File: queue_spsc_locked.h

package info (click to toggle)
etlcpp 20.39.4%2Bdfsg-3
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 18,232 kB
  • sloc: cpp: 245,721; ansic: 10,254; sh: 1,481; asm: 301; python: 281; makefile: 24
file content (903 lines) | stat: -rw-r--r-- 29,548 bytes parent folder | download
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
///\file

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2019 John Wellbelove

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions :

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
******************************************************************************/

#ifndef ETL_SPSC_QUEUE_LOCKED_INCLUDED
#define ETL_SPSC_QUEUE_LOCKED_INCLUDED

#include "platform.h"
#include "memory.h"
#include "parameter_type.h"
#include "memory_model.h"
#include "integral_limits.h"
#include "function.h"
#include "utility.h"
#include "placement_new.h"

#include <stddef.h>
#include <stdint.h>

namespace etl
{
  template <size_t MEMORY_MODEL = etl::memory_model::MEMORY_MODEL_LARGE>
  class iqueue_spsc_locked_base
  {
  public:

    /// The type used for determining the size of queue.
    typedef typename etl::size_type_lookup<MEMORY_MODEL>::type size_type;

    //*************************************************************************
    /// How much free space available in the queue.
    //*************************************************************************
    size_type available_from_unlocked() const
    {
      return available_implementation();
    }

    //*************************************************************************
    /// Is the queue full?
    //*************************************************************************
    bool full_from_unlocked() const
    {
      return full_implementation();
    }

    //*************************************************************************
    /// How many items in the queue?
    //*************************************************************************
    size_type size_from_unlocked() const
    {
      return size_implementation();
    }

    //*************************************************************************
    /// Is the queue empty?
    //*************************************************************************
    bool empty_from_unlocked() const
    {
      return empty_implementation();
    }

    //*************************************************************************
    /// How many items can the queue hold.
    //*************************************************************************
    size_type capacity() const
    {
      return MAX_SIZE;
    }

    //*************************************************************************
    /// How many items can the queue hold.
    //*************************************************************************
    size_type max_size() const
    {
      return MAX_SIZE;
    }

  protected:

    iqueue_spsc_locked_base(size_type max_size_)
      : write_index(0),
        read_index(0),
        current_size(0),
        MAX_SIZE(max_size_)
    {
    }

    //*************************************************************************
    /// Calculate the next index.
    //*************************************************************************
    static size_type get_next_index(size_type index, size_type maximum)
    {
      ++index;

      if (index == maximum) ETL_UNLIKELY
      {
        index = 0;
      }

      return index;
    }

    size_type write_index;    ///< Where to input new data.
    size_type read_index;     ///< Where to get the oldest data.
    size_type current_size;   ///< The current size of the queue.
    const size_type MAX_SIZE; ///< The maximum number of items in the queue.

  protected:

    //*************************************************************************
    /// How much free space available in the queue.
    //*************************************************************************
    size_type available_implementation() const
    {
      return MAX_SIZE - current_size;
    }

    //*************************************************************************
    /// Is the queue full?
    //*************************************************************************
    bool full_implementation() const
    {
      return (current_size == MAX_SIZE);
    }

    //*************************************************************************
    /// How many items in the queue?
    //*************************************************************************
    size_type size_implementation() const
    {
      return current_size;
    }

    //*************************************************************************
    /// Is the queue empty?
    //*************************************************************************
    bool empty_implementation() const
    {
      return (current_size == 0);
    }

    //*************************************************************************
    /// Destructor.
    //*************************************************************************
#if defined(ETL_POLYMORPHIC_SPSC_QUEUE_ISR) || defined(ETL_POLYMORPHIC_CONTAINERS)
  public:
    virtual ~iqueue_spsc_locked_base()
    {
    }
#else
  protected:
    ~iqueue_spsc_locked_base()
    {
    }
#endif
  };

