Resolve various iOS crashes relating to bad access from multiple thre…

…ads (#129)
fluttercommunity · Dec 22, 2020 · cdd295f · cdd295f
1 parent 9dd202a
commit cdd295f
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Showing 8 changed files with 90 additions and 7 deletions.
diff --git a/example/integration_test/flutter_uploader_test.dart b/example/integration_test/flutter_uploader_test.dart
@@ -65,6 +65,27 @@ void main() {
       expect(res.status, UploadTaskStatus.complete);
     });
 
+    testWidgets('multiple uploads stresstest', (WidgetTester tester) async {
+      final taskIds = <String>[];
+      for (var i = 0; i < 10; i++) {
+        taskIds.add(await uploader.enqueue(
+          MultipartFormDataUpload(url: url.toString(), files: [
+            FileItem(path: await _tmpFile(), field: 'file'),
+          ]),
+        ));
+      }
+
+      final res = await Future.wait(
+        taskIds.map(
+          (taskId) => uploader.result.firstWhere(isCompleted(taskId)),
+        ),
+      );
+
+      for (var i = 0; i < res.length; i++) {
+        expect(res[i].taskId, taskIds[i]);
+      }
+    });
+
     testWidgets('can submit custom data', (tester) async {
       var fileItem = FileItem(path: await _tmpFile(), field: 'file');
 
@@ -85,7 +106,6 @@ void main() {
 
       final res = await uploader.result.firstWhere(isCompleted(taskId));
       final json = jsonDecode(res.response);
-      print(json);
 
       expect(json['request']['fields']['simpleKey'], 'simpleValue');
       expect(jsonDecode(json['request']['fields']['listOf']),
@@ -192,6 +212,25 @@ void main() {
       expect(res.status, UploadTaskStatus.complete);
     });
 
+    testWidgets('multiple uploads stresstest', (WidgetTester tester) async {
+      final taskIds = <String>[];
+      for (var i = 0; i < 10; i++) {
+        taskIds.add(await uploader.enqueue(
+          RawUpload(url: url.toString(), path: await _tmpFile()),
+        ));
+      }
+
+      final res = await Future.wait(
+        taskIds.map(
+          (taskId) => uploader.result.firstWhere(isCompleted(taskId)),
+        ),
+      );
+
+      for (var i = 0; i < res.length; i++) {
+        expect(res[i].taskId, taskIds[i]);
+      }
+    });
+
     testWidgets("can overwrite 'Accept' header", (WidgetTester tester) async {
       final taskId = await uploader.enqueue(RawUpload(
         url: url.toString(),

diff --git a/example/ios/Runner.xcodeproj/project.pbxproj b/example/ios/Runner.xcodeproj/project.pbxproj
@@ -293,11 +293,11 @@
 				"${PODS_ROOT}/../Flutter/Flutter.framework",
 				"${BUILT_PRODUCTS_DIR}/SDWebImage/SDWebImage.framework",
 				"${BUILT_PRODUCTS_DIR}/SwiftyGif/SwiftyGif.framework",
-				"${BUILT_PRODUCTS_DIR}/e2e/e2e.framework",
 				"${BUILT_PRODUCTS_DIR}/file_picker/file_picker.framework",
 				"${BUILT_PRODUCTS_DIR}/flutter_local_notifications/flutter_local_notifications.framework",
 				"${BUILT_PRODUCTS_DIR}/flutter_uploader/flutter_uploader.framework",
 				"${BUILT_PRODUCTS_DIR}/image_picker/image_picker.framework",
+				"${BUILT_PRODUCTS_DIR}/integration_test/integration_test.framework",
 				"${BUILT_PRODUCTS_DIR}/path_provider/path_provider.framework",
 				"${BUILT_PRODUCTS_DIR}/shared_preferences/shared_preferences.framework",
 			);
@@ -309,11 +309,11 @@
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/Flutter.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/SDWebImage.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/SwiftyGif.framework",
-				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/e2e.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/file_picker.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/flutter_local_notifications.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/flutter_uploader.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/image_picker.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/integration_test.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/path_provider.framework",
 				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/shared_preferences.framework",
 			);

diff --git a/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme b/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
@@ -61,7 +61,7 @@
       </BuildableProductRunnable>
    </LaunchAction>
    <ProfileAction
-      buildConfiguration = "Profile"
+      buildConfiguration = "Debug"
       shouldUseLaunchSchemeArgsEnv = "YES"
       savedToolIdentifier = ""
       useCustomWorkingDirectory = "NO"

diff --git a/example/ios/Runner/Info.plist b/example/ios/Runner/Info.plist
@@ -34,7 +34,7 @@
 	<key>FUMaximumConnectionsPerHost</key>
 	<integer>5</integer>
 	<key>FUMaximumUploadOperation</key>
-	<integer>1</integer>
+	<integer>3</integer>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>NSCameraUsageDescription</key>

diff --git a/example/lib/upload_screen.dart b/example/lib/upload_screen.dart
@@ -181,7 +181,7 @@ class _UploadScreenState extends State<UploadScreen> {
       allowCompression: false,
       allowMultiple: true,
     );
-    if (files.count > 0) {
+    if (files != null && files.count > 0) {
       if (binary) {
         for (var file in files.files) {
           _handleFileUpload([file.path]);

diff --git a/ios/Classes/CachingStreamHandler.swift b/ios/Classes/CachingStreamHandler.swift
@@ -11,23 +11,31 @@ class CachingStreamHandler<T>: NSObject, FlutterStreamHandler {
     var cache: [String:T] = [:]
 
     var eventSink: FlutterEventSink?
+
+    private let cacheSemaphore = DispatchSemaphore(value: 1)
 
     func add(_ id: String, _ value: T) {
+        cacheSemaphore.wait()
         cache[id] = value
-
+        cacheSemaphore.signal()
+
         if let sink = eventSink {
             sink(value)
         }
     }
 
     func clear() {
+        cacheSemaphore.wait()
         cache.removeAll()
+        cacheSemaphore.signal()
     }
 
     func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? {
+        cacheSemaphore.wait()
         for cacheEntry in cache {
             events(cacheEntry.value)
         }
+        cacheSemaphore.signal()
 
         self.eventSink = events
 

diff --git a/ios/Classes/EngineManager.swift b/ios/Classes/EngineManager.swift
@@ -10,8 +10,16 @@ import Foundation
 class EngineManager {
     private var headlessRunner: FlutterEngine?
     public var registerPlugins: FlutterPluginRegistrantCallback?
+
+    private let semaphore = DispatchSemaphore(value: 1)
 
     private func startEngineIfNeeded() {
+        semaphore.wait()
+
+        defer {
+            semaphore.signal()
+        }
+
         guard let callbackHandle = UploaderDefaults.shared.callbackHandle else {
             if let runner = headlessRunner {
                 runner.destroyContext()

diff --git a/ios/Classes/URLSessionUploader.swift b/ios/Classes/URLSessionUploader.swift
@@ -18,6 +18,9 @@ class URLSessionUploader: NSObject {
 
     var session: URLSession?
     let queue = OperationQueue()
+
+    // Accessing uploadedData & runningTaskById will require exclusive access
+    private let semaphore = DispatchSemaphore(value: 1)
 
     // Reference for uploaded data.
     var uploadedData = [String: Data]()
@@ -51,7 +54,10 @@ class URLSessionUploader: NSObject {
         delegates.uploadEnqueued(taskId: taskId)
 
         uploadTask.resume()
+
+        semaphore.wait()
         self.runningTaskById[taskId] = UploadTask(taskId: taskId, status: .enqueue, progress: 0)
+        semaphore.signal()
 
         return uploadTask
     }
@@ -153,6 +159,11 @@ extension URLSessionUploader: URLSessionDelegate, URLSessionDataDelegate, URLSes
     }
 
     func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
+        semaphore.wait()
+        defer {
+            semaphore.signal()
+        }
+
         NSLog("URLSessionDidReceiveData:")
 
         guard let uploadTask = dataTask as? URLSessionUploadTask else {
@@ -179,6 +190,11 @@ extension URLSessionUploader: URLSessionDelegate, URLSessionDataDelegate, URLSes
     }
 
     public func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
+        semaphore.wait()
+        defer {
+            semaphore.signal()
+        }
+
         if totalBytesExpectedToSend == NSURLSessionTransferSizeUnknown {
             NSLog("Unknown transfer size")
         } else {
@@ -191,6 +207,7 @@ extension URLSessionUploader: URLSessionDelegate, URLSessionDataDelegate, URLSes
             let bytesExpectedToSend = Double(integerLiteral: totalBytesExpectedToSend)
             let tBytesSent = Double(integerLiteral: totalBytesSent)
             let progress = round(Double(tBytesSent / bytesExpectedToSend * 100))
+
             let runningTask = self.runningTaskById[taskId]
             NSLog("URLSessionDidSendBodyData: taskId: \(taskId), byteSent: \(bytesSent), totalBytesSent: \(totalBytesSent), totalBytesExpectedToSend: \(totalBytesExpectedToSend), progress:\(progress)")
 
@@ -211,7 +228,13 @@ extension URLSessionUploader: URLSessionDelegate, URLSessionDataDelegate, URLSes
 
     public func urlSessionDidFinishEvents(forBackgroundURLSession session: URLSession) {
         NSLog("URLSessionDidFinishEvents:")
+
         session.getTasksWithCompletionHandler { (_, uploadTasks, _) in
+            self.semaphore.wait()
+            defer {
+                self.semaphore.signal()
+            }
+
             if uploadTasks.isEmpty {
                 NSLog("all upload tasks have been completed")
 
@@ -222,6 +245,11 @@ extension URLSessionUploader: URLSessionDelegate, URLSessionDataDelegate, URLSes
     }
 
     public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
+        semaphore.wait()
+        defer {
+            semaphore.signal()
+        }
+
         guard let uploadTask = task as? URLSessionUploadTask else {
             NSLog("URLSessionDidCompleteWithError: not an uplaod task")
             return