3 // Copyright (C) 2008, 2009
4 // Free Software Foundation, Inc.
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)
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.
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.
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/>.
26 /** @file bits/atomic_2.h
27 * This is an internal header file, included by other library headers.
28 * You should not attempt to use it directly.
31 #ifndef _GLIBCXX_ATOMIC_2_H
32 #define _GLIBCXX_ATOMIC_2_H 1
34 #pragma GCC system_header
36 // _GLIBCXX_BEGIN_NAMESPACE(std)
38 // 2 == __atomic2 == Always lock-free
40 // _GLIBCXX_ATOMIC_BUILTINS_1
41 // _GLIBCXX_ATOMIC_BUILTINS_2
42 // _GLIBCXX_ATOMIC_BUILTINS_4
43 // _GLIBCXX_ATOMIC_BUILTINS_8
47 struct atomic_flag : private __atomic_flag_base
49 atomic_flag() = default;
50 ~atomic_flag() = default;
51 atomic_flag(const atomic_flag&) = delete;
52 atomic_flag& operator=(const atomic_flag&) = delete;
54 atomic_flag(bool __i) { _M_i = __i; } // XXX deleted copy ctor != agg
57 test_and_set(memory_order __m = memory_order_seq_cst) volatile
59 // Redundant synchronize if built-in for lock is a full barrier.
60 if (__m != memory_order_acquire && __m != memory_order_acq_rel)
62 return __sync_lock_test_and_set(&_M_i, 1);
66 clear(memory_order __m = memory_order_seq_cst) volatile
68 __glibcxx_assert(__m != memory_order_consume);
69 __glibcxx_assert(__m != memory_order_acquire);
70 __glibcxx_assert(__m != memory_order_acq_rel);
72 __sync_lock_release(&_M_i);
73 if (__m != memory_order_acquire && __m != memory_order_acq_rel)
79 /// 29.4.2, address types
86 atomic_address() = default;
87 ~atomic_address() = default;
88 atomic_address(const atomic_address&) = delete;
89 atomic_address& operator=(const atomic_address&) = delete;
91 atomic_address(void* __v) { _M_i = __v; }
94 is_lock_free() const volatile
98 store(void* __v, memory_order __m = memory_order_seq_cst) volatile
100 __glibcxx_assert(__m != memory_order_acquire);
101 __glibcxx_assert(__m != memory_order_acq_rel);
102 __glibcxx_assert(__m != memory_order_consume);
104 if (__m == memory_order_relaxed)
108 // write_mem_barrier();
110 if (__m = memory_order_seq_cst)
111 __sync_synchronize();
116 load(memory_order __m = memory_order_seq_cst) const volatile
118 __glibcxx_assert(__m != memory_order_release);
119 __glibcxx_assert(__m != memory_order_acq_rel);
121 __sync_synchronize();
123 __sync_synchronize();
128 exchange(void* __v, memory_order __m = memory_order_seq_cst) volatile
130 // XXX built-in assumes memory_order_acquire.
131 return __sync_lock_test_and_set(&_M_i, __v);
135 compare_exchange_weak(void*& __v1, void* __v2, memory_order __m1,
136 memory_order __m2) volatile
137 { return compare_exchange_strong(__v1, __v2, __m1, __m2); }
140 compare_exchange_weak(void*& __v1, void* __v2,
141 memory_order __m = memory_order_seq_cst) volatile
143 return compare_exchange_weak(__v1, __v2, __m,
144 __calculate_memory_order(__m));
148 compare_exchange_strong(void*& __v1, void* __v2, memory_order __m1,
149 memory_order __m2) volatile
151 __glibcxx_assert(__m2 != memory_order_release);
152 __glibcxx_assert(__m2 != memory_order_acq_rel);
153 __glibcxx_assert(__m2 <= __m1);
156 void* __v1n = __sync_val_compare_and_swap(&_M_i, __v1o, __v2);
158 // Assume extra stores (of same value) allowed in true case.
160 return __v1o == __v1n;
164 compare_exchange_strong(void*& __v1, void* __v2,
165 memory_order __m = memory_order_seq_cst) volatile
167 return compare_exchange_strong(__v1, __v2, __m,
168 __calculate_memory_order(__m));
172 fetch_add(ptrdiff_t __d, memory_order __m = memory_order_seq_cst) volatile
173 { return __sync_fetch_and_add(&_M_i, __d); }
176 fetch_sub(ptrdiff_t __d, memory_order __m = memory_order_seq_cst) volatile
177 { return __sync_fetch_and_sub(&_M_i, __d); }
179 operator void*() const volatile
183 operator=(void* __v) // XXX volatile
190 operator+=(ptrdiff_t __d) volatile
191 { return __sync_add_and_fetch(&_M_i, __d); }
194 operator-=(ptrdiff_t __d) volatile
195 { return __sync_sub_and_fetch(&_M_i, __d); }
198 // 29.3.1 atomic integral types
199 // For each of the integral types, define atomic_[integral type] struct
203 // atomic_schar signed char
204 // atomic_uchar unsigned char
205 // atomic_short short
206 // atomic_ushort unsigned short
208 // atomic_uint unsigned int
210 // atomic_ulong unsigned long
211 // atomic_llong long long
212 // atomic_ullong unsigned long long
213 // atomic_char16_t char16_t
214 // atomic_char32_t char32_t
215 // atomic_wchar_t wchar_t
218 // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or 8 bytes,
219 // since that is what GCC built-in functions for atomic memory access work on.
220 template<typename _ITp>
224 typedef _ITp __integral_type;
226 __integral_type _M_i;
229 __atomic_base() = default;
230 ~__atomic_base() = default;
231 __atomic_base(const __atomic_base&) = delete;
232 __atomic_base& operator=(const __atomic_base&) = delete;
234 // Requires __integral_type convertible to _M_base._M_i.