  //***************************************************************************
  ///\ingroup queue_spsc
  ///\brief This is the base for all queue_spsc_locked that contain a particular type.
  ///\details Normally a reference to this type will be taken from a derived queue_spsc_locked.
  /// This queue supports concurrent access by one producer and one consumer.
  /// \tparam T The type of value that the queue_spsc_locked holds.
  //***************************************************************************
  template <typename T, const size_t MEMORY_MODEL = etl::memory_model::MEMORY_MODEL_LARGE>
  class iqueue_spsc_locked : public iqueue_spsc_locked_base<MEMORY_MODEL>
  {
  private:

    typedef iqueue_spsc_locked_base<MEMORY_MODEL> base_t;

  public:

    typedef T                          value_type;       ///< The type stored in the queue.
    typedef T&                         reference;        ///< A reference to the type used in the queue.
    typedef const T&                   const_reference;  ///< A const reference to the type used in the queue.
#if ETL_USING_CPP11
    typedef T&&                        rvalue_reference; ///< An rvalue reference to the type used in the queue.
#endif
    typedef typename base_t::size_type size_type;        ///< The type used for determining the size of the queue.

    //*************************************************************************
    /// Push a value to the queue.
    //*************************************************************************
    bool push_from_unlocked(const_reference value)
    {
      return push_implementation(value);
    }

    //*************************************************************************
    /// Push a value to the queue.
    //*************************************************************************
    bool push(const_reference value)
    {
      lock();

      bool result = push_implementation(value);

      unlock();

      return result;
    }

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_QUEUE_LOCKED_FORCE_CPP03_IMPLEMENTATION)
    //*************************************************************************
    /// Push a value to the queue.
    /// Unlocked.
    //*************************************************************************
    bool push_from_unlocked(rvalue_reference value)
    {
      return push_implementation(etl::move(value));
    }

    //*************************************************************************
    /// Push a value to the queue.
    /// Locked.
    //*************************************************************************
    bool push(rvalue_reference value)
    {
      lock();

      bool result = push_implementation(etl::move(value));

      unlock();

      return result;
    }
#endif

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_QUEUE_LOCKED_FORCE_CPP03_IMPLEMENTATION)
    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// Unlocked.
    //*************************************************************************
    template <typename ... Args>
    bool emplace_from_unlocked(Args&&... args)
    {
      return emplace_implementation(etl::forward<Args>(args)...);
    }
    
    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// Locked.
    //*************************************************************************
    template <typename ... Args>
    bool emplace(Args&&... args)
    {
      lock();

      bool result = emplace_implementation(etl::forward<Args>(args)...);

      unlock();

      return result;
    }
#else
    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1>
    bool emplace_from_unlocked(const T1& value1)
    {
      return emplace_implementation(value1);
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2>
    bool emplace_from_unlocked(const T1& value1, const T2& value2)
    {
      return emplace_implementation(value1, value2);
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2, typename T3>
    bool emplace_from_unlocked(const T1& value1, const T2& value2, const T3& value3)
    {
      return emplace_implementation(value1, value2, value3);
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2, typename T3, typename T4>
    bool emplace_from_unlocked(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
    {
      return emplace_implementation(value1, value2, value3, value4);
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    bool emplace()
    {
      lock();

      bool result = emplace_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1>
    bool emplace(const T1& value1)
    {
      lock();

      bool result = emplace_implementation(value1);

      unlock();

      return result;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2>
    bool emplace(const T1& value1, const T2& value2)
    {
      lock();

      bool result = emplace_implementation(value1, value2);

      unlock();

      return result;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2, typename T3>
    bool emplace(const T1& value1, const T2& value2, const T3& value3)
    {
      lock();

      bool result = emplace_implementation(value1, value2, value3);

      unlock();

      return result;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// If asserts or exceptions are enabled, throws an etl::queue_full if the queue if already full.
    //*************************************************************************
    template <typename T1, typename T2, typename T3, typename T4>
    bool emplace(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
    {
      lock();

      bool result = emplace_implementation(value1, value2, value3, value4);

      unlock();

      return result;
    }
#endif

    //*************************************************************************
    /// Pop a value from the queue.
    /// Unlocked
    //*************************************************************************
    bool pop_from_unlocked(reference value)
    {
      return pop_implementation(value);;
    }

