| 1 | /*␊ |
| 2 | * Copyright (c) 2004-2006 Apple Computer, 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,␊ |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.␊ |
| 18 | * Please see the License for the specific language governing rights and␊ |
| 19 | * limitations under the License.␊ |
| 20 | * ␊ |
| 21 | * @APPLE_LICENSE_HEADER_END@␊ |
| 22 | */␊ |
| 23 | ␊ |
| 24 | #ifndef _OSATOMIC_H_␊ |
| 25 | #define _OSATOMIC_H_␊ |
| 26 | ␊ |
| 27 | #include <stddef.h>␊ |
| 28 | #include <sys/cdefs.h>␊ |
| 29 | #include <stdint.h>␊ |
| 30 | #include <stdbool.h>␊ |
| 31 | ␊ |
| 32 | #include <Availability.h>␊ |
| 33 | ␊ |
| 34 | /*! @header␊ |
| 35 | * These are the preferred versions of the atomic and synchronization operations.␊ |
| 36 | * Their implementation is customized at boot time for the platform, including␊ |
| 37 | * late-breaking errata fixes as necessary. They are thread safe.␊ |
| 38 | *␊ |
| 39 | * WARNING: all addresses passed to these functions must be "naturally aligned",␊ |
| 40 | * i.e. * <code>int32_t</code> pointers must be 32-bit aligned (low 2 bits of␊ |
| 41 | * address are zeroes), and <code>int64_t</code> pointers must be 64-bit aligned␊ |
| 42 | * (low 3 bits of address are zeroes.)␊ |
| 43 | *␊ |
| 44 | * Note that some versions of the atomic functions incorporate memory barriers␊ |
| 45 | * and some do not. Barriers strictly order memory access on weakly-ordered␊ |
| 46 | * architectures such as PPC. All loads and stores that appear (in sequential␊ |
| 47 | * program order) before the barrier are guaranteed to complete before any␊ |
| 48 | * load or store that appears after the barrier.␊ |
| 49 | *␊ |
| 50 | * On a uniprocessor system, the barrier operation is typically a no-op. On a␊ |
| 51 | * multiprocessor system, the barrier can be quite expensive on some platforms,␊ |
| 52 | * such as PPC.␊ |
| 53 | *␊ |
| 54 | * Most code should use the barrier functions to ensure that memory shared between␊ |
| 55 | * threads is properly synchronized. For example, if you want to initialize␊ |
| 56 | * a shared data structure and then atomically increment a variable to indicate␊ |
| 57 | * that the initialization is complete, you must use {@link OSAtomicIncrement32Barrier}␊ |
| 58 | * to ensure that the stores to your data structure complete before the atomic␊ |
| 59 | * increment.␊ |
| 60 | *␊ |
| 61 | * Likewise, the consumer of that data structure must use {@link OSAtomicDecrement32Barrier},␊ |
| 62 | * in order to ensure that their loads of the structure are not executed before␊ |
| 63 | * the atomic decrement. On the other hand, if you are simply incrementing a global␊ |
| 64 | * counter, then it is safe and potentially faster to use {@link OSAtomicIncrement32}.␊ |
| 65 | *␊ |
| 66 | * If you are unsure which version to use, prefer the barrier variants as they are␊ |
| 67 | * safer.␊ |
| 68 | *␊ |
| 69 | * The spinlock and queue operations always incorporate a barrier.␊ |
| 70 | *␊ |
| 71 | * For the kernel-space version of this header, see␊ |
| 72 | * {@link //apple_ref/doc/header/OSAtomic.h OSAtomic.h (Kernel Framework)}␊ |
| 73 | *␊ |
| 74 | * @apiuid //apple_ref/doc/header/user_space_OSAtomic.h␊ |
| 75 | */ ␊ |
| 76 | __BEGIN_DECLS␊ |
| 77 | ␊ |
| 78 | ␊ |
| 79 | /*! @group Arithmetic functions␊ |
| 80 | All functions in this group return the new value.␊ |
| 81 | */␊ |
| 82 | ␊ |
| 83 | /*! @abstract Atomically adds two 32-bit values.␊ |
| 84 | @discussion␊ |
| 85 | ␉This function adds the value given by <code>__theAmount</code> to the␊ |
| 86 | ␉value in the memory location referenced by <code>__theValue</code>,␊ |
| 87 | ␉storing the result back to that memory location atomically.␊ |
| 88 | @result Returns the new value.␊ |
| 89 | */␊ |
| 90 | int32_t␉OSAtomicAdd32( int32_t __theAmount, volatile int32_t *__theValue );␊ |
| 91 | ␊ |
| 92 | ␊ |
| 93 | /*! @abstract Atomically adds two 32-bit values.␊ |
| 94 | @discussion␊ |
| 95 | ␉This function adds the value given by <code>__theAmount</code> to the␊ |
| 96 | ␉value in the memory location referenced by <code>__theValue</code>,␊ |
| 97 | ␉storing the result back to that memory location atomically.␊ |
| 98 | ␊ |
| 99 | ␉This function is equivalent to {@link OSAtomicAdd32}␊ |
| 100 | ␉except that it also introduces a barrier.␊ |
| 101 | @result Returns the new value.␊ |
| 102 | */␊ |
| 103 | int32_t␉OSAtomicAdd32Barrier( int32_t __theAmount, volatile int32_t *__theValue );␊ |
