1 /*
2  * Copyright (c) 2004-2016 Apple Inc. All rights reserved.
3  *
4  * @APPLE_LICENSE_HEADER_START@
5  *
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
11  * file.
12  *
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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21  * @APPLE_LICENSE_HEADER_END@
22  */
23 
24 #ifndef _OSSPINLOCK_DEPRECATED_H_
25 #define _OSSPINLOCK_DEPRECATED_H_
26 
27 /*! @header
28  * These are deprecated legacy interfaces for userspace spinlocks.
29  *
30  * These interfaces should no longer be used, particularily in situations where
31  * threads of differing priorities may contend on the same spinlock.
32  *
33  * The interfaces in <os/lock.h> should be used instead in cases where a very
34  * low-level lock primitive is required. In general however, using higher level
35  * synchronization primitives such as those provided by the pthread or dispatch
36  * subsystems should be preferred.
37  *
38  * Define OSSPINLOCK_USE_INLINED=1 to get inline implementations of these
39  * interfaces in terms of the <os/lock.h> primitives. This is intended as a
40  * transition convenience, direct use of those primitives is preferred.
41  */
42 
43 #ifndef OSSPINLOCK_DEPRECATED
44 #define OSSPINLOCK_DEPRECATED 1
45 #define OSSPINLOCK_DEPRECATED_MSG(_r) "Use " #_r "() from <os/lock.h> instead"
46 #define OSSPINLOCK_DEPRECATED_REPLACE_WITH(_r) \
47 	__OS_AVAILABILITY_MSG(macosx, deprecated=10.12, OSSPINLOCK_DEPRECATED_MSG(_r)) \
48 	__OS_AVAILABILITY_MSG(ios, deprecated=10.0, OSSPINLOCK_DEPRECATED_MSG(_r)) \
49 	__OS_AVAILABILITY_MSG(tvos, deprecated=10.0, OSSPINLOCK_DEPRECATED_MSG(_r)) \
50 	__OS_AVAILABILITY_MSG(watchos, deprecated=3.0, OSSPINLOCK_DEPRECATED_MSG(_r))
51 #else
52 #undef OSSPINLOCK_DEPRECATED
53 #define OSSPINLOCK_DEPRECATED 0
54 #define OSSPINLOCK_DEPRECATED_REPLACE_WITH(_r)
55 #endif
56 
57 #if !(defined(OSSPINLOCK_USE_INLINED) && OSSPINLOCK_USE_INLINED)
58 
59 #include    <sys/cdefs.h>
60 #include    <stddef.h>
61 #include    <stdint.h>
62 #include    <stdbool.h>
63 #include    <Availability.h>
64 
65 __BEGIN_DECLS
66 
67 /*! @abstract The default value for an <code>OSSpinLock</code>.
68     @discussion
69 	The convention is that unlocked is zero, locked is nonzero.
70  */
71 #define	OS_SPINLOCK_INIT    0
72 
73 
74 /*! @abstract Data type for a spinlock.
75     @discussion
76 	You should always initialize a spinlock to {@link OS_SPINLOCK_INIT} before
77 	using it.
78  */
79 typedef int32_t OSSpinLock OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock);
80 
81 
82 /*! @abstract Locks a spinlock if it would not block
83     @result
84 	Returns <code>false</code> if the lock was already held by another thread,
85 	<code>true</code> if it took the lock successfully.
86  */
87 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_trylock)
88 __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
89 bool    OSSpinLockTry( volatile OSSpinLock *__lock );
90 
91 
92 /*! @abstract Locks a spinlock
93     @discussion
94 	Although the lock operation spins, it employs various strategies to back
95 	off if the lock is held.
96  */
97 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_lock)
98 __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
99 void    OSSpinLockLock( volatile OSSpinLock *__lock );
100 
101 
102 /*! @abstract Unlocks a spinlock */
103 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_unlock)
104 __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
105 void    OSSpinLockUnlock( volatile OSSpinLock *__lock );
106 
107 __END_DECLS
108 
109 #else /* OSSPINLOCK_USE_INLINED */
110 
111 /*
112  * Inline implementations of the legacy OSSpinLock interfaces in terms of the
113  * of the <os/lock.h> primitives. Direct use of those primitives is preferred.