    //*************************************************************************
    /// Pop a value from the queue.
    //*************************************************************************
    bool pop(reference value)
    {
      lock();

      bool result = pop_implementation(value);

      unlock();

      return result;
    }

    //*************************************************************************
    /// Pop a value from the queue and discard.
    /// Unlocked
    //*************************************************************************
    bool pop_from_unlocked()
    {
      return pop_implementation();
    }

    //*************************************************************************
    /// Pop a value from the queue and discard.
    //*************************************************************************
    bool pop()
    {
      lock();

      bool result = pop_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    /// Unlocked
    //*************************************************************************
    reference front_from_unlocked()
    {
      return front_implementation();
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    /// Unlocked
    //*************************************************************************
    const_reference front_from_unlocked() const
    {
      return front_implementation();
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    //*************************************************************************
    reference front()
    {
      lock();

      reference result = front_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    //*************************************************************************
    const_reference front() const
    {
      lock();

      const_reference result = front_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Clear the queue from the ISR.
    //*************************************************************************
    void clear_from_unlocked()
    {
      while (pop_implementation())
      {
        // Do nothing.
      }
    }

    //*************************************************************************
    /// Clear the queue.
    //*************************************************************************
    void clear()
    {
      lock();

      while (pop_implementation())
      {
        // Do nothing.
      }

      unlock();
    }

    //*************************************************************************
    /// How much free space available in the queue.
    //*************************************************************************
    size_type available() const
    {
      lock();

      size_type result = this->available_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Is the queue full?
    //*************************************************************************
    bool full() const
    {
      lock();

      size_type result = this->full_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// How many items in the queue?
    //*************************************************************************
    size_type size() const
    {
      lock();

      size_type result = this->size_implementation();

      unlock();

      return result;
    }

    //*************************************************************************
    /// Is the queue empty?
    //*************************************************************************
    bool empty() const
    {
      lock();

      bool result = this->empty_implementation();

      unlock();

      return result;
    }

  protected:

    //*************************************************************************
    /// The constructor that is called from derived classes.
    //*************************************************************************
    iqueue_spsc_locked(T* p_buffer_, size_type max_size_, const etl::ifunction<void>& lock_, const etl::ifunction<void>& unlock_)
      : base_t(max_size_)
      , p_buffer(p_buffer_)
      , lock(lock_)
      , unlock(unlock_)
    {
    }

  private:

    //*************************************************************************
    /// Push a value to the queue.
    //*************************************************************************
    bool push_implementation(const_reference value)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(value);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_QUEUE_LOCKED_FORCE_CPP03_IMPLEMENTATION)
    //*************************************************************************
    /// Push a value to the queue.
    /// Unlocked.
    //*************************************************************************
    bool push_implementation(rvalue_reference value)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(etl::move(value));

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }
#endif

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_QUEUE_LOCKED_FORCE_CPP03_IMPLEMENTATION)
    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    /// Unlocked.
    //*************************************************************************
    template <typename ... Args>
    bool emplace_implementation(Args&&... args)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(etl::forward<Args>(args)...);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }
#else
    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    //*************************************************************************
    bool emplace_implementation()
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T();

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    //*************************************************************************
    template <typename T1>
    bool emplace_implementation(const T1& value1)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(value1);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    //*************************************************************************
    template <typename T1, typename T2>
    bool emplace_implementation(const T1& value1, const T2& value2)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(value1, value2);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    //*************************************************************************
    template <typename T1, typename T2, typename T3>
    bool emplace_implementation(const T1& value1, const T2& value2, const T3& value3)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(value1, value2, value3);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }

    //*************************************************************************
    /// Constructs a value in the queue 'in place'.
    //*************************************************************************
    template <typename T1, typename T2, typename T3, typename T4>
    bool emplace_implementation(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
    {
      if (this->current_size != this->MAX_SIZE)
      {
        ::new (&p_buffer[this->write_index]) T(value1, value2, value3, value4);

        this->write_index = this->get_next_index(this->write_index, this->MAX_SIZE);

        ++this->current_size;

        return true;
      }

      // Queue is full.
      return false;
    }
#endif

    //*************************************************************************
    /// Pop a value from the queue.
    /// Unlocked
    //*************************************************************************
    bool pop_implementation(reference value)
    {
      if (this->current_size == 0)
      {
        // Queue is empty
        return false;
      }