| 104 | ␊ |
| 105 | ␊ |
| 106 | /*! @abstract Atomically increments a 32-bit value.␊ |
| 107 | */␊ |
| 108 | __inline static␊ |
| 109 | int32_t␉OSAtomicIncrement32( volatile int32_t *__theValue )␊ |
| 110 | { return OSAtomicAdd32( 1, __theValue); }␊ |
| 111 | ␊ |
| 112 | ␊ |
| 113 | /*! @abstract Atomically increments a 32-bit value with a barrier.␊ |
| 114 | @discussion␊ |
| 115 | ␉This function is equivalent to {@link OSAtomicIncrement32}␊ |
| 116 | ␉except that it also introduces a barrier.␊ |
| 117 | @result Returns the new value.␊ |
| 118 | */␊ |
| 119 | __inline static␊ |
| 120 | int32_t␉OSAtomicIncrement32Barrier( volatile int32_t *__theValue )␊ |
| 121 | { return OSAtomicAdd32Barrier( 1, __theValue); }␊ |
| 122 | ␊ |
| 123 | /*! @abstract Atomically decrements a 32-bit value. */␊ |
| 124 | __inline static␊ |
| 125 | int32_t␉OSAtomicDecrement32( volatile int32_t *__theValue )␊ |
| 126 | { return OSAtomicAdd32( -1, __theValue); }␊ |
| 127 | ␊ |
| 128 | /*! @abstract Atomically increments a 32-bit value with a barrier.␊ |
| 129 | @discussion␊ |
| 130 | ␉This function is equivalent to {@link OSAtomicDecrement32}␊ |
| 131 | ␉except that it also introduces a barrier.␊ |
| 132 | @result Returns the new value.␊ |
| 133 | */␊ |
| 134 | __inline static␊ |
| 135 | int32_t␉OSAtomicDecrement32Barrier( volatile int32_t *__theValue )␊ |
| 136 | { return OSAtomicAdd32Barrier( -1, __theValue); }␊ |
| 137 | ␊ |
| 138 | ␊ |
| 139 | /*! @abstract Atomically adds two 64-bit values.␊ |
| 140 | @discussion␊ |
| 141 | ␉This function adds the value given by <code>__theAmount</code> to the␊ |
| 142 | ␉value in the memory location referenced by <code>__theValue</code>,␊ |
| 143 | ␉storing the result back to that memory location atomically.␊ |
| 144 | */␊ |
| 145 | int64_t␉OSAtomicAdd64( int64_t __theAmount, volatile int64_t *__theValue );␊ |
| 146 | ␊ |
| 147 | ␊ |
| 148 | /*! @abstract Atomically adds two 64-bit values with a barrier.␊ |
| 149 | @discussion␊ |
| 150 | ␉This function adds the value given by <code>__theAmount</code> to the␊ |
| 151 | ␉value in the memory location referenced by <code>__theValue</code>,␊ |
| 152 | ␉storing the result back to that memory location atomically.␊ |
| 153 | ␊ |
| 154 | ␉This function is equivalent to {@link OSAtomicAdd64}␊ |
| 155 | ␉except that it also introduces a barrier.␊ |
| 156 | @result Returns the new value.␊ |
| 157 | */␊ |
| 158 | int64_t␉OSAtomicAdd64Barrier( int64_t __theAmount, volatile int64_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_3_2); ␊ |
| 159 | ␊ |
| 160 | ␊ |
| 161 | /*! @abstract Atomically increments a 64-bit value. */␊ |
| 162 | __inline static␊ |
| 163 | int64_t␉OSAtomicIncrement64( volatile int64_t *__theValue )␊ |
| 164 | { return OSAtomicAdd64( 1, __theValue); }␊ |
| 165 | ␊ |
| 166 | /*! @abstract Atomically increments a 64-bit value with a barrier.␊ |
| 167 | @discussion␊ |
| 168 | ␉This function is equivalent to {@link OSAtomicIncrement64}␊ |
| 169 | ␉except that it also introduces a barrier.␊ |
| 170 | @result Returns the new value.␊ |
| 171 | */␊ |
| 172 | __inline static␊ |
| 173 | int64_t␉OSAtomicIncrement64Barrier( volatile int64_t *__theValue )␊ |
| 174 | { return OSAtomicAdd64Barrier( 1, __theValue); }␊ |
| 175 | ␊ |
| 176 | ␊ |
| 177 | /*! @abstract Atomically decrements a 64-bit value.␊ |
| 178 | @discussion␊ |
| 179 | ␉This function is equivalent to {@link OSAtomicIncrement64}␊ |
| 180 | ␉except that it also introduces a barrier.␊ |
| 181 | @result Returns the new value.␊ |
| 182 | */␊ |
| 183 | __inline static␊ |
| 184 | int64_t␉OSAtomicDecrement64( volatile int64_t *__theValue )␊ |
| 185 | { return OSAtomicAdd64( -1, __theValue); }␊ |
| 186 | ␊ |
| 187 | ␊ |
| 188 | /*! @abstract Atomically decrements a 64-bit value with a barrier.␊ |
| 189 | @discussion␊ |
| 190 | ␉This function is equivalent to {@link OSAtomicDecrement64}␊ |
| 191 | ␉except that it also introduces a barrier.␊ |
| 192 | @result Returns the new value.␊ |
| 193 | */␊ |
| 194 | __inline static␊ |
| 195 | int64_t␉OSAtomicDecrement64Barrier( volatile int64_t *__theValue )␊ |
| 196 | { return OSAtomicAdd64Barrier( -1, __theValue); }␊ |
| 197 | ␊ |
| 198 | ␊ |
| 199 | /*! @group Boolean functions (AND, OR, XOR)␊ |
| 200 | * ␊ |
| 201 | * @discussion Functions in this group come in four variants for each operation:␊ |
| 202 | * with and without barriers, and functions that return the original value or␊ |
| 203 | * the result value of the operation.␊ |
| 204 | * ␊ |
| 205 | * The "Orig" versions return the original value, (before the operation); the non-Orig␊ |
| 206 | * versions return the value after the operation. All are layered on top of␊ |
| 207 | * {@link OSAtomicCompareAndSwap32} and similar.␊ |
| 208 | */␊ |
| 209 | ␊ |
| 210 | /*! @abstract Atomic bitwise OR of two 32-bit values.␊ |
| 211 | @discussion␊ |
| 212 | ␉This function performs the bitwise OR of the value given by <code>__theMask</code>␊ |
| 213 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 214 | ␉storing the result back to that memory location atomically.␊ |
| 215 | @result Returns the new value.␊ |
| 216 | */␊ |
| 217 | int32_t␉OSAtomicOr32( uint32_t __theMask, volatile uint32_t *__theValue );␊ |
| 218 | ␊ |
| 219 | ␊ |
| 220 | /*! @abstract Atomic bitwise OR of two 32-bit values with barrier.␊ |
| 221 | @discussion␊ |
| 222 | ␉This function performs the bitwise OR of the value given by <code>__theMask</code>␊ |
| 223 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 224 | ␉storing the result back to that memory location atomically.␊ |
| 225 | ␊ |
| 226 | ␉This function is equivalent to {@link OSAtomicOr32}␊ |
| 227 | ␉except that it also introduces a barrier.␊ |
| 228 | @result Returns the new value.␊ |
| 229 | */␊ |
| 230 | int32_t␉OSAtomicOr32Barrier( uint32_t __theMask, volatile uint32_t *__theValue );␊ |
| 231 | ␊ |
| 232 | ␊ |
| 233 | /*! @abstract Atomic bitwise OR of two 32-bit values returning original.␊ |
| 234 | @discussion␊ |
| 235 | ␉This function performs the bitwise OR of the value given by <code>__theMask</code>␊ |
| 236 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 237 | ␉storing the result back to that memory location atomically.␊ |
| 238 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 239 | */␊ |
| 240 | int32_t␉OSAtomicOr32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 241 | ␊ |
| 242 | ␊ |
| 243 | /*! @abstract Atomic bitwise OR of two 32-bit values returning original with barrier.␊ |
| 244 | @discussion␊ |
| 245 | ␉This function performs the bitwise OR of the value given by <code>__theMask</code>␊ |
| 246 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 247 | ␉storing the result back to that memory location atomically.␊ |
| 248 | ␊ |
| 249 | ␉This function is equivalent to {@link OSAtomicOr32Orig}␊ |
| 250 | ␉except that it also introduces a barrier.␊ |
| 251 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 252 | */␊ |
| 253 | int32_t␉OSAtomicOr32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 254 | ␊ |
| 255 | ␊ |
| 256 | ␊ |
| 257 | ␊ |
| 258 | /*! @abstract Atomic bitwise AND of two 32-bit values.␊ |
| 259 | @discussion␊ |
| 260 | ␉This function performs the bitwise AND of the value given by <code>__theMask</code>␊ |
| 261 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 262 | ␉storing the result back to that memory location atomically.␊ |
| 263 | @result Returns the new value.␊ |
| 264 | */␊ |
| 265 | int32_t␉OSAtomicAnd32( uint32_t __theMask, volatile uint32_t *__theValue ); ␊ |
| 266 | ␊ |
| 267 | ␊ |
| 268 | /*! @abstract Atomic bitwise AND of two 32-bit values with barrier.␊ |
| 269 | @discussion␊ |
| 270 | ␉This function performs the bitwise AND of the value given by <code>__theMask</code>␊ |
| 271 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 272 | ␉storing the result back to that memory location atomically.␊ |
| 273 | ␊ |
| 274 | ␉This function is equivalent to {@link OSAtomicAnd32}␊ |
| 275 | ␉except that it also introduces a barrier.␊ |
| 276 | @result Returns the new value.␊ |
| 277 | */␊ |
| 278 | int32_t␉OSAtomicAnd32Barrier( uint32_t __theMask, volatile uint32_t *__theValue ); ␊ |
| 279 | ␊ |
| 280 | ␊ |
| 281 | /*! @abstract Atomic bitwise AND of two 32-bit values returning original.␊ |
| 282 | @discussion␊ |
| 283 | ␉This function performs the bitwise AND of the value given by <code>__theMask</code>␊ |
| 284 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 285 | ␉storing the result back to that memory location atomically.␊ |
| 286 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 287 | */␊ |
| 288 | int32_t␉OSAtomicAnd32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 289 | ␊ |
| 290 | ␊ |
| 291 | /*! @abstract Atomic bitwise AND of two 32-bit values returning original with barrier.␊ |
| 292 | @discussion␊ |
| 293 | ␉This function performs the bitwise AND of the value given by <code>__theMask</code>␊ |
| 294 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 295 | ␉storing the result back to that memory location atomically.␊ |
| 296 | ␊ |
| 297 | ␉This function is equivalent to {@link OSAtomicAnd32Orig}␊ |
| 298 | ␉except that it also introduces a barrier.␊ |
| 299 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 300 | */␊ |
| 301 | int32_t␉OSAtomicAnd32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 302 | ␊ |
| 303 | ␊ |
| 304 | ␊ |
| 305 | ␊ |
| 306 | /*! @abstract Atomic bitwise XOR of two 32-bit values.␊ |
| 307 | @discussion␊ |
| 308 | ␉This function performs the bitwise XOR of the value given by <code>__theMask</code>␊ |
| 309 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 310 | ␉storing the result back to that memory location atomically.␊ |
| 311 | @result Returns the new value.␊ |
| 312 | */␊ |
| 313 | int32_t␉OSAtomicXor32( uint32_t __theMask, volatile uint32_t *__theValue );␊ |
| 314 | ␊ |
| 315 | ␊ |
| 316 | /*! @abstract Atomic bitwise XOR of two 32-bit values with barrier.␊ |
| 317 | @discussion␊ |
| 318 | ␉This function performs the bitwise XOR of the value given by <code>__theMask</code>␊ |
| 319 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 320 | ␉storing the result back to that memory location atomically.␊ |
| 321 | ␊ |
| 322 | ␉This function is equivalent to {@link OSAtomicXor32}␊ |
| 323 | ␉except that it also introduces a barrier.␊ |
| 324 | @result Returns the new value.␊ |
| 325 | */␊ |
| 326 | int32_t␉OSAtomicXor32Barrier( uint32_t __theMask, volatile uint32_t *__theValue );␊ |
| 327 | ␊ |
| 328 | ␊ |
| 329 | /*! @abstract Atomic bitwise XOR of two 32-bit values returning original.␊ |
| 330 | @discussion␊ |
| 331 | ␉This function performs the bitwise XOR of the value given by <code>__theMask</code>␊ |
| 332 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 333 | ␉storing the result back to that memory location atomically.␊ |
| 334 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 335 | */␊ |
| 336 | int32_t␉OSAtomicXor32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 337 | ␊ |
| 338 | ␊ |
| 339 | /*! @abstract Atomic bitwise XOR of two 32-bit values returning original with barrier.␊ |
| 340 | @discussion␊ |
| 341 | ␉This function performs the bitwise XOR of the value given by <code>__theMask</code>␊ |
| 342 | ␉with the value in the memory location referenced by <code>__theValue</code>,␊ |
| 343 | ␉storing the result back to that memory location atomically.␊ |
| 344 | ␊ |
| 345 | ␉This function is equivalent to {@link OSAtomicXor32Orig}␊ |
| 346 | ␉except that it also introduces a barrier.␊ |
| 347 | @result Returns the original value referenced by <code>__theValue</code>.␊ |
| 348 | */␊ |
| 349 | int32_t␉OSAtomicXor32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);␊ |
| 350 | ␊ |
| 351 | ␊ |
| 352 | /*! @group Compare and swap␊ |
| 353 | * Functions in this group return true if the swap occured. There are several versions,␊ |
| 354 | * depending on data type and on whether or not a barrier is used.␊ |
| 355 | */␊ |
| 356 | ␊ |
| 357 | ␊ |
| 358 | /*! @abstract Compare and swap for 32-bit values.␊ |
| 359 | @discussion␊ |
| 360 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 361 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 362 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 363 | ␉that memory location atomically.␊ |
| 364 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 365 | */␊ |
| 366 | bool OSAtomicCompareAndSwap32( int32_t __oldValue, int32_t __newValue, volatile int32_t *__theValue );␊ |
| 367 | ␊ |
| 368 | ␊ |
| 369 | /*! @abstract Compare and swap for 32-bit values with barrier.␊ |
| 370 | @discussion␊ |
| 371 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 372 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 373 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 374 | ␉that memory location atomically.␊ |
| 375 | ␊ |
| 376 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap32}␊ |
| 377 | ␉except that it also introduces a barrier.␊ |
| 378 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 379 | */␊ |
| 380 | bool OSAtomicCompareAndSwap32Barrier( int32_t __oldValue, int32_t __newValue, volatile int32_t *__theValue );␊ |
| 381 | ␊ |
| 382 | ␊ |
| 383 | /*! @abstract Compare and swap pointers.␊ |
| 384 | @discussion␊ |
| 385 | ␉This function compares the pointer stored in <code>__oldValue</code> to the pointer␊ |
| 386 | ␉in the memory location referenced by <code>__theValue</code>. If the pointers␊ |
| 387 | ␉match, this function stores the pointer from <code>__newValue</code> into␊ |
| 388 | ␉that memory location atomically.␊ |
| 389 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 390 | */␊ |
| 391 | bool␉OSAtomicCompareAndSwapPtr( void *__oldValue, void *__newValue, void * volatile *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 392 | ␊ |
| 393 | ␊ |
| 394 | /*! @abstract Compare and swap pointers with barrier.␊ |
| 395 | @discussion␊ |
| 396 | ␉This function compares the pointer stored in <code>__oldValue</code> to the pointer␊ |
| 397 | ␉in the memory location referenced by <code>__theValue</code>. If the pointers␊ |
| 398 | ␉match, this function stores the pointer from <code>__newValue</code> into␊ |
| 399 | ␉that memory location atomically.␊ |
| 400 | ␊ |
| 401 | ␉This function is equivalent to {@link OSAtomicCompareAndSwapPtr}␊ |
| 402 | ␉except that it also introduces a barrier.␊ |
| 403 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 404 | */␊ |
| 405 | bool␉OSAtomicCompareAndSwapPtrBarrier( void *__oldValue, void *__newValue, void * volatile *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 406 | ␊ |
| 407 | ␊ |
| 408 | /*! @abstract Compare and swap for <code>int</code> values.␊ |
| 409 | @discussion␊ |
| 410 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 411 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 412 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 413 | ␉that memory location atomically.␊ |
| 414 | ␊ |
| 415 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap32}.␊ |
| 416 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 417 | */␊ |
| 418 | bool␉OSAtomicCompareAndSwapInt( int __oldValue, int __newValue, volatile int *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 419 | ␊ |
| 420 | ␊ |
| 421 | /*! @abstract Compare and swap for <code>int</code> values.␊ |
| 422 | @discussion␊ |
| 423 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 424 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 425 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 426 | ␉that memory location atomically.␊ |
| 427 | ␊ |
| 428 | ␉This function is equivalent to {@link OSAtomicCompareAndSwapInt}␊ |
| 429 | ␉except that it also introduces a barrier.␊ |
| 430 | ␊ |
| 431 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap32Barrier}.␊ |
| 432 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 433 | */␊ |
| 434 | bool␉OSAtomicCompareAndSwapIntBarrier( int __oldValue, int __newValue, volatile int *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 435 | ␊ |
| 436 | ␊ |
| 437 | /*! @abstract Compare and swap for <code>long</code> values.␊ |
| 438 | @discussion␊ |
| 439 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 440 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 441 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 442 | ␉that memory location atomically.␊ |
| 443 | ␊ |
| 444 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap32} on 32-bit architectures, ␊ |
| 445 | ␉or {@link OSAtomicCompareAndSwap64} on 64-bit architectures.␊ |
| 446 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 447 | */␊ |
| 448 | bool␉OSAtomicCompareAndSwapLong( long __oldValue, long __newValue, volatile long *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 449 | ␊ |
| 450 | ␊ |
| 451 | /*! @abstract Compare and swap for <code>long</code> values.␊ |
| 452 | @discussion␊ |
| 453 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 454 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 455 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 456 | ␉that memory location atomically.␊ |
| 457 | ␊ |
| 458 | ␉This function is equivalent to {@link OSAtomicCompareAndSwapLong}␊ |
| 459 | ␉except that it also introduces a barrier.␊ |
| 460 | ␊ |
| 461 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap32} on 32-bit architectures, ␊ |
| 462 | ␉or {@link OSAtomicCompareAndSwap64} on 64-bit architectures.␊ |
| 463 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 464 | */␊ |
| 465 | bool␉OSAtomicCompareAndSwapLongBarrier( long __oldValue, long __newValue, volatile long *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);␊ |
| 466 | ␊ |
| 467 | ␊ |
| 468 | /*! @abstract Compare and swap for <code>uint64_t</code> values.␊ |
| 469 | @discussion␊ |
| 470 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 471 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 472 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 473 | ␉that memory location atomically.␊ |
| 474 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 475 | */␊ |
| 476 | bool OSAtomicCompareAndSwap64( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue );␊ |
| 477 | ␊ |
| 478 | ␊ |
| 479 | /*! @abstract Compare and swap for <code>uint64_t</code> values.␊ |
| 480 | @discussion␊ |
| 481 | ␉This function compares the value in <code>__oldValue</code> to the value␊ |
| 482 | ␉in the memory location referenced by <code>__theValue</code>. If the values␊ |
| 483 | ␉match, this function stores the value from <code>__newValue</code> into␊ |
| 484 | ␉that memory location atomically.␊ |
| 485 | ␊ |
| 486 | ␉This function is equivalent to {@link OSAtomicCompareAndSwap64}␊ |
| 487 | ␉except that it also introduces a barrier.␊ |
| 488 | @result Returns TRUE on a match, FALSE otherwise.␊ |
| 489 | */␊ |
| 490 | bool OSAtomicCompareAndSwap64Barrier( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_3_2);␊ |
| 491 | ␊ |
| 492 | ␊ |
| 493 | /* Test and set. They return the original value of the bit, and operate on bit (0x80>>(n&7))␊ |
| 494 | * in byte ((char*)theAddress + (n>>3)).␊ |
| 495 | */␊ |
| 496 | /*! @abstract Atomic test and set␊ |
| 497 | @discussion␊ |
| 498 | ␉This function tests a bit in the value referenced by <code>__theAddress</code>␊ |
| 499 | ␉and if it is not set, sets it. The bit is chosen by the value of <code>__n</code>.␊ |
| 500 | ␉The bits are numbered in order beginning with bit 1 as the lowest order bit.␊ |
| 501 | ␊ |
| 502 | ␉For example, if <code>__theAddress</code> points to a 64-bit value,␊ |
| 503 | ␉to compare the value of the highest bit, you would specify <code>64</code> for␊ |
| 504 | ␉<code>__n</code>.␊ |
| 505 | @result␊ |
| 506 | ␉Returns the original value of the bit being tested.␊ |
| 507 | */␊ |
| 508 | bool OSAtomicTestAndSet( uint32_t __n, volatile void *__theAddress );␊ |
| 509 | ␊ |
| 510 | ␊ |
| 511 | /*! @abstract Atomic test and set with barrier␊ |
| 512 | @discussion␊ |
| 513 | ␉This function tests a bit in the value referenced by <code>__theAddress</code>␊ |
| 514 | ␉and if it is not set, sets it. The bit is chosen by the value of <code>__n</code>.␊ |
| 515 | ␉The bits are numbered in order beginning with bit 1 as the lowest order bit.␊ |
| 516 | ␊ |
| 517 | ␉For example, if <code>__theAddress</code> points to a 64-bit value,␊ |
| 518 | ␉to compare the value of the highest bit, you would specify <code>64</code> for␊ |
| 519 | ␉<code>__n</code>.␊ |
| 520 | ␊ |
| 521 | ␉This function is equivalent to {@link OSAtomicTestAndSet}␊ |
| 522 | ␉except that it also introduces a barrier.␊ |
| 523 | @result␊ |
| 524 | ␉Returns the original value of the bit being tested.␊ |
| 525 | */␊ |
| 526 | ␊ |
| 527 | bool OSAtomicTestAndSetBarrier( uint32_t __n, volatile void *__theAddress );␊ |
| 528 | ␊ |
| 529 | ␊ |
| 530 | ␊ |
| 531 | /*! @abstract Atomic test and clear␊ |
| 532 | @discussion␊ |
| 533 | ␉This function tests a bit in the value referenced by <code>__theAddress</code>␊ |
| 534 | ␉and if it is not cleared, clears it. The bit is chosen by the value of <code>__n</code>.␊ |
| 535 | ␉The bits are numbered in order beginning with bit 1 as the lowest order bit.␊ |
| 536 | ␊ |
| 537 | ␉For example, if <code>__theAddress</code> points to a 64-bit value,␊ |
| 538 | ␉to compare the value of the highest bit, you would specify <code>64</code> for␊ |
| 539 | ␉<code>__n</code>.␊ |
| 540 | @result␊ |
| 541 | ␉Returns the original value of the bit being tested.␊ |
| 542 | */␊ |
| 543 | bool OSAtomicTestAndClear( uint32_t __n, volatile void *__theAddress );␊ |
| 544 | ␊ |
| 545 | ␊ |
| 546 | /*! @abstract Atomic test and clear␊ |
| 547 | @discussion␊ |
| 548 | ␉This function tests a bit in the value referenced by <code>__theAddress</code>␊ |
| 549 | ␉and if it is not cleared, clears it. The bit is chosen by the value of <code>__n</code>.␊ |
| 550 | ␉The bits are numbered in order beginning with bit 1 as the lowest order bit.␊ |
| 551 | ␊ |
| 552 | ␉For example, if <code>__theAddress</code> points to a 64-bit value,␊ |
| 553 | ␉to compare the value of the highest bit, you would specify <code>64</code> for␊ |
