forked from FreeRTOS/FreeRTOS-Kernel
-
Notifications
You must be signed in to change notification settings - Fork 0
/
stream_buffer.c
1455 lines (1264 loc) · 61 KB
/
stream_buffer.c
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
/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* 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.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* Standard includes. */
#include <stdint.h>
#include <string.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "stream_buffer.h"
#if ( configUSE_TASK_NOTIFICATIONS != 1 )
#error configUSE_TASK_NOTIFICATIONS must be set to 1 to build stream_buffer.c
#endif
#if ( INCLUDE_xTaskGetCurrentTaskHandle != 1 )
#error INCLUDE_xTaskGetCurrentTaskHandle must be set to 1 to build stream_buffer.c
#endif
/* Lint e961, e9021 and e750 are suppressed as a MISRA exception justified
* because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined
* for the header files above, but not in this file, in order to generate the
* correct privileged Vs unprivileged linkage and placement. */
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750 !e9021. */
/* If the user has not provided application specific Rx notification macros,
* or #defined the notification macros away, then provide default implementations
* that uses task notifications. */
/*lint -save -e9026 Function like macros allowed and needed here so they can be overridden. */
#ifndef sbRECEIVE_COMPLETED
#define sbRECEIVE_COMPLETED( pxStreamBuffer ) \
vTaskSuspendAll(); \
{ \
if( ( pxStreamBuffer )->xTaskWaitingToSend != NULL ) \
{ \
( void ) xTaskNotify( ( pxStreamBuffer )->xTaskWaitingToSend, \
( uint32_t ) 0, \
eNoAction ); \
( pxStreamBuffer )->xTaskWaitingToSend = NULL; \
} \
} \
( void ) xTaskResumeAll()
#endif /* sbRECEIVE_COMPLETED */
/* If user has provided a per-instance receive complete callback, then
* invoke the callback else use the receive complete macro which is provided by default for all instances.
*/
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
#define prvRECEIVE_COMPLETED( pxStreamBuffer ) \
do { \
if( ( pxStreamBuffer )->pxReceiveCompletedCallback != NULL ) \
{ \
( pxStreamBuffer )->pxReceiveCompletedCallback( ( pxStreamBuffer ), pdFALSE, NULL ); \
} \
else \
{ \
sbRECEIVE_COMPLETED( ( pxStreamBuffer ) ); \
} \
} while( 0 )
#else /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#define prvRECEIVE_COMPLETED( pxStreamBuffer ) sbRECEIVE_COMPLETED( ( pxStreamBuffer ) )
#endif /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#ifndef sbRECEIVE_COMPLETED_FROM_ISR
#define sbRECEIVE_COMPLETED_FROM_ISR( pxStreamBuffer, \
pxHigherPriorityTaskWoken ) \
do { \
UBaseType_t uxSavedInterruptStatus; \
\
uxSavedInterruptStatus = taskENTER_CRITICAL_FROM_ISR(); \
{ \
if( ( pxStreamBuffer )->xTaskWaitingToSend != NULL ) \
{ \
( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToSend, \
( uint32_t ) 0, \
eNoAction, \
( pxHigherPriorityTaskWoken ) ); \
( pxStreamBuffer )->xTaskWaitingToSend = NULL; \
} \
} \
taskEXIT_CRITICAL_FROM_ISR( uxSavedInterruptStatus ); \
} while( 0 )
#endif /* sbRECEIVE_COMPLETED_FROM_ISR */
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
#define prvRECEIVE_COMPLETED_FROM_ISR( pxStreamBuffer, \
pxHigherPriorityTaskWoken ) \
do { \
if( ( pxStreamBuffer )->pxReceiveCompletedCallback != NULL ) \
{ \
( pxStreamBuffer )->pxReceiveCompletedCallback( ( pxStreamBuffer ), pdTRUE, ( pxHigherPriorityTaskWoken ) ); \
} \
else \
{ \
sbRECEIVE_COMPLETED_FROM_ISR( ( pxStreamBuffer ), ( pxHigherPriorityTaskWoken ) ); \
} \
} while( 0 )
#else /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#define prvRECEIVE_COMPLETED_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken ) \
sbRECEIVE_COMPLETED_FROM_ISR( ( pxStreamBuffer ), ( pxHigherPriorityTaskWoken ) )
#endif /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
/* If the user has not provided an application specific Tx notification macro,
* or #defined the notification macro away, then provide a default
* implementation that uses task notifications.
