src/object_internal.h

   1 /*
   2  * Copyright (c) 2008-2010 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                 const struct dispatch_##super##_vtable_s _dispatch_##name##_vtable = { \
  57                         ._os_obj_xref_dispose = _dispatch_xref_dispose, \
  58                         ._os_obj_dispose = _dispatch_dispose, \
  59                         __VA_ARGS__ \
  60                 }
  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 const struct dispatch_##name##_vtable_s { \
  67                         _OS_OBJECT_CLASS_HEADER(); \
  68                         DISPATCH_VTABLE_HEADER(name); \
  69                 } _dispatch_##name##_vtable
  70 #define DISPATCH_CLASS_DECL(name) DISPATCH_SUBCLASS_DECL(name, dispatch_object)
  71 #define DISPATCH_INTERNAL_SUBCLASS_DECL(name, super) \
  72                 DISPATCH_DECL_INTERNAL_SUBCLASS(dispatch_##name, dispatch_##super); \
  73                 DISPATCH_DECL_SUBCLASS_INTERFACE(dispatch_##name, dispatch_##super) \
  74                 extern const struct dispatch_##super##_vtable_s _dispatch_##name##_vtable
  75 #define DISPATCH_VTABLE_INSTANCE(name, ...) \
  76                 DISPATCH_VTABLE_SUBCLASS_INSTANCE(name, name, __VA_ARGS__)
  77 #define DISPATCH_VTABLE(name) &_dispatch_##name##_vtable
  78
  79 #define DISPATCH_VTABLE_HEADER(x) \
  80         unsigned long const do_type; \
  81         const char *const do_kind; \
  82         size_t (*const do_debug)(struct dispatch_##x##_s *, char *, size_t); \
  83         struct dispatch_queue_s *(*const do_invoke)(struct dispatch_##x##_s *); \
  84         bool (*const do_probe)(struct dispatch_##x##_s *); \
  85         void (*const do_dispose)(struct dispatch_##x##_s *)
  86
  87 #define dx_type(x) (x)->do_vtable->do_type
  88 #define dx_kind(x) (x)->do_vtable->do_kind
  89 #define dx_debug(x, y, z) (x)->do_vtable->do_debug((x), (y), (z))
  90 #define dx_dispose(x) (x)->do_vtable->do_dispose(x)
  91 #define dx_invoke(x) (x)->do_vtable->do_invoke(x)
  92 #define dx_probe(x) (x)->do_vtable->do_probe(x)
  93
  94 #define DISPATCH_STRUCT_HEADER(x) \
  95         _OS_OBJECT_HEADER( \
  96         const struct dispatch_##x##_vtable_s *do_vtable, \
  97         do_ref_cnt, \
  98         do_xref_cnt); \
  99         struct dispatch_##x##_s *volatile do_next; \
 100         struct dispatch_queue_s *do_targetq; \
 101         void *do_ctxt; \
 102         void *do_finalizer; \
 103         unsigned int do_suspend_cnt;
 104
 105 #define DISPATCH_OBJECT_GLOBAL_REFCNT           _OS_OBJECT_GLOBAL_REFCNT
 106 // "word and bit" must be a power of two to be safely subtracted
 107 #define DISPATCH_OBJECT_SUSPEND_LOCK            1u
 108 #define DISPATCH_OBJECT_SUSPEND_INTERVAL        2u
 109 #define DISPATCH_OBJECT_SUSPENDED(x) \
 110                 ((x)->do_suspend_cnt >= DISPATCH_OBJECT_SUSPEND_INTERVAL)
 111 #ifdef __LP64__
 112 // the bottom nibble must not be zero, the rest of the bits should be random
 113 // we sign extend the 64-bit version so that a better instruction encoding is
 114 // generated on Intel
 115 #define DISPATCH_OBJECT_LISTLESS ((void *)0xffffffff89abcdef)
 116 #else
 117 #define DISPATCH_OBJECT_LISTLESS ((void *)0x89abcdef)
 118 #endif
 119
 120 enum {
 121         _DISPATCH_CONTINUATION_TYPE     =    0x00000, // meta-type for continuations
