryCount: 8) {
+            return attempt(maxRetryCount: 8, recoveringOn: LokiAPI.workQueue) {
                 LokiFileServerProxy(for: server).perform(request).map2 { _ in }
             }.handlingInvalidAuthTokenIfNeeded(for: server).recover2 { error in
                 print("Couldn't update device links due to error: \(error).")

SignalServiceKit/src/Loki/API/LokiPoller.swift

@@ -10,7 +10,7 @@ public final class LokiPoller : NSObject {
     private var pollCount = 0
 
     // MARK: Settings
-    private static let retryInterval: TimeInterval = 1
+    private static let retryInterval: TimeInterval = 0.25
     /// After polling a given snode this many times we always switch to a new one.
     ///
     /// The reason for doing this is that sometimes a snode will be giving us successful responses while

SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift

@@ -83,7 +83,9 @@ public enum OnionRequestAPI {
                     unusedSnodes.remove(candidate) // All used snodes should be unique
                     print("[Loki] [Onion Request API] Testing guard snode: \(candidate).")
                     // Loop until a reliable guard snode is found
-                    return testSnode(candidate).map2 { candidate }.recover2 { _ in getGuardSnode() }
+                    return testSnode(candidate).map2 { candidate }.recover(on: DispatchQueue.main) { _ in
+                        withDelay(0.25, completionQueue: LokiAPI.workQueue) { getGuardSnode() }
+                    }
                 }
                 let promises = (0..<guardSnodeCount).map { _ in getGuardSnode() }
                 return when(fulfilled: promises).map2 { guardSnodes in

SignalServiceKit/src/Loki/API/Open Groups/LokiPublicChatAPI.swift

@@ -175,7 +175,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
         let (promise, seal) = Promise<LokiPublicChatMessage>.pending()
         DispatchQueue.global(qos: .userInitiated).async { [privateKey = userKeyPair.privateKey] in
             guard let signedMessage = message.sign(with: privateKey) else { return seal.reject(LokiDotNetAPIError.signingFailed) }
-            attempt(maxRetryCount: maxRetryCount) {
+            attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
                 getAuthToken(for: server).then2 { token -> Promise<LokiPublicChatMessage> in
                     let url = URL(string: "\(server)/channels/\(channel)/messages")!
                     let parameters = signedMessage.toJSON()
@@ -244,7 +244,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
         let isModerationRequest = !isSentByUser
         print("[Loki] Deleting message with ID: \(messageID) for public chat channel with ID: \(channel) on server: \(server) (isModerationRequest = \(isModerationRequest)).")
         let urlAsString = isSentByUser ? "\(server)/channels/\(channel)/messages/\(messageID)" : "\(server)/loki/v1/moderation/message/\(messageID)"
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<Void> in
                 let url = URL(string: urlAsString)!
                 let request = TSRequest(url: url, method: "DELETE", parameters: [:])
@@ -292,7 +292,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
     public static func setDisplayName(to newDisplayName: String?, on server: String) -> Promise<Void> {
         print("[Loki] Updating display name on server: \(server).")
         let parameters: JSON = [ "name" : (newDisplayName ?? "") ]
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<Void> in
                 let url = URL(string: "\(server)/users/me")!
                 let request = TSRequest(url: url, method: "PATCH", parameters: parameters)
@@ -317,7 +317,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
             annotation["value"] = [ "profileKey" : profileKey.base64EncodedString(), "url" : url ]
         }
         let parameters: JSON = [ "annotations" : [ annotation ] ]
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<Void> in
                 let url = URL(string: "\(server)/users/me")!
                 let request = TSRequest(url: url, method: "PATCH", parameters: parameters)
@@ -382,7 +382,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
     }
     
     public static func getInfo(for channel: UInt64, on server: String) -> Promise<LokiPublicChatInfo> {
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<LokiPublicChatInfo> in
                 let url = URL(string: "\(server)/channels/\(channel)?include_annotations=1")!
                 let request = TSRequest(url: url)
@@ -413,7 +413,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
     }
 
     public static func join(_ channel: UInt64, on server: String) -> Promise<Void> {
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<Void> in
                 let url = URL(string: "\(server)/channels/\(channel)/subscribe")!
                 let request = TSRequest(url: url, method: "POST", parameters: [:])
@@ -426,7 +426,7 @@ public final class LokiPublicChatAPI : LokiDotNetAPI {
     }
 
     public static func leave(_ channel: UInt64, on server: String) -> Promise<Void> {
-        return attempt(maxRetryCount: maxRetryCount) {
+        return attempt(maxRetryCount: maxRetryCount, recoveringOn: LokiAPI.workQueue) {
             getAuthToken(for: server).then2 { token -> Promise<Void> in
                 let url = URL(string: "\(server)/channels/\(channel)/subscribe")!
                 let request = TSRequest(url: url, method: "DELETE", parameters: [:])

SignalServiceKit/src/Loki/Utilities/Promise+Delaying.swift

@@ -0,0 +1,11 @@
+import PromiseKit
+
+/// Delay the execution of the promise constructed in `body` by `delay` seconds.
+internal func withDelay<T>(_ delay: TimeInterval, completionQueue: DispatchQueue, body: @escaping () -> Promise<T>) -> Promise<T> {
+    AssertIsOnMainThread() // Timers don't do well on background queues
+    let (promise, seal) = Promise<T>.pending()
+    Timer.scheduledTimer(withTimeInterval: delay, repeats: false) { _ in
+        body().done(on: completionQueue) { seal.fulfill($0) }.catch(on: completionQueue) { seal.reject($0) }
+    }
+    return promise
+}

SignalServiceKit/src/Loki/Utilities/Promise+Retrying.swift

@@ -1,7 +1,7 @@
 import PromiseKit
 
 /// Retry the promise constructed in `body` up to `maxRetryCount` times.
-internal func attempt<T>(maxRetryCount: UInt, recoveringOn queue: DispatchQueue = .global(qos: .default), body: @escaping () -> Promise<T>) -> Promise<T> {
+internal func attempt<T>(maxRetryCount: UInt, recoveringOn queue: DispatchQueue, body: @escaping () -> Promise<T>) -> Promise<T> {
     var retryCount = 0
     func attempt() -> Promise<T> {
         return body().recover(on: queue) { error -> Promise<T> in