object.h

Introduction

Use the links in the table of contents to the left to access the documentation.

Functions

_dispatch_object_validate

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_cancel(void *)

Cancel the specified object.

dispatch_cancel(void *)

Cancel the specified object.

dispatch_notify(void *, dispatch_object_t, dispatch_block_t)

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

dispatch_notify(void *, dispatch_object_t, dispatch_block_t)

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t(dispatch_object)

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t(dispatch_object_t)

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_testcancel(void *)

Test whether the specified object has been canceled

dispatch_testcancel(void *)

Test whether the specified object has been canceled

dispatch_wait(void *, dispatch_time_t)

Wait synchronously for an object or until the specified timeout has elapsed.

dispatch_wait(void *, dispatch_time_t)

Wait synchronously for an object or until the specified timeout has elapsed.

operator dispatch_object_s

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

operator dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

OS_OBJECT_DECL_CLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

_dispatch_object_validate

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 void _dispatch_object_validate(
    dispatch_object_t object) 

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

dispatch_cancel(void *)

Cancel the specified object.

  DISPATCH_UNAVAILABLE  void dispatch_cancel(
    void *object);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_cancel or dispatch_source_cancel, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_cancel(void *)

Cancel the specified object.

  DISPATCH_UNAVAILABLE  void dispatch_cancel(
    void *object);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_cancel or dispatch_source_cancel, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_notify(void *, dispatch_object_t, dispatch_block_t)

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

  DISPATCH_UNAVAILABLE  void dispatch_notify(
    void *object,
    dispatch_object_t queue, 
    dispatch_block_t notification_block);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_notify or dispatch_group_notify, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_notify(void *, dispatch_object_t, dispatch_block_t)

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

  DISPATCH_UNAVAILABLE  void dispatch_notify(
    void *object,
    dispatch_object_t queue, 
    dispatch_block_t notification_block);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_notify or dispatch_group_notify, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 /*
 * Dispatch objects are NOT C++ objects. Nevertheless, we can at least keep C++
 * aware of type compatibility.
    */
typedef struct dispatch_object_s { 
    private: dispatch_object_s(); 
    ~dispatch_object_s(); 
    dispatch_object_s(
        const dispatch_object_s &); 
    void operator=(
        const dispatch_object_s &); 
} *dispatch_object_t;  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

dispatch_object_t(dispatch_object)

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 /*
 * By default, dispatch objects are declared as Objective-C types when building
 * with an Objective-C compiler. This allows them to participate in ARC, in RR
 * management by the Blocks runtime and in leaks checking by the static
 * analyzer, and enables them to be added to Cocoa collections.
 * See <os/object.h> for details.
    */
OS_OBJECT_DECL_CLASS(
    dispatch_object);  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

dispatch_object_t(dispatch_object_t)

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 void _dispatch_object_validate(
    dispatch_object_t object) 

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

dispatch_testcancel(void *)

Test whether the specified object has been canceled

  DISPATCH_UNAVAILABLE   intptr_t dispatch_testcancel(
    void *object);  

Parameters

Return Value

Non-zero if canceled and zero if not canceled.

Discussion

Type-generic macro that maps to dispatch_block_testcancel or dispatch_source_testcancel, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_testcancel(void *)

Test whether the specified object has been canceled

  DISPATCH_UNAVAILABLE   intptr_t dispatch_testcancel(
    void *object);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_testcancel or dispatch_source_testcancel, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_wait(void *, dispatch_time_t)

Wait synchronously for an object or until the specified timeout has elapsed.

  DISPATCH_UNAVAILABLE DISPATCH_NONNULL1  intptr_t dispatch_wait(
    void *object,
    dispatch_time_t timeout);  

Parameters

Return Value

Returns zero on success or non-zero on error (i.e. timed out).

Discussion

Type-generic macro that maps to dispatch_block_wait, dispatch_group_wait or dispatch_semaphore_wait, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

dispatch_wait(void *, dispatch_time_t)

Wait synchronously for an object or until the specified timeout has elapsed.

