1/*
2 * Block_private.h
3 *
4 * Copyright 2008-2010 Apple, Inc. Permission is hereby granted, free of charge,
5 * to any person obtaining a copy of this software and associated documentation
6 * files (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to permit
9 * persons to whom the Software is furnished to do so, subject to the following
10 * conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 *
23 */
24
25#ifndef _BLOCK_PRIVATE_H_
26#define _BLOCK_PRIVATE_H_
27
28#if !defined(BLOCK_EXPORT)
29#   if defined(__cplusplus)
30#       define BLOCK_EXPORT extern "C"
31#   else
32#       define BLOCK_EXPORT extern
33#   endif
34#endif
35
36#ifndef _MSC_VER
37#include <stdbool.h>
38#else
39/* MSVC doesn't have <stdbool.h>. Compensate. */
40typedef char bool;
41#define true (bool)1
42#define false (bool)0
43#endif
44
45#if defined(__cplusplus)
46extern "C" {
47#endif
48
49
50enum {
51    BLOCK_REFCOUNT_MASK =     (0xffff),
52    BLOCK_NEEDS_FREE =        (1 << 24),
53    BLOCK_HAS_COPY_DISPOSE =  (1 << 25),
54    BLOCK_HAS_CTOR =          (1 << 26), /* Helpers have C++ code. */
55    BLOCK_IS_GC =             (1 << 27),
56    BLOCK_IS_GLOBAL =         (1 << 28),
57    BLOCK_HAS_DESCRIPTOR =    (1 << 29)
58};
59
60
61/* Revised new layout. */
62struct Block_descriptor {
63    unsigned long int reserved;
64    unsigned long int size;
65    void (*copy)(void *dst, void *src);
66    void (*dispose)(void *);
67};
68
69
70struct Block_layout {
71    void *isa;
72    int flags;
73    int reserved;
74    void (*invoke)(void *, ...);
75    struct Block_descriptor *descriptor;
76    /* Imported variables. */
77};
78
79
80struct Block_byref {
81    void *isa;
82    struct Block_byref *forwarding;
83    int flags; /* refcount; */
84    int size;
85    void (*byref_keep)(struct Block_byref *dst, struct Block_byref *src);
86    void (*byref_destroy)(struct Block_byref *);
87    /* long shared[0]; */
88};
89
90
91struct Block_byref_header {
92    void *isa;
93    struct Block_byref *forwarding;
94    int flags;
95    int size;
96};
97
98
99/* Runtime support functions used by compiler when generating copy/dispose helpers. */
100
101enum {
102    /* See function implementation for a more complete description of these fields and combinations */
103    BLOCK_FIELD_IS_OBJECT   =  3,  /* id, NSObject, __attribute__((NSObject)), block, ... */
104    BLOCK_FIELD_IS_BLOCK    =  7,  /* a block variable */
105    BLOCK_FIELD_IS_BYREF    =  8,  /* the on stack structure holding the __block variable */
106    BLOCK_FIELD_IS_WEAK     = 16,  /* declared __weak, only used in byref copy helpers */
107    BLOCK_BYREF_CALLER      = 128  /* called from __block (byref) copy/dispose support routines. */
108};
109
110/* Runtime entry point called by compiler when assigning objects inside copy helper routines */
111BLOCK_EXPORT void _Block_object_assign(void *destAddr, const void *object, const int flags);
112    /* BLOCK_FIELD_IS_BYREF is only used from within block copy helpers */
113
114
115/* runtime entry point called by the compiler when disposing of objects inside dispose helper routine */
116BLOCK_EXPORT void _Block_object_dispose(const void *object, const int flags);
117
118
119
120/* Other support functions */
121
122/* Runtime entry to get total size of a closure */
123BLOCK_EXPORT unsigned long int Block_size(void *block_basic);
124
125
126
127/* the raw data space for runtime classes for blocks */
128/* class+meta used for stack, malloc, and collectable based blocks */
129BLOCK_EXPORT void * _NSConcreteStackBlock[32];
130BLOCK_EXPORT void * _NSConcreteMallocBlock[32];
131BLOCK_EXPORT void * _NSConcreteAutoBlock[32];
132BLOCK_EXPORT void * _NSConcreteFinalizingBlock[32];
133BLOCK_EXPORT void * _NSConcreteGlobalBlock[32];
134BLOCK_EXPORT void * _NSConcreteWeakBlockVariable[32];
135
136
137/* the intercept routines that must be used under GC */
138BLOCK_EXPORT void _Block_use_GC( void *(*alloc)(const unsigned long, const bool isOne, const bool isObject),
139                                  void (*setHasRefcount)(const void *, const bool),
140                                  void (*gc_assign_strong)(void *, void **),
141                                  void (*gc_assign_weak)(const void *, void *),
142                                  void (*gc_memmove)(void *, void *, unsigned long));
143
144/* earlier version, now simply transitional */
145BLOCK_EXPORT void _Block_use_GC5( void *(*alloc)(const unsigned long, const bool isOne, const bool isObject),
146                                  void (*setHasRefcount)(const void *, const bool),
147                                  void (*gc_assign_strong)(void *, void **),
148                                  void (*gc_assign_weak)(const void *, void *));
149
150BLOCK_EXPORT void _Block_use_RR( void (*retain)(const void *),
151                                 void (*release)(const void *));
152
153/* make a collectable GC heap based Block.  Not useful under non-GC. */
154BLOCK_EXPORT void *_Block_copy_collectable(const void *aBlock);
155
156/* thread-unsafe diagnostic */
157BLOCK_EXPORT const char *_Block_dump(const void *block);
158
159
160/* Obsolete */
161
162/* first layout */
163struct Block_basic {
164    void *isa;
165    int Block_flags;  /* int32_t */
166    int Block_size;  /* XXX should be packed into Block_flags */
167    void (*Block_invoke)(void *);
168    void (*Block_copy)(void *dst, void *src);  /* iff BLOCK_HAS_COPY_DISPOSE */
169    void (*Block_dispose)(void *);             /* iff BLOCK_HAS_COPY_DISPOSE */
170    /* long params[0];  // where const imports, __block storage references, etc. get laid down */
171};
172
173
174#if defined(__cplusplus)
175}
176#endif
177
178
179#endif /* _BLOCK_PRIVATE_H_ */
180