*/
#ifndef sbSEND_COMPLETED
#define sbSEND_COMPLETED( pxStreamBuffer ) \
vTaskSuspendAll(); \
{ \
if( ( pxStreamBuffer )->xTaskWaitingToReceive != NULL ) \
{ \
( void ) xTaskNotify( ( pxStreamBuffer )->xTaskWaitingToReceive, \
( uint32_t ) 0, \
eNoAction ); \
( pxStreamBuffer )->xTaskWaitingToReceive = NULL; \
} \
} \
( void ) xTaskResumeAll()
#endif /* sbSEND_COMPLETED */
/* If user has provided a per-instance send completed callback, then
* invoke the callback else use the send complete macro which is provided by default for all instances.
*/
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
#define prvSEND_COMPLETED( pxStreamBuffer ) \
do { \
if( ( pxStreamBuffer )->pxSendCompletedCallback != NULL ) \
{ \
pxStreamBuffer->pxSendCompletedCallback( ( pxStreamBuffer ), pdFALSE, NULL ); \
} \
else \
{ \
sbSEND_COMPLETED( ( pxStreamBuffer ) ); \
} \
} while( 0 )
#else /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#define prvSEND_COMPLETED( pxStreamBuffer ) sbSEND_COMPLETED( ( pxStreamBuffer ) )
#endif /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#ifndef sbSEND_COMPLETE_FROM_ISR
#define sbSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken ) \
do { \
UBaseType_t uxSavedInterruptStatus; \
\
uxSavedInterruptStatus = taskENTER_CRITICAL_FROM_ISR(); \
{ \
if( ( pxStreamBuffer )->xTaskWaitingToReceive != NULL ) \
{ \
( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToReceive, \
( uint32_t ) 0, \
eNoAction, \
( pxHigherPriorityTaskWoken ) ); \
( pxStreamBuffer )->xTaskWaitingToReceive = NULL; \
} \
} \
taskEXIT_CRITICAL_FROM_ISR( uxSavedInterruptStatus ); \
} while( 0 )
#endif /* sbSEND_COMPLETE_FROM_ISR */
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
#define prvSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken ) \
do { \
if( ( pxStreamBuffer )->pxSendCompletedCallback != NULL ) \
{ \
( pxStreamBuffer )->pxSendCompletedCallback( ( pxStreamBuffer ), pdTRUE, ( pxHigherPriorityTaskWoken ) ); \
} \
else \
{ \
sbSEND_COMPLETE_FROM_ISR( ( pxStreamBuffer ), ( pxHigherPriorityTaskWoken ) ); \
} \
} while( 0 )
#else /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
#define prvSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken ) \
sbSEND_COMPLETE_FROM_ISR( ( pxStreamBuffer ), ( pxHigherPriorityTaskWoken ) )
#endif /* if ( configUSE_SB_COMPLETED_CALLBACK == 1 ) */
/*lint -restore (9026) */
/* The number of bytes used to hold the length of a message in the buffer. */
#define sbBYTES_TO_STORE_MESSAGE_LENGTH ( sizeof( configMESSAGE_BUFFER_LENGTH_TYPE ) )
/* Bits stored in the ucFlags field of the stream buffer. */
#define sbFLAGS_IS_MESSAGE_BUFFER ( ( uint8_t ) 1 ) /* Set if the stream buffer was created as a message buffer, in which case it holds discrete messages rather than a stream. */
#define sbFLAGS_IS_STATICALLY_ALLOCATED ( ( uint8_t ) 2 ) /* Set if the stream buffer was created using statically allocated memory. */
/*-----------------------------------------------------------*/
/* Structure that hold state information on the buffer. */
typedef struct StreamBufferDef_t /*lint !e9058 Style convention uses tag. */
{
volatile size_t xTail; /* Index to the next item to read within the buffer. */
volatile size_t xHead; /* Index to the next item to write within the buffer. */
size_t xLength; /* The length of the buffer pointed to by pucBuffer. */
size_t xTriggerLevelBytes; /* The number of bytes that must be in the stream buffer before a task that is waiting for data is unblocked. */
volatile TaskHandle_t xTaskWaitingToReceive; /* Holds the handle of a task waiting for data, or NULL if no tasks are waiting. */
