src/object_internal.h

   1 /*
   2  * Copyright (c) 2008-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_OBJECT_INTERNAL__
  28 #define __DISPATCH_OBJECT_INTERNAL__
  29
  30 #if OS_OBJECT_USE_OBJC
  31 #define DISPATCH_DECL_INTERNAL_SUBCLASS(name, super) \
  32                 OS_OBJECT_DECL_SUBCLASS(name, super)
  33 #define DISPATCH_DECL_INTERNAL(name) \
  34                 DISPATCH_DECL_INTERNAL_SUBCLASS(name, dispatch_object)
  35 #define DISPATCH_DECL_SUBCLASS_INTERFACE(name, super) \
  36                 _OS_OBJECT_DECL_SUBCLASS_INTERFACE(name, super)
  37 #else
  38 #define DISPATCH_DECL_INTERNAL_SUBCLASS(name, super) DISPATCH_DECL(name)
  39 #define DISPATCH_DECL_INTERNAL(name) DISPATCH_DECL(name)
  40 #define DISPATCH_DECL_SUBCLASS_INTERFACE(name, super)
  41 #endif // OS_OBJECT_USE_OBJC
  42
  43 #if USE_OBJC
  44 #define DISPATCH_CLASS(name) OS_OBJECT_CLASS(dispatch_##name)
  45 // ObjC classes and dispatch vtables are co-located via linker order and alias
  46 // files rdar://10640168
  47 #define DISPATCH_VTABLE_SUBCLASS_INSTANCE(name, super, ...) \
  48                 __attribute__((section("__DATA,__objc_data"), used)) \
  49                 static const struct { \
  50                         DISPATCH_VTABLE_HEADER(super); \
  51                 } DISPATCH_CONCAT(_,DISPATCH_CLASS(name##_vtable)) = { \
  52                         __VA_ARGS__ \
  53                 }
  54 #else
  55 #define DISPATCH_VTABLE_SUBCLASS_INSTANCE(name, super, ...) \
  56                 DISPATCH_CONST_STRUCT_INSTANCE(dispatch_##super##_vtable_s, \
  57                         _dispatch_##name##_vtable, \
  58                         ._os_obj_xref_dispose = _dispatch_xref_dispose, \
  59                         ._os_obj_dispose = _dispatch_dispose, \
  60                         __VA_ARGS__)
  61 #endif // USE_OBJC
  62
  63 #define DISPATCH_SUBCLASS_DECL(name, super) \
  64                 DISPATCH_DECL_SUBCLASS_INTERFACE(dispatch_##name, super) \
  65                 struct dispatch_##name##_s; \
  66                 extern DISPATCH_CONST_STRUCT_DECL(dispatch_##name##_vtable_s, \
  67                         _dispatch_##name##_vtable, \
  68                 { \
  69                         _OS_OBJECT_CLASS_HEADER(); \
  70                         DISPATCH_VTABLE_HEADER(name); \
  71                 })
  72 #define DISPATCH_CLASS_DECL(name) DISPATCH_SUBCLASS_DECL(name, dispatch_object)
  73 #define DISPATCH_INTERNAL_SUBCLASS_DECL(name, super) \
  74                 DISPATCH_DECL_INTERNAL_SUBCLASS(dispatch_##name, dispatch_##super); \
  75                 DISPATCH_DECL_SUBCLASS_INTERFACE(dispatch_##name, dispatch_##super) \
  76                 extern DISPATCH_CONST_STRUCT_DECL(dispatch_##super##_vtable_s, \
  77                 _dispatch_##name##_vtable)
  78 #define DISPATCH_VTABLE_INSTANCE(name, ...) \
  79                 DISPATCH_VTABLE_SUBCLASS_INSTANCE(name, name, __VA_ARGS__)
  80 #define DISPATCH_VTABLE(name) &_dispatch_##name##_vtable
  81
  82 #if !TARGET_OS_WIN32
  83 #define DISPATCH_VTABLE_HEADER(x) \
  84         unsigned long const do_type; \
  85         const char *const do_kind; \
  86         size_t (*const do_debug)(struct dispatch_##x##_s *, char *, size_t); \
  87         void (*const do_invoke)(struct dispatch_##x##_s *); \
  88         unsigned long (*const do_probe)(struct dispatch_##x##_s *); \
  89         void (*const do_dispose)(struct dispatch_##x##_s *);
  90 #else
  91 // Cannot be const on Win32 because we initialize at runtime.