  DISPATCH_UNAVAILABLE DISPATCH_NONNULL1  intptr_t dispatch_wait(
    void *object,
    dispatch_time_t timeout);  

Parameters

Discussion

Type-generic macro that maps to dispatch_block_wait, dispatch_group_wait or dispatch_semaphore_wait, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

operator dispatch_object_s

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 /*
 * Dispatch objects are NOT C++ objects. Nevertheless, we can at least keep C++
 * aware of type compatibility.
    */
typedef struct dispatch_object_s { 
    private: dispatch_object_s(); 
    ~dispatch_object_s(); 
    dispatch_object_s(
        const dispatch_object_s &); 
    void operator=(
        const dispatch_object_s &); 
} *dispatch_object_t;  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

operator dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 /*
 * Dispatch objects are NOT C++ objects. Nevertheless, we can at least keep C++
 * aware of type compatibility.
    */
typedef struct dispatch_object_s { 
    private: dispatch_object_s(); 
    ~dispatch_object_s(); 
    dispatch_object_s(
        const dispatch_object_s &); 
    void operator=(
        const dispatch_object_s &); 
} *dispatch_object_t;  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

OS_OBJECT_DECL_CLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 /*
 * By default, dispatch objects are declared as Objective-C types when building
 * with an Objective-C compiler. This allows them to participate in ARC, in RR
 * management by the Blocks runtime and in leaks checking by the static
 * analyzer, and enables them to be added to Cocoa collections.
 * See <os/object.h> for details.
    */
OS_OBJECT_DECL_CLASS(
    dispatch_object);  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

Typedefs

dispatch_block_t

The type of blocks submitted to dispatch queues, which take no arguments and have no return value.

dispatch_object_t

Programmatically log debug information about a dispatch object.

DISPATCH_TRANSPARENT_UNION

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_block_t

The type of blocks submitted to dispatch queues, which take no arguments and have no return value.

  typedef void (^dispatch_block_t)(
    void);  

Discussion

When not building with Objective-C ARC, a block object allocated on or copied to the heap must be released with a -[release] message or the Block_release() function.

The declaration of a block literal allocates storage on the stack. Therefore, this is an invalid construct: dispatch_block_t block; if (x) { block = ^{ printf("true\n"); }; } else { block = ^{ printf("false\n"); }; } block(); // unsafe!!!

What is happening behind the scenes: if (x) { struct Block __tmp_1 = ...; // setup details block = &__tmp_1; } else { struct Block __tmp_2 = ...; // setup details block = &__tmp_2; }

As the example demonstrates, the address of a stack variable is escaping the scope in which it is allocated. That is a classic C bug.

Instead, the block literal must be copied to the heap with the Block_copy() function or by sending it a -[copy] message.

See Also

dispatch_object_t

Programmatically log debug information about a dispatch object.