volatile TaskHandle_t xTaskWaitingToSend; /* Holds the handle of a task waiting to send data to a message buffer that is full. */
uint8_t * pucBuffer; /* Points to the buffer itself - that is - the RAM that stores the data passed through the buffer. */
uint8_t ucFlags;
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxStreamBufferNumber; /* Used for tracing purposes. */
#endif
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
StreamBufferCallbackFunction_t pxSendCompletedCallback; /* Optional callback called on send complete. sbSEND_COMPLETED is called if this is NULL. */
StreamBufferCallbackFunction_t pxReceiveCompletedCallback; /* Optional callback called on receive complete. sbRECEIVE_COMPLETED is called if this is NULL. */
#endif
} StreamBuffer_t;
/*
* The number of bytes available to be read from the buffer.
*/
static size_t prvBytesInBuffer( const StreamBuffer_t * const pxStreamBuffer ) PRIVILEGED_FUNCTION;
/*
* Add xCount bytes from pucData into the pxStreamBuffer's data storage area.
* This function does not update the buffer's xHead pointer, so multiple writes
* may be chained together "atomically". This is useful for Message Buffers where
* the length and data bytes are written in two separate chunks, and we don't want
* the reader to see the buffer as having grown until after all data is copied over.
* This function takes a custom xHead value to indicate where to write to (necessary
* for chaining) and returns the the resulting xHead position.
* To mark the write as complete, manually set the buffer's xHead field with the
* returned xHead from this function.
*/
static size_t prvWriteBytesToBuffer( StreamBuffer_t * const pxStreamBuffer,
const uint8_t * pucData,
size_t xCount,
size_t xHead ) PRIVILEGED_FUNCTION;
/*
* If the stream buffer is being used as a message buffer, then reads an entire
* message out of the buffer. If the stream buffer is being used as a stream
* buffer then read as many bytes as possible from the buffer.
* prvReadBytesFromBuffer() is called to actually extract the bytes from the
* buffer's data storage area.
*/
static size_t prvReadMessageFromBuffer( StreamBuffer_t * pxStreamBuffer,
void * pvRxData,
size_t xBufferLengthBytes,
size_t xBytesAvailable ) PRIVILEGED_FUNCTION;
/*
* If the stream buffer is being used as a message buffer, then writes an entire
* message to the buffer. If the stream buffer is being used as a stream
* buffer then write as many bytes as possible to the buffer.
* prvWriteBytestoBuffer() is called to actually send the bytes to the buffer's
* data storage area.
*/
static size_t prvWriteMessageToBuffer( StreamBuffer_t * const pxStreamBuffer,
const void * pvTxData,
size_t xDataLengthBytes,
size_t xSpace,
size_t xRequiredSpace ) PRIVILEGED_FUNCTION;
/*
* Copies xCount bytes from the pxStreamBuffer's data storage area to pucData.
* This function does not update the buffer's xTail pointer, so multiple reads
* may be chained together "atomically". This is useful for Message Buffers where
* the length and data bytes are read in two separate chunks, and we don't want
* the writer to see the buffer as having more free space until after all data is
* copied over, especially if we have to abort the read due to insufficient receiving space.
* This function takes a custom xTail value to indicate where to read from (necessary
* for chaining) and returns the the resulting xTail position.
* To mark the read as complete, manually set the buffer's xTail field with the
* returned xTail from this function.
