2 * Copyright (c) 2004-2007 Apple Inc. All rights reserved.
4 * @APPLE_LICENSE_HEADER_START@
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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18 * Please see the License for the specific language governing rights and
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27 #include <objc/objc.h>
28 #include <malloc/malloc.h>
32 #include <Availability.h>
33 #include <AvailabilityMacros.h>
34 #include <TargetConditionals.h>
37 #include <sys/types.h>
38 #include <libkern/OSAtomic.h>
40 # define WINVER 0x0501 // target Windows XP and later
41 # define _WIN32_WINNT 0x0501 // target Windows XP and later
42 # define WIN32_LEAN_AND_MEAN
43 // workaround: windef.h typedefs BOOL as int
50 /* GC is unsupported on some architectures. */
52 #if TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32
57 /* objc_collect() options */
60 OBJC_RATIO_COLLECTION
= (0 << 0), // run "ratio" generational collections, then a full
61 OBJC_GENERATIONAL_COLLECTION
= (1 << 0), // run fast incremental collection
62 OBJC_FULL_COLLECTION
= (2 << 0), // run full collection.
63 OBJC_EXHAUSTIVE_COLLECTION
= (3 << 0), // run full collections until memory available stops improving
65 OBJC_COLLECT_IF_NEEDED
= (1 << 3), // run collection only if needed (allocation threshold exceeded)
66 OBJC_WAIT_UNTIL_DONE
= (1 << 4), // wait (when possible) for collection to end before returning (when collector is running on dedicated thread)
69 /* objc_clear_stack() options */
71 OBJC_CLEAR_RESIDENT_STACK
= (1 << 0)
79 /* Collection utilities */
81 OBJC_EXPORT
void objc_collect(unsigned long options
)
82 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
);
83 OBJC_EXPORT BOOL
objc_collectingEnabled(void)
84 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
85 OBJC_EXPORT malloc_zone_t
*objc_collectableZone(void)
86 __OSX_AVAILABLE_STARTING(__MAC_10_7
, __IPHONE_NA
);
88 /* GC configuration */
90 /* Tells collector to wait until specified bytes have been allocated before trying to collect again. */
91 OBJC_EXPORT
void objc_setCollectionThreshold(size_t threshold
)
92 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
94 /* Tells collector to run a full collection for every ratio generational collections. */
95 OBJC_EXPORT
void objc_setCollectionRatio(size_t ratio
)
96 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
99 // GC-safe compare-and-swap
102 /* Atomic update, with write barrier. */
103 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapPtr(id predicate
, id replacement
, volatile id
*objectLocation
)
104 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
105 /* "Barrier" version also includes memory barrier. */
106 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapPtrBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
107 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
109 // atomic update of a global variable
110 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapGlobal(id predicate
, id replacement
, volatile id
*objectLocation
)
111 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
112 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapGlobalBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
113 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
114 // atomic update of an instance variable
115 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapInstanceVariable(id predicate
, id replacement
, volatile id
*objectLocation
)
116 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
117 OBJC_EXPORT BOOL
objc_atomicCompareAndSwapInstanceVariableBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
118 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
) OBJC_ARC_UNAVAILABLE
;
122 // Read and write barriers
125 OBJC_EXPORT id
objc_assign_strongCast(id val
, id
*dest
)
126 __OSX_AVAILABLE_STARTING(__MAC_10_4
, __IPHONE_NA
);
127 OBJC_EXPORT id
objc_assign_global(id val
, id
*dest
)
128 __OSX_AVAILABLE_STARTING(__MAC_10_4
, __IPHONE_NA
);
129 OBJC_EXPORT id
objc_assign_threadlocal(id val
, id
*dest
)
130 __OSX_AVAILABLE_STARTING(__MAC_10_7
, __IPHONE_NA
);
131 OBJC_EXPORT id
objc_assign_ivar(id value
, id dest
, ptrdiff_t offset
)
132 __OSX_AVAILABLE_STARTING(__MAC_10_4
, __IPHONE_NA
);
133 OBJC_EXPORT
void *objc_memmove_collectable(void *dst
, const void *src
, size_t size
)
134 __OSX_AVAILABLE_STARTING(__MAC_10_4
, __IPHONE_NA
);
136 OBJC_EXPORT id
objc_read_weak(id
*location
)
137 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
138 OBJC_EXPORT id
objc_assign_weak(id value
, id
*location
)
139 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
146 /* Register the calling thread with the garbage collector. */
147 OBJC_EXPORT
void objc_registerThreadWithCollector(void)
148 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
);
150 /* Unregisters the calling thread with the garbage collector.
