Let the batcher create it’s own serial default queue

Author: denrase

Sources/Sentry/SentryClient.m

@@ -116,17 +116,7 @@ - (instancetype)initWithOptions:(SentryOptions *)options
         self.timezone = timezone;
         self.attachmentProcessors = [[NSMutableArray alloc] init];
 
-        // Uses DEFAULT priority (not LOW) because captureLogs() is called synchronously during
-        // app lifecycle events (willResignActive, willTerminate) and needs to complete quickly.
-        dispatch_queue_attr_t attributes
-            = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_DEFAULT, 0);
-        SentryDispatchQueueWrapper *logBatcherQueue =
-            [[SentryDispatchQueueWrapper alloc] initWithName:"io.sentry.log-batcher"
-                                                  attributes:attributes];
-
-        self.logBatcher = [[SentryLogBatcher alloc] initWithOptions:options
-                                                      dispatchQueue:logBatcherQueue
-                                                           delegate:self];
+        self.logBatcher = [[SentryLogBatcher alloc] initWithOptions:options delegate:self];
 
         // The SDK stores the installationID in a file. The first call requires file IO. To avoid
         // executing this on the main thread, we cache the installationID async here.

Sources/Sentry/_SentryDispatchQueueWrapperInternal.m

@@ -7,11 +7,17 @@ @implementation _SentryDispatchQueueWrapperInternal
 
 - (instancetype)init
 {
-    // DISPATCH_QUEUE_SERIAL_WITH_AUTORELEASE_POOL is requires iOS 10. Since we are targeting
-    // iOS 9 we need to manually add the autoreleasepool.
-    dispatch_queue_attr_t attributes = dispatch_queue_attr_make_with_qos_class(
-        DISPATCH_QUEUE_SERIAL, DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
-    self = [self initWithName:"io.sentry.default" attributes:attributes];
+    self = [self initWithName:"io.sentry.default"];
+    return self;
+}
+
+- (instancetype)initWithName:(const char *)name
+{
+    if (self = [super init]) {
+        dispatch_queue_attr_t attributes
+            = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_DEFAULT, 0);
+        _queue = dispatch_queue_create(name, attributes);
+    }
     return self;
 }
 

Sources/Sentry/include/_SentryDispatchQueueWrapperInternal.h

@@ -12,6 +12,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (strong, nonatomic) dispatch_queue_t queue;
 
+- (instancetype)initWithName:(const char *)name;
+
 - (instancetype)initWithName:(const char *)name
                   attributes:(nullable dispatch_queue_attr_t)attributes;
 

Sources/Swift/Helper/SentryDispatchQueueWrapper.swift

@@ -10,6 +10,10 @@
     public override init() {
         internalWrapper = _SentryDispatchQueueWrapperInternal()
     }
+
+    public init(name: UnsafePointer<CChar>) {
+        internalWrapper = _SentryDispatchQueueWrapperInternal(name: name)
+    }
 
     public init(name: UnsafePointer<CChar>, relativePriority: Int32) {
         internalWrapper = _SentryDispatchQueueWrapperInternal(name: name, relativePriority: relativePriority)

Sources/Swift/Tools/SentryLogBatcher.swift

@@ -26,20 +26,19 @@ import Foundation
     private weak var delegate: SentryLogBatcherDelegate?
 
     /// Convenience initializer with default flush timeout, max log count (100), and buffer size.
+    /// Creates its own serial dispatch queue with DEFAULT QoS for thread-safe access to mutable state.
     /// - Parameters:
     ///   - options: The Sentry configuration options
-    ///   - dispatchQueue: A **serial** dispatch queue wrapper for thread-safe access to mutable state
     ///   - delegate: The delegate to handle captured log batches
     ///
-    /// - Important: The `dispatchQueue` parameter MUST be a serial queue to ensure thread safety.
-    ///              Passing a concurrent queue will result in undefined behavior and potential data races.
-    ///
+    /// - Note: Uses DEFAULT priority (not LOW) because captureLogs() is called synchronously during
+    ///         app lifecycle events (willResignActive, willTerminate) and needs to complete quickly.
     /// - Note: Setting `maxLogCount` to 100. While Replay hard limit is 1000, we keep this lower, as it's hard to lower once released.
     @_spi(Private) public convenience init(
         options: Options,
-        dispatchQueue: SentryDispatchQueueWrapper,
         delegate: SentryLogBatcherDelegate
     ) {
+        let dispatchQueue = SentryDispatchQueueWrapper(name: "io.sentry.log-batcher")
         self.init(
             options: options,
             flushTimeout: 5,

Tests/SentryTests/Networking/SentryDispatchQueueWrapperTests.m

@@ -77,6 +77,26 @@ - (void)testInitWithNameAndAttributes_customAttributes_shouldCreateQueueWithGive
     XCTAssertEqual(actualQoSClass, QOS_CLASS_UNSPECIFIED);
     XCTAssertEqual(actualRelativePriority, 0);
 }
+
+- (void)testInitWithName_shouldCreateQueueWithDefaultQoS
+{
+    // -- Arrange --
+    const char *queueName = "sentry-dispatch-factory.test-default-qos";
+
+    // -- Act --
+    SentryDispatchQueueWrapper *wrappedQueue =
+        [[SentryDispatchQueueWrapper alloc] initWithName:queueName];
+
+    // -- Assert --
+    const char *actualName = dispatch_queue_get_label(wrappedQueue.queue);
+    XCTAssertEqual(strcmp(actualName, queueName), 0);
+
+    int actualRelativePriority;
+    dispatch_qos_class_t actualQoSClass
+        = dispatch_queue_get_qos_class(wrappedQueue.queue, &actualRelativePriority);
+    XCTAssertEqual(actualQoSClass, QOS_CLASS_DEFAULT);
+    XCTAssertEqual(actualRelativePriority, 0);
+}
 @end
 
 NS_ASSUME_NONNULL_END

Tests/SentryTests/SentryClientTests.swift

@@ -2398,6 +2398,9 @@ class SentryClientTests: XCTestCase {
         let testDelegate = TestLogBatcherDelegateForClient()
         let testBatcher = TestLogBatcherForClient(
             options: sut.options,
+            flushTimeout: 5,
+            maxLogCount: 100,
+            maxBufferSizeBytes: 1_024 * 1_024,
             dispatchQueue: TestSentryDispatchQueueWrapper(),
             delegate: testDelegate
         )
@@ -2426,6 +2429,9 @@ class SentryClientTests: XCTestCase {
         let testDelegate = TestLogBatcherDelegateForClient()
         let testBatcher = TestLogBatcherForClient(
             options: sut.options,
+            flushTimeout: 5,
+            maxLogCount: 100,
+            maxBufferSizeBytes: 1_024 * 1_024,
             dispatchQueue: TestSentryDispatchQueueWrapper(),
             delegate: testDelegate
         )
@@ -2444,6 +2450,9 @@ class SentryClientTests: XCTestCase {
         let testDelegate = TestLogBatcherDelegateForClient()
         let testBatcher = TestLogBatcherForClient(
             options: sut.options,
+            flushTimeout: 5,
+            maxLogCount: 100,
+            maxBufferSizeBytes: 1_024 * 1_024,
             dispatchQueue: TestSentryDispatchQueueWrapper(),
             delegate: testDelegate
         )