| 554 | ␉<code>__n</code>.␊ |
| 555 | ␊ |
| 556 | ␉This function is equivalent to {@link OSAtomicTestAndSet}␊ |
| 557 | ␉except that it also introduces a barrier.␊ |
| 558 | @result␊ |
| 559 | ␉Returns the original value of the bit being tested.␊ |
| 560 | */␊ |
| 561 | bool OSAtomicTestAndClearBarrier( uint32_t __n, volatile void *__theAddress );␊ |
| 562 | ␊ |
| 563 | ␊ |
| 564 | /*! @group Spinlocks␊ |
| 565 | * These spinlocks use memory barriers as required to synchronize access to shared␊ |
| 566 | * memory protected by the lock.␊ |
| 567 | */␊ |
| 568 | ␊ |
| 569 | /*! @abstract The default value for an <code>OSSpinLock</code>.␊ |
| 570 | @discussion␊ |
| 571 | ␉The convention is that unlocked is zero, locked is nonzero.␊ |
| 572 | */␊ |
| 573 | #define␉OS_SPINLOCK_INIT 0␊ |
| 574 | ␊ |
| 575 | ␊ |
| 576 | /*! @abstract Data type for a spinlock.␊ |
| 577 | @discussion␊ |
| 578 | ␉You should always initialize a spinlock to {@link OS_SPINLOCK_INIT} before␊ |
| 579 | ␉using it.␊ |
| 580 | */␊ |
| 581 | typedef int32_t OSSpinLock;␊ |
| 582 | ␊ |
| 583 | ␊ |
| 584 | /*! @abstract Locks a spinlock if it would not block␊ |
| 585 | @result␊ |
| 586 | ␉Returns <code>false</code> if the lock was already held by another thread,␊ |
| 587 | ␉<code>true</code> if it took the lock successfully. ␊ |
| 588 | */␊ |
| 589 | bool OSSpinLockTry( volatile OSSpinLock *__lock );␊ |
| 590 | ␊ |
| 591 | ␊ |
| 592 | /*! @abstract Locks a spinlock␊ |
| 593 | @discussion␊ |
| 594 | ␉Although the lock operation spins, it employs various strategies␊ |
| 595 | to back off if the lock is held, making it immune to most priority-inversion␊ |
| 596 | ␉livelocks.␊ |
| 597 | */␊ |
| 598 | void OSSpinLockLock( volatile OSSpinLock *__lock );␊ |
| 599 | ␊ |
| 600 | ␊ |
| 601 | /*! @abstract Unlocks a spinlock */␊ |
| 602 | void OSSpinLockUnlock( volatile OSSpinLock *__lock );␊ |
| 603 | ␊ |
| 604 | ␊ |
| 605 | /*! @group Lockless atomic enqueue and dequeue␊ |
| 606 | * These routines manipulate singly-linked LIFO lists.␊ |
| 607 | */␊ |
| 608 | ␊ |
| 609 | /*! @abstract The data structure for a queue head.␊ |
| 610 | @discussion␊ |
| 611 | ␉You should always initialize a queue head structure with the␊ |
| 612 | ␉initialization vector {@link OS_ATOMIC_QUEUE_INIT} before use.␊ |
| 613 | */␊ |
| 614 | #if defined(__x86_64__)␊ |
| 615 | ␊ |
| 616 | typedef volatile struct {␊ |
| 617 | ␉void␉*opaque1;␊ |
| 618 | ␉long␉ opaque2;␊ |
| 619 | } __attribute__ ((aligned (16))) OSQueueHead;␊ |
| 620 | ␊ |
| 621 | #else␊ |
| 622 | ␊ |
| 623 | typedef volatile struct {␊ |
| 624 | ␉void␉*opaque1;␊ |
| 625 | ␉long␉ opaque2;␊ |
| 626 | } OSQueueHead;␊ |
| 627 | ␊ |
| 628 | #endif␊ |
| 629 | ␊ |
| 630 | /*! @abstract The initialization vector for a queue head. */␊ |
| 631 | #define␉OS_ATOMIC_QUEUE_INIT␉{ NULL, 0 }␊ |
| 632 | ␊ |
| 633 | /*! @abstract Enqueue an item onto a list.␊ |
| 634 | @discussion␊ |
| 635 | ␉Memory barriers are incorporated as needed to permit thread-safe access␊ |
| 636 | ␉to the queue element.␊ |
| 637 | @param __list␊ |
| 638 | ␉The list on which you want to enqueue the item.␊ |
| 639 | @param __new␊ |
| 640 | ␉The item to add.␊ |
| 641 | @param __offset␊ |
| 642 | ␉The "offset" parameter is the offset (in bytes) of the link field␊ |
| 643 | ␉from the beginning of the data structure being queued (<code>__new</code>).␊ |
| 644 | ␉The link field should be a pointer type.␊ |
| 645 | ␉The <code>__offset</code> value needs to be same for all enqueuing and␊ |
| 646 | ␉dequeuing operations on the same queue, even if different structure types␊ |
| 647 | ␉are enqueued on that queue. The use of <code>offsetset()</code>, defined in␊ |
| 648 | ␉<code>stddef.h</code> is the common way to specify the <code>__offset</code>␊ |
| 649 | ␉value.␊ |
| 650 | */␊ |
| 651 | void OSAtomicEnqueue( OSQueueHead *__list, void *__new, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_4_0);␊ |
| 652 | ␊ |
| 653 | ␊ |
| 654 | /*! @abstract Dequeue an item from a list.␊ |
| 655 | @discussion␊ |
| 656 | ␉Memory barriers are incorporated as needed to permit thread-safe access␊ |
| 657 | ␉to the queue element.␊ |
| 658 | @param __list␊ |
| 659 | ␉The list on which you want to enqueue the item.␊ |
| 660 | @param __offset␊ |
| 661 | ␉The "offset" parameter is the offset (in bytes) of the link field␊ |
| 662 | ␉from the beginning of the data structure being queued (<code>__new</code>).␊ |