#if ( OS_OBJECT_USE_OBJC) 
 /*
 * By default, dispatch objects are declared as Objective-C types when building
 * with an Objective-C compiler. This allows them to participate in ARC, in RR
 * management by the Blocks runtime and in leaks checking by the static
 * analyzer, and enables them to be added to Cocoa collections.
 * See <os/object.h> for details.
    */
OS_OBJECT_DECL_CLASS(
    dispatch_object);  
#if ( OS_OBJECT_SWIFT3) 
 #define DISPATCH_DECL(name) OS_OBJECT_DECL_SUBCLASS_SWIFT(name, dispatch_object) 
#define DISPATCH_DECL_SUBCLASS(name, base) OS_OBJECT_DECL_SUBCLASS_SWIFT(name, base) 
#else 
// OS_OBJECT_SWIFT3 
#define DISPATCH_DECL(name) OS_OBJECT_DECL_SUBCLASS(name, dispatch_object) 
#define DISPATCH_DECL_SUBCLASS(name, base) OS_OBJECT_DECL_SUBCLASS(name, base) 
 void _dispatch_object_validate(
    dispatch_object_t object) 
#endif 
// OS_OBJECT_SWIFT3 
 #define DISPATCH_GLOBAL_OBJECT(type, object)  
#define DISPATCH_RETURNS_RETAINED OS_OBJECT_RETURNS_RETAINED 
#if ( defined(__cplusplus) && !defined(__DISPATCH_BUILDING_DISPATCH__)) 
 /*
 * Dispatch objects are NOT C++ objects. Nevertheless, we can at least keep C++
 * aware of type compatibility.
    */
typedef struct dispatch_object_s { 
    private: dispatch_object_s(); 
    ~dispatch_object_s(); 
    dispatch_object_s(
        const dispatch_object_s &); 
    void operator=(
        const dispatch_object_s &); 
} *dispatch_object_t;  
#define DISPATCH_DECL(name) \ 
    typedef struct name##_s : public dispatch_object_s {} *name##_t 
#define DISPATCH_DECL_SUBCLASS(name, base) \ 
    typedef struct name##_s : public base##_s {} *name##_t 
#define DISPATCH_GLOBAL_OBJECT(type, object)  
#define DISPATCH_RETURNS_RETAINED 
#else 
/* Plain C */
#if (ndef __DISPATCH_BUILDING_DISPATCH__) 
 typedef union { 
    struct _os_object_s *_os_obj; 
    struct dispatch_object_s *_do; 
    struct dispatch_queue_s *_dq; 
    struct dispatch_queue_attr_s *_dqa; 
    struct dispatch_group_s *_dg; 
    struct dispatch_source_s *_ds; 
    struct dispatch_mach_s *_dm; 
    struct dispatch_mach_msg_s *_dmsg; 
    struct dispatch_semaphore_s *_dsema; 
    struct dispatch_data_s *_ddata; 
    struct dispatch_io_s *_dchannel; 
} dispatch_object_t DISPATCH_TRANSPARENT_UNION;  
#endif 
// !__DISPATCH_BUILDING_DISPATCH__ 
#define DISPATCH_DECL(name) typedef struct name##_s *name##_t 
#define DISPATCH_DECL_SUBCLASS(name, base) typedef base##_t name##_t 
#define DISPATCH_GLOBAL_OBJECT(type, object)  
#define DISPATCH_RETURNS_RETAINED 
#endif  
 #if ( OS_OBJECT_SWIFT3 && OS_OBJECT_USE_OBJC) 
 #define DISPATCH_SOURCE_TYPE_DECL(name) \ 
    struct dispatch_source_type_s \ 
    _dispatch_source_type_##name; \ 
    OS_OBJECT_DECL_PROTOCOL(dispatch_source_##name, <OS_dispatch_source>); \ 
    OS_OBJECT_CLASS_IMPLEMENTS_PROTOCOL( \ 
    dispatch_source, dispatch_source_##name) 
#define DISPATCH_SOURCE_DECL(name) \ 
    typedef struct name_s *name_t; \ 
    OS_OBJECT_DECL_PROTOCOL(name, <NSObject>); \ 
    OS_OBJECT_CLASS_IMPLEMENTS_PROTOCOL(name, name) 
#if (ndef typedef struct name_s *name_t OS_OBJECT_DECL_SWIFT(name) 
#endif 
// DISPATCH_DATA_DECL 
#else 
 #define DISPATCH_SOURCE_DECL(name) \ 
    typedef struct name_s *name_t; 
#define DISPATCH_DATA_DECL(name) typedef struct name_s *name_t 
#define DISPATCH_SOURCE_TYPE_DECL(name) \ 
    const struct dispatch_source_type_s \ 
    _dispatch_source_type_##name 
#endif  
 #if (defined( 1)) 
  typedef void (^dispatch_block_t)(
    void);  
#endif 
// __BLOCKS__ 
    (
    macos(