  92 #define DISPATCH_VTABLE_HEADER(x) \
  93         unsigned long do_type; \
  94         const char *do_kind; \
  95         size_t (*do_debug)(struct dispatch_##x##_s *, char *, size_t); \
  96         void (*do_invoke)(struct dispatch_##x##_s *); \
  97         unsigned long (*do_probe)(struct dispatch_##x##_s *); \
  98         void (*do_dispose)(struct dispatch_##x##_s *);
  99 #endif
 100
 101 #define dx_type(x) (x)->do_vtable->do_type
 102 #define dx_metatype(x) ((x)->do_vtable->do_type & _DISPATCH_META_TYPE_MASK)
 103 #define dx_kind(x) (x)->do_vtable->do_kind
 104 #define dx_debug(x, y, z) (x)->do_vtable->do_debug((x), (y), (z))
 105 #define dx_dispose(x) (x)->do_vtable->do_dispose(x)
 106 #define dx_invoke(x) (x)->do_vtable->do_invoke(x)
 107 #define dx_probe(x) (x)->do_vtable->do_probe(x)
 108
 109 #define DISPATCH_STRUCT_HEADER(x) \
 110         _OS_OBJECT_HEADER( \
 111         const struct dispatch_##x##_vtable_s *do_vtable, \
 112         do_ref_cnt, \
 113         do_xref_cnt); \
 114         struct dispatch_##x##_s *volatile do_next; \
 115         struct dispatch_queue_s *do_targetq; \
 116         void *do_ctxt; \
 117         void *do_finalizer; \
 118         unsigned int volatile do_suspend_cnt;
 119
 120 #define DISPATCH_OBJECT_GLOBAL_REFCNT           _OS_OBJECT_GLOBAL_REFCNT
 121 // "word and bit" must be a power of two to be safely subtracted
 122 #define DISPATCH_OBJECT_SUSPEND_LOCK            1u
 123 #define DISPATCH_OBJECT_SUSPEND_INTERVAL        2u
 124 #define DISPATCH_OBJECT_SUSPENDED(x) \
 125                 ((x)->do_suspend_cnt >= DISPATCH_OBJECT_SUSPEND_INTERVAL)
 126 #ifdef __LP64__
 127 // the bottom nibble must not be zero, the rest of the bits should be random
 128 // we sign extend the 64-bit version so that a better instruction encoding is
 129 // generated on Intel
 130 #define DISPATCH_OBJECT_LISTLESS ((void *)0xffffffff89abcdef)
 131 #else
 132 #define DISPATCH_OBJECT_LISTLESS ((void *)0x89abcdef)
 133 #endif
 134
 135 enum {
 136         _DISPATCH_CONTINUATION_TYPE     =    0x00000, // meta-type for continuations
 137         _DISPATCH_QUEUE_TYPE                    =    0x10000, // meta-type for queues
 138         _DISPATCH_SOURCE_TYPE                   =    0x20000, // meta-type for sources
 139         _DISPATCH_SEMAPHORE_TYPE                =    0x30000, // meta-type for semaphores
 140         _DISPATCH_NODE_TYPE                     =    0x40000, // meta-type for data node
 141         _DISPATCH_IO_TYPE                               =    0x50000, // meta-type for io channels
 142         _DISPATCH_OPERATION_TYPE                =    0x60000, // meta-type for io operations
 143         _DISPATCH_DISK_TYPE                     =    0x70000, // meta-type for io disks
 144         _DISPATCH_META_TYPE_MASK                =  0xfff0000, // mask for object meta-types
 145         _DISPATCH_ATTR_TYPE                     = 0x10000000, // meta-type for attributes
 146
 147         DISPATCH_CONTINUATION_TYPE              = _DISPATCH_CONTINUATION_TYPE,
 148
 149         DISPATCH_DATA_TYPE                              = 1 | _DISPATCH_NODE_TYPE,
 150         DISPATCH_MACH_MSG_TYPE                          = 2 | _DISPATCH_NODE_TYPE,
 151
 152         DISPATCH_IO_TYPE                                = _DISPATCH_IO_TYPE,
 153         DISPATCH_OPERATION_TYPE                 = _DISPATCH_OPERATION_TYPE,
 154         DISPATCH_DISK_TYPE                              = _DISPATCH_DISK_TYPE,
 155
 156         DISPATCH_QUEUE_ATTR_TYPE                = _DISPATCH_QUEUE_TYPE |_DISPATCH_ATTR_TYPE,
 157
 158         DISPATCH_QUEUE_TYPE                     = 1 | _DISPATCH_QUEUE_TYPE,
 159         DISPATCH_QUEUE_ROOT_TYPE                = 2 | _DISPATCH_QUEUE_TYPE,
 160         DISPATCH_QUEUE_MGR_TYPE         = 3 | _DISPATCH_QUEUE_TYPE,
 161         DISPATCH_QUEUE_SPECIFIC_TYPE    = 4 | _DISPATCH_QUEUE_TYPE,
 162
 163         DISPATCH_SEMAPHORE_TYPE         = 1 | _DISPATCH_SEMAPHORE_TYPE,
 164         DISPATCH_GROUP_TYPE                     = 2 | _DISPATCH_SEMAPHORE_TYPE,
 165