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_QUEUE_LOCKABLE_FORCE_CPP03_IMPLEMENTATION)
      value = etl::move(p_buffer[this->read_index]);
#else
      value = p_buffer[this->read_index];
#endif

      p_buffer[this->read_index].~T();

      this->read_index = this->get_next_index(this->read_index, this->MAX_SIZE);

      --this->current_size;

      return true;
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    /// Unlocked
    //*************************************************************************
    reference front_implementation()
    {
      return p_buffer[this->read_index];
    }

    //*************************************************************************
    /// Peek a value from the front of the queue.
    /// Unlocked
    //*************************************************************************
    const_reference front_implementation() const
    {
      return p_buffer[this->read_index];
    }

    //*************************************************************************
    /// Pop a value from the queue.
    /// Unlocked
    //*************************************************************************
    bool pop_implementation()
    {
      if (this->current_size == 0)
      {
        // Queue is empty
        return false;
      }

      p_buffer[this->read_index].~T();

      this->read_index = this->get_next_index(this->read_index, this->MAX_SIZE);

      --this->current_size;

      return true;
    }

    // Disable copy construction and assignment.
    iqueue_spsc_locked(const iqueue_spsc_locked&) ETL_DELETE;
    iqueue_spsc_locked& operator =(const iqueue_spsc_locked&) ETL_DELETE;

#if ETL_USING_CPP11
    iqueue_spsc_locked(iqueue_spsc_locked&&) = delete;
    iqueue_spsc_locked& operator =(iqueue_spsc_locked&&) = delete;
#endif

    T* p_buffer; ///< The internal buffer.

    const etl::ifunction<void>& lock;   ///< The callback that locks interrupts.
    const etl::ifunction<void>& unlock; ///< The callback that unlocks interrupts.
  };

  //***************************************************************************
  ///\ingroup queue_spsc
  /// A fixed capacity spsc queue.
  /// This queue supports concurrent access by one producer and one consumer.
  /// \tparam T            The type this queue should support.
  /// \tparam SIZE         The maximum capacity of the queue.
  /// \tparam MEMORY_MODEL The memory model for the queue. Determines the type of the internal counter variables.
  //***************************************************************************
  template <typename T, size_t SIZE, const size_t MEMORY_MODEL = etl::memory_model::MEMORY_MODEL_LARGE>
  class queue_spsc_locked : public etl::iqueue_spsc_locked<T, MEMORY_MODEL>
  {
  private:

    typedef etl::iqueue_spsc_locked<T, MEMORY_MODEL> base_t;

  public:

    typedef typename base_t::size_type size_type;

    ETL_STATIC_ASSERT((SIZE <= etl::integral_limits<size_type>::max), "Size too large for memory model");

    static ETL_CONSTANT size_type MAX_SIZE = size_type(SIZE);

    //*************************************************************************
    /// Default constructor.
    //*************************************************************************

    queue_spsc_locked(const etl::ifunction<void>& lock_,
                      const etl::ifunction<void>& unlock_)
      : base_t(reinterpret_cast<T*>(buffer.raw), MAX_SIZE, lock_, unlock_)
    {
    }

    //*************************************************************************
    /// Destructor.
    //*************************************************************************
    ~queue_spsc_locked()
    {
      base_t::clear();
    }

  private:

    queue_spsc_locked(const queue_spsc_locked&) ETL_DELETE;
    queue_spsc_locked& operator = (const queue_spsc_locked&) ETL_DELETE;

#if ETL_USING_CPP11
    queue_spsc_locked(queue_spsc_locked&&) = delete;
    queue_spsc_locked& operator =(queue_spsc_locked&&) = delete;
#endif

    /// The uninitialised buffer of T used in the queue_lockable.
    etl::uninitialized_buffer_of<T, MAX_SIZE> buffer;
  };

  template <typename T, size_t SIZE, const size_t MEMORY_MODEL>
  ETL_CONSTANT typename queue_spsc_locked<T, SIZE, MEMORY_MODEL>::size_type queue_spsc_locked<T, SIZE, MEMORY_MODEL>::MAX_SIZE;
}

#endif