| 663 | ␉The link field should be a pointer type.␊ |
| 664 | ␉The <code>__offset</code> value needs to be same for all enqueuing and␊ |
| 665 | ␉dequeuing operations on the same queue, even if different structure types␊ |
| 666 | ␉are enqueued on that queue. The use of <code>offsetset()</code>, defined in␊ |
| 667 | ␉<code>stddef.h</code> is the common way to specify the <code>__offset</code>␊ |
| 668 | ␉value.␊ |
| 669 | @result␊ |
| 670 | ␉Returns the most recently enqueued element, or <code>NULL</code> if the␊ |
| 671 | ␉list is empty. ␊ |
| 672 | */␊ |
| 673 | void* OSAtomicDequeue( OSQueueHead *__list, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_4_0);␊ |
| 674 | ␊ |
| 675 | #if defined(__x86_64__) || defined(__i386__)␊ |
| 676 | ␊ |
| 677 | /*! @group Lockless atomic fifo enqueue and dequeue␊ |
| 678 | * These routines manipulate singly-linked FIFO lists.␊ |
| 679 | */␊ |
| 680 | ␊ |
| 681 | /*! @abstract The data structure for a fifo queue head.␊ |
| 682 | @discussion␊ |
| 683 | ␉You should always initialize a fifo queue head structure with the␊ |
| 684 | ␉initialization vector {@link OS_ATOMIC_FIFO_QUEUE_INIT} before use.␊ |
| 685 | */␊ |
| 686 | #if defined(__x86_64__)␊ |
| 687 | ␊ |
| 688 | typedef␉volatile struct {␊ |
| 689 | ␉void␉*opaque1;␊ |
| 690 | ␉void␉*opaque2;␊ |
| 691 | ␉int␉ opaque3;␊ |
| 692 | } __attribute__ ((aligned (16))) OSFifoQueueHead;␊ |
| 693 | ␊ |
| 694 | #else␊ |
| 695 | ␊ |
| 696 | typedef␉volatile struct {␊ |
| 697 | ␉void␉*opaque1;␊ |
| 698 | ␉void␉*opaque2;␊ |
| 699 | ␉int␉ opaque3;␊ |
| 700 | } OSFifoQueueHead;␊ |
| 701 | ␊ |
| 702 | #endif␊ |
| 703 | ␊ |
| 704 | /*! @abstract The initialization vector for a fifo queue head. */␊ |
| 705 | #define OS_ATOMIC_FIFO_QUEUE_INIT { NULL, NULL, 0 }␊ |
| 706 | ␊ |
| 707 | /*! @abstract Enqueue an item onto a list.␊ |
| 708 | @discussion␊ |
| 709 | ␉Memory barriers are incorporated as needed to permit thread-safe access␊ |
| 710 | ␉to the queue element.␊ |
| 711 | @param __list␊ |
| 712 | ␉The list on which you want to enqueue the item.␊ |
| 713 | @param __new␊ |
| 714 | ␉The item to add.␊ |
| 715 | @param __offset␊ |
| 716 | ␉The "offset" parameter is the offset (in bytes) of the link field␊ |
| 717 | ␉from the beginning of the data structure being queued (<code>__new</code>).␊ |
| 718 | ␉The link field should be a pointer type.␊ |
| 719 | ␉The <code>__offset</code> value needs to be same for all enqueuing and␊ |
| 720 | ␉dequeuing operations on the same queue, even if different structure types␊ |
| 721 | ␉are enqueued on that queue. The use of <code>offsetset()</code>, defined in␊ |
| 722 | ␉<code>stddef.h</code> is the common way to specify the <code>__offset</code>␊ |
| 723 | ␉value.␊ |
| 724 | */␊ |
| 725 | void OSAtomicFifoEnqueue( OSFifoQueueHead *__list, void *__new, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);␊ |
| 726 | ␊ |
| 727 | /*! @abstract Dequeue an item from a list.␊ |
| 728 | @discussion␊ |
| 729 | ␉Memory barriers are incorporated as needed to permit thread-safe access␊ |
| 730 | ␉to the queue element.␊ |
| 731 | @param __list␊ |
| 732 | ␉The list on which you want to enqueue the item.␊ |
| 733 | @param __offset␊ |
| 734 | ␉The "offset" parameter is the offset (in bytes) of the link field␊ |
| 735 | ␉from the beginning of the data structure being queued (<code>__new</code>).␊ |
| 736 | ␉The link field should be a pointer type.␊ |
| 737 | ␉The <code>__offset</code> value needs to be same for all enqueuing and␊ |
| 738 | ␉dequeuing operations on the same queue, even if different structure types␊ |
| 739 | ␉are enqueued on that queue. The use of <code>offsetset()</code>, defined in␊ |
| 740 | ␉<code>stddef.h</code> is the common way to specify the <code>__offset</code>␊ |
| 741 | ␉value.␊ |
| 742 | @result␊ |
| 743 | ␉Returns the oldest enqueued element, or <code>NULL</code> if the␊ |
| 744 | ␉list is empty. ␊ |
| 745 | */␊ |
| 746 | void* OSAtomicFifoDequeue( OSFifoQueueHead *__list, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);␊ |
| 747 | ␊ |
| 748 | #endif /* __i386__ || __x86_64__ */␊ |
| 749 | ␊ |
| 750 | /*! @group Memory barriers */␊ |
| 751 | ␊ |
| 752 | /*! @abstract Memory barrier.␊ |
| 753 | @discussion␊ |
| 754 | ␉This function serves as both a read and write barrier.␊ |
| 755 | */␊ |
| 756 | void OSMemoryBarrier( void );␊ |
| 757 | ␊ |
| 758 | __END_DECLS␊ |
| 759 | ␊ |
| 760 | #endif /* _OSATOMIC_H_ */␊ |
| 761 | |