        10.6),
    ios(
        4.0))   void dispatch_retain(
    dispatch_object_t object);  
#if ( OS_OBJECT_USE_OBJC_RETAIN_RELEASE) 
#define dispatch_retain(object) \ 
    __extension__({ dispatch_object_t _o = (object); \ 
    _dispatch_object_validate(_o); (void)[_o retain]; }) 
#endif  
  (
    macos(
        10.6),
    ios(
        4.0))   void dispatch_release(
    dispatch_object_t object);  
#if ( OS_OBJECT_USE_OBJC_RETAIN_RELEASE) 
#define dispatch_release(object) \ 
    __extension__({ dispatch_object_t _o = (object); \ 
    _dispatch_object_validate(_o); [_o release]; }) 
#endif  
  (
    macos(
        10.6),
    ios(
        4.0))   void *_Nullable dispatch_get_context(
    dispatch_object_t object);  
 (
    macos(
        10.6),
    ios(
        4.0))  void dispatch_set_context(
    dispatch_object_t object,
    void *_Nullable context);  
 (
    macos(
        10.6),
    ios(
        4.0))  void dispatch_set_finalizer_f(
    dispatch_object_t object, 
    dispatch_function_t _Nullable finalizer);  
 (
    macos(
        10.12),
    ios(
        10.0),
    tvos(
        10.0),
    watchos(
        3.0))  void dispatch_activate(
    dispatch_object_t object);  
 (
    macos(
        10.6),
    ios(
        4.0))  void dispatch_suspend(
    dispatch_object_t object);  
 (
    macos(
        10.6),
    ios(
        4.0))  void dispatch_resume(
    dispatch_object_t object);  
#if (defined( 1)) 
  DISPATCH_UNAVAILABLE DISPATCH_NONNULL1  intptr_t dispatch_wait(
    void *object,
    dispatch_time_t timeout);  
#if ( __has_extension(c_generic_selections)) 
 #define dispatch_wait(object, timeout) \ 
    _Generic((object), \ 
    dispatch_block_t:dispatch_block_wait, \ 
    dispatch_group_t:dispatch_group_wait, \ 
    dispatch_semaphore_t:dispatch_semaphore_wait \ 
    )((object),(timeout)) 
#endif  
  DISPATCH_UNAVAILABLE  void dispatch_notify(
    void *object,
    dispatch_object_t queue, 
    dispatch_block_t notification_block);  
#if ( __has_extension(c_generic_selections)) 
 #define dispatch_notify(object, queue, notification_block) \ 
    _Generic((object), \ 
    dispatch_block_t:dispatch_block_notify, \ 
    dispatch_group_t:dispatch_group_notify \ 
    )((object),(queue), (notification_block)) 
#endif  
  DISPATCH_UNAVAILABLE  void dispatch_cancel(
    void *object);  
#if ( __has_extension(c_generic_selections)) 
 #define dispatch_cancel(object) \ 
    _Generic((object), \ 
    dispatch_block_t:dispatch_block_cancel, \ 
    dispatch_source_t:dispatch_source_cancel \ 
    )((object)) 
#endif  
  DISPATCH_UNAVAILABLE   intptr_t dispatch_testcancel(
    void *object);  
#if ( __has_extension(c_generic_selections)) 
 #define dispatch_testcancel(object) \ 
    _Generic((object), \ 
    dispatch_block_t:dispatch_block_testcancel, \ 
    dispatch_source_t:dispatch_source_testcancel \ 
    )((object)) 
#endif  
#endif 
// __BLOCKS__ 
  (
    "unsupported interface",
    macos(
        10.6,
        10.9),
    ios(
        4.0,
        6.0)) DISPATCH_NONNULL2 DISPATCH_COLD __attribute__((__format__(printf,
        2,3))) void dispatch_debug(
    dispatch_object_t object,
    const char *message,
    ...);  
(
    "unsupported interface",
    macos(
        10.6,
        10.9),
    ios(
        4.0,
        6.0)) DISPATCH_NONNULL2 DISPATCH_COLD __attribute__((__format__(printf,
        2,0))) void dispatch_debugv(
    dispatch_object_t object,
    const char *message,
    va_list ap);  
  DISPATCH_ASSUME_NONNULL_END   #endif 
/* __DISPATCH_OBJECT__ */