 166         DISPATCH_SOURCE_KEVENT_TYPE     = 1 | _DISPATCH_SOURCE_TYPE,
 167         DISPATCH_MACH_CHANNEL_TYPE      = 2 | _DISPATCH_SOURCE_TYPE,
 168 };
 169
 170 DISPATCH_SUBCLASS_DECL(object, object);
 171 struct dispatch_object_s {
 172         DISPATCH_STRUCT_HEADER(object);
 173 };
 174
 175 size_t _dispatch_object_debug_attr(dispatch_object_t dou, char* buf,
 176                 size_t bufsiz);
 177 void *_dispatch_alloc(const void *vtable, size_t size);
 178 void _dispatch_xref_dispose(dispatch_object_t dou);
 179 void _dispatch_dispose(dispatch_object_t dou);
 180 #if DISPATCH_COCOA_COMPAT
 181 void *_dispatch_autorelease_pool_push(void);
 182 void _dispatch_autorelease_pool_pop(void *context);
 183 #endif
 184
 185 #if USE_OBJC
 186 #include <objc/runtime.h>
 187
 188 #define OS_OBJC_CLASS_SYMBOL(name) \
 189                 DISPATCH_CONCAT(OBJC_CLASS_$_,name)
 190 #define OS_OBJC_CLASS_DECL(name) \
 191                 extern void *OS_OBJC_CLASS_SYMBOL(name)
 192 #define OS_OBJC_CLASS(name) \
 193                 ((Class)&OS_OBJC_CLASS_SYMBOL(name))
 194 #define OS_OBJECT_OBJC_CLASS_DECL(name) \
 195                 OS_OBJC_CLASS_DECL(OS_OBJECT_CLASS(name))
 196 #define OS_OBJECT_OBJC_CLASS(name) \
 197                 OS_OBJC_CLASS(OS_OBJECT_CLASS(name))
 198 #define DISPATCH_OBJC_CLASS_DECL(name) \
 199                 OS_OBJC_CLASS_DECL(DISPATCH_CLASS(name))
 200 #define DISPATCH_OBJC_CLASS(name) \
 201                 OS_OBJC_CLASS(DISPATCH_CLASS(name))
 202
 203 OS_OBJECT_OBJC_CLASS_DECL(object);
 204 DISPATCH_OBJC_CLASS_DECL(object);
 205
 206 // ObjC toll-free bridging, keep in sync with libdispatch.order file
 207 #define DISPATCH_OBJECT_TFB(f, o, ...) \
 208         if (slowpath((uintptr_t)((o)._os_obj->os_obj_isa) & 1) || \
 209                         slowpath((Class)((o)._os_obj->os_obj_isa) < \
 210                                         DISPATCH_OBJC_CLASS(object)) || \
 211                         slowpath((Class)((o)._os_obj->os_obj_isa) >= \
 212                                         OS_OBJECT_OBJC_CLASS(object))) { \
 213                 return f((o), ##__VA_ARGS__); \
 214         }
 215
 216 id _dispatch_objc_alloc(Class cls, size_t size);
 217 void _dispatch_objc_retain(dispatch_object_t dou);
 218 void _dispatch_objc_release(dispatch_object_t dou);
 219 void _dispatch_objc_set_context(dispatch_object_t dou, void *context);
 220 void *_dispatch_objc_get_context(dispatch_object_t dou);
 221 void _dispatch_objc_set_finalizer_f(dispatch_object_t dou,
 222                 dispatch_function_t finalizer);
 223 void _dispatch_objc_set_target_queue(dispatch_object_t dou,
 224                 dispatch_queue_t queue);
 225 void _dispatch_objc_suspend(dispatch_object_t dou);
 226 void _dispatch_objc_resume(dispatch_object_t dou);
 227 size_t _dispatch_objc_debug(dispatch_object_t dou, char* buf, size_t bufsiz);
 228
 229 #if __OBJC2__
 230 @interface NSObject (DISPATCH_CONCAT(_,DISPATCH_CLASS(object)))
 231 - (void)_setContext:(void*)context;
 232 - (void*)_getContext;
 233 - (void)_setFinalizer:(dispatch_function_t)finalizer;
 234 - (void)_setTargetQueue:(dispatch_queue_t)queue;
 235 - (void)_suspend;
 236 - (void)_resume;
 237 @end
 238 #endif // __OBJC2__
 239 #else // USE_OBJC
 240 #define DISPATCH_OBJECT_TFB(f, o, ...)
 241 #endif // USE_OBJC
 242
 243 #pragma mark -
 244 #pragma mark _os_object_s
 245
 246 typedef struct _os_object_class_s {
 247         _OS_OBJECT_CLASS_HEADER();
 248 } _os_object_class_s;
 249
 250 typedef struct _os_object_s {
 251         _OS_OBJECT_HEADER(
 252         const _os_object_class_s *os_obj_isa,
 253         os_obj_ref_cnt,
 254         os_obj_xref_cnt);
 255 } _os_object_s;
 256
 257 void _os_object_init(void);
 258 unsigned long _os_object_retain_count(_os_object_t obj);
 259 bool _os_object_retain_weak(_os_object_t obj);
 260 bool _os_object_allows_weak_reference(_os_object_t obj);
 261 void _os_object_dispose(_os_object_t obj);
 262 void _os_object_xref_dispose(_os_object_t obj);
 263
 264 #endif // __DISPATCH_OBJECT_INTERNAL__