# Dispatch Objects The basic behaviors supported by all dispatch types. ## Discussion There are many types of dispatch objects, including [`dispatch_queue_t`](/documentation/Dispatch/dispatch_queue_t), [`dispatch_group_t`](/documentation/Dispatch/dispatch_group_t), and [`dispatch_source_t`](/documentation/Dispatch/dispatch_source_t). The base dispatch object interfaces allow you to manage memory, pause and resume execution, define object context, log task data, and more. By default, dispatch objects are declared as Objective-C types when you build them with an Objective-C compiler. This behavior lets you adopt ARC and enable memory leak checks by the static analyzer. It also lets you add your objects to Cocoa collections. ## Topics ### Activating, Suspending, and Resuming the Object [`func activate()`](/documentation/Dispatch/DispatchObject/activate()) Activates the dispatch object. [`func suspend()`](/documentation/Dispatch/DispatchObject/suspend()) Suspends the invocation of block objects on a dispatch object. [`func resume()`](/documentation/Dispatch/DispatchObject/resume()) Resumes the invocation of block objects on a dispatch object. [`typealias dispatch_object_t`](/documentation/Dispatch/dispatch_object_t) A dispatch object. ### Changing the Assigned Target Queue [`func setTarget(queue: dispatch_queue_t?)`](/documentation/Dispatch/DispatchObject/setTarget(queue:)) Specifies the dispatch queue on which to perform work associated with the current object. ### Updating Contextual Data [`extern void *dispatch_get_context(dispatch_object_t object);`](/documentation/Dispatch/dispatch_get_context) Returns the application-defined context of an object. [`extern void dispatch_set_context(dispatch_object_t object, void *context);`](/documentation/Dispatch/dispatch_set_context) Associates an application-defined context with the object. ### Managing Memory [`extern void dispatch_retain(dispatch_object_t object);`](/documentation/Dispatch/dispatch_retain) Increments the reference count (the retain count) of a dispatch object. [`extern void dispatch_release(dispatch_object_t object);`](/documentation/Dispatch/dispatch_release) Decrements the reference count (the retain count) of a dispatch object. [`extern void dispatch_set_finalizer_f(dispatch_object_t object, dispatch_function_t finalizer);`](/documentation/Dispatch/dispatch_set_finalizer_f) Sets the finalizer function for a dispatch object. ### Introspecting a Dispatch Object [`extern void dispatch_introspection_hook_queue_create(dispatch_queue_t queue);`](/documentation/Dispatch/dispatch_introspection_hook_queue_create) [`extern void dispatch_introspection_hook_queue_destroy(dispatch_queue_t queue);`](/documentation/Dispatch/dispatch_introspection_hook_queue_destroy) [`extern void dispatch_introspection_hook_queue_item_enqueue(dispatch_queue_t queue, dispatch_object_t item);`](/documentation/Dispatch/dispatch_introspection_hook_queue_item_enqueue) [`extern void dispatch_introspection_hook_queue_item_dequeue(dispatch_queue_t queue, dispatch_object_t item);`](/documentation/Dispatch/dispatch_introspection_hook_queue_item_dequeue) [`extern void dispatch_introspection_hook_queue_callout_begin(dispatch_queue_t queue, void *context, dispatch_function_t function);`](/documentation/Dispatch/dispatch_introspection_hook_queue_callout_begin) [`extern void dispatch_introspection_hook_queue_callout_end(dispatch_queue_t queue, void *context, dispatch_function_t function);`](/documentation/Dispatch/dispatch_introspection_hook_queue_callout_end) [`extern void dispatch_introspection_hook_queue_item_complete(dispatch_object_t item);`](/documentation/Dispatch/dispatch_introspection_hook_queue_item_complete) --- 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)