151 Unregistration also happens automatically at thread exit. */
152 OBJC_EXPORT
void objc_unregisterThreadWithCollector(void)
153 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
);
155 /* To be called from code which must only execute on a registered thread. */
156 /* If the calling thread is unregistered then an error message is emitted and the thread is implicitly registered. */
157 OBJC_EXPORT
void objc_assertRegisteredThreadWithCollector(void)
158 __OSX_AVAILABLE_STARTING(__MAC_10_6
, __IPHONE_NA
);
160 /* Erases any stale references in unused parts of the stack. */
161 OBJC_EXPORT
void objc_clear_stack(unsigned long options
)
162 __OSX_AVAILABLE_STARTING(__MAC_10_5
, __IPHONE_NA
);
169 /* Returns true if object has been scheduled for finalization. Can be used to avoid operations that may lead to resurrection, which are fatal. */
170 OBJC_EXPORT BOOL
objc_is_finalized(void *ptr
)
171 __OSX_AVAILABLE_STARTING(__MAC_10_4
, __IPHONE_NA
);
173 // Deprcated. Tells runtime to issue finalize calls on the main thread only.
174 OBJC_EXPORT
void objc_finalizeOnMainThread(Class cls
)
175 AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER_BUT_DEPRECATED
;
182 /* Deprecated. Use objc_collectingEnabled() instead. */
183 OBJC_EXPORT BOOL
objc_collecting_enabled(void)
184 __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_4
,__MAC_10_5
, __IPHONE_NA
,__IPHONE_NA
);
185 /* Deprecated. Use objc_setCollectionThreshold() instead. */
186 OBJC_EXPORT
void objc_set_collection_threshold(size_t threshold
)
187 __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_4
,__MAC_10_5
, __IPHONE_NA
,__IPHONE_NA
);
188 /* Deprecated. Use objc_setCollectionRatio() instead. */
189 OBJC_EXPORT
void objc_set_collection_ratio(size_t ratio
)
190 __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_4
,__MAC_10_5
, __IPHONE_NA
,__IPHONE_NA
);
191 /* Deprecated. Use objc_startCollectorThread() instead. */
192 OBJC_EXPORT
void objc_start_collector_thread(void)
193 __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_4
,__MAC_10_5
, __IPHONE_NA
,__IPHONE_NA
);
194 /* Deprecated. No replacement. Formerly told the collector to run using a dedicated background thread. */
195 OBJC_EXPORT
void objc_startCollectorThread(void)
196 __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_5
,__MAC_10_7
, __IPHONE_NA
,__IPHONE_NA
);
199 /* Deprecated. Use class_createInstance() instead. */
200 OBJC_EXPORT id
objc_allocate_object(Class cls
, int extra
)
201 AVAILABLE_MAC_OS_X_VERSION_10_4_AND_LATER_BUT_DEPRECATED
;
204 /* !defined(OBJC_NO_GC) */
206 /* defined(OBJC_NO_GC) */
209 /* Non-GC declarations */
211 static OBJC_INLINE
void objc_collect(unsigned long options __unused
) { }
212 static OBJC_INLINE BOOL
objc_collectingEnabled(void) { return NO
; }
213 static OBJC_INLINE
void objc_setCollectionThreshold(size_t threshold __unused
) { }
214 static OBJC_INLINE
void objc_setCollectionRatio(size_t ratio __unused
) { }
215 static OBJC_INLINE
void objc_startCollectorThread(void) { }
218 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapPtr(id predicate
, id replacement
, volatile id
*objectLocation
)
219 { void *original
= InterlockedCompareExchangePointer((void * volatile *)objectLocation
, (void *)replacement
, (void *)predicate
); return (original
== predicate
); }
221 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapPtrBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
222 { void *original
= InterlockedCompareExchangePointer((void * volatile *)objectLocation
, (void *)replacement
, (void *)predicate
); return (original
== predicate
); }
224 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapPtr(id predicate
, id replacement
, volatile id
*objectLocation
)
225 { return OSAtomicCompareAndSwapPtr((void *)predicate
, (void *)replacement
, (void * volatile *)objectLocation
); }
227 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapPtrBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
228 { return OSAtomicCompareAndSwapPtrBarrier((void *)predicate
, (void *)replacement
, (void * volatile *)objectLocation
); }
231 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapGlobal(id predicate
, id replacement
, volatile id
*objectLocation
)
232 { return objc_atomicCompareAndSwapPtr(predicate
, replacement
, objectLocation
); }
234 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapGlobalBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
235 { return objc_atomicCompareAndSwapPtrBarrier(predicate
, replacement
, objectLocation
); }
237 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapInstanceVariable(id predicate
, id replacement
, volatile id
*objectLocation
)
238 { return objc_atomicCompareAndSwapPtr(predicate
, replacement
, objectLocation
); }
240 static OBJC_INLINE BOOL
objc_atomicCompareAndSwapInstanceVariableBarrier(id predicate
, id replacement
, volatile id
*objectLocation
)
241 { return objc_atomicCompareAndSwapPtrBarrier(predicate
, replacement
, objectLocation
); }
244 static OBJC_INLINE id
objc_assign_strongCast(id val
, id
*dest
)
245 { return (*dest
= val
); }
247 static OBJC_INLINE id
objc_assign_global(id val
, id
*dest
)
248 { return (*dest
= val
); }
250 static OBJC_INLINE id
objc_assign_ivar(id val
, id dest
, ptrdiff_t offset
)
251 { return (*(id
*)((char *)dest
+offset
) = val
); }
253 static OBJC_INLINE
void *objc_memmove_collectable(void *dst
, const void *src
, size_t size
)
254 { return memmove(dst
, src
, size
); }
256 static OBJC_INLINE id
objc_read_weak(id
*location
)
257 { return *location
; }
259 static OBJC_INLINE id
objc_assign_weak(id value
, id
*location
)
260 { return (*location
= value
); }
262 static OBJC_INLINE
void objc_finalizeOnMainThread(Class cls __unused
) { }
263 static OBJC_INLINE BOOL
objc_is_finalized(void *ptr __unused
) { return NO
; }
264 static OBJC_INLINE
void objc_clear_stack(unsigned long options __unused
) { }
266 static OBJC_INLINE BOOL
objc_collecting_enabled(void) { return NO
; }
267 static OBJC_INLINE
void objc_set_collection_threshold(size_t threshold __unused
) { }
268 static OBJC_INLINE
void objc_set_collection_ratio(size_t ratio __unused
) { }
269 static OBJC_INLINE
void objc_start_collector_thread(void) { }
271 OBJC_EXPORT id
class_createInstance(Class cls
, size_t extraBytes
)
272 __OSX_AVAILABLE_STARTING(__MAC_10_0
, __IPHONE_2_0
);
273 static OBJC_INLINE id
objc_allocate_object(Class cls
, int extra
)
274 { return class_createInstance(cls
, extra
); }
276 static OBJC_INLINE
void objc_registerThreadWithCollector() { }
277 static OBJC_INLINE
void objc_unregisterThreadWithCollector() { }
278 static OBJC_INLINE
void objc_assertRegisteredThreadWithCollector() { }
280 /* defined(OBJC_NO_GC) */
284 #if TARGET_OS_EMBEDDED
286 OBJC_GENERATIONAL
= (1 << 0)
288 static OBJC_INLINE
void objc_collect_if_needed(unsigned long options
) __attribute__((deprecated
));
289 static OBJC_INLINE
void objc_collect_if_needed(unsigned long options __unused
) { }