 122         _DISPATCH_QUEUE_TYPE                    =    0x10000, // meta-type for queues
 123         _DISPATCH_SOURCE_TYPE                   =    0x20000, // meta-type for sources
 124         _DISPATCH_SEMAPHORE_TYPE                =    0x30000, // meta-type for semaphores
 125         _DISPATCH_NODE_TYPE                     =    0x40000, // meta-type for data node
 126         _DISPATCH_IO_TYPE                               =    0x50000, // meta-type for io channels
 127         _DISPATCH_OPERATION_TYPE                =    0x60000, // meta-type for io operations
 128         _DISPATCH_DISK_TYPE                     =    0x70000, // meta-type for io disks
 129         _DISPATCH_META_TYPE_MASK                =  0xfff0000, // mask for object meta-types
 130         _DISPATCH_ATTR_TYPE                     = 0x10000000, // meta-type for attributes
 131
 132         DISPATCH_CONTINUATION_TYPE              = _DISPATCH_CONTINUATION_TYPE,
 133
 134         DISPATCH_DATA_TYPE                              = _DISPATCH_NODE_TYPE,
 135
 136         DISPATCH_IO_TYPE                                = _DISPATCH_IO_TYPE,
 137         DISPATCH_OPERATION_TYPE                 = _DISPATCH_OPERATION_TYPE,
 138         DISPATCH_DISK_TYPE                              = _DISPATCH_DISK_TYPE,
 139
 140         DISPATCH_QUEUE_ATTR_TYPE                = _DISPATCH_QUEUE_TYPE |_DISPATCH_ATTR_TYPE,
 141
 142         DISPATCH_QUEUE_TYPE                     = 1 | _DISPATCH_QUEUE_TYPE,
 143         DISPATCH_QUEUE_GLOBAL_TYPE              = 2 | _DISPATCH_QUEUE_TYPE,
 144         DISPATCH_QUEUE_MGR_TYPE         = 3 | _DISPATCH_QUEUE_TYPE,
 145         DISPATCH_QUEUE_SPECIFIC_TYPE    = 4 | _DISPATCH_QUEUE_TYPE,
 146
 147         DISPATCH_SEMAPHORE_TYPE         = 1 | _DISPATCH_SEMAPHORE_TYPE,
 148         DISPATCH_GROUP_TYPE                     = 2 | _DISPATCH_SEMAPHORE_TYPE,
 149
 150         DISPATCH_SOURCE_KEVENT_TYPE     = 1 | _DISPATCH_SOURCE_TYPE,
 151 };
 152
 153 DISPATCH_SUBCLASS_DECL(object, object);
 154 struct dispatch_object_s {
 155         DISPATCH_STRUCT_HEADER(object);
 156 };
 157
 158 size_t _dispatch_object_debug_attr(dispatch_object_t dou, char* buf,
 159                 size_t bufsiz);
 160 void *_dispatch_alloc(const void *vtable, size_t size);
 161 void _dispatch_retain(dispatch_object_t dou);
 162 void _dispatch_release(dispatch_object_t dou);
 163 void _dispatch_xref_dispose(dispatch_object_t dou);
 164 void _dispatch_dispose(dispatch_object_t dou);
 165 #if DISPATCH_COCOA_COMPAT
 166 void *_dispatch_autorelease_pool_push(void);
 167 void _dispatch_autorelease_pool_pop(void *context);
 168 #endif
 169
 170 typedef struct _os_object_class_s {
 171         _OS_OBJECT_CLASS_HEADER();
 172 } _os_object_class_s;
 173
 174 typedef struct _os_object_s {
 175         _OS_OBJECT_HEADER(
 176         const _os_object_class_s *os_obj_isa,
 177         os_obj_ref_cnt,
 178         os_obj_xref_cnt);
 179 } _os_object_s;
 180
 181 void _os_object_init(void);
 182 unsigned long _os_object_retain_count(_os_object_t obj);
 183 bool _os_object_retain_weak(_os_object_t obj);
 184 bool _os_object_allows_weak_reference(_os_object_t obj);
 185 void _os_object_dispose(_os_object_t obj);
 186 void _os_object_xref_dispose(_os_object_t obj);
 187
 188 #endif