Parameters

Return Value

Non-zero if canceled and zero if not canceled.

Discussion

Programmatically log debug information about a dispatch object. By default, the log output is sent to syslog at notice level. In the debug version of the library, the log output is sent to a file in /var/tmp. The log output destination can be configured via the LIBDISPATCH_LOG environment variable, valid values are: YES, NO, syslog, stderr, file.

This function is deprecated and will be removed in a future release. Objective-C callers may use -debugDescription instead.

See Also

Availability

DISPATCH_TRANSPARENT_UNION

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 typedef union { 
    struct _os_object_s *_os_obj; 
    struct dispatch_object_s *_do; 
    struct dispatch_queue_s *_dq; 
    struct dispatch_queue_attr_s *_dqa; 
    struct dispatch_group_s *_dg; 
    struct dispatch_source_s *_ds; 
    struct dispatch_mach_s *_dm; 
    struct dispatch_mach_msg_s *_dmsg; 
    struct dispatch_semaphore_s *_dsema; 
    struct dispatch_data_s *_ddata; 
    struct dispatch_io_s *_dchannel; 
} dispatch_object_t DISPATCH_TRANSPARENT_UNION;  

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

Macro Definitions

dispatch_cancel

Cancel the specified object.

DISPATCH_DATA_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL_SUBCLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL_SUBCLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL_SUBCLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_DECL_SUBCLASS

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_GLOBAL_OBJECT

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_GLOBAL_OBJECT

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_GLOBAL_OBJECT

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_notify

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_object_t

Increment the reference count of a dispatch object.

dispatch_object_t

Decrement the reference count of a dispatch object.

dispatch_object_t

Wait synchronously for an object or until the specified timeout has elapsed.

dispatch_object_t

Schedule a notification block to be submitted to a queue when the execution of a specified object has completed.

dispatch_object_t

Cancel the specified object.

dispatch_object_t

Test whether the specified object has been canceled

dispatch_release

Decrement the reference count of a dispatch object.

dispatch_retain

Increment the reference count of a dispatch object.

DISPATCH_RETURNS_RETAINED

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_RETURNS_RETAINED

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_RETURNS_RETAINED

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_SOURCE_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_SOURCE_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_SOURCE_TYPE_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

DISPATCH_SOURCE_TYPE_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

dispatch_testcancel

Test whether the specified object has been canceled

dispatch_wait

Wait synchronously for an object or until the specified timeout has elapsed.

dispatch_cancel

Cancel the specified object.

 #define dispatch_cancel(object) \ 
    _Generic((object), \ 
    dispatch_block_t:dispatch_block_cancel, \ 
    dispatch_source_t:dispatch_source_cancel \ 
    )((object)) 

Parameters

Discussion

Type-generic macro that maps to dispatch_block_cancel or dispatch_source_cancel, depending on the type of the first argument. See documentation for these functions for more details. This function is unavailable for any other object type.

See Also

DISPATCH_DATA_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

#define DISPATCH_DATA_DECL(name) typedef struct name_s *name_t 

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

 #define DISPATCH_DECL(name) OS_OBJECT_DECL_SUBCLASS_SWIFT(name, dispatch_object) 

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also

DISPATCH_DECL

Abstract base type for all dispatch objects. The details of the type definition are language-specific.

// OS_OBJECT_SWIFT3 
#define DISPATCH_DECL(name) OS_OBJECT_DECL_SUBCLASS(name, dispatch_object) 

Discussion

Dispatch objects are reference counted via calls to dispatch_retain() and dispatch_release().

See Also