1/*
2 * Block_private.h
3 *
4 * Copyright 2008-2009 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#include <stdbool.h>
37
38#if defined(__cplusplus)
39extern "C" {
40#endif
41
42
43enum {
44    BLOCK_REFCOUNT_MASK =     (0xffff),
45    BLOCK_NEEDS_FREE =        (1 << 24),
46    BLOCK_HAS_COPY_DISPOSE =  (1 << 25),
47    BLOCK_HAS_CTOR =          (1 << 26), /* Helpers have C++ code. */
48    BLOCK_IS_GC =             (1 << 27),
49    BLOCK_IS_GLOBAL =         (1 << 28),
50    BLOCK_HAS_DESCRIPTOR =    (1 << 29)
51};
52
53
54/* Revised new layout. */
55struct Block_descriptor {
56    unsigned long int reserved;
57    unsigned long int size;
58    void (*copy)(void *dst, void *src);
59    void (*dispose)(void *);
60};
61
62
63struct Block_layout {
64    void *isa;
65    int flags;
66    int reserved;
67    void (*invoke)(void *, ...);
68    struct Block_descriptor *descriptor;
69    /* Imported variables. */
70};
71
72
73struct Block_byref {
74    void *isa;
75    struct Block_byref *forwarding;
76    int flags; /* refcount; */
77    int size;
78    void (*byref_keep)(struct Block_byref *dst, struct Block_byref *src);
79    void (*byref_destroy)(struct Block_byref *);
80    /* long shared[0]; */
81};
82
83
84struct Block_byref_header {
85    void *isa;
86    struct Block_byref *forwarding;
87    int flags;
88    int size;
89};
90
91
92/* Runtime support functions used by compiler when generating copy/dispose helpers. */
93
94enum {
95    /* See function implementation for a more complete description of these fields and combinations */
96    BLOCK_FIELD_IS_OBJECT   =  3,  /* id, NSObject, __attribute__((NSObject)), block, ... */
97    BLOCK_FIELD_IS_BLOCK    =  7,  /* a block variable */
98    BLOCK_FIELD_IS_BYREF    =  8,  /* the on stack structure holding the __block variable */
99    BLOCK_FIELD_IS_WEAK     = 16,  /* declared __weak, only used in byref copy helpers */
100    BLOCK_BYREF_CALLER      = 128  /* called from __block (byref) copy/dispose support routines. */
101};
102
103/* Runtime entry point called by compiler when assigning objects inside copy helper routines */
104BLOCK_EXPORT void _Block_object_assign(void *destAddr, const void *object, const int flags);
105    /* BLOCK_FIELD_IS_BYREF is only used from within block copy helpers */
106
107
108/* runtime entry point called by the compiler when disposing of objects inside dispose helper routine */
109BLOCK_EXPORT void _Block_object_dispose(const void *object, const int flags);
110
111
112
113/* Other support functions */
114
115/* Runtime entry to get total size of a closure */
116BLOCK_EXPORT unsigned long int Block_size(void *block_basic);
117
118
119
120/* the raw data space for runtime classes for blocks */
121/* class+meta used for stack, malloc, and collectable based blocks */
122BLOCK_EXPORT void * _NSConcreteStackBlock[32];
123BLOCK_EXPORT void * _NSConcreteMallocBlock[32];
124BLOCK_EXPORT void * _NSConcreteAutoBlock[32];
125BLOCK_EXPORT void * _NSConcreteFinalizingBlock[32];
126BLOCK_EXPORT void * _NSConcreteGlobalBlock[32];
127BLOCK_EXPORT void * _NSConcreteWeakBlockVariable[32];
128
129
130/* the intercept routines that must be used under GC */
131BLOCK_EXPORT void _Block_use_GC( void *(*alloc)(const unsigned long, const bool isOne, const bool isObject),
132                                  void (*setHasRefcount)(const void *, const bool),
133                                  void (*gc_assign_strong)(void *, void **),
134                                  void (*gc_assign_weak)(const void *, void *),
135                                  void (*gc_memmove)(void *, void *, unsigned long));
136
137/* earlier version, now simply transitional */
138BLOCK_EXPORT void _Block_use_GC5( 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
143BLOCK_EXPORT void _Block_use_RR( void (*retain)(const void *),
144                                 void (*release)(const void *));
145
146/* make a collectable GC heap based Block.  Not useful under non-GC. */
147BLOCK_EXPORT void *_Block_copy_collectable(const void *aBlock);
148
149/* thread-unsafe diagnostic */
150BLOCK_EXPORT const char *_Block_dump(const void *block);
151
152
153/* Obsolete */
154
155/* first layout */
156struct Block_basic {
157    void *isa;
158    int Block_flags;  /* int32_t */
159    int Block_size;  /* XXX should be packed into Block_flags */
160    void (*Block_invoke)(void *);
161    void (*Block_copy)(void *dst, void *src);  /* iff BLOCK_HAS_COPY_DISPOSE */
162    void (*Block_dispose)(void *);             /* iff BLOCK_HAS_COPY_DISPOSE */
163    /* long params[0];  // where const imports, __block storage references, etc. get laid down */
164};
165
166
167#if defined(__cplusplus)
168}
169#endif
170
171
172#endif /* _BLOCK_PRIVATE_H_ */
173