1page.title=RenderScript Atomic Update Functions 2 3@jd:body 4 5<div class='renderscript'> 6<h2>Overview</h2> 7<p> To update values shared between multiple threads, use the functions below. 8They ensure that the values are atomically updated, i.e. that the memory 9reads, the updates, and the memory writes are done in the right order. 10</p> 11 12<p> These functions are slower than their non-atomic equivalents, so use 13them only when synchronization is needed. 14</p> 15 16<p> Note that in RenderScript, your code is likely to be running in separate 17threads even though you did not explicitely create them. The RenderScript 18runtime will very often split the execution of one kernel across multiple 19threads. Updating globals should be done with atomic functions. If possible, 20modify your algorithm to avoid them altogether. 21</p> 22<h2>Summary</h2> 23<table class='jd-sumtable'><tbody> 24 <tr><th colspan='2'>Functions</th></tr> 25 <tr class='alt-color api apilevel-1'> 26 <td class='jd-linkcol'> 27 <a href='rs_atomic.html#android_rs:rsAtomicAdd'>rsAtomicAdd</a> 28 </td> 29 <td class='jd-descrcol' width='100%'> 30 Thread-safe addition 31 </td> 32 </tr> 33 <tr class='alt-color api apilevel-1'> 34 <td class='jd-linkcol'> 35 <a href='rs_atomic.html#android_rs:rsAtomicAnd'>rsAtomicAnd</a> 36 </td> 37 <td class='jd-descrcol' width='100%'> 38 Thread-safe bitwise and 39 </td> 40 </tr> 41 <tr class='alt-color api apilevel-1'> 42 <td class='jd-linkcol'> 43 <a href='rs_atomic.html#android_rs:rsAtomicCas'>rsAtomicCas</a> 44 </td> 45 <td class='jd-descrcol' width='100%'> 46 Thread-safe compare and set 47 </td> 48 </tr> 49 <tr class='alt-color api apilevel-1'> 50 <td class='jd-linkcol'> 51 <a href='rs_atomic.html#android_rs:rsAtomicDec'>rsAtomicDec</a> 52 </td> 53 <td class='jd-descrcol' width='100%'> 54 Thread-safe decrement 55 </td> 56 </tr> 57 <tr class='alt-color api apilevel-1'> 58 <td class='jd-linkcol'> 59 <a href='rs_atomic.html#android_rs:rsAtomicInc'>rsAtomicInc</a> 60 </td> 61 <td class='jd-descrcol' width='100%'> 62 Thread-safe increment 63 </td> 64 </tr> 65 <tr class='alt-color api apilevel-1'> 66 <td class='jd-linkcol'> 67 <a href='rs_atomic.html#android_rs:rsAtomicMax'>rsAtomicMax</a> 68 </td> 69 <td class='jd-descrcol' width='100%'> 70 Thread-safe maximum 71 </td> 72 </tr> 73 <tr class='alt-color api apilevel-1'> 74 <td class='jd-linkcol'> 75 <a href='rs_atomic.html#android_rs:rsAtomicMin'>rsAtomicMin</a> 76 </td> 77 <td class='jd-descrcol' width='100%'> 78 Thread-safe minimum 79 </td> 80 </tr> 81 <tr class='alt-color api apilevel-1'> 82 <td class='jd-linkcol'> 83 <a href='rs_atomic.html#android_rs:rsAtomicOr'>rsAtomicOr</a> 84 </td> 85 <td class='jd-descrcol' width='100%'> 86 Thread-safe bitwise or 87 </td> 88 </tr> 89 <tr class='alt-color api apilevel-1'> 90 <td class='jd-linkcol'> 91 <a href='rs_atomic.html#android_rs:rsAtomicSub'>rsAtomicSub</a> 92 </td> 93 <td class='jd-descrcol' width='100%'> 94 Thread-safe subtraction 95 </td> 96 </tr> 97 <tr class='alt-color api apilevel-1'> 98 <td class='jd-linkcol'> 99 <a href='rs_atomic.html#android_rs:rsAtomicXor'>rsAtomicXor</a> 100 </td> 101 <td class='jd-descrcol' width='100%'> 102 Thread-safe bitwise exclusive or 103 </td> 104 </tr> 105</tbody></table> 106<h2>Functions</h2> 107<a name='android_rs:rsAtomicAdd'></a> 108<div class='jd-details'> 109 <h4 class='jd-details-title'> 110 <span class='sympad'>rsAtomicAdd</span> 111 <span class='normal'>: Thread-safe addition</span> 112 </h4> 113 <div class='jd-details-descr'> 114 <table class='jd-tagtable'><tbody> 115 <tr> 116 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicAdd(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 117</td> 118 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 119 </td> 120 </tr> 121 <tr> 122 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicAdd(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 123</td> 124 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 125 </td> 126 </tr> 127 </tbody></table> 128 </div> 129 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 130 <table class='jd-tagtable'><tbody> 131 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 132 <tr><th>value</th><td>Amount to add.</td></tr> 133 </tbody></table> 134 </div> 135 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 136 <table class='jd-tagtable'><tbody> 137 <tr><td>Value of *addr prior to the operation.</td></tr> 138 </tbody></table> 139 </div> 140 <div class='jd-tagdata jd-tagdescr'> 141<p> Atomicly adds a value to the value at addr, i.e. <code>*addr += value</code>. 142</p> 143 </div> 144</div> 145 146<a name='android_rs:rsAtomicAnd'></a> 147<div class='jd-details'> 148 <h4 class='jd-details-title'> 149 <span class='sympad'>rsAtomicAnd</span> 150 <span class='normal'>: Thread-safe bitwise and</span> 151 </h4> 152 <div class='jd-details-descr'> 153 <table class='jd-tagtable'><tbody> 154 <tr> 155 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicAnd(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 156</td> 157 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 158 </td> 159 </tr> 160 <tr> 161 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicAnd(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 162</td> 163 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 164 </td> 165 </tr> 166 </tbody></table> 167 </div> 168 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 169 <table class='jd-tagtable'><tbody> 170 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 171 <tr><th>value</th><td>Value to and with.</td></tr> 172 </tbody></table> 173 </div> 174 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 175 <table class='jd-tagtable'><tbody> 176 <tr><td>Value of *addr prior to the operation.</td></tr> 177 </tbody></table> 178 </div> 179 <div class='jd-tagdata jd-tagdescr'> 180<p> Atomicly performs a bitwise and of two values, storing the result back at addr, 181i.e. <code>*addr &= value</code>. 182</p> 183 </div> 184</div> 185 186<a name='android_rs:rsAtomicCas'></a> 187<div class='jd-details'> 188 <h4 class='jd-details-title'> 189 <span class='sympad'>rsAtomicCas</span> 190 <span class='normal'>: Thread-safe compare and set</span> 191 </h4> 192 <div class='jd-details-descr'> 193 <table class='jd-tagtable'><tbody> 194 <tr> 195 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicCas(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> compareValue, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> newValue); 196</td> 197 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 198 </td> 199 </tr> 200 <tr> 201 <td><a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> rsAtomicCas(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> compareValue, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> newValue); 202</td> 203 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 204 </td> 205 </tr> 206 </tbody></table> 207 </div> 208 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 209 <table class='jd-tagtable'><tbody> 210 <tr><th>addr</th><td>Address of the value to compare and replace if the test passes.</td></tr> 211 <tr><th>compareValue</th><td>Value to test *addr against.</td></tr> 212 <tr><th>newValue</th><td>Value to write if the test passes.</td></tr> 213 </tbody></table> 214 </div> 215 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 216 <table class='jd-tagtable'><tbody> 217 <tr><td>Value of *addr prior to the operation.</td></tr> 218 </tbody></table> 219 </div> 220 <div class='jd-tagdata jd-tagdescr'> 221<p> If the value at addr matches compareValue then the newValue is written at addr, 222i.e. <code>if (*addr == compareValue) { *addr = newValue; }</code>. 223</p> 224 225<p> You can check that the value was written by checking that the value returned 226by rsAtomicCas() is compareValue. 227</p> 228 </div> 229</div> 230 231<a name='android_rs:rsAtomicDec'></a> 232<div class='jd-details'> 233 <h4 class='jd-details-title'> 234 <span class='sympad'>rsAtomicDec</span> 235 <span class='normal'>: Thread-safe decrement</span> 236 </h4> 237 <div class='jd-details-descr'> 238 <table class='jd-tagtable'><tbody> 239 <tr> 240 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicDec(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr); 241</td> 242 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 243 </td> 244 </tr> 245 <tr> 246 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicDec(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr); 247</td> 248 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 249 </td> 250 </tr> 251 </tbody></table> 252 </div> 253 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 254 <table class='jd-tagtable'><tbody> 255 <tr><th>addr</th><td>Address of the value to decrement.</td></tr> 256 </tbody></table> 257 </div> 258 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 259 <table class='jd-tagtable'><tbody> 260 <tr><td>Value of *addr prior to the operation.</td></tr> 261 </tbody></table> 262 </div> 263 <div class='jd-tagdata jd-tagdescr'> 264<p> Atomicly subtracts one from the value at addr. This is equivalent to <code><a href='rs_atomic.html#android_rs:rsAtomicSub'>rsAtomicSub</a>(addr, 1)</code>. 265</p> 266 </div> 267</div> 268 269<a name='android_rs:rsAtomicInc'></a> 270<div class='jd-details'> 271 <h4 class='jd-details-title'> 272 <span class='sympad'>rsAtomicInc</span> 273 <span class='normal'>: Thread-safe increment</span> 274 </h4> 275 <div class='jd-details-descr'> 276 <table class='jd-tagtable'><tbody> 277 <tr> 278 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicInc(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr); 279</td> 280 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 281 </td> 282 </tr> 283 <tr> 284 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicInc(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr); 285</td> 286 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 287 </td> 288 </tr> 289 </tbody></table> 290 </div> 291 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 292 <table class='jd-tagtable'><tbody> 293 <tr><th>addr</th><td>Address of the value to increment.</td></tr> 294 </tbody></table> 295 </div> 296 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 297 <table class='jd-tagtable'><tbody> 298 <tr><td>Value of *addr prior to the operation.</td></tr> 299 </tbody></table> 300 </div> 301 <div class='jd-tagdata jd-tagdescr'> 302<p> Atomicly adds one to the value at addr. This is equivalent to <code><a href='rs_atomic.html#android_rs:rsAtomicAdd'>rsAtomicAdd</a>(addr, 1)</code>. 303</p> 304 </div> 305</div> 306 307<a name='android_rs:rsAtomicMax'></a> 308<div class='jd-details'> 309 <h4 class='jd-details-title'> 310 <span class='sympad'>rsAtomicMax</span> 311 <span class='normal'>: Thread-safe maximum</span> 312 </h4> 313 <div class='jd-details-descr'> 314 <table class='jd-tagtable'><tbody> 315 <tr> 316 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicMax(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 317</td> 318 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 319 </td> 320 </tr> 321 <tr> 322 <td><a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> rsAtomicMax(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 323</td> 324 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 325 </td> 326 </tr> 327 </tbody></table> 328 </div> 329 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 330 <table class='jd-tagtable'><tbody> 331 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 332 <tr><th>value</th><td>Comparison value.</td></tr> 333 </tbody></table> 334 </div> 335 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 336 <table class='jd-tagtable'><tbody> 337 <tr><td>Value of *addr prior to the operation.</td></tr> 338 </tbody></table> 339 </div> 340 <div class='jd-tagdata jd-tagdescr'> 341<p> Atomicly sets the value at addr to the maximum of *addr and value, i.e. 342<code>*addr = max(*addr, value)</code>. 343</p> 344 </div> 345</div> 346 347<a name='android_rs:rsAtomicMin'></a> 348<div class='jd-details'> 349 <h4 class='jd-details-title'> 350 <span class='sympad'>rsAtomicMin</span> 351 <span class='normal'>: Thread-safe minimum</span> 352 </h4> 353 <div class='jd-details-descr'> 354 <table class='jd-tagtable'><tbody> 355 <tr> 356 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicMin(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 357</td> 358 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 359 </td> 360 </tr> 361 <tr> 362 <td><a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> rsAtomicMin(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 363</td> 364 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 365 </td> 366 </tr> 367 </tbody></table> 368 </div> 369 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 370 <table class='jd-tagtable'><tbody> 371 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 372 <tr><th>value</th><td>Comparison value.</td></tr> 373 </tbody></table> 374 </div> 375 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 376 <table class='jd-tagtable'><tbody> 377 <tr><td>Value of *addr prior to the operation.</td></tr> 378 </tbody></table> 379 </div> 380 <div class='jd-tagdata jd-tagdescr'> 381<p> Atomicly sets the value at addr to the minimum of *addr and value, i.e. 382<code>*addr = min(*addr, value)</code>. 383</p> 384 </div> 385</div> 386 387<a name='android_rs:rsAtomicOr'></a> 388<div class='jd-details'> 389 <h4 class='jd-details-title'> 390 <span class='sympad'>rsAtomicOr</span> 391 <span class='normal'>: Thread-safe bitwise or</span> 392 </h4> 393 <div class='jd-details-descr'> 394 <table class='jd-tagtable'><tbody> 395 <tr> 396 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicOr(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 397</td> 398 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 399 </td> 400 </tr> 401 <tr> 402 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicOr(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 403</td> 404 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 405 </td> 406 </tr> 407 </tbody></table> 408 </div> 409 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 410 <table class='jd-tagtable'><tbody> 411 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 412 <tr><th>value</th><td>Value to or with.</td></tr> 413 </tbody></table> 414 </div> 415 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 416 <table class='jd-tagtable'><tbody> 417 <tr><td>Value of *addr prior to the operation.</td></tr> 418 </tbody></table> 419 </div> 420 <div class='jd-tagdata jd-tagdescr'> 421<p> Atomicly perform a bitwise or two values, storing the result at addr, 422i.e. <code>*addr |= value</code>. 423</p> 424 </div> 425</div> 426 427<a name='android_rs:rsAtomicSub'></a> 428<div class='jd-details'> 429 <h4 class='jd-details-title'> 430 <span class='sympad'>rsAtomicSub</span> 431 <span class='normal'>: Thread-safe subtraction</span> 432 </h4> 433 <div class='jd-details-descr'> 434 <table class='jd-tagtable'><tbody> 435 <tr> 436 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicSub(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 437</td> 438 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 439 </td> 440 </tr> 441 <tr> 442 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicSub(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 443</td> 444 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 445 </td> 446 </tr> 447 </tbody></table> 448 </div> 449 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 450 <table class='jd-tagtable'><tbody> 451 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 452 <tr><th>value</th><td>Amount to subtract.</td></tr> 453 </tbody></table> 454 </div> 455 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 456 <table class='jd-tagtable'><tbody> 457 <tr><td>Value of *addr prior to the operation.</td></tr> 458 </tbody></table> 459 </div> 460 <div class='jd-tagdata jd-tagdescr'> 461<p> Atomicly subtracts a value from the value at addr, i.e. <code>*addr -= value</code>. 462</p> 463 </div> 464</div> 465 466<a name='android_rs:rsAtomicXor'></a> 467<div class='jd-details'> 468 <h4 class='jd-details-title'> 469 <span class='sympad'>rsAtomicXor</span> 470 <span class='normal'>: Thread-safe bitwise exclusive or</span> 471 </h4> 472 <div class='jd-details-descr'> 473 <table class='jd-tagtable'><tbody> 474 <tr> 475 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicXor(volatile <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a>* addr, <a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> value); 476</td> 477 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 14</a> 478 </td> 479 </tr> 480 <tr> 481 <td><a href='rs_value_types.html#android_rs:int32_t'>int32_t</a> rsAtomicXor(volatile <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a>* addr, <a href='rs_value_types.html#android_rs:uint32_t'>uint32_t</a> value); 482</td> 483 <td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 20</a> 484 </td> 485 </tr> 486 </tbody></table> 487 </div> 488 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Parameters</h5> 489 <table class='jd-tagtable'><tbody> 490 <tr><th>addr</th><td>Address of the value to modify.</td></tr> 491 <tr><th>value</th><td>Value to xor with.</td></tr> 492 </tbody></table> 493 </div> 494 <div class='jd-tagdata'> <h5 class='jd-tagtitle'>Returns</h5> 495 <table class='jd-tagtable'><tbody> 496 <tr><td>Value of *addr prior to the operation.</td></tr> 497 </tbody></table> 498 </div> 499 <div class='jd-tagdata jd-tagdescr'> 500<p> Atomicly performs a bitwise xor of two values, storing the result at addr, 501i.e. <code>*addr ^= value</code>. 502</p> 503 </div> 504</div> 505 506</div> 507