1 // -*- C++ -*- header. 2 3 // Copyright (C) 2008, 2009 4 // Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /** @file bits/atomic_0.h 27 * This is an internal header file, included by other library headers. 28 * You should not attempt to use it directly. 29 */ 30 31 #ifndef _GLIBCXX_ATOMIC_0_H 32 #define _GLIBCXX_ATOMIC_0_H 1 33 34 #pragma GCC system_header 35 36 // _GLIBCXX_BEGIN_NAMESPACE(std) 37 38 // 0 == __atomic0 == Never lock-free 39 namespace __atomic0 40 { 41 struct atomic_flag; 42 43 // Implementation specific defines. 44 #define _ATOMIC_LOAD_(__a, __x) \ 45 ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_; \ 46 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); \ 47 __atomic_flag_wait_explicit(__g, __x); \ 48 __typeof__ _ATOMIC_MEMBER_ __r = *__p; \ 49 atomic_flag_clear_explicit(__g, __x); \ 50 __r; }) 51 52 #define _ATOMIC_STORE_(__a, __m, __x) \ 53 ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_; \ 54 __typeof__(__m) __v = (__m); \ 55 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); \ 56 __atomic_flag_wait_explicit(__g, __x); \ 57 *__p = __v; \ 58 atomic_flag_clear_explicit(__g, __x); \ 59 __v; }) 60 61 #define _ATOMIC_MODIFY_(__a, __o, __m, __x) \ 62 ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_; \ 63 __typeof__(__m) __v = (__m); \ 64 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); \ 65 __atomic_flag_wait_explicit(__g, __x); \ 66 __typeof__ _ATOMIC_MEMBER_ __r = *__p; \ 67 *__p __o __v; \ 68 atomic_flag_clear_explicit(__g, __x); \ 69 __r; }) 70 71 #define _ATOMIC_CMPEXCHNG_(__a, __e, __m, __x) \ 72 ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_; \ 73 __typeof__(__e) __q = (__e); \ 74 __typeof__(__m) __v = (__m); \ 75 bool __r; \ 76 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); \ 77 __atomic_flag_wait_explicit(__g, __x); \ 78 __typeof__ _ATOMIC_MEMBER_ __t__ = *__p; \ 79 if (__t__ == *__q) { *__p = __v; __r = true; } \ 80 else { *__q = __t__; __r = false; } \ 81 atomic_flag_clear_explicit(__g, __x); \ 82 __r; }) 83 84 /// atomic_flag 85 struct atomic_flag : public __atomic_flag_base 86 { 87 atomic_flag() = default; 88 ~atomic_flag() = default; 89 atomic_flag(const atomic_flag&) = delete; 90 atomic_flag& operator=(const atomic_flag&) = delete; 91 92 // Conversion to ATOMIC_FLAG_INIT. 93 atomic_flag(bool __i): __atomic_flag_base({ __i }) { } 94 95 bool 96 test_and_set(memory_order __m = memory_order_seq_cst) volatile; 97 98 void 99 clear(memory_order __m = memory_order_seq_cst) volatile; 100 }; 101 102 /// 29.4.2, address types 103 struct atomic_address 104 { 105 private: 106 void* _M_i; 107 108 public: 109 atomic_address() = default; 110 ~atomic_address() = default; 111 atomic_address(const atomic_address&) = delete; 112 atomic_address& operator=(const atomic_address&) = delete; 113 114 atomic_address(void* __v) { _M_i = __v; } 115 116 bool 117 is_lock_free() const volatile 118 { return false; } 119 120 void 121 store(void* __v, memory_order __m = memory_order_seq_cst) volatile 122 { 123 __glibcxx_assert(__m != memory_order_acquire); 124 __glibcxx_assert(__m != memory_order_acq_rel); 125 __glibcxx_assert(__m != memory_order_consume); 126 _ATOMIC_STORE_(this, __v, __m); 127 } 128 129 void* 130 load(memory_order __m = memory_order_seq_cst) const volatile 131 { 132 __glibcxx_assert(__m != memory_order_release); 133 __glibcxx_assert(__m != memory_order_acq_rel); 134 return _ATOMIC_LOAD_(this, __m); 135 } 136 137 void* 138 exchange(void* __v, memory_order __m = memory_order_seq_cst) volatile 139 { return _ATOMIC_MODIFY_(this, =, __v, __m); } 140 141 bool 142 compare_exchange_weak(void*& __v1, void* __v2, memory_order __m1, 143 memory_order __m2) volatile 144 { 145 __glibcxx_assert(__m2 != memory_order_release); 146 __glibcxx_assert(__m2 != memory_order_acq_rel); 147 __glibcxx_assert(__m2 <= __m1); 148 return _ATOMIC_CMPEXCHNG_(this, &__v1, __v2, __m1); 149 } 150 151 bool 152 compare_exchange_weak(void*& __v1, void* __v2, 153 memory_order __m = memory_order_seq_cst) volatile 154 { 155 return compare_exchange_weak(__v1, __v2, __m, 156 __calculate_memory_order(__m)); 157 } 158 159 bool 160 compare_exchange_strong(void*& __v1, void* __v2, memory_order __m1, 161 memory_order __m2) volatile 162 { 163 __glibcxx_assert(__m2 != memory_order_release); 164 __glibcxx_assert(__m2 != memory_order_acq_rel); 165 __glibcxx_assert(__m2 <= __m1); 166 return _ATOMIC_CMPEXCHNG_(this, &__v1, __v2, __m1); 167 } 168 169 bool 170 compare_exchange_strong(void*& __v1, void* __v2, 171 memory_order __m = memory_order_seq_cst) volatile 172 { 173 return compare_exchange_strong(__v1, __v2, __m, 174 __calculate_memory_order(__m)); 175 } 176 177 void* 178 fetch_add(ptrdiff_t __d, memory_order __m = memory_order_seq_cst) volatile 179 { 180 void* volatile* __p = &(_M_i); 181 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); 182 __atomic_flag_wait_explicit(__g, __m); 183 void* __r = *__p; 184 *__p = (void*)((char*)(*__p) + __d); 185 atomic_flag_clear_explicit(__g, __m); 186 return __r; 187 } 188 189 void* 190 fetch_sub(ptrdiff_t __d, memory_order __m = memory_order_seq_cst) volatile 191 { 192 void* volatile* __p = &(_M_i); 193 volatile __atomic_flag_base* __g = __atomic_flag_for_address(__p); 194 __atomic_flag_wait_explicit(__g, __m); 195 void* __r = *__p; 196 *__p = (void*)((char*)(*__p) - __d); 197 atomic_flag_clear_explicit(__g, __m); 198 return __r; 199 } 200 201 operator void*() const volatile 202 { return load(); } 203 204 void* 205 operator=(void* __v) // XXX volatile 206 { 207 store(__v); 208 return __v; 209 } 210 211 void* 212 operator+=(ptrdiff_t __d) volatile 213 { return fetch_add(__d) + __d; } 214 215 void* 216 operator-=(ptrdiff_t __d) volatile 217 { return fetch_sub(__d) - __d; } 218 }; 219 220 221 // 29.3.1 atomic integral types 222 // For each of the integral types, define atomic_[integral type] struct 223 // 224 // atomic_bool bool 225 // atomic_char char 226 // atomic_schar signed char 227 // atomic_uchar unsigned char 228 // atomic_short short 229 // atomic_ushort unsigned short 230 // atomic_int int 231 // atomic_uint unsigned int 232 // atomic_long long 233 // atomic_ulong unsigned long 234 // atomic_llong long long 235 // atomic_ullong unsigned long long 236 // atomic_char16_t char16_t 237 // atomic_char32_t char32_t 238 // atomic_wchar_t wchar_t 239 240 // Base type. 241 // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or 8 bytes, 242 // since that is what GCC built-in functions for atomic memory access work on. 243 template<typename _ITp> 244 struct __atomic_base 245 { 246 private: 247 typedef _ITp __integral_type; 248 249 __integral_type _M_i; 250 251 public: 252 __atomic_base() = default; 253 ~__atomic_base() = default; 254 __atomic_base(const __atomic_base&) = delete; 255 __atomic_base& operator=(const __atomic_base&) = delete; 256 257 // Requires __integral_type convertible to _M_base._M_i. 258 __atomic_base(__integral_type __i) { _M_i = __i; } 259 260 operator __integral_type() const volatile 261 { return load(); } 262 263 __integral_type 264 operator=(__integral_type __i) // XXX volatile 265 { 266 store(__i); 267 return __i; 268 } 269 270 __integral_type 271 operator++(int) volatile 272 { return fetch_add(1); } 273 274 __integral_type 275 operator--(int) volatile 276 { return fetch_sub(1); } 277 278 __integral_type 279 operator++() volatile 280 { return fetch_add(1) + 1; } 281 282 __integral_type 283 operator--() volatile 284 { return fetch_sub(1) - 1; } 285 286 __integral_type 287 operator+=(__integral_type __i) volatile 288 { return fetch_add(__i) + __i; } 289 290 __integral_type 291 operator-=(__integral_type __i) volatile 292 { return fetch_sub(__i) - __i; } 293 294 __integral_type 295 operator&=(__integral_type __i) volatile 296 { return fetch_and(__i) & __i; } 297 298 __integral_type 299 operator|=(__integral_type __i) volatile 300 { return fetch_or(__i) | __i; } 301 302 __integral_type 303 operator^=(__integral_type __i) volatile 304 { return fetch_xor(__i) ^ __i; } 305 306 bool 307 is_lock_free() const volatile 308 { return false; } 309 310 void 311 store(__integral_type __i, 312 memory_order __m = memory_order_seq_cst) volatile 313 { 314 __glibcxx_assert(__m != memory_order_acquire); 315 __glibcxx_assert(__m != memory_order_acq_rel); 316 __glibcxx_assert(__m != memory_order_consume); 317 _ATOMIC_STORE_(this, __i, __m); 318 } 319 320 __integral_type 321 load(memory_order __m = memory_order_seq_cst) const volatile 322 { 323 __glibcxx_assert(__m != memory_order_release); 324 __glibcxx_assert(__m != memory_order_acq_rel); 325 return _ATOMIC_LOAD_(this, __m); 326 } 327 328 __integral_type 329 exchange(__integral_type __i, 330 memory_order __m = memory_order_seq_cst) volatile 331 { return _ATOMIC_MODIFY_(this, =, __i, __m); } 332 333 bool 334 compare_exchange_weak(__integral_type& __i1, __integral_type __i2, 335 memory_order __m1, memory_order __m2) volatile 336 { 337 __glibcxx_assert(__m2 != memory_order_release); 338 __glibcxx_assert(__m2 != memory_order_acq_rel); 339 __glibcxx_assert(__m2 <= __m1); 340 return _ATOMIC_CMPEXCHNG_(this, &__i1, __i2, __m1); 341 } 342 343 bool 344 compare_exchange_weak(__integral_type& __i1, __integral_type __i2, 345 memory_order __m = memory_order_seq_cst) volatile 346 { 347 return compare_exchange_weak(__i1, __i2, __m, 348 __calculate_memory_order(__m)); 349 } 350 351 bool 352 compare_exchange_strong(__integral_type& __i1, __integral_type __i2, 353 memory_order __m1, memory_order __m2) volatile 354 { 355 __glibcxx_assert(__m2 != memory_order_release); 356 __glibcxx_assert(__m2 != memory_order_acq_rel); 357 __glibcxx_assert(__m2 <= __m1); 358 return _ATOMIC_CMPEXCHNG_(this, &__i1, __i2, __m1); 359 } 360 361 bool 362 compare_exchange_strong(__integral_type& __i1, __integral_type __i2, 363 memory_order __m = memory_order_seq_cst) volatile 364 { 365 return compare_exchange_strong(__i1, __i2, __m, 366 __calculate_memory_order(__m)); 367 } 368 369 __integral_type 370 fetch_add(__integral_type __i, 371 memory_order __m = memory_order_seq_cst) volatile 372 { return _ATOMIC_MODIFY_(this, +=, __i, __m); } 373 374 __integral_type 375 fetch_sub(__integral_type __i, 376 memory_order __m = memory_order_seq_cst) volatile 377 { return _ATOMIC_MODIFY_(this, -=, __i, __m); } 378 379 __integral_type 380 fetch_and(__integral_type __i, 381 memory_order __m = memory_order_seq_cst) volatile 382 { return _ATOMIC_MODIFY_(this, &=, __i, __m); } 383 384 __integral_type 385 fetch_or(__integral_type __i, 386 memory_order __m = memory_order_seq_cst) volatile 387 { return _ATOMIC_MODIFY_(this, |=, __i, __m); } 388 389 __integral_type 390 fetch_xor(__integral_type __i, 391 memory_order __m = memory_order_seq_cst) volatile 392 { return _ATOMIC_MODIFY_(this, ^=, __i, __m); } 393 }; 394 395 396 /// atomic_bool 397 // NB: No operators or fetch-operations for this type. 398 struct atomic_bool 399 { 400 private: 401 __atomic_base<bool> _M_base; 402 403 public: 404 atomic_bool() = default; 405 ~atomic_bool() = default; 406 atomic_bool(const atomic_bool&) = delete; 407 atomic_bool& operator=(const atomic_bool&) = delete; 408 409 atomic_bool(bool __i) : _M_base(__i) { } 410 411 bool 412 operator=(bool __i) // XXX volatile 413 { return _M_base.operator=(__i); } 414 415 operator bool() const volatile 416 { return _M_base.load(); } 417 418 bool 419 is_lock_free() const volatile 420 { return _M_base.is_lock_free(); } 421 422 void 423 store(bool __i, memory_order __m = memory_order_seq_cst) volatile 424 { _M_base.store(__i, __m); } 425 426 bool 427 load(memory_order __m = memory_order_seq_cst) const volatile 428 { return _M_base.load(__m); } 429 430 bool 431 exchange(bool __i, memory_order __m = memory_order_seq_cst) volatile 432 { return _M_base.exchange(__i, __m); } 433 434 bool 435 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1, 436 memory_order __m2) volatile 437 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); } 438 439 bool 440 compare_exchange_weak(bool& __i1, bool __i2, 441 memory_order __m = memory_order_seq_cst) volatile 442 { return _M_base.compare_exchange_weak(__i1, __i2, __m); } 443 444 bool 445 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1, 446 memory_order __m2) volatile 447 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); } 448 449 450 bool 451 compare_exchange_strong(bool& __i1, bool __i2, 452 memory_order __m = memory_order_seq_cst) volatile 453 { return _M_base.compare_exchange_strong(__i1, __i2, __m); } 454 }; 455 456 #undef _ATOMIC_LOAD_ 457 #undef _ATOMIC_STORE_ 458 #undef _ATOMIC_MODIFY_ 459 #undef _ATOMIC_CMPEXCHNG_ 460 } // namespace __atomic0 461 462 // _GLIBCXX_END_NAMESPACE 463 464 #endif 465