235 __atomic_base(__integral_type __i) { _M_i = __i; }
237 operator __integral_type() const volatile
241 operator=(__integral_type __i) // XXX volatile
248 operator++(int) volatile
249 { return fetch_add(1); }
252 operator--(int) volatile
253 { return fetch_sub(1); }
256 operator++() volatile
257 { return __sync_add_and_fetch(&_M_i, 1); }
260 operator--() volatile
261 { return __sync_sub_and_fetch(&_M_i, 1); }
264 operator+=(__integral_type __i) volatile
265 { return __sync_add_and_fetch(&_M_i, __i); }
268 operator-=(__integral_type __i) volatile
269 { return __sync_sub_and_fetch(&_M_i, __i); }
272 operator&=(__integral_type __i) volatile
273 { return __sync_and_and_fetch(&_M_i, __i); }
276 operator|=(__integral_type __i) volatile
277 { return __sync_or_and_fetch(&_M_i, __i); }
280 operator^=(__integral_type __i) volatile
281 { return __sync_xor_and_fetch(&_M_i, __i); }
284 is_lock_free() const volatile
288 store(__integral_type __i,
289 memory_order __m = memory_order_seq_cst) volatile
291 __glibcxx_assert(__m != memory_order_acquire);
292 __glibcxx_assert(__m != memory_order_acq_rel);
293 __glibcxx_assert(__m != memory_order_consume);
295 if (__m == memory_order_relaxed)
299 // write_mem_barrier();
301 if (__m = memory_order_seq_cst)
302 __sync_synchronize();
307 load(memory_order __m = memory_order_seq_cst) const volatile
309 __glibcxx_assert(__m != memory_order_release);
310 __glibcxx_assert(__m != memory_order_acq_rel);
312 __sync_synchronize();
313 __integral_type __ret = _M_i;
314 __sync_synchronize();
319 exchange(__integral_type __i,
320 memory_order __m = memory_order_seq_cst) volatile
322 // XXX built-in assumes memory_order_acquire.
323 return __sync_lock_test_and_set(&_M_i, __i);
327 compare_exchange_weak(__integral_type& __i1, __integral_type __i2,
328 memory_order __m1, memory_order __m2) volatile
329 { return compare_exchange_strong(__i1, __i2, __m1, __m2); }
332 compare_exchange_weak(__integral_type& __i1, __integral_type __i2,
333 memory_order __m = memory_order_seq_cst) volatile
335 return compare_exchange_weak(__i1, __i2, __m,
336 __calculate_memory_order(__m));
340 compare_exchange_strong(__integral_type& __i1, __integral_type __i2,
341 memory_order __m1, memory_order __m2) volatile
343 __glibcxx_assert(__m2 != memory_order_release);
344 __glibcxx_assert(__m2 != memory_order_acq_rel);
345 __glibcxx_assert(__m2 <= __m1);
347 __integral_type __i1o = __i1;
348 __integral_type __i1n = __sync_val_compare_and_swap(&_M_i, __i1o, __i2);
350 // Assume extra stores (of same value) allowed in true case.
352 return __i1o == __i1n;
356 compare_exchange_strong(__integral_type& __i1, __integral_type __i2,
357 memory_order __m = memory_order_seq_cst) volatile
359 return compare_exchange_strong(__i1, __i2, __m,
360 __calculate_memory_order(__m));
364 fetch_add(__integral_type __i,
365 memory_order __m = memory_order_seq_cst) volatile
366 { return __sync_fetch_and_add(&_M_i, __i); }
369 fetch_sub(__integral_type __i,
370 memory_order __m = memory_order_seq_cst) volatile
371 { return __sync_fetch_and_sub(&_M_i, __i); }
374 fetch_and(__integral_type __i,
375 memory_order __m = memory_order_seq_cst) volatile
376 { return __sync_fetch_and_and(&_M_i, __i); }
379 fetch_or(__integral_type __i,
380 memory_order __m = memory_order_seq_cst) volatile
381 { return __sync_fetch_and_or(&_M_i, __i); }
384 fetch_xor(__integral_type __i,
385 memory_order __m = memory_order_seq_cst) volatile
386 { return __sync_fetch_and_xor(&_M_i, __i); }
391 // NB: No operators or fetch-operations for this type.
395 __atomic_base<bool> _M_base;
398 atomic_bool() = default;
399 ~atomic_bool() = default;
400 atomic_bool(const atomic_bool&) = delete;
401 atomic_bool& operator=(const atomic_bool&) = delete;
403 atomic_bool(bool __i) : _M_base(__i) { }
406 operator=(bool __i) // XXX volatile
407 { return _M_base.operator=(__i); }
409 operator bool() const volatile
410 { return _M_base.load(); }
413 is_lock_free() const volatile
414 { return _M_base.is_lock_free(); }
417 store(bool __i, memory_order __m = memory_order_seq_cst) volatile
418 { _M_base.store(__i, __m); }
421 load(memory_order __m = memory_order_seq_cst) const volatile
422 { return _M_base.load(__m); }
425 exchange(bool __i, memory_order __m = memory_order_seq_cst) volatile
426 { return _M_base.exchange(__i, __m); }
429 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
430 memory_order __m2) volatile
431 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
434 compare_exchange_weak(bool& __i1, bool __i2,
435 memory_order __m = memory_order_seq_cst) volatile
436 { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
439 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
440 memory_order __m2) volatile
441 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
445 compare_exchange_strong(bool& __i1, bool __i2,
446 memory_order __m = memory_order_seq_cst) volatile
447 { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
449 } // namespace __atomic2
451 // _GLIBCXX_END_NAMESPACE