*/
static size_t prvReadBytesFromBuffer( StreamBuffer_t * pxStreamBuffer,
uint8_t * pucData,
size_t xCount,
size_t xTail ) PRIVILEGED_FUNCTION;
/*
* Called by both pxStreamBufferCreate() and pxStreamBufferCreateStatic() to
* initialise the members of the newly created stream buffer structure.
*/
static void prvInitialiseNewStreamBuffer( StreamBuffer_t * const pxStreamBuffer,
uint8_t * const pucBuffer,
size_t xBufferSizeBytes,
size_t xTriggerLevelBytes,
uint8_t ucFlags,
StreamBufferCallbackFunction_t pxSendCompletedCallback,
StreamBufferCallbackFunction_t pxReceiveCompletedCallback ) PRIVILEGED_FUNCTION;
/*-----------------------------------------------------------*/
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
StreamBufferHandle_t xStreamBufferGenericCreate( size_t xBufferSizeBytes,
size_t xTriggerLevelBytes,
BaseType_t xIsMessageBuffer,
StreamBufferCallbackFunction_t pxSendCompletedCallback,
StreamBufferCallbackFunction_t pxReceiveCompletedCallback )
{
void * pvAllocatedMemory;
uint8_t ucFlags;
/* In case the stream buffer is going to be used as a message buffer
* (that is, it will hold discrete messages with a little meta data that
* says how big the next message is) check the buffer will be large enough
* to hold at least one message. */
if( xIsMessageBuffer == pdTRUE )
{
/* Is a message buffer but not statically allocated. */
ucFlags = sbFLAGS_IS_MESSAGE_BUFFER;
configASSERT( xBufferSizeBytes > sbBYTES_TO_STORE_MESSAGE_LENGTH );
}
else
{
/* Not a message buffer and not statically allocated. */
ucFlags = 0;
configASSERT( xBufferSizeBytes > 0 );
}
configASSERT( xTriggerLevelBytes <= xBufferSizeBytes );
/* A trigger level of 0 would cause a waiting task to unblock even when
* the buffer was empty. */
if( xTriggerLevelBytes == ( size_t ) 0 )
{
xTriggerLevelBytes = ( size_t ) 1;
}
/* A stream buffer requires a StreamBuffer_t structure and a buffer.
* Both are allocated in a single call to pvPortMalloc(). The
* StreamBuffer_t structure is placed at the start of the allocated memory
* and the buffer follows immediately after. The requested size is
* incremented so the free space is returned as the user would expect -
* this is a quirk of the implementation that means otherwise the free
* space would be reported as one byte smaller than would be logically
* expected. */
if( xBufferSizeBytes < ( xBufferSizeBytes + 1 + sizeof( StreamBuffer_t ) ) )
{
xBufferSizeBytes++;
pvAllocatedMemory = pvPortMalloc( xBufferSizeBytes + sizeof( StreamBuffer_t ) );
}
else
{
pvAllocatedMemory = NULL;
}
if( pvAllocatedMemory != NULL )
{
prvInitialiseNewStreamBuffer( ( StreamBuffer_t * ) pvAllocatedMemory, /* Structure at the start of the allocated memory. */ /*lint !e9087 Safe cast as allocated memory is aligned. */ /*lint !e826 Area is not too small and alignment is guaranteed provided malloc() behaves as expected and returns aligned buffer. */
( ( uint8_t * ) pvAllocatedMemory ) + sizeof( StreamBuffer_t ), /* Storage area follows. */ /*lint !e9016 Indexing past structure valid for uint8_t pointer, also storage area has no alignment requirement. */
xBufferSizeBytes,
xTriggerLevelBytes,
ucFlags,
pxSendCompletedCallback,
pxReceiveCompletedCallback );
traceSTREAM_BUFFER_CREATE( ( ( StreamBuffer_t * ) pvAllocatedMemory ), xIsMessageBuffer );
}
else
{
traceSTREAM_BUFFER_CREATE_FAILED( xIsMessageBuffer );
}
return ( StreamBufferHandle_t ) pvAllocatