1 // -*- C++ -*- header. 2 3 // Copyright (C) 2008-2022 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file bits/atomic_base.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{atomic} 28 */ 29 30 #ifndef _GLIBCXX_ATOMIC_BASE_H 31 #define _GLIBCXX_ATOMIC_BASE_H 1 32 33 #pragma GCC system_header 34 35 #include <bits/c++config.h> 36 #include <stdint.h> 37 #include <bits/atomic_lockfree_defines.h> 38 #include <bits/move.h> 39 40 #if __cplusplus > 201703L && _GLIBCXX_HOSTED 41 #include <bits/atomic_wait.h> 42 #endif 43 44 #ifndef _GLIBCXX_ALWAYS_INLINE 45 #define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__)) 46 #endif 47 48 namespace std _GLIBCXX_VISIBILITY(default) 49 { 50 _GLIBCXX_BEGIN_NAMESPACE_VERSION 51 52 /** 53 * @defgroup atomics Atomics 54 * 55 * Components for performing atomic operations. 56 * @{ 57 */ 58 59 /// Enumeration for memory_order 60 #if __cplusplus > 201703L 61 enum class memory_order : int 62 { 63 relaxed, 64 consume, 65 acquire, 66 release, 67 acq_rel, 68 seq_cst 69 }; 70 71 inline constexpr memory_order memory_order_relaxed = memory_order::relaxed; 72 inline constexpr memory_order memory_order_consume = memory_order::consume; 73 inline constexpr memory_order memory_order_acquire = memory_order::acquire; 74 inline constexpr memory_order memory_order_release = memory_order::release; 75 inline constexpr memory_order memory_order_acq_rel = memory_order::acq_rel; 76 inline constexpr memory_order memory_order_seq_cst = memory_order::seq_cst; 77 #else 78 typedef enum memory_order 79 { 80 memory_order_relaxed, 81 memory_order_consume, 82 memory_order_acquire, 83 memory_order_release, 84 memory_order_acq_rel, 85 memory_order_seq_cst 86 } memory_order; 87 #endif 88 89 enum __memory_order_modifier 90 { 91 __memory_order_mask = 0x0ffff, 92 __memory_order_modifier_mask = 0xffff0000, 93 __memory_order_hle_acquire = 0x10000, 94 __memory_order_hle_release = 0x20000 95 }; 96 97 constexpr memory_order 98 operator|(memory_order __m, __memory_order_modifier __mod) 99 { 100 return memory_order(int(__m) | int(__mod)); 101 } 102 103 constexpr memory_order 104 operator&(memory_order __m, __memory_order_modifier __mod) 105 { 106 return memory_order(int(__m) & int(__mod)); 107 } 108 109 // Drop release ordering as per [atomics.types.operations.req]/21 110 constexpr memory_order 111 __cmpexch_failure_order2(memory_order __m) noexcept 112 { 113 return __m == memory_order_acq_rel ? memory_order_acquire 114 : __m == memory_order_release ? memory_order_relaxed : __m; 115 } 116 117 constexpr memory_order 118 __cmpexch_failure_order(memory_order __m) noexcept 119 { 120 return memory_order(__cmpexch_failure_order2(__m & __memory_order_mask) 121 | __memory_order_modifier(__m & __memory_order_modifier_mask)); 122 } 123 124 constexpr bool 125 __is_valid_cmpexch_failure_order(memory_order __m) noexcept 126 { 127 return (__m & __memory_order_mask) != memory_order_release 128 && (__m & __memory_order_mask) != memory_order_acq_rel; 129 } 130 131 _GLIBCXX_ALWAYS_INLINE void 132 atomic_thread_fence(memory_order __m) noexcept 133 { __atomic_thread_fence(int(__m)); } 134 135 _GLIBCXX_ALWAYS_INLINE void 136 atomic_signal_fence(memory_order __m) noexcept 137 { __atomic_signal_fence(int(__m)); } 138 139 /// kill_dependency 140 template<typename _Tp> 141 inline _Tp 142 kill_dependency(_Tp __y) noexcept 143 { 144 _Tp __ret(__y); 145 return __ret; 146 } 147 148 // Base types for atomics. 149 template<typename _IntTp> 150 struct __atomic_base; 151 152 #if __cplusplus <= 201703L 153 # define _GLIBCXX20_INIT(I) 154 #else 155 # define __cpp_lib_atomic_value_initialization 201911L 156 # define _GLIBCXX20_INIT(I) = I 157 #endif 158 159 #define ATOMIC_VAR_INIT(_VI) { _VI } 160 161 template<typename _Tp> 162 struct atomic; 163 164 template<typename _Tp> 165 struct atomic<_Tp*>; 166 167 /* The target's "set" value for test-and-set may not be exactly 1. */ 168 #if __GCC_ATOMIC_TEST_AND_SET_TRUEVAL == 1 169 typedef bool __atomic_flag_data_type; 170 #else 171 typedef unsigned char __atomic_flag_data_type; 172 #endif 173 174 /** 175 * @brief Base type for atomic_flag. 176 * 177 * Base type is POD with data, allowing atomic_flag to derive from 178 * it and meet the standard layout type requirement. In addition to 179 * compatibility with a C interface, this allows different 180 * implementations of atomic_flag to use the same atomic operation 181 * functions, via a standard conversion to the __atomic_flag_base 182 * argument. 183 */ 184 _GLIBCXX_BEGIN_EXTERN_C 185 186 struct __atomic_flag_base 187 { 188 __atomic_flag_data_type _M_i _GLIBCXX20_INIT({}); 189 }; 190 191 _GLIBCXX_END_EXTERN_C 192 193 #define ATOMIC_FLAG_INIT { 0 } 194 195 /// atomic_flag 196 struct atomic_flag : public __atomic_flag_base 197 { 198 atomic_flag() noexcept = default; 199 ~atomic_flag() noexcept = default; 200 atomic_flag(const atomic_flag&) = delete; 201 atomic_flag& operator=(const atomic_flag&) = delete; 202 atomic_flag& operator=(const atomic_flag&) volatile = delete; 203 204 // Conversion to ATOMIC_FLAG_INIT. 205 constexpr atomic_flag(bool __i) noexcept 206 : __atomic_flag_base{ _S_init(__i) } 207 { } 208 209 _GLIBCXX_ALWAYS_INLINE bool 210 test_and_set(memory_order __m = memory_order_seq_cst) noexcept 211 { 212 return __atomic_test_and_set (&_M_i, int(__m)); 213 } 214 215 _GLIBCXX_ALWAYS_INLINE bool 216 test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept 217 { 218 return __atomic_test_and_set (&_M_i, int(__m)); 219 } 220 221 #if __cplusplus > 201703L 222 #define __cpp_lib_atomic_flag_test 201907L 223 224 _GLIBCXX_ALWAYS_INLINE bool 225 test(memory_order __m = memory_order_seq_cst) const noexcept 226 { 227 __atomic_flag_data_type __v; 228 __atomic_load(&_M_i, &__v, int(__m)); 229 return __v == __GCC_ATOMIC_TEST_AND_SET_TRUEVAL; 230 } 231 232 _GLIBCXX_ALWAYS_INLINE bool 233 test(memory_order __m = memory_order_seq_cst) const volatile noexcept 234 { 235 __atomic_flag_data_type __v; 236 __atomic_load(&_M_i, &__v, int(__m)); 237 return __v == __GCC_ATOMIC_TEST_AND_SET_TRUEVAL; 238 } 239 240 #if __cpp_lib_atomic_wait 241 _GLIBCXX_ALWAYS_INLINE void 242 wait(bool __old, 243 memory_order __m = memory_order_seq_cst) const noexcept 244 { 245 const __atomic_flag_data_type __v 246 = __old ? __GCC_ATOMIC_TEST_AND_SET_TRUEVAL : 0; 247 248 std::__atomic_wait_address_v(&_M_i, __v, 249 [__m, this] { return __atomic_load_n(&_M_i, int(__m)); }); 250 } 251 252 // TODO add const volatile overload 253 254 _GLIBCXX_ALWAYS_INLINE void 255 notify_one() noexcept 256 { std::__atomic_notify_address(&_M_i, false); } 257 258 // TODO add const volatile overload 259 260 _GLIBCXX_ALWAYS_INLINE void 261 notify_all() noexcept 262 { std::__atomic_notify_address(&_M_i, true); } 263 264 // TODO add const volatile overload 265 #endif // __cpp_lib_atomic_wait 266 #endif // C++20 267 268 _GLIBCXX_ALWAYS_INLINE void 269 clear(memory_order __m = memory_order_seq_cst) noexcept 270 { 271 memory_order __b __attribute__ ((__unused__)) 272 = __m & __memory_order_mask; 273 __glibcxx_assert(__b != memory_order_consume); 274 __glibcxx_assert(__b != memory_order_acquire); 275 __glibcxx_assert(__b != memory_order_acq_rel); 276 277 __atomic_clear (&_M_i, int(__m)); 278 } 279 280 _GLIBCXX_ALWAYS_INLINE void 281 clear(memory_order __m = memory_order_seq_cst) volatile noexcept 282 { 283 memory_order __b __attribute__ ((__unused__)) 284 = __m & __memory_order_mask; 285 __glibcxx_assert(__b != memory_order_consume); 286 __glibcxx_assert(__b != memory_order_acquire); 287 __glibcxx_assert(__b != memory_order_acq_rel); 288 289 __atomic_clear (&_M_i, int(__m)); 290 } 291 292 private: 293 static constexpr __atomic_flag_data_type 294 _S_init(bool __i) 295 { return __i ? __GCC_ATOMIC_TEST_AND_SET_TRUEVAL : 0; } 296 }; 297 298 299 /// Base class for atomic integrals. 300 // 301 // For each of the integral types, define atomic_[integral type] struct 302 // 303 // atomic_bool bool 304 // atomic_char char 305 // atomic_schar signed char 306 // atomic_uchar unsigned char 307 // atomic_short short 308 // atomic_ushort unsigned short 309 // atomic_int int 310 // atomic_uint unsigned int 311 // atomic_long long 312 // atomic_ulong unsigned long 313 // atomic_llong long long 314 // atomic_ullong unsigned long long 315 // atomic_char8_t char8_t 316 // atomic_char16_t char16_t 317 // atomic_char32_t char32_t 318 // atomic_wchar_t wchar_t 319 // 320 // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or 321 // 8 bytes, since that is what GCC built-in functions for atomic 322 // memory access expect. 323 template<typename _ITp> 324 struct __atomic_base 325 { 326 using value_type = _ITp; 327 using difference_type = value_type; 328 329 private: 330 typedef _ITp __int_type; 331 332 static constexpr int _S_alignment = 333 sizeof(_ITp) > alignof(_ITp) ? sizeof(_ITp) : alignof(_ITp); 334 335 alignas(_S_alignment) __int_type _M_i _GLIBCXX20_INIT(0); 336 337 public: 338 __atomic_base() noexcept = default; 339 ~__atomic_base() noexcept = default; 340 __atomic_base(const __atomic_base&) = delete; 341 __atomic_base& operator=(const __atomic_base&) = delete; 342 __atomic_base& operator=(const __atomic_base&) volatile = delete; 343 344 // Requires __int_type convertible to _M_i. 345 constexpr __atomic_base(__int_type __i) noexcept : _M_i (__i) { } 346 347 operator __int_type() const noexcept 348 { return load(); } 349 350 operator __int_type() const volatile noexcept 351 { return load(); } 352 353 __int_type 354 operator=(__int_type __i) noexcept 355 { 356 store(__i); 357 return __i; 358 } 359 360 __int_type 361 operator=(__int_type __i) volatile noexcept 362 { 363 store(__i); 364 return __i; 365 } 366 367 __int_type 368 operator++(int) noexcept 369 { return fetch_add(1); } 370 371 __int_type 372 operator++(int) volatile noexcept 373 { return fetch_add(1); } 374 375 __int_type 376 operator--(int) noexcept 377 { return fetch_sub(1); } 378 379 __int_type 380 operator--(int) volatile noexcept 381 { return fetch_sub(1); } 382 383 __int_type 384 operator++() noexcept 385 { return __atomic_add_fetch(&_M_i, 1, int(memory_order_seq_cst)); } 386 387 __int_type 388 operator++() volatile noexcept 389 { return __atomic_add_fetch(&_M_i, 1, int(memory_order_seq_cst)); } 390 391 __int_type 392 operator--() noexcept 393 { return __atomic_sub_fetch(&_M_i, 1, int(memory_order_seq_cst)); } 394 395 __int_type 396 operator--() volatile noexcept 397 { return __atomic_sub_fetch(&_M_i, 1, int(memory_order_seq_cst)); } 398 399 __int_type 400 operator+=(__int_type __i) noexcept 401 { return __atomic_add_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 402 403 __int_type 404 operator+=(__int_type __i) volatile noexcept 405 { return __atomic_add_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 406 407 __int_type 408 operator-=(__int_type __i) noexcept 409 { return __atomic_sub_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 410 411 __int_type 412 operator-=(__int_type __i) volatile noexcept 413 { return __atomic_sub_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 414 415 __int_type 416 operator&=(__int_type __i) noexcept 417 { return __atomic_and_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 418 419 __int_type 420 operator&=(__int_type __i) volatile noexcept 421 { return __atomic_and_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 422 423 __int_type 424 operator|=(__int_type __i) noexcept 425 { return __atomic_or_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 426 427 __int_type 428 operator|=(__int_type __i) volatile noexcept 429 { return __atomic_or_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 430 431 __int_type 432 operator^=(__int_type __i) noexcept 433 { return __atomic_xor_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 434 435 __int_type 436 operator^=(__int_type __i) volatile noexcept 437 { return __atomic_xor_fetch(&_M_i, __i, int(memory_order_seq_cst)); } 438 439 bool 440 is_lock_free() const noexcept 441 { 442 // Use a fake, minimally aligned pointer. 443 return __atomic_is_lock_free(sizeof(_M_i), 444 reinterpret_cast<void *>(-_S_alignment)); 445 } 446 447 bool 448 is_lock_free() const volatile noexcept 449 { 450 // Use a fake, minimally aligned pointer. 451 return __atomic_is_lock_free(sizeof(_M_i), 452 reinterpret_cast<void *>(-_S_alignment)); 453 } 454 455 _GLIBCXX_ALWAYS_INLINE void 456 store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept 457 { 458 memory_order __b __attribute__ ((__unused__)) 459 = __m & __memory_order_mask; 460 __glibcxx_assert(__b != memory_order_acquire); 461 __glibcxx_assert(__b != memory_order_acq_rel); 462 __glibcxx_assert(__b != memory_order_consume); 463 464 __atomic_store_n(&_M_i, __i, int(__m)); 465 } 466 467 _GLIBCXX_ALWAYS_INLINE void 468 store(__int_type __i, 469 memory_order __m = memory_order_seq_cst) volatile noexcept 470 { 471 memory_order __b __attribute__ ((__unused__)) 472 = __m & __memory_order_mask; 473 __glibcxx_assert(__b != memory_order_acquire); 474 __glibcxx_assert(__b != memory_order_acq_rel); 475 __glibcxx_assert(__b != memory_order_consume); 476 477 __atomic_store_n(&_M_i, __i, int(__m)); 478 } 479 480 _GLIBCXX_ALWAYS_INLINE __int_type 481 load(memory_order __m = memory_order_seq_cst) const noexcept 482 { 483 memory_order __b __attribute__ ((__unused__)) 484 = __m & __memory_order_mask; 485 __glibcxx_assert(__b != memory_order_release); 486 __glibcxx_assert(__b != memory_order_acq_rel); 487 488 return __atomic_load_n(&_M_i, int(__m)); 489 } 490 491 _GLIBCXX_ALWAYS_INLINE __int_type 492 load(memory_order __m = memory_order_seq_cst) const volatile noexcept 493 { 494 memory_order __b __attribute__ ((__unused__)) 495 = __m & __memory_order_mask; 496 __glibcxx_assert(__b != memory_order_release); 497 __glibcxx_assert(__b != memory_order_acq_rel); 498 499 return __atomic_load_n(&_M_i, int(__m)); 500 } 501 502 _GLIBCXX_ALWAYS_INLINE __int_type 503 exchange(__int_type __i, 504 memory_order __m = memory_order_seq_cst) noexcept 505 { 506 return __atomic_exchange_n(&_M_i, __i, int(__m)); 507 } 508 509 510 _GLIBCXX_ALWAYS_INLINE __int_type 511 exchange(__int_type __i, 512 memory_order __m = memory_order_seq_cst) volatile noexcept 513 { 514 return __atomic_exchange_n(&_M_i, __i, int(__m)); 515 } 516 517 _GLIBCXX_ALWAYS_INLINE bool 518 compare_exchange_weak(__int_type& __i1, __int_type __i2, 519 memory_order __m1, memory_order __m2) noexcept 520 { 521 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 522 523 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, 524 int(__m1), int(__m2)); 525 } 526 527 _GLIBCXX_ALWAYS_INLINE bool 528 compare_exchange_weak(__int_type& __i1, __int_type __i2, 529 memory_order __m1, 530 memory_order __m2) volatile noexcept 531 { 532 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 533 534 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, 535 int(__m1), int(__m2)); 536 } 537 538 _GLIBCXX_ALWAYS_INLINE bool 539 compare_exchange_weak(__int_type& __i1, __int_type __i2, 540 memory_order __m = memory_order_seq_cst) noexcept 541 { 542 return compare_exchange_weak(__i1, __i2, __m, 543 __cmpexch_failure_order(__m)); 544 } 545 546 _GLIBCXX_ALWAYS_INLINE bool 547 compare_exchange_weak(__int_type& __i1, __int_type __i2, 548 memory_order __m = memory_order_seq_cst) volatile noexcept 549 { 550 return compare_exchange_weak(__i1, __i2, __m, 551 __cmpexch_failure_order(__m)); 552 } 553 554 _GLIBCXX_ALWAYS_INLINE bool 555 compare_exchange_strong(__int_type& __i1, __int_type __i2, 556 memory_order __m1, memory_order __m2) noexcept 557 { 558 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 559 560 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, 561 int(__m1), int(__m2)); 562 } 563 564 _GLIBCXX_ALWAYS_INLINE bool 565 compare_exchange_strong(__int_type& __i1, __int_type __i2, 566 memory_order __m1, 567 memory_order __m2) volatile noexcept 568 { 569 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 570 571 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, 572 int(__m1), int(__m2)); 573 } 574 575 _GLIBCXX_ALWAYS_INLINE bool 576 compare_exchange_strong(__int_type& __i1, __int_type __i2, 577 memory_order __m = memory_order_seq_cst) noexcept 578 { 579 return compare_exchange_strong(__i1, __i2, __m, 580 __cmpexch_failure_order(__m)); 581 } 582 583 _GLIBCXX_ALWAYS_INLINE bool 584 compare_exchange_strong(__int_type& __i1, __int_type __i2, 585 memory_order __m = memory_order_seq_cst) volatile noexcept 586 { 587 return compare_exchange_strong(__i1, __i2, __m, 588 __cmpexch_failure_order(__m)); 589 } 590 591 #if __cpp_lib_atomic_wait 592 _GLIBCXX_ALWAYS_INLINE void 593 wait(__int_type __old, 594 memory_order __m = memory_order_seq_cst) const noexcept 595 { 596 std::__atomic_wait_address_v(&_M_i, __old, 597 [__m, this] { return this->load(__m); }); 598 } 599 600 // TODO add const volatile overload 601 602 _GLIBCXX_ALWAYS_INLINE void 603 notify_one() noexcept 604 { std::__atomic_notify_address(&_M_i, false); } 605 606 // TODO add const volatile overload 607 608 _GLIBCXX_ALWAYS_INLINE void 609 notify_all() noexcept 610 { std::__atomic_notify_address(&_M_i, true); } 611 612 // TODO add const volatile overload 613 #endif // __cpp_lib_atomic_wait 614 615 _GLIBCXX_ALWAYS_INLINE __int_type 616 fetch_add(__int_type __i, 617 memory_order __m = memory_order_seq_cst) noexcept 618 { return __atomic_fetch_add(&_M_i, __i, int(__m)); } 619 620 _GLIBCXX_ALWAYS_INLINE __int_type 621 fetch_add(__int_type __i, 622 memory_order __m = memory_order_seq_cst) volatile noexcept 623 { return __atomic_fetch_add(&_M_i, __i, int(__m)); } 624 625 _GLIBCXX_ALWAYS_INLINE __int_type 626 fetch_sub(__int_type __i, 627 memory_order __m = memory_order_seq_cst) noexcept 628 { return __atomic_fetch_sub(&_M_i, __i, int(__m)); } 629 630 _GLIBCXX_ALWAYS_INLINE __int_type 631 fetch_sub(__int_type __i, 632 memory_order __m = memory_order_seq_cst) volatile noexcept 633 { return __atomic_fetch_sub(&_M_i, __i, int(__m)); } 634 635 _GLIBCXX_ALWAYS_INLINE __int_type 636 fetch_and(__int_type __i, 637 memory_order __m = memory_order_seq_cst) noexcept 638 { return __atomic_fetch_and(&_M_i, __i, int(__m)); } 639 640 _GLIBCXX_ALWAYS_INLINE __int_type 641 fetch_and(__int_type __i, 642 memory_order __m = memory_order_seq_cst) volatile noexcept 643 { return __atomic_fetch_and(&_M_i, __i, int(__m)); } 644 645 _GLIBCXX_ALWAYS_INLINE __int_type 646 fetch_or(__int_type __i, 647 memory_order __m = memory_order_seq_cst) noexcept 648 { return __atomic_fetch_or(&_M_i, __i, int(__m)); } 649 650 _GLIBCXX_ALWAYS_INLINE __int_type 651 fetch_or(__int_type __i, 652 memory_order __m = memory_order_seq_cst) volatile noexcept 653 { return __atomic_fetch_or(&_M_i, __i, int(__m)); } 654 655 _GLIBCXX_ALWAYS_INLINE __int_type 656 fetch_xor(__int_type __i, 657 memory_order __m = memory_order_seq_cst) noexcept 658 { return __atomic_fetch_xor(&_M_i, __i, int(__m)); } 659 660 _GLIBCXX_ALWAYS_INLINE __int_type 661 fetch_xor(__int_type __i, 662 memory_order __m = memory_order_seq_cst) volatile noexcept 663 { return __atomic_fetch_xor(&_M_i, __i, int(__m)); } 664 }; 665 666 667 /// Partial specialization for pointer types. 668 template<typename _PTp> 669 struct __atomic_base<_PTp*> 670 { 671 private: 672 typedef _PTp* __pointer_type; 673 674 __pointer_type _M_p _GLIBCXX20_INIT(nullptr); 675 676 // Factored out to facilitate explicit specialization. 677 constexpr ptrdiff_t 678 _M_type_size(ptrdiff_t __d) const { return __d * sizeof(_PTp); } 679 680 constexpr ptrdiff_t 681 _M_type_size(ptrdiff_t __d) const volatile { return __d * sizeof(_PTp); } 682 683 public: 684 __atomic_base() noexcept = default; 685 ~__atomic_base() noexcept = default; 686 __atomic_base(const __atomic_base&) = delete; 687 __atomic_base& operator=(const __atomic_base&) = delete; 688 __atomic_base& operator=(const __atomic_base&) volatile = delete; 689 690 // Requires __pointer_type convertible to _M_p. 691 constexpr __atomic_base(__pointer_type __p) noexcept : _M_p (__p) { } 692 693 operator __pointer_type() const noexcept 694 { return load(); } 695 696 operator __pointer_type() const volatile noexcept 697 { return load(); } 698 699 __pointer_type 700 operator=(__pointer_type __p) noexcept 701 { 702 store(__p); 703 return __p; 704 } 705 706 __pointer_type 707 operator=(__pointer_type __p) volatile noexcept 708 { 709 store(__p); 710 return __p; 711 } 712 713 __pointer_type 714 operator++(int) noexcept 715 { return fetch_add(1); } 716 717 __pointer_type 718 operator++(int) volatile noexcept 719 { return fetch_add(1); } 720 721 __pointer_type 722 operator--(int) noexcept 723 { return fetch_sub(1); } 724 725 __pointer_type 726 operator--(int) volatile noexcept 727 { return fetch_sub(1); } 728 729 __pointer_type 730 operator++() noexcept 731 { return __atomic_add_fetch(&_M_p, _M_type_size(1), 732 int(memory_order_seq_cst)); } 733 734 __pointer_type 735 operator++() volatile noexcept 736 { return __atomic_add_fetch(&_M_p, _M_type_size(1), 737 int(memory_order_seq_cst)); } 738 739 __pointer_type 740 operator--() noexcept 741 { return __atomic_sub_fetch(&_M_p, _M_type_size(1), 742 int(memory_order_seq_cst)); } 743 744 __pointer_type 745 operator--() volatile noexcept 746 { return __atomic_sub_fetch(&_M_p, _M_type_size(1), 747 int(memory_order_seq_cst)); } 748 749 __pointer_type 750 operator+=(ptrdiff_t __d) noexcept 751 { return __atomic_add_fetch(&_M_p, _M_type_size(__d), 752 int(memory_order_seq_cst)); } 753 754 __pointer_type 755 operator+=(ptrdiff_t __d) volatile noexcept 756 { return __atomic_add_fetch(&_M_p, _M_type_size(__d), 757 int(memory_order_seq_cst)); } 758 759 __pointer_type 760 operator-=(ptrdiff_t __d) noexcept 761 { return __atomic_sub_fetch(&_M_p, _M_type_size(__d), 762 int(memory_order_seq_cst)); } 763 764 __pointer_type 765 operator-=(ptrdiff_t __d) volatile noexcept 766 { return __atomic_sub_fetch(&_M_p, _M_type_size(__d), 767 int(memory_order_seq_cst)); } 768 769 bool 770 is_lock_free() const noexcept 771 { 772 // Produce a fake, minimally aligned pointer. 773 return __atomic_is_lock_free(sizeof(_M_p), 774 reinterpret_cast<void *>(-__alignof(_M_p))); 775 } 776 777 bool 778 is_lock_free() const volatile noexcept 779 { 780 // Produce a fake, minimally aligned pointer. 781 return __atomic_is_lock_free(sizeof(_M_p), 782 reinterpret_cast<void *>(-__alignof(_M_p))); 783 } 784 785 _GLIBCXX_ALWAYS_INLINE void 786 store(__pointer_type __p, 787 memory_order __m = memory_order_seq_cst) noexcept 788 { 789 memory_order __b __attribute__ ((__unused__)) 790 = __m & __memory_order_mask; 791 792 __glibcxx_assert(__b != memory_order_acquire); 793 __glibcxx_assert(__b != memory_order_acq_rel); 794 __glibcxx_assert(__b != memory_order_consume); 795 796 __atomic_store_n(&_M_p, __p, int(__m)); 797 } 798 799 _GLIBCXX_ALWAYS_INLINE void 800 store(__pointer_type __p, 801 memory_order __m = memory_order_seq_cst) volatile noexcept 802 { 803 memory_order __b __attribute__ ((__unused__)) 804 = __m & __memory_order_mask; 805 __glibcxx_assert(__b != memory_order_acquire); 806 __glibcxx_assert(__b != memory_order_acq_rel); 807 __glibcxx_assert(__b != memory_order_consume); 808 809 __atomic_store_n(&_M_p, __p, int(__m)); 810 } 811 812 _GLIBCXX_ALWAYS_INLINE __pointer_type 813 load(memory_order __m = memory_order_seq_cst) const noexcept 814 { 815 memory_order __b __attribute__ ((__unused__)) 816 = __m & __memory_order_mask; 817 __glibcxx_assert(__b != memory_order_release); 818 __glibcxx_assert(__b != memory_order_acq_rel); 819 820 return __atomic_load_n(&_M_p, int(__m)); 821 } 822 823 _GLIBCXX_ALWAYS_INLINE __pointer_type 824 load(memory_order __m = memory_order_seq_cst) const volatile noexcept 825 { 826 memory_order __b __attribute__ ((__unused__)) 827 = __m & __memory_order_mask; 828 __glibcxx_assert(__b != memory_order_release); 829 __glibcxx_assert(__b != memory_order_acq_rel); 830 831 return __atomic_load_n(&_M_p, int(__m)); 832 } 833 834 _GLIBCXX_ALWAYS_INLINE __pointer_type 835 exchange(__pointer_type __p, 836 memory_order __m = memory_order_seq_cst) noexcept 837 { 838 return __atomic_exchange_n(&_M_p, __p, int(__m)); 839 } 840 841 842 _GLIBCXX_ALWAYS_INLINE __pointer_type 843 exchange(__pointer_type __p, 844 memory_order __m = memory_order_seq_cst) volatile noexcept 845 { 846 return __atomic_exchange_n(&_M_p, __p, int(__m)); 847 } 848 849 _GLIBCXX_ALWAYS_INLINE bool 850 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2, 851 memory_order __m1, 852 memory_order __m2) noexcept 853 { 854 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 855 856 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 1, 857 int(__m1), int(__m2)); 858 } 859 860 _GLIBCXX_ALWAYS_INLINE bool 861 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2, 862 memory_order __m1, 863 memory_order __m2) volatile noexcept 864 { 865 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 866 867 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 1, 868 int(__m1), int(__m2)); 869 } 870 871 _GLIBCXX_ALWAYS_INLINE bool 872 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2, 873 memory_order __m1, 874 memory_order __m2) noexcept 875 { 876 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 877 878 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, 879 int(__m1), int(__m2)); 880 } 881 882 _GLIBCXX_ALWAYS_INLINE bool 883 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2, 884 memory_order __m1, 885 memory_order __m2) volatile noexcept 886 { 887 __glibcxx_assert(__is_valid_cmpexch_failure_order(__m2)); 888 889 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, 890 int(__m1), int(__m2)); 891 } 892 893 #if __cpp_lib_atomic_wait 894 _GLIBCXX_ALWAYS_INLINE void 895 wait(__pointer_type __old, 896 memory_order __m = memory_order_seq_cst) const noexcept 897 { 898 std::__atomic_wait_address_v(&_M_p, __old, 899 [__m, this] 900 { return this->load(__m); }); 901 } 902 903 // TODO add const volatile overload 904 905 _GLIBCXX_ALWAYS_INLINE void 906 notify_one() const noexcept 907 { std::__atomic_notify_address(&_M_p, false); } 908 909 // TODO add const volatile overload 910 911 _GLIBCXX_ALWAYS_INLINE void 912 notify_all() const noexcept 913 { std::__atomic_notify_address(&_M_p, true); } 914 915 // TODO add const volatile overload 916 #endif // __cpp_lib_atomic_wait 917 918 _GLIBCXX_ALWAYS_INLINE __pointer_type 919 fetch_add(ptrdiff_t __d, 920 memory_order __m = memory_order_seq_cst) noexcept 921 { return __atomic_fetch_add(&_M_p, _M_type_size(__d), int(__m)); } 922 923 _GLIBCXX_ALWAYS_INLINE __pointer_type 924 fetch_add(ptrdiff_t __d, 925 memory_order __m = memory_order_seq_cst) volatile noexcept 926 { return __atomic_fetch_add(&_M_p, _M_type_size(__d), int(__m)); } 927 928 _GLIBCXX_ALWAYS_INLINE __pointer_type 929 fetch_sub(ptrdiff_t __d, 930 memory_order __m = memory_order_seq_cst) noexcept 931 { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), int(__m)); } 932 933 _GLIBCXX_ALWAYS_INLINE __pointer_type 934 fetch_sub(ptrdiff_t __d, 935 memory_order __m = memory_order_seq_cst) volatile noexcept 936 { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), int(__m)); } 937 }; 938 939 #if __cplusplus > 201703L 940 // Implementation details of atomic_ref and atomic<floating-point>. 941 namespace __atomic_impl 942 { 943 // Remove volatile and create a non-deduced context for value arguments. 944 template<typename _Tp> 945 using _Val = remove_volatile_t<_Tp>; 946 947 // As above, but for difference_type arguments. 948 template<typename _Tp> 949 using _Diff = __conditional_t<is_pointer_v<_Tp>, ptrdiff_t, _Val<_Tp>>; 950 951 template<size_t _Size, size_t _Align> 952 _GLIBCXX_ALWAYS_INLINE bool 953 is_lock_free() noexcept 954 { 955 // Produce a fake, minimally aligned pointer. 956 return __atomic_is_lock_free(_Size, reinterpret_cast<void *>(-_Align)); 957 } 958 959 template<typename _Tp> 960 _GLIBCXX_ALWAYS_INLINE void 961 store(_Tp* __ptr, _Val<_Tp> __t, memory_order __m) noexcept 962 { __atomic_store(__ptr, std::__addressof(__t), int(__m)); } 963 964 template<typename _Tp> 965 _GLIBCXX_ALWAYS_INLINE _Val<_Tp> 966 load(const _Tp* __ptr, memory_order __m) noexcept 967 { 968 alignas(_Tp) unsigned char __buf[sizeof(_Tp)]; 969 auto* __dest = reinterpret_cast<_Val<_Tp>*>(__buf); 970 __atomic_load(__ptr, __dest, int(__m)); 971 return *__dest; 972 } 973 974 template<typename _Tp> 975 _GLIBCXX_ALWAYS_INLINE _Val<_Tp> 976 exchange(_Tp* __ptr, _Val<_Tp> __desired, memory_order __m) noexcept 977 { 978 alignas(_Tp) unsigned char __buf[sizeof(_Tp)]; 979 auto* __dest = reinterpret_cast<_Val<_Tp>*>(__buf); 980 __atomic_exchange(__ptr, std::__addressof(__desired), __dest, int(__m)); 981 return *__dest; 982 } 983 984 template<typename _Tp> 985 _GLIBCXX_ALWAYS_INLINE bool 986 compare_exchange_weak(_Tp* __ptr, _Val<_Tp>& __expected, 987 _Val<_Tp> __desired, memory_order __success, 988 memory_order __failure) noexcept 989 { 990 __glibcxx_assert(__is_valid_cmpexch_failure_order(__failure)); 991 992 return __atomic_compare_exchange(__ptr, std::__addressof(__expected), 993 std::__addressof(__desired), true, 994 int(__success), int(__failure)); 995 } 996 997 template<typename _Tp> 998 _GLIBCXX_ALWAYS_INLINE bool 999 compare_exchange_strong(_Tp* __ptr, _Val<_Tp>& __expected, 1000 _Val<_Tp> __desired, memory_order __success, 1001 memory_order __failure) noexcept 1002 { 1003 __glibcxx_assert(__is_valid_cmpexch_failure_order(__failure)); 1004 1005 return __atomic_compare_exchange(__ptr, std::__addressof(__expected), 1006 std::__addressof(__desired), false, 1007 int(__success), int(__failure)); 1008 } 1009 1010 #if __cpp_lib_atomic_wait 1011 template<typename _Tp> 1012 _GLIBCXX_ALWAYS_INLINE void 1013 wait(const _Tp* __ptr, _Val<_Tp> __old, 1014 memory_order __m = memory_order_seq_cst) noexcept 1015 { 1016 std::__atomic_wait_address_v(__ptr, __old, 1017 [__ptr, __m]() { return __atomic_impl::load(__ptr, __m); }); 1018 } 1019 1020 // TODO add const volatile overload 1021 1022 template<typename _Tp> 1023 _GLIBCXX_ALWAYS_INLINE void 1024 notify_one(const _Tp* __ptr) noexcept 1025 { std::__atomic_notify_address(__ptr, false); } 1026 1027 // TODO add const volatile overload 1028 1029 template<typename _Tp> 1030 _GLIBCXX_ALWAYS_INLINE void 1031 notify_all(const _Tp* __ptr) noexcept 1032 { std::__atomic_notify_address(__ptr, true); } 1033 1034 // TODO add const volatile overload 1035 #endif // __cpp_lib_atomic_wait 1036 1037 template<typename _Tp> 1038 _GLIBCXX_ALWAYS_INLINE _Tp 1039 fetch_add(_Tp* __ptr, _Diff<_Tp> __i, memory_order __m) noexcept 1040 { return __atomic_fetch_add(__ptr, __i, int(__m)); } 1041 1042 template<typename _Tp> 1043 _GLIBCXX_ALWAYS_INLINE _Tp 1044 fetch_sub(_Tp* __ptr, _Diff<_Tp> __i, memory_order __m) noexcept 1045 { return __atomic_fetch_sub(__ptr, __i, int(__m)); } 1046 1047 template<typename _Tp> 1048 _GLIBCXX_ALWAYS_INLINE _Tp 1049 fetch_and(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept 1050 { return __atomic_fetch_and(__ptr, __i, int(__m)); } 1051 1052 template<typename _Tp> 1053 _GLIBCXX_ALWAYS_INLINE _Tp 1054 fetch_or(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept 1055 { return __atomic_fetch_or(__ptr, __i, int(__m)); } 1056 1057 template<typename _Tp> 1058 _GLIBCXX_ALWAYS_INLINE _Tp 1059 fetch_xor(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept 1060 { return __atomic_fetch_xor(__ptr, __i, int(__m)); } 1061 1062 template<typename _Tp> 1063 _GLIBCXX_ALWAYS_INLINE _Tp 1064 __add_fetch(_Tp* __ptr, _Diff<_Tp> __i) noexcept 1065 { return __atomic_add_fetch(__ptr, __i, __ATOMIC_SEQ_CST); } 1066 1067 template<typename _Tp> 1068 _GLIBCXX_ALWAYS_INLINE _Tp 1069 __sub_fetch(_Tp* __ptr, _Diff<_Tp> __i) noexcept 1070 { return __atomic_sub_fetch(__ptr, __i, __ATOMIC_SEQ_CST); } 1071 1072 template<typename _Tp> 1073 _GLIBCXX_ALWAYS_INLINE _Tp 1074 __and_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept 1075 { return __atomic_and_fetch(__ptr, __i, __ATOMIC_SEQ_CST); } 1076 1077 template<typename _Tp> 1078 _GLIBCXX_ALWAYS_INLINE _Tp 1079 __or_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept 1080 { return __atomic_or_fetch(__ptr, __i, __ATOMIC_SEQ_CST); } 1081 1082 template<typename _Tp> 1083 _GLIBCXX_ALWAYS_INLINE _Tp 1084 __xor_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept 1085 { return __atomic_xor_fetch(__ptr, __i, __ATOMIC_SEQ_CST); } 1086 1087 template<typename _Tp> 1088 _Tp 1089 __fetch_add_flt(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept 1090 { 1091 _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed); 1092 _Val<_Tp> __newval = __oldval + __i; 1093 while (!compare_exchange_weak(__ptr, __oldval, __newval, __m, 1094 memory_order_relaxed)) 1095 __newval = __oldval + __i; 1096 return __oldval; 1097 } 1098 1099 template<typename _Tp> 1100 _Tp 1101 __fetch_sub_flt(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept 1102 { 1103 _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed); 1104 _Val<_Tp> __newval = __oldval - __i; 1105 while (!compare_exchange_weak(__ptr, __oldval, __newval, __m, 1106 memory_order_relaxed)) 1107 __newval = __oldval - __i; 1108 return __oldval; 1109 } 1110 1111 template<typename _Tp> 1112 _Tp 1113 __add_fetch_flt(_Tp* __ptr, _Val<_Tp> __i) noexcept 1114 { 1115 _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed); 1116 _Val<_Tp> __newval = __oldval + __i; 1117 while (!compare_exchange_weak(__ptr, __oldval, __newval, 1118 memory_order_seq_cst, 1119 memory_order_relaxed)) 1120 __newval = __oldval + __i; 1121 return __newval; 1122 } 1123 1124 template<typename _Tp> 1125 _Tp 1126 __sub_fetch_flt(_Tp* __ptr, _Val<_Tp> __i) noexcept 1127 { 1128 _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed); 1129 _Val<_Tp> __newval = __oldval - __i; 1130 while (!compare_exchange_weak(__ptr, __oldval, __newval, 1131 memory_order_seq_cst, 1132 memory_order_relaxed)) 1133 __newval = __oldval - __i; 1134 return __newval; 1135 } 1136 } // namespace __atomic_impl 1137 1138 // base class for atomic<floating-point-type> 1139 template<typename _Fp> 1140 struct __atomic_float 1141 { 1142 static_assert(is_floating_point_v<_Fp>); 1143 1144 static constexpr size_t _S_alignment = __alignof__(_Fp); 1145 1146 public: 1147 using value_type = _Fp; 1148 using difference_type = value_type; 1149 1150 static constexpr bool is_always_lock_free 1151 = __atomic_always_lock_free(sizeof(_Fp), 0); 1152 1153 __atomic_float() = default; 1154 1155 constexpr 1156 __atomic_float(_Fp __t) : _M_fp(__t) 1157 { } 1158 1159 __atomic_float(const __atomic_float&) = delete; 1160 __atomic_float& operator=(const __atomic_float&) = delete; 1161 __atomic_float& operator=(const __atomic_float&) volatile = delete; 1162 1163 _Fp 1164 operator=(_Fp __t) volatile noexcept 1165 { 1166 this->store(__t); 1167 return __t; 1168 } 1169 1170 _Fp 1171 operator=(_Fp __t) noexcept 1172 { 1173 this->store(__t); 1174 return __t; 1175 } 1176 1177 bool 1178 is_lock_free() const volatile noexcept 1179 { return __atomic_impl::is_lock_free<sizeof(_Fp), _S_alignment>(); } 1180 1181 bool 1182 is_lock_free() const noexcept 1183 { return __atomic_impl::is_lock_free<sizeof(_Fp), _S_alignment>(); } 1184 1185 void 1186 store(_Fp __t, memory_order __m = memory_order_seq_cst) volatile noexcept 1187 { __atomic_impl::store(&_M_fp, __t, __m); } 1188 1189 void 1190 store(_Fp __t, memory_order __m = memory_order_seq_cst) noexcept 1191 { __atomic_impl::store(&_M_fp, __t, __m); } 1192 1193 _Fp 1194 load(memory_order __m = memory_order_seq_cst) const volatile noexcept 1195 { return __atomic_impl::load(&_M_fp, __m); } 1196 1197 _Fp 1198 load(memory_order __m = memory_order_seq_cst) const noexcept 1199 { return __atomic_impl::load(&_M_fp, __m); } 1200 1201 operator _Fp() const volatile noexcept { return this->load(); } 1202 operator _Fp() const noexcept { return this->load(); } 1203 1204 _Fp 1205 exchange(_Fp __desired, 1206 memory_order __m = memory_order_seq_cst) volatile noexcept 1207 { return __atomic_impl::exchange(&_M_fp, __desired, __m); } 1208 1209 _Fp 1210 exchange(_Fp __desired, 1211 memory_order __m = memory_order_seq_cst) noexcept 1212 { return __atomic_impl::exchange(&_M_fp, __desired, __m); } 1213 1214 bool 1215 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1216 memory_order __success, 1217 memory_order __failure) noexcept 1218 { 1219 return __atomic_impl::compare_exchange_weak(&_M_fp, 1220 __expected, __desired, 1221 __success, __failure); 1222 } 1223 1224 bool 1225 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1226 memory_order __success, 1227 memory_order __failure) volatile noexcept 1228 { 1229 return __atomic_impl::compare_exchange_weak(&_M_fp, 1230 __expected, __desired, 1231 __success, __failure); 1232 } 1233 1234 bool 1235 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1236 memory_order __success, 1237 memory_order __failure) noexcept 1238 { 1239 return __atomic_impl::compare_exchange_strong(&_M_fp, 1240 __expected, __desired, 1241 __success, __failure); 1242 } 1243 1244 bool 1245 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1246 memory_order __success, 1247 memory_order __failure) volatile noexcept 1248 { 1249 return __atomic_impl::compare_exchange_strong(&_M_fp, 1250 __expected, __desired, 1251 __success, __failure); 1252 } 1253 1254 bool 1255 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1256 memory_order __order = memory_order_seq_cst) 1257 noexcept 1258 { 1259 return compare_exchange_weak(__expected, __desired, __order, 1260 __cmpexch_failure_order(__order)); 1261 } 1262 1263 bool 1264 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1265 memory_order __order = memory_order_seq_cst) 1266 volatile noexcept 1267 { 1268 return compare_exchange_weak(__expected, __desired, __order, 1269 __cmpexch_failure_order(__order)); 1270 } 1271 1272 bool 1273 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1274 memory_order __order = memory_order_seq_cst) 1275 noexcept 1276 { 1277 return compare_exchange_strong(__expected, __desired, __order, 1278 __cmpexch_failure_order(__order)); 1279 } 1280 1281 bool 1282 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1283 memory_order __order = memory_order_seq_cst) 1284 volatile noexcept 1285 { 1286 return compare_exchange_strong(__expected, __desired, __order, 1287 __cmpexch_failure_order(__order)); 1288 } 1289 1290 #if __cpp_lib_atomic_wait 1291 _GLIBCXX_ALWAYS_INLINE void 1292 wait(_Fp __old, memory_order __m = memory_order_seq_cst) const noexcept 1293 { __atomic_impl::wait(&_M_fp, __old, __m); } 1294 1295 // TODO add const volatile overload 1296 1297 _GLIBCXX_ALWAYS_INLINE void 1298 notify_one() const noexcept 1299 { __atomic_impl::notify_one(&_M_fp); } 1300 1301 // TODO add const volatile overload 1302 1303 _GLIBCXX_ALWAYS_INLINE void 1304 notify_all() const noexcept 1305 { __atomic_impl::notify_all(&_M_fp); } 1306 1307 // TODO add const volatile overload 1308 #endif // __cpp_lib_atomic_wait 1309 1310 value_type 1311 fetch_add(value_type __i, 1312 memory_order __m = memory_order_seq_cst) noexcept 1313 { return __atomic_impl::__fetch_add_flt(&_M_fp, __i, __m); } 1314 1315 value_type 1316 fetch_add(value_type __i, 1317 memory_order __m = memory_order_seq_cst) volatile noexcept 1318 { return __atomic_impl::__fetch_add_flt(&_M_fp, __i, __m); } 1319 1320 value_type 1321 fetch_sub(value_type __i, 1322 memory_order __m = memory_order_seq_cst) noexcept 1323 { return __atomic_impl::__fetch_sub_flt(&_M_fp, __i, __m); } 1324 1325 value_type 1326 fetch_sub(value_type __i, 1327 memory_order __m = memory_order_seq_cst) volatile noexcept 1328 { return __atomic_impl::__fetch_sub_flt(&_M_fp, __i, __m); } 1329 1330 value_type 1331 operator+=(value_type __i) noexcept 1332 { return __atomic_impl::__add_fetch_flt(&_M_fp, __i); } 1333 1334 value_type 1335 operator+=(value_type __i) volatile noexcept 1336 { return __atomic_impl::__add_fetch_flt(&_M_fp, __i); } 1337 1338 value_type 1339 operator-=(value_type __i) noexcept 1340 { return __atomic_impl::__sub_fetch_flt(&_M_fp, __i); } 1341 1342 value_type 1343 operator-=(value_type __i) volatile noexcept 1344 { return __atomic_impl::__sub_fetch_flt(&_M_fp, __i); } 1345 1346 private: 1347 alignas(_S_alignment) _Fp _M_fp _GLIBCXX20_INIT(0); 1348 }; 1349 #undef _GLIBCXX20_INIT 1350 1351 template<typename _Tp, 1352 bool = is_integral_v<_Tp>, bool = is_floating_point_v<_Tp>> 1353 struct __atomic_ref; 1354 1355 // base class for non-integral, non-floating-point, non-pointer types 1356 template<typename _Tp> 1357 struct __atomic_ref<_Tp, false, false> 1358 { 1359 static_assert(is_trivially_copyable_v<_Tp>); 1360 1361 // 1/2/4/8/16-byte types must be aligned to at least their size. 1362 static constexpr int _S_min_alignment 1363 = (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16 1364 ? 0 : sizeof(_Tp); 1365 1366 public: 1367 using value_type = _Tp; 1368 1369 static constexpr bool is_always_lock_free 1370 = __atomic_always_lock_free(sizeof(_Tp), 0); 1371 1372 static constexpr size_t required_alignment 1373 = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp); 1374 1375 __atomic_ref& operator=(const __atomic_ref&) = delete; 1376 1377 explicit 1378 __atomic_ref(_Tp& __t) : _M_ptr(std::__addressof(__t)) 1379 { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); } 1380 1381 __atomic_ref(const __atomic_ref&) noexcept = default; 1382 1383 _Tp 1384 operator=(_Tp __t) const noexcept 1385 { 1386 this->store(__t); 1387 return __t; 1388 } 1389 1390 operator _Tp() const noexcept { return this->load(); } 1391 1392 bool 1393 is_lock_free() const noexcept 1394 { return __atomic_impl::is_lock_free<sizeof(_Tp), required_alignment>(); } 1395 1396 void 1397 store(_Tp __t, memory_order __m = memory_order_seq_cst) const noexcept 1398 { __atomic_impl::store(_M_ptr, __t, __m); } 1399 1400 _Tp 1401 load(memory_order __m = memory_order_seq_cst) const noexcept 1402 { return __atomic_impl::load(_M_ptr, __m); } 1403 1404 _Tp 1405 exchange(_Tp __desired, memory_order __m = memory_order_seq_cst) 1406 const noexcept 1407 { return __atomic_impl::exchange(_M_ptr, __desired, __m); } 1408 1409 bool 1410 compare_exchange_weak(_Tp& __expected, _Tp __desired, 1411 memory_order __success, 1412 memory_order __failure) const noexcept 1413 { 1414 return __atomic_impl::compare_exchange_weak(_M_ptr, 1415 __expected, __desired, 1416 __success, __failure); 1417 } 1418 1419 bool 1420 compare_exchange_strong(_Tp& __expected, _Tp __desired, 1421 memory_order __success, 1422 memory_order __failure) const noexcept 1423 { 1424 return __atomic_impl::compare_exchange_strong(_M_ptr, 1425 __expected, __desired, 1426 __success, __failure); 1427 } 1428 1429 bool 1430 compare_exchange_weak(_Tp& __expected, _Tp __desired, 1431 memory_order __order = memory_order_seq_cst) 1432 const noexcept 1433 { 1434 return compare_exchange_weak(__expected, __desired, __order, 1435 __cmpexch_failure_order(__order)); 1436 } 1437 1438 bool 1439 compare_exchange_strong(_Tp& __expected, _Tp __desired, 1440 memory_order __order = memory_order_seq_cst) 1441 const noexcept 1442 { 1443 return compare_exchange_strong(__expected, __desired, __order, 1444 __cmpexch_failure_order(__order)); 1445 } 1446 1447 #if __cpp_lib_atomic_wait 1448 _GLIBCXX_ALWAYS_INLINE void 1449 wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept 1450 { __atomic_impl::wait(_M_ptr, __old, __m); } 1451 1452 // TODO add const volatile overload 1453 1454 _GLIBCXX_ALWAYS_INLINE void 1455 notify_one() const noexcept 1456 { __atomic_impl::notify_one(_M_ptr); } 1457 1458 // TODO add const volatile overload 1459 1460 _GLIBCXX_ALWAYS_INLINE void 1461 notify_all() const noexcept 1462 { __atomic_impl::notify_all(_M_ptr); } 1463 1464 // TODO add const volatile overload 1465 #endif // __cpp_lib_atomic_wait 1466 1467 private: 1468 _Tp* _M_ptr; 1469 }; 1470 1471 // base class for atomic_ref<integral-type> 1472 template<typename _Tp> 1473 struct __atomic_ref<_Tp, true, false> 1474 { 1475 static_assert(is_integral_v<_Tp>); 1476 1477 public: 1478 using value_type = _Tp; 1479 using difference_type = value_type; 1480 1481 static constexpr bool is_always_lock_free 1482 = __atomic_always_lock_free(sizeof(_Tp), 0); 1483 1484 static constexpr size_t required_alignment 1485 = sizeof(_Tp) > alignof(_Tp) ? sizeof(_Tp) : alignof(_Tp); 1486 1487 __atomic_ref() = delete; 1488 __atomic_ref& operator=(const __atomic_ref&) = delete; 1489 1490 explicit 1491 __atomic_ref(_Tp& __t) : _M_ptr(&__t) 1492 { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); } 1493 1494 __atomic_ref(const __atomic_ref&) noexcept = default; 1495 1496 _Tp 1497 operator=(_Tp __t) const noexcept 1498 { 1499 this->store(__t); 1500 return __t; 1501 } 1502 1503 operator _Tp() const noexcept { return this->load(); } 1504 1505 bool 1506 is_lock_free() const noexcept 1507 { 1508 return __atomic_impl::is_lock_free<sizeof(_Tp), required_alignment>(); 1509 } 1510 1511 void 1512 store(_Tp __t, memory_order __m = memory_order_seq_cst) const noexcept 1513 { __atomic_impl::store(_M_ptr, __t, __m); } 1514 1515 _Tp 1516 load(memory_order __m = memory_order_seq_cst) const noexcept 1517 { return __atomic_impl::load(_M_ptr, __m); } 1518 1519 _Tp 1520 exchange(_Tp __desired, 1521 memory_order __m = memory_order_seq_cst) const noexcept 1522 { return __atomic_impl::exchange(_M_ptr, __desired, __m); } 1523 1524 bool 1525 compare_exchange_weak(_Tp& __expected, _Tp __desired, 1526 memory_order __success, 1527 memory_order __failure) const noexcept 1528 { 1529 return __atomic_impl::compare_exchange_weak(_M_ptr, 1530 __expected, __desired, 1531 __success, __failure); 1532 } 1533 1534 bool 1535 compare_exchange_strong(_Tp& __expected, _Tp __desired, 1536 memory_order __success, 1537 memory_order __failure) const noexcept 1538 { 1539 return __atomic_impl::compare_exchange_strong(_M_ptr, 1540 __expected, __desired, 1541 __success, __failure); 1542 } 1543 1544 bool 1545 compare_exchange_weak(_Tp& __expected, _Tp __desired, 1546 memory_order __order = memory_order_seq_cst) 1547 const noexcept 1548 { 1549 return compare_exchange_weak(__expected, __desired, __order, 1550 __cmpexch_failure_order(__order)); 1551 } 1552 1553 bool 1554 compare_exchange_strong(_Tp& __expected, _Tp __desired, 1555 memory_order __order = memory_order_seq_cst) 1556 const noexcept 1557 { 1558 return compare_exchange_strong(__expected, __desired, __order, 1559 __cmpexch_failure_order(__order)); 1560 } 1561 1562 #if __cpp_lib_atomic_wait 1563 _GLIBCXX_ALWAYS_INLINE void 1564 wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept 1565 { __atomic_impl::wait(_M_ptr, __old, __m); } 1566 1567 // TODO add const volatile overload 1568 1569 _GLIBCXX_ALWAYS_INLINE void 1570 notify_one() const noexcept 1571 { __atomic_impl::notify_one(_M_ptr); } 1572 1573 // TODO add const volatile overload 1574 1575 _GLIBCXX_ALWAYS_INLINE void 1576 notify_all() const noexcept 1577 { __atomic_impl::notify_all(_M_ptr); } 1578 1579 // TODO add const volatile overload 1580 #endif // __cpp_lib_atomic_wait 1581 1582 value_type 1583 fetch_add(value_type __i, 1584 memory_order __m = memory_order_seq_cst) const noexcept 1585 { return __atomic_impl::fetch_add(_M_ptr, __i, __m); } 1586 1587 value_type 1588 fetch_sub(value_type __i, 1589 memory_order __m = memory_order_seq_cst) const noexcept 1590 { return __atomic_impl::fetch_sub(_M_ptr, __i, __m); } 1591 1592 value_type 1593 fetch_and(value_type __i, 1594 memory_order __m = memory_order_seq_cst) const noexcept 1595 { return __atomic_impl::fetch_and(_M_ptr, __i, __m); } 1596 1597 value_type 1598 fetch_or(value_type __i, 1599 memory_order __m = memory_order_seq_cst) const noexcept 1600 { return __atomic_impl::fetch_or(_M_ptr, __i, __m); } 1601 1602 value_type 1603 fetch_xor(value_type __i, 1604 memory_order __m = memory_order_seq_cst) const noexcept 1605 { return __atomic_impl::fetch_xor(_M_ptr, __i, __m); } 1606 1607 _GLIBCXX_ALWAYS_INLINE value_type 1608 operator++(int) const noexcept 1609 { return fetch_add(1); } 1610 1611 _GLIBCXX_ALWAYS_INLINE value_type 1612 operator--(int) const noexcept 1613 { return fetch_sub(1); } 1614 1615 value_type 1616 operator++() const noexcept 1617 { return __atomic_impl::__add_fetch(_M_ptr, value_type(1)); } 1618 1619 value_type 1620 operator--() const noexcept 1621 { return __atomic_impl::__sub_fetch(_M_ptr, value_type(1)); } 1622 1623 value_type 1624 operator+=(value_type __i) const noexcept 1625 { return __atomic_impl::__add_fetch(_M_ptr, __i); } 1626 1627 value_type 1628 operator-=(value_type __i) const noexcept 1629 { return __atomic_impl::__sub_fetch(_M_ptr, __i); } 1630 1631 value_type 1632 operator&=(value_type __i) const noexcept 1633 { return __atomic_impl::__and_fetch(_M_ptr, __i); } 1634 1635 value_type 1636 operator|=(value_type __i) const noexcept 1637 { return __atomic_impl::__or_fetch(_M_ptr, __i); } 1638 1639 value_type 1640 operator^=(value_type __i) const noexcept 1641 { return __atomic_impl::__xor_fetch(_M_ptr, __i); } 1642 1643 private: 1644 _Tp* _M_ptr; 1645 }; 1646 1647 // base class for atomic_ref<floating-point-type> 1648 template<typename _Fp> 1649 struct __atomic_ref<_Fp, false, true> 1650 { 1651 static_assert(is_floating_point_v<_Fp>); 1652 1653 public: 1654 using value_type = _Fp; 1655 using difference_type = value_type; 1656 1657 static constexpr bool is_always_lock_free 1658 = __atomic_always_lock_free(sizeof(_Fp), 0); 1659 1660 static constexpr size_t required_alignment = __alignof__(_Fp); 1661 1662 __atomic_ref() = delete; 1663 __atomic_ref& operator=(const __atomic_ref&) = delete; 1664 1665 explicit 1666 __atomic_ref(_Fp& __t) : _M_ptr(&__t) 1667 { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); } 1668 1669 __atomic_ref(const __atomic_ref&) noexcept = default; 1670 1671 _Fp 1672 operator=(_Fp __t) const noexcept 1673 { 1674 this->store(__t); 1675 return __t; 1676 } 1677 1678 operator _Fp() const noexcept { return this->load(); } 1679 1680 bool 1681 is_lock_free() const noexcept 1682 { 1683 return __atomic_impl::is_lock_free<sizeof(_Fp), required_alignment>(); 1684 } 1685 1686 void 1687 store(_Fp __t, memory_order __m = memory_order_seq_cst) const noexcept 1688 { __atomic_impl::store(_M_ptr, __t, __m); } 1689 1690 _Fp 1691 load(memory_order __m = memory_order_seq_cst) const noexcept 1692 { return __atomic_impl::load(_M_ptr, __m); } 1693 1694 _Fp 1695 exchange(_Fp __desired, 1696 memory_order __m = memory_order_seq_cst) const noexcept 1697 { return __atomic_impl::exchange(_M_ptr, __desired, __m); } 1698 1699 bool 1700 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1701 memory_order __success, 1702 memory_order __failure) const noexcept 1703 { 1704 return __atomic_impl::compare_exchange_weak(_M_ptr, 1705 __expected, __desired, 1706 __success, __failure); 1707 } 1708 1709 bool 1710 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1711 memory_order __success, 1712 memory_order __failure) const noexcept 1713 { 1714 return __atomic_impl::compare_exchange_strong(_M_ptr, 1715 __expected, __desired, 1716 __success, __failure); 1717 } 1718 1719 bool 1720 compare_exchange_weak(_Fp& __expected, _Fp __desired, 1721 memory_order __order = memory_order_seq_cst) 1722 const noexcept 1723 { 1724 return compare_exchange_weak(__expected, __desired, __order, 1725 __cmpexch_failure_order(__order)); 1726 } 1727 1728 bool 1729 compare_exchange_strong(_Fp& __expected, _Fp __desired, 1730 memory_order __order = memory_order_seq_cst) 1731 const noexcept 1732 { 1733 return compare_exchange_strong(__expected, __desired, __order, 1734 __cmpexch_failure_order(__order)); 1735 } 1736 1737 #if __cpp_lib_atomic_wait 1738 _GLIBCXX_ALWAYS_INLINE void 1739 wait(_Fp __old, memory_order __m = memory_order_seq_cst) const noexcept 1740 { __atomic_impl::wait(_M_ptr, __old, __m); } 1741 1742 // TODO add const volatile overload 1743 1744 _GLIBCXX_ALWAYS_INLINE void 1745 notify_one() const noexcept 1746 { __atomic_impl::notify_one(_M_ptr); } 1747 1748 // TODO add const volatile overload 1749 1750 _GLIBCXX_ALWAYS_INLINE void 1751 notify_all() const noexcept 1752 { __atomic_impl::notify_all(_M_ptr); } 1753 1754 // TODO add const volatile overload 1755 #endif // __cpp_lib_atomic_wait 1756 1757 value_type 1758 fetch_add(value_type __i, 1759 memory_order __m = memory_order_seq_cst) const noexcept 1760 { return __atomic_impl::__fetch_add_flt(_M_ptr, __i, __m); } 1761 1762 value_type 1763 fetch_sub(value_type __i, 1764 memory_order __m = memory_order_seq_cst) const noexcept 1765 { return __atomic_impl::__fetch_sub_flt(_M_ptr, __i, __m); } 1766 1767 value_type 1768 operator+=(value_type __i) const noexcept 1769 { return __atomic_impl::__add_fetch_flt(_M_ptr, __i); } 1770 1771 value_type 1772 operator-=(value_type __i) const noexcept 1773 { return __atomic_impl::__sub_fetch_flt(_M_ptr, __i); } 1774 1775 private: 1776 _Fp* _M_ptr; 1777 }; 1778 1779 // base class for atomic_ref<pointer-type> 1780 template<typename _Tp> 1781 struct __atomic_ref<_Tp*, false, false> 1782 { 1783 public: 1784 using value_type = _Tp*; 1785 using difference_type = ptrdiff_t; 1786 1787 static constexpr bool is_always_lock_free = ATOMIC_POINTER_LOCK_FREE == 2; 1788 1789 static constexpr size_t required_alignment = __alignof__(_Tp*); 1790 1791 __atomic_ref() = delete; 1792 __atomic_ref& operator=(const __atomic_ref&) = delete; 1793 1794 explicit 1795 __atomic_ref(_Tp*& __t) : _M_ptr(std::__addressof(__t)) 1796 { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); } 1797 1798 __atomic_ref(const __atomic_ref&) noexcept = default; 1799 1800 _Tp* 1801 operator=(_Tp* __t) const noexcept 1802 { 1803 this->store(__t); 1804 return __t; 1805 } 1806 1807 operator _Tp*() const noexcept { return this->load(); } 1808 1809 bool 1810 is_lock_free() const noexcept 1811 { 1812 return __atomic_impl::is_lock_free<sizeof(_Tp*), required_alignment>(); 1813 } 1814 1815 void 1816 store(_Tp* __t, memory_order __m = memory_order_seq_cst) const noexcept 1817 { __atomic_impl::store(_M_ptr, __t, __m); } 1818 1819 _Tp* 1820 load(memory_order __m = memory_order_seq_cst) const noexcept 1821 { return __atomic_impl::load(_M_ptr, __m); } 1822 1823 _Tp* 1824 exchange(_Tp* __desired, 1825 memory_order __m = memory_order_seq_cst) const noexcept 1826 { return __atomic_impl::exchange(_M_ptr, __desired, __m); } 1827 1828 bool 1829 compare_exchange_weak(_Tp*& __expected, _Tp* __desired, 1830 memory_order __success, 1831 memory_order __failure) const noexcept 1832 { 1833 return __atomic_impl::compare_exchange_weak(_M_ptr, 1834 __expected, __desired, 1835 __success, __failure); 1836 } 1837 1838 bool 1839 compare_exchange_strong(_Tp*& __expected, _Tp* __desired, 1840 memory_order __success, 1841 memory_order __failure) const noexcept 1842 { 1843 return __atomic_impl::compare_exchange_strong(_M_ptr, 1844 __expected, __desired, 1845 __success, __failure); 1846 } 1847 1848 bool 1849 compare_exchange_weak(_Tp*& __expected, _Tp* __desired, 1850 memory_order __order = memory_order_seq_cst) 1851 const noexcept 1852 { 1853 return compare_exchange_weak(__expected, __desired, __order, 1854 __cmpexch_failure_order(__order)); 1855 } 1856 1857 bool 1858 compare_exchange_strong(_Tp*& __expected, _Tp* __desired, 1859 memory_order __order = memory_order_seq_cst) 1860 const noexcept 1861 { 1862 return compare_exchange_strong(__expected, __desired, __order, 1863 __cmpexch_failure_order(__order)); 1864 } 1865 1866 #if __cpp_lib_atomic_wait 1867 _GLIBCXX_ALWAYS_INLINE void 1868 wait(_Tp* __old, memory_order __m = memory_order_seq_cst) const noexcept 1869 { __atomic_impl::wait(_M_ptr, __old, __m); } 1870 1871 // TODO add const volatile overload 1872 1873 _GLIBCXX_ALWAYS_INLINE void 1874 notify_one() const noexcept 1875 { __atomic_impl::notify_one(_M_ptr); } 1876 1877 // TODO add const volatile overload 1878 1879 _GLIBCXX_ALWAYS_INLINE void 1880 notify_all() const noexcept 1881 { __atomic_impl::notify_all(_M_ptr); } 1882 1883 // TODO add const volatile overload 1884 #endif // __cpp_lib_atomic_wait 1885 1886 _GLIBCXX_ALWAYS_INLINE value_type 1887 fetch_add(difference_type __d, 1888 memory_order __m = memory_order_seq_cst) const noexcept 1889 { return __atomic_impl::fetch_add(_M_ptr, _S_type_size(__d), __m); } 1890 1891 _GLIBCXX_ALWAYS_INLINE value_type 1892 fetch_sub(difference_type __d, 1893 memory_order __m = memory_order_seq_cst) const noexcept 1894 { return __atomic_impl::fetch_sub(_M_ptr, _S_type_size(__d), __m); } 1895 1896 value_type 1897 operator++(int) const noexcept 1898 { return fetch_add(1); } 1899 1900 value_type 1901 operator--(int) const noexcept 1902 { return fetch_sub(1); } 1903 1904 value_type 1905 operator++() const noexcept 1906 { 1907 return __atomic_impl::__add_fetch(_M_ptr, _S_type_size(1)); 1908 } 1909 1910 value_type 1911 operator--() const noexcept 1912 { 1913 return __atomic_impl::__sub_fetch(_M_ptr, _S_type_size(1)); 1914 } 1915 1916 value_type 1917 operator+=(difference_type __d) const noexcept 1918 { 1919 return __atomic_impl::__add_fetch(_M_ptr, _S_type_size(__d)); 1920 } 1921 1922 value_type 1923 operator-=(difference_type __d) const noexcept 1924 { 1925 return __atomic_impl::__sub_fetch(_M_ptr, _S_type_size(__d)); 1926 } 1927 1928 private: 1929 static constexpr ptrdiff_t 1930 _S_type_size(ptrdiff_t __d) noexcept 1931 { 1932 static_assert(is_object_v<_Tp>); 1933 return __d * sizeof(_Tp); 1934 } 1935 1936 _Tp** _M_ptr; 1937 }; 1938 1939 #endif // C++2a 1940 1941 /// @} group atomics 1942 1943 _GLIBCXX_END_NAMESPACE_VERSION 1944 } // namespace std 1945 1946 #endif 1947