114  *
115  * NOTE: the locked value of os_unfair_lock is implementation defined and
116  * subject to change, code that relies on the specific locked value used by the
117  * legacy OSSpinLock interface WILL break when using these inline
118  * implementations in terms of os_unfair_lock.
119  */
120 
121 #if !OSSPINLOCK_USE_INLINED_TRANSPARENT
122 
123 #include <os/lock.h>
124 
125 __BEGIN_DECLS
126 
127 #if __has_attribute(always_inline)
128 #define OSSPINLOCK_INLINE static __inline
129 #else
130 #define OSSPINLOCK_INLINE static __inline __attribute__((__always_inline__))
131 #endif
132 
133 #define OS_SPINLOCK_INIT 0
134 typedef int32_t OSSpinLock;
135 
136 #if  __has_extension(c_static_assert)
137 _Static_assert(sizeof(OSSpinLock) == sizeof(os_unfair_lock),
138 		"Incompatible os_unfair_lock type");
139 #endif
140 
141 OSSPINLOCK_INLINE
142 void
143 OSSpinLockLock(volatile OSSpinLock *__lock)
144 {
145 	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
146 	return os_unfair_lock_lock(lock);
147 }
148 
149 OSSPINLOCK_INLINE
150 bool
151 OSSpinLockTry(volatile OSSpinLock *__lock)
152 {
153 	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
154 	return os_unfair_lock_trylock(lock);
155 }
156 
157 OSSPINLOCK_INLINE
158 void
159 OSSpinLockUnlock(volatile OSSpinLock *__lock)
160 {
161 	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
162 	return os_unfair_lock_unlock(lock);
163 }
164 
165 #undef OSSPINLOCK_INLINE
166 
167 __END_DECLS
168 
169 #else /* OSSPINLOCK_USE_INLINED_TRANSPARENT */
170 
171 #include    <sys/cdefs.h>
172 #include    <stddef.h>
173 #include    <stdint.h>
174 #include    <stdbool.h>
175 #include    <Availability.h>
176 
177 #define OS_NOSPIN_LOCK_AVAILABILITY \
178 		__OSX_AVAILABLE(10.12) __IOS_AVAILABLE(10.0) \
179 		__TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
180 
181 __BEGIN_DECLS
182 
183 #define OS_SPINLOCK_INIT 0
184 typedef int32_t OSSpinLock OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock);
185 typedef volatile OSSpinLock *_os_nospin_lock_t
186 		OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_t);
187 
188 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_lock)
189 OS_NOSPIN_LOCK_AVAILABILITY
190 void _os_nospin_lock_lock(_os_nospin_lock_t lock);
191 #undef OSSpinLockLock
192 #define OSSpinLockLock(lock) _os_nospin_lock_lock(lock)
193 
194 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_trylock)
195 OS_NOSPIN_LOCK_AVAILABILITY
196 bool _os_nospin_lock_trylock(_os_nospin_lock_t lock);
197 #undef OSSpinLockTry
198 #define OSSpinLockTry(lock) _os_nospin_lock_trylock(lock)
199 
200 OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_unlock)
201 OS_NOSPIN_LOCK_AVAILABILITY
202 void _os_nospin_lock_unlock(_os_nospin_lock_t lock);
203 #undef OSSpinLockUnlock
204 #define OSSpinLockUnlock(lock) _os_nospin_lock_unlock(lock)
205 
206 __END_DECLS
207 
208 #endif /* OSSPINLOCK_USE_INLINED_TRANSPARENT */
209 
210 #endif /* OSSPINLOCK_USE_INLINED */
211 
212 #endif /* _OSSPINLOCK_DEPRECATED_H_ */