# addImmediateTaskUnlessCancelled(name:priority:executorPreference:operation:) Add a child task to the group and immediately start running it in the context of the calling thread/task. ``` mutating func addImmediateTaskUnlessCancelled(name: String? = nil, priority: TaskPriority? = nil, executorPreference taskExecutor: consuming (any TaskExecutor)? = nil, operation: sending @escaping @isolated(any) () async throws -> ChildTaskResult) -> Bool ``` ## Parameters `name` Human readable name of this task. `priority` The priority of the operation task. Omit this parameter or pass `nil` to inherit the task group’s base priority. `taskExecutor` The task executor that the child task should be started on and keep using. Explicitly passing `nil` as the executor preference is equivalent to calling the `addImmediateTaskUnlessCancelled` method without a preference, and effectively means to inherit the outer context’s executor preference. You can also pass the [`globalConcurrentExecutor`](/documentation/Swift/globalConcurrentExecutor) global executor explicitly. `operation` The operation to execute as part of the task group. ## Return Value `true` if the child task was added to the group; otherwise `false`. ## Discussion This function *starts* the created task on the calling context. The task will continue executing on the caller’s context until it suspends, and after suspension will resume on the adequate executor. For a nonisolated operation this means running on the global concurrent pool, and on an isolated operation it means the appropriate executor of that isolation context. As indicated by the lack of `async` on this method, this method does *not* suspend, and instead takes over the calling task’s (thread’s) execution in a synchronous manner. Other than the execution semantics discussed above, the created task is semantically equivalent to its basic version which can be created using [`addTask(priority:operation:)`](/documentation/Swift/ThrowingTaskGroup/addTask(priority:operation:)). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)