aboutsummaryrefslogtreecommitdiff
path: root/libstdc++-v3/include/std/atomic
blob: 125e37a2838ae74de7df3d2e7a90b3eb3aef0152 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
// -*- C++ -*- header.

// Copyright (C) 2008-2015 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file include/atomic
 *  This is a Standard C++ Library header.
 */

// Based on "C++ Atomic Types and Operations" by Hans Boehm and Lawrence Crowl.
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html

#ifndef _GLIBCXX_ATOMIC
#define _GLIBCXX_ATOMIC 1

#pragma GCC system_header

#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else

#include <bits/atomic_base.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   * @addtogroup atomics
   * @{
   */

  template<typename _Tp>
    struct atomic;

  /// atomic<bool>
  // NB: No operators or fetch-operations for this type.
  template<>
  struct atomic<bool>
  {
  private:
    __atomic_base<bool>	_M_base;

  public:
    atomic() noexcept = default;
    ~atomic() noexcept = default;
    atomic(const atomic&) = delete;
    atomic& operator=(const atomic&) = delete;
    atomic& operator=(const atomic&) volatile = delete;

    constexpr atomic(bool __i) noexcept : _M_base(__i) { }

    bool
    operator=(bool __i) noexcept
    { return _M_base.operator=(__i); }

    bool
    operator=(bool __i) volatile noexcept
    { return _M_base.operator=(__i); }

    operator bool() const noexcept
    { return _M_base.load(); }

    operator bool() const volatile noexcept
    { return _M_base.load(); }

    bool
    is_lock_free() const noexcept { return _M_base.is_lock_free(); }

    bool
    is_lock_free() const volatile noexcept { return _M_base.is_lock_free(); }

    void
    store(bool __i, memory_order __m = memory_order_seq_cst) noexcept
    { _M_base.store(__i, __m); }

    void
    store(bool __i, memory_order __m = memory_order_seq_cst) volatile noexcept
    { _M_base.store(__i, __m); }

    bool
    load(memory_order __m = memory_order_seq_cst) const noexcept
    { return _M_base.load(__m); }

    bool
    load(memory_order __m = memory_order_seq_cst) const volatile noexcept
    { return _M_base.load(__m); }

    bool
    exchange(bool __i, memory_order __m = memory_order_seq_cst) noexcept
    { return _M_base.exchange(__i, __m); }

    bool
    exchange(bool __i,
	     memory_order __m = memory_order_seq_cst) volatile noexcept
    { return _M_base.exchange(__i, __m); }

    bool
    compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
			  memory_order __m2) noexcept
    { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }

    bool
    compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
			  memory_order __m2) volatile noexcept
    { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }

    bool
    compare_exchange_weak(bool& __i1, bool __i2,
			  memory_order __m = memory_order_seq_cst) noexcept
    { return _M_base.compare_exchange_weak(__i1, __i2, __m); }

    bool
    compare_exchange_weak(bool& __i1, bool __i2,
		     memory_order __m = memory_order_seq_cst) volatile noexcept
    { return _M_base.compare_exchange_weak(__i1, __i2, __m); }

    bool
    compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
			    memory_order __m2) noexcept
    { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }

    bool
    compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
			    memory_order __m2) volatile noexcept
    { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }

    bool
    compare_exchange_strong(bool& __i1, bool __i2,
			    memory_order __m = memory_order_seq_cst) noexcept
    { return _M_base.compare_exchange_strong(__i1, __i2, __m); }

    bool
    compare_exchange_strong(bool& __i1, bool __i2,
		    memory_order __m = memory_order_seq_cst) volatile noexcept
    { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
  };


  /**
   *  @brief Generic atomic type, primary class template.
   *
   *  @tparam _Tp  Type to be made atomic, must be trivally copyable.
   */
  template<typename _Tp>
    struct atomic
    {
    private:
      // Align 1/2/4/8/16-byte types to at least their size.
      static constexpr int _S_min_alignment
	= (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
	? 0 : sizeof(_Tp);

      static constexpr int _S_alignment
        = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);

      alignas(_S_alignment) _Tp _M_i;

      static_assert(__is_trivially_copyable(_Tp),
		    "std::atomic requires a trivially copyable type");

      static_assert(sizeof(_Tp) > 0,
		    "Incomplete or zero-sized types are not supported");

    public:
      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(_Tp __i) noexcept : _M_i(__i) { }

      operator _Tp() const noexcept
      { return load(); }

      operator _Tp() const volatile noexcept
      { return load(); }

      _Tp
      operator=(_Tp __i) noexcept 
      { store(__i); return __i; }

      _Tp
      operator=(_Tp __i) volatile noexcept 
      { store(__i); return __i; }

      bool
      is_lock_free() const noexcept
      {
	// Produce a fake, minimally aligned pointer.
	void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
	return __atomic_is_lock_free(sizeof(_M_i), __a);
      }

      bool
      is_lock_free() const volatile noexcept
      {
	// Produce a fake, minimally aligned pointer.
	void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
	return __atomic_is_lock_free(sizeof(_M_i), __a);
      }

      void
      store(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
      { __atomic_store(&_M_i, &__i, __m); }

      void
      store(_Tp __i, memory_order __m = memory_order_seq_cst) volatile noexcept
      { __atomic_store(&_M_i, &__i, __m); }

      _Tp
      load(memory_order __m = memory_order_seq_cst) const noexcept
      { 
        _Tp tmp;
	__atomic_load(&_M_i, &tmp, __m);
	return tmp;
      }

      _Tp
      load(memory_order __m = memory_order_seq_cst) const volatile noexcept
      { 
        _Tp tmp;
	__atomic_load(&_M_i, &tmp, __m);
	return tmp;
      }

      _Tp
      exchange(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
      { 
        _Tp tmp;
	__atomic_exchange(&_M_i, &__i, &tmp, __m);
	return tmp;
      }

      _Tp
      exchange(_Tp __i, 
	       memory_order __m = memory_order_seq_cst) volatile noexcept
      { 
        _Tp tmp;
	__atomic_exchange(&_M_i, &__i, &tmp, __m);
	return tmp;
      }

      bool
      compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s, 
			    memory_order __f) noexcept
      {
	return __atomic_compare_exchange(&_M_i, &__e, &__i, true, __s, __f);
      }

      bool
      compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s, 
			    memory_order __f) volatile noexcept
      {
	return __atomic_compare_exchange(&_M_i, &__e, &__i, true, __s, __f);
      }

      bool
      compare_exchange_weak(_Tp& __e, _Tp __i,
			    memory_order __m = memory_order_seq_cst) noexcept
      { return compare_exchange_weak(__e, __i, __m,
                                     __cmpexch_failure_order(__m)); }

      bool
      compare_exchange_weak(_Tp& __e, _Tp __i,
		     memory_order __m = memory_order_seq_cst) volatile noexcept
      { return compare_exchange_weak(__e, __i, __m,
                                     __cmpexch_failure_order(__m)); }

      bool
      compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s, 
			      memory_order __f) noexcept
      {
	return __atomic_compare_exchange(&_M_i, &__e, &__i, false, __s, __f);
      }

      bool
      compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s, 
			      memory_order __f) volatile noexcept
      {
	return __atomic_compare_exchange(&_M_i, &__e, &__i, false, __s, __f);
      }

      bool
      compare_exchange_strong(_Tp& __e, _Tp __i,
			       memory_order __m = memory_order_seq_cst) noexcept
      { return compare_exchange_strong(__e, __i, __m,
                                       __cmpexch_failure_order(__m)); }

      bool
      compare_exchange_strong(_Tp& __e, _Tp __i,
		     memory_order __m = memory_order_seq_cst) volatile noexcept
      { return compare_exchange_strong(__e, __i, __m,
                                       __cmpexch_failure_order(__m)); }
    };


  /// Partial specialization for pointer types.
  template<typename _Tp>
    struct atomic<_Tp*>
    {
      typedef _Tp* 			__pointer_type;
      typedef __atomic_base<_Tp*>	__base_type;
      __base_type			_M_b;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }

      operator __pointer_type() const noexcept
      { return __pointer_type(_M_b); }

      operator __pointer_type() const volatile noexcept
      { return __pointer_type(_M_b); }

      __pointer_type
      operator=(__pointer_type __p) noexcept
      { return _M_b.operator=(__p); }

      __pointer_type
      operator=(__pointer_type __p) volatile noexcept
      { return _M_b.operator=(__p); }

      __pointer_type
      operator++(int) noexcept
      { return _M_b++; }

      __pointer_type
      operator++(int) volatile noexcept
      { return _M_b++; }

      __pointer_type
      operator--(int) noexcept
      { return _M_b--; }

      __pointer_type
      operator--(int) volatile noexcept
      { return _M_b--; }

      __pointer_type
      operator++() noexcept
      { return ++_M_b; }

      __pointer_type
      operator++() volatile noexcept
      { return ++_M_b; }

      __pointer_type
      operator--() noexcept
      { return --_M_b; }

      __pointer_type
      operator--() volatile noexcept
      { return --_M_b; }

      __pointer_type
      operator+=(ptrdiff_t __d) noexcept
      { return _M_b.operator+=(__d); }

      __pointer_type
      operator+=(ptrdiff_t __d) volatile noexcept
      { return _M_b.operator+=(__d); }

      __pointer_type
      operator-=(ptrdiff_t __d) noexcept
      { return _M_b.operator-=(__d); }

      __pointer_type
      operator-=(ptrdiff_t __d) volatile noexcept
      { return _M_b.operator-=(__d); }

      bool
      is_lock_free() const noexcept
      { return _M_b.is_lock_free(); }

      bool
      is_lock_free() const volatile noexcept
      { return _M_b.is_lock_free(); }

      void
      store(__pointer_type __p,
	    memory_order __m = memory_order_seq_cst) noexcept
      { return _M_b.store(__p, __m); }

      void
      store(__pointer_type __p,
	    memory_order __m = memory_order_seq_cst) volatile noexcept
      { return _M_b.store(__p, __m); }

      __pointer_type
      load(memory_order __m = memory_order_seq_cst) const noexcept
      { return _M_b.load(__m); }

      __pointer_type
      load(memory_order __m = memory_order_seq_cst) const volatile noexcept
      { return _M_b.load(__m); }

      __pointer_type
      exchange(__pointer_type __p,
	       memory_order __m = memory_order_seq_cst) noexcept
      { return _M_b.exchange(__p, __m); }

      __pointer_type
      exchange(__pointer_type __p,
	       memory_order __m = memory_order_seq_cst) volatile noexcept
      { return _M_b.exchange(__p, __m); }

      bool
      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
			    memory_order __m1, memory_order __m2) noexcept
      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }

      bool
      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
			    memory_order __m1,
			    memory_order __m2) volatile noexcept
      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }

      bool
      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
			    memory_order __m = memory_order_seq_cst) noexcept
      {
	return compare_exchange_weak(__p1, __p2, __m,
				     __cmpexch_failure_order(__m));
      }

      bool
      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
		    memory_order __m = memory_order_seq_cst) volatile noexcept
      {
	return compare_exchange_weak(__p1, __p2, __m,
				     __cmpexch_failure_order(__m));
      }

      bool
      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
			      memory_order __m1, memory_order __m2) noexcept
      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }

      bool
      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
			      memory_order __m1,
			      memory_order __m2) volatile noexcept
      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }

      bool
      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
			      memory_order __m = memory_order_seq_cst) noexcept
      {
	return _M_b.compare_exchange_strong(__p1, __p2, __m,
					    __cmpexch_failure_order(__m));
      }

      bool
      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
		    memory_order __m = memory_order_seq_cst) volatile noexcept
      {
	return _M_b.compare_exchange_strong(__p1, __p2, __m,
					    __cmpexch_failure_order(__m));
      }

      __pointer_type
      fetch_add(ptrdiff_t __d,
		memory_order __m = memory_order_seq_cst) noexcept
      { return _M_b.fetch_add(__d, __m); }

      __pointer_type
      fetch_add(ptrdiff_t __d,
		memory_order __m = memory_order_seq_cst) volatile noexcept
      { return _M_b.fetch_add(__d, __m); }

      __pointer_type
      fetch_sub(ptrdiff_t __d,
		memory_order __m = memory_order_seq_cst) noexcept
      { return _M_b.fetch_sub(__d, __m); }

      __pointer_type
      fetch_sub(ptrdiff_t __d,
		memory_order __m = memory_order_seq_cst) volatile noexcept
      { return _M_b.fetch_sub(__d, __m); }
    };


  /// Explicit specialization for char.
  template<>
    struct atomic<char> : __atomic_base<char>
    {
      typedef char 			__integral_type;
      typedef __atomic_base<char> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for signed char.
  template<>
    struct atomic<signed char> : __atomic_base<signed char>
    {
      typedef signed char 		__integral_type;
      typedef __atomic_base<signed char> 	__base_type;

      atomic() noexcept= default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for unsigned char.
  template<>
    struct atomic<unsigned char> : __atomic_base<unsigned char>
    {
      typedef unsigned char 		__integral_type;
      typedef __atomic_base<unsigned char> 	__base_type;

      atomic() noexcept= default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for short.
  template<>
    struct atomic<short> : __atomic_base<short>
    {
      typedef short 			__integral_type;
      typedef __atomic_base<short> 		__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for unsigned short.
  template<>
    struct atomic<unsigned short> : __atomic_base<unsigned short>
    {
      typedef unsigned short 	      	__integral_type;
      typedef __atomic_base<unsigned short> 		__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for int.
  template<>
    struct atomic<int> : __atomic_base<int>
    {
      typedef int 			__integral_type;
      typedef __atomic_base<int> 		__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for unsigned int.
  template<>
    struct atomic<unsigned int> : __atomic_base<unsigned int>
    {
      typedef unsigned int		__integral_type;
      typedef __atomic_base<unsigned int> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for long.
  template<>
    struct atomic<long> : __atomic_base<long>
    {
      typedef long 			__integral_type;
      typedef __atomic_base<long> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for unsigned long.
  template<>
    struct atomic<unsigned long> : __atomic_base<unsigned long>
    {
      typedef unsigned long 		__integral_type;
      typedef __atomic_base<unsigned long> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for long long.
  template<>
    struct atomic<long long> : __atomic_base<long long>
    {
      typedef long long 		__integral_type;
      typedef __atomic_base<long long> 		__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for unsigned long long.
  template<>
    struct atomic<unsigned long long> : __atomic_base<unsigned long long>
    {
      typedef unsigned long long       	__integral_type;
      typedef __atomic_base<unsigned long long> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for wchar_t.
  template<>
    struct atomic<wchar_t> : __atomic_base<wchar_t>
    {
      typedef wchar_t 			__integral_type;
      typedef __atomic_base<wchar_t> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for char16_t.
  template<>
    struct atomic<char16_t> : __atomic_base<char16_t>
    {
      typedef char16_t 			__integral_type;
      typedef __atomic_base<char16_t> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };

  /// Explicit specialization for char32_t.
  template<>
    struct atomic<char32_t> : __atomic_base<char32_t>
    {
      typedef char32_t 			__integral_type;
      typedef __atomic_base<char32_t> 	__base_type;

      atomic() noexcept = default;
      ~atomic() noexcept = default;
      atomic(const atomic&) = delete;
      atomic& operator=(const atomic&) = delete;
      atomic& operator=(const atomic&) volatile = delete;

      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }

      using __base_type::operator __integral_type;
      using __base_type::operator=;
    };


  /// atomic_bool
  typedef atomic<bool>			atomic_bool;

  /// atomic_char
  typedef atomic<char>			atomic_char;

  /// atomic_schar
  typedef atomic<signed char>		atomic_schar;

  /// atomic_uchar
  typedef atomic<unsigned char>		atomic_uchar;

  /// atomic_short
  typedef atomic<short>			atomic_short;

  /// atomic_ushort
  typedef atomic<unsigned short>	atomic_ushort;

  /// atomic_int
  typedef atomic<int>			atomic_int;

  /// atomic_uint
  typedef atomic<unsigned int>		atomic_uint;

  /// atomic_long
  typedef atomic<long>			atomic_long;

  /// atomic_ulong
  typedef atomic<unsigned long>		atomic_ulong;

  /// atomic_llong
  typedef atomic<long long>		atomic_llong;

  /// atomic_ullong
  typedef atomic<unsigned long long>	atomic_ullong;

  /// atomic_wchar_t
  typedef atomic<wchar_t>		atomic_wchar_t;

  /// atomic_char16_t
  typedef atomic<char16_t>		atomic_char16_t;

  /// atomic_char32_t
  typedef atomic<char32_t>		atomic_char32_t;


  /// atomic_int_least8_t
  typedef atomic<int_least8_t>		atomic_int_least8_t;

  /// atomic_uint_least8_t
  typedef atomic<uint_least8_t>		atomic_uint_least8_t;

  /// atomic_int_least16_t
  typedef atomic<int_least16_t>		atomic_int_least16_t;

  /// atomic_uint_least16_t
  typedef atomic<uint_least16_t>	atomic_uint_least16_t;

  /// atomic_int_least32_t
  typedef atomic<int_least32_t>		atomic_int_least32_t;

  /// atomic_uint_least32_t
  typedef atomic<uint_least32_t>	atomic_uint_least32_t;

  /// atomic_int_least64_t
  typedef atomic<int_least64_t>		atomic_int_least64_t;

  /// atomic_uint_least64_t
  typedef atomic<uint_least64_t>	atomic_uint_least64_t;


  /// atomic_int_fast8_t
  typedef atomic<int_fast8_t>		atomic_int_fast8_t;

  /// atomic_uint_fast8_t
  typedef atomic<uint_fast8_t>		atomic_uint_fast8_t;

  /// atomic_int_fast16_t
  typedef atomic<int_fast16_t>		atomic_int_fast16_t;

  /// atomic_uint_fast16_t
  typedef atomic<uint_fast16_t>		atomic_uint_fast16_t;

  /// atomic_int_fast32_t
  typedef atomic<int_fast32_t>		atomic_int_fast32_t;

  /// atomic_uint_fast32_t
  typedef atomic<uint_fast32_t>		atomic_uint_fast32_t;

  /// atomic_int_fast64_t
  typedef atomic<int_fast64_t>		atomic_int_fast64_t;

  /// atomic_uint_fast64_t
  typedef atomic<uint_fast64_t>		atomic_uint_fast64_t;


  /// atomic_intptr_t
  typedef atomic<intptr_t>		atomic_intptr_t;

  /// atomic_uintptr_t
  typedef atomic<uintptr_t>		atomic_uintptr_t;

  /// atomic_size_t
  typedef atomic<size_t>		atomic_size_t;

  /// atomic_intmax_t
  typedef atomic<intmax_t>		atomic_intmax_t;

  /// atomic_uintmax_t
  typedef atomic<uintmax_t>		atomic_uintmax_t;

  /// atomic_ptrdiff_t
  typedef atomic<ptrdiff_t>		atomic_ptrdiff_t;


  // Function definitions, atomic_flag operations.
  inline bool
  atomic_flag_test_and_set_explicit(atomic_flag* __a,
				    memory_order __m) noexcept
  { return __a->test_and_set(__m); }

  inline bool
  atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
				    memory_order __m) noexcept
  { return __a->test_and_set(__m); }

  inline void
  atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
  { __a->clear(__m); }

  inline void
  atomic_flag_clear_explicit(volatile atomic_flag* __a,
			     memory_order __m) noexcept
  { __a->clear(__m); }

  inline bool
  atomic_flag_test_and_set(atomic_flag* __a) noexcept
  { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }

  inline bool
  atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
  { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }

  inline void
  atomic_flag_clear(atomic_flag* __a) noexcept
  { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }

  inline void
  atomic_flag_clear(volatile atomic_flag* __a) noexcept
  { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }


  // Function templates generally applicable to atomic types.
  template<typename _ITp>
    inline bool
    atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
    { return __a->is_lock_free(); }

  template<typename _ITp>
    inline bool
    atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
    { return __a->is_lock_free(); }

  template<typename _ITp>
    inline void
    atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept
    { __a->store(__i, memory_order_relaxed); }

  template<typename _ITp>
    inline void
    atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept
    { __a->store(__i, memory_order_relaxed); }

  template<typename _ITp>
    inline void
    atomic_store_explicit(atomic<_ITp>* __a, _ITp __i,
			  memory_order __m) noexcept
    { __a->store(__i, __m); }

  template<typename _ITp>
    inline void
    atomic_store_explicit(volatile atomic<_ITp>* __a, _ITp __i,
			  memory_order __m) noexcept
    { __a->store(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
    { return __a->load(__m); }

  template<typename _ITp>
    inline _ITp
    atomic_load_explicit(const volatile atomic<_ITp>* __a,
			 memory_order __m) noexcept
    { return __a->load(__m); }

  template<typename _ITp>
    inline _ITp
    atomic_exchange_explicit(atomic<_ITp>* __a, _ITp __i,
			     memory_order __m) noexcept
    { return __a->exchange(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_exchange_explicit(volatile atomic<_ITp>* __a, _ITp __i,
			     memory_order __m) noexcept
    { return __a->exchange(__i, __m); }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
					  _ITp* __i1, _ITp __i2,
					  memory_order __m1,
					  memory_order __m2) noexcept
    { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
					  _ITp* __i1, _ITp __i2,
					  memory_order __m1,
					  memory_order __m2) noexcept
    { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
					    _ITp* __i1, _ITp __i2,
					    memory_order __m1,
					    memory_order __m2) noexcept
    { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
					    _ITp* __i1, _ITp __i2,
					    memory_order __m1,
					    memory_order __m2) noexcept
    { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }


  template<typename _ITp>
    inline void
    atomic_store(atomic<_ITp>* __a, _ITp __i) noexcept
    { atomic_store_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline void
    atomic_store(volatile atomic<_ITp>* __a, _ITp __i) noexcept
    { atomic_store_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_load(const atomic<_ITp>* __a) noexcept
    { return atomic_load_explicit(__a, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_load(const volatile atomic<_ITp>* __a) noexcept
    { return atomic_load_explicit(__a, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_exchange(atomic<_ITp>* __a, _ITp __i) noexcept
    { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_exchange(volatile atomic<_ITp>* __a, _ITp __i) noexcept
    { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_weak(atomic<_ITp>* __a,
				 _ITp* __i1, _ITp __i2) noexcept
    {
      return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
						   memory_order_seq_cst,
						   memory_order_seq_cst);
    }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
				 _ITp* __i1, _ITp __i2) noexcept
    {
      return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
						   memory_order_seq_cst,
						   memory_order_seq_cst);
    }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_strong(atomic<_ITp>* __a,
				   _ITp* __i1, _ITp __i2) noexcept
    {
      return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
						     memory_order_seq_cst,
						     memory_order_seq_cst);
    }

  template<typename _ITp>
    inline bool
    atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
				   _ITp* __i1, _ITp __i2) noexcept
    {
      return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
						     memory_order_seq_cst,
						     memory_order_seq_cst);
    }

  // Function templates for atomic_integral operations only, using
  // __atomic_base. Template argument should be constricted to
  // intergral types as specified in the standard, excluding address
  // types.
  template<typename _ITp>
    inline _ITp
    atomic_fetch_add_explicit(__atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_add(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_add_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_add(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_sub_explicit(__atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_sub(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_sub_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_sub(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_and_explicit(__atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_and(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_and(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_or_explicit(__atomic_base<_ITp>* __a, _ITp __i,
			     memory_order __m) noexcept
    { return __a->fetch_or(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
			     memory_order __m) noexcept
    { return __a->fetch_or(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_xor(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
			      memory_order __m) noexcept
    { return __a->fetch_xor(__i, __m); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_add(__atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_add(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_sub(__atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_sub(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_and(__atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_and(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_or(__atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_or(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_xor(__atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }

  template<typename _ITp>
    inline _ITp
    atomic_fetch_xor(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
    { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }


  // Partial specializations for pointers.
  template<typename _ITp>
    inline _ITp*
    atomic_fetch_add_explicit(atomic<_ITp*>* __a, ptrdiff_t __d,
			      memory_order __m) noexcept
    { return __a->fetch_add(__d, __m); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_add_explicit(volatile atomic<_ITp*>* __a, ptrdiff_t __d,
			      memory_order __m) noexcept
    { return __a->fetch_add(__d, __m); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_add(volatile atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
    { return __a->fetch_add(__d); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_add(atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
    { return __a->fetch_add(__d); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_sub_explicit(volatile atomic<_ITp*>* __a,
			      ptrdiff_t __d, memory_order __m) noexcept
    { return __a->fetch_sub(__d, __m); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_sub_explicit(atomic<_ITp*>* __a, ptrdiff_t __d,
			      memory_order __m) noexcept
    { return __a->fetch_sub(__d, __m); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_sub(volatile atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
    { return __a->fetch_sub(__d); }

  template<typename _ITp>
    inline _ITp*
    atomic_fetch_sub(atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
    { return __a->fetch_sub(__d); }
  // @} group atomics

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif // C++11

#endif // _GLIBCXX_ATOMIC