prevent deadlock on background thread access to Flagship singleton

.github/workflows/flagship_ci.yml

@@ -10,10 +10,10 @@ jobs:
     strategy:
       matrix:
         run-config:
-          - { scheme: 'Flagship', destination: 'platform=iOS Simulator,name=iPhone SE (3rd generation)', label: 'iOS'}
+          - { scheme: 'Flagship', destination: 'platform=iOS Simulator,name=iPhone 17', label: 'iOS'}
           - { scheme: 'Flagship-tvOS', destination: 'platform=tvOS Simulator,name=Apple TV', label: 'tvOS' }
           - { scheme: 'Flagship-macOS', destination: 'platform=macOS', label: 'macOS'}
-          - { scheme: 'Flagship-watchOS', destination: 'platform=watchOS Simulator,name=Apple Watch SE (40mm) (2nd generation)', label: 'watchOS'}
+          - { scheme: 'Flagship-watchOS', destination: 'platform=watchOS Simulator,name=Apple Watch Ultra 3 (49mm),OS=26.2', label: 'watchOS'}
 
 
     steps:
@@ -28,7 +28,7 @@ jobs:
      - name: Checkout Project
        uses: actions/checkout@v4
      - name: Test SDK Flagship
-       run:  xcodebuild test -project Flagship/Flagship.xcodeproj -scheme "Flagship" -destination "platform=iOS Simulator,name=iPhone SE (3rd generation)" -enableCodeCoverage YES
+       run:  xcodebuild test -project Flagship/Flagship.xcodeproj -scheme "Flagship" -destination "platform=iOS Simulator,name=iPhone 17" -enableCodeCoverage YES
      - name: Upload coverage to Codecov
        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24
        with:

FlagShip.podspec

@@ -9,7 +9,7 @@
 Pod::Spec.new do |s|
   s.name             = "FlagShip"
 
-  s.version          = "4.0.2"
+  s.version          = "4.0.3"
   s.summary          = "Flagship SDK"
 
 # This description is used to generate tags and improve search results.

FlagShip/FlagShipTests/FlagshipBucketingTest.swift

@@ -94,9 +94,19 @@ class FlagshipBucketingTest: XCTestCase {
         Flagship.sharedInstance.start(envId: "gk87t3jggr10c6l6sdob", apiKey: "apiKey", config: fsConfig ?? FSConfigBuilder().build())
         /// Create new visitor
         testVisitor = Flagship.sharedInstance.newVisitor(visitorId: "korso", hasConsented: true).withFetchFlagsStatus { _, _ in
+
+            guard let visitor = self.testVisitor else {
+                XCTFail("testVisitor is nil in fetch flags callback")
+                expectationSync.fulfill()
+                return
+            }
+
+            XCTAssertEqual(visitor.visitorId, "korso", "Unexpected visitorId in fetch flags callback")
+
             // Get from alloc 100
-            let flag2 = self.testVisitor?.getFlag(key: "stringFlag")
-            XCTAssertTrue(flag2?.value(defaultValue: "default") == "default")
+            let flag2 = visitor.getFlag(key: "stringFlag")
+            XCTAssertEqual(flag2.value(defaultValue: "default"), "default")
+
             expectationSync.fulfill()
         }.build()
         /// Erase all cached data

FlagShip/FlagShipTests/FlagshipTests.swift

@@ -10,45 +10,47 @@
 @testable import Flagship
 
 class FlagshipTests: XCTestCase {
-
-    override func setUpWithError() throws {
-
-    }
-
-
-    func testStart(){
-
+    override func setUpWithError() throws {}
+
+    func testStart() {
         Flagship.sharedInstance.start(envId: "gk87t3jggr10c6l6sdob", apiKey: "apiKey")
         XCTAssert(Flagship.sharedInstance.envId == "gk87t3jggr10c6l6sdob")
         XCTAssert(Flagship.sharedInstance.apiKey == "apiKey")
         XCTAssert(Flagship.sharedInstance.currentStatus == .SDK_INITIALIZED)
-        
+
         XCTAssert(Flagship.sharedInstance.currentConfig.logLevel == .ALL)
         XCTAssert(Flagship.sharedInstance.currentConfig.mode == .DECISION_API)
         XCTAssert(Flagship.sharedInstance.currentConfig.timeout == 2)
-
     }
-
-
-    func testStartWithConfig(){
-
+
+    func testStartWithConfig() {
         let fsConfig = FSConfigBuilder().DecisionApi().withTimeout(12).build()
         Flagship.sharedInstance.start(envId: "gk87t3jggr10c6l6sdob", apiKey: "apiKey", config: fsConfig)
         XCTAssert(Flagship.sharedInstance.envId == "gk87t3jggr10c6l6sdob")
         XCTAssert(Flagship.sharedInstance.apiKey == "apiKey")
         XCTAssert(Flagship.sharedInstance.currentStatus == .SDK_INITIALIZED)
-        
+
         XCTAssert(Flagship.sharedInstance.currentConfig.logLevel == .ALL)
         XCTAssert(Flagship.sharedInstance.currentConfig.mode == .DECISION_API)
-        XCTAssert(Flagship.sharedInstance.currentConfig.timeout == 12/1000)
-
+        XCTAssert(Flagship.sharedInstance.currentConfig.timeout == 12 / 1000)
     }
-    
-    func testLogManager(){
+
+    func testLogManager() {
         let customLoger = FSLogManager()
         customLoger.level = .WARNING
         customLoger.onLog(level: .DEBUG, tag: "testTag", message: "testMsg")
-        XCTAssertTrue( customLoger.getLevel() == .WARNING)
+        XCTAssertTrue(customLoger.getLevel() == .WARNING)
+    }
+
+    func testInitFromThread() {
+        let expectation = XCTestExpectation(description: "Init Flagship from background thread completion handler")
+
+        DispatchQueue.global(qos: .userInitiated).async {
+            Flagship.sharedInstance.start(envId: "gk87t3jggr10c6l6sdob", apiKey: "apiKey")
+            XCTAssert(Flagship.sharedInstance.currentStatus == .SDK_INITIALIZED)
+            expectation.fulfill()
+        }
+
+        wait(for: [expectation], timeout: 10.0)
     }
-
 }

FlagShip/Flagship.xcodeproj/project.pbxproj

@@ -1793,7 +1793,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 4.0.2;
+				MARKETING_VERSION = 4.0.3;
 				OTHER_LDFLAGS = "";
 				OTHER_SWIFT_FLAGS = "";
 				PRODUCT_BUNDLE_IDENTIFIER = ABTasty.FlagShip;
@@ -1826,7 +1826,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 4.0.2;
+				MARKETING_VERSION = 4.0.3;
 				OTHER_LDFLAGS = "";
 				OTHER_SWIFT_FLAGS = "";
 				PRODUCT_BUNDLE_IDENTIFIER = ABTasty.FlagShip;

FlagShip/Source/Core/Flagship.swift

@@ -9,12 +9,10 @@
 public class Flagship: NSObject {
     let fsQueue = DispatchQueue(label: "flagship.queue", attributes: .concurrent)
 
-    // envId
     var envId: String?
     // apiKey
     var apiKey: String?
-    // Configuration
-    var currentConfig: FlagshipConfig = FSConfigBuilder().build()
+
     // Current visitor
     @objc public private(set) var sharedVisitor: FSVisitor?
     // Enabale Log
@@ -36,9 +34,25 @@
             }
         }
     }
-    
+
     private var _currentStatus: FSSdkStatus = .SDK_NOT_INITIALIZED
 
+    // Configuration
+    private var _currentConfig: FlagshipConfig = FSConfigBuilder().build()
+
+    var currentConfig: FlagshipConfig {
+        get { fsQueue.sync { _currentConfig } }
+        set { fsQueue.async(flags: .barrier) { self._currentConfig = newValue } }
+    }
+
+    /// Synchronously update the current configuration.
+    /// Used during SDK start to ensure the config is visible before updating status.
+    private func setCurrentConfigSync(_ config: FlagshipConfig) {
+        fsQueue.sync(flags: .barrier) {
+            self._currentConfig = config
+        }
+    }
+
     // Shared instace
     @objc public static let sharedInstance: Flagship = {
         let instance = Flagship()
@@ -48,9 +62,11 @@
 
     override private init() {
         lastInitializationTimestamp = FSTools.getUtcTimestamp()
-    }
+     }
 
-    @objc public func start(envId: String, apiKey: String, config: FlagshipConfig = FSConfigBuilder().build()) {
+    @objc public func start(envId: String, apiKey: String, config: FlagshipConfig? = nil) {
+        let resolvedConfig = config ?? FSConfigBuilder().build()
+
         // Check the environmentId
         if FSTools.chekcXidEnvironment(envId) {
             Flagship.sharedInstance.envId = envId
@@ -66,13 +82,13 @@
         self.apiKey = apiKey
 
         // Set configuration
-        Flagship.sharedInstance.currentConfig = config
+        Flagship.sharedInstance.setCurrentConfigSync(resolvedConfig)
 
-        switch config.mode { case .DECISION_API:
+        switch resolvedConfig.mode { case .DECISION_API:
             Flagship.sharedInstance.updateStatus(.SDK_INITIALIZED)
         case .BUCKETING:
             // Init the polling script
-            pollingScript = FSPollingScript(pollingTime: config.pollingTime)
+            pollingScript = FSPollingScript(pollingTime: resolvedConfig.pollingTime)
             // Update status depend on the buckeitng file
             Flagship.sharedInstance.updateStatus(FSStorageManager.bucketingScriptAlreadyAvailable() ? .SDK_INITIALIZED : .SDK_INITIALIZING)
         }
@@ -113,8 +129,11 @@
 
     // Reset the sdk
     func reset() {
-        sharedVisitor = nil
-        currentStatus = .SDK_NOT_INITIALIZED
+        fsQueue.sync(flags: .barrier) {
+            self.sharedVisitor = nil
+            self._currentStatus = .SDK_NOT_INITIALIZED
+            self._currentConfig = FSConfigBuilder().build()
+        }
     }
 
     // Create new visitor
@@ -129,16 +148,13 @@
 
     // Update status
     func updateStatus(_ newStatus: FSSdkStatus) {
-        // _ if the staus has not changed then no need to trigger the callback
-        if newStatus == currentStatus {
-            return
-        }
-        // Update the status
-        currentStatus = newStatus
-        // Trigger the callback
-        if let callbackListener = currentConfig.onSdkStatusChanged {
-            callbackListener(newStatus)
+        var callbackListener: ((FSSdkStatus) -> Void)?
+        fsQueue.sync(flags: .barrier) {
+            guard newStatus != self._currentStatus else { return }
+            self._currentStatus = newStatus
+            callbackListener = self._currentConfig.onSdkStatusChanged
         }
+        callbackListener?(newStatus)
     }
 
     // When close is called will trigger all hits present in batch

FlagShip/Source/Tools/FlagShipVersion.swift

@@ -8,4 +8,4 @@
 import Foundation
 
 /// This file is automatically updated  2.0.0
-public let FlagShipVersion = "4.0.2"
+public let FlagShipVersion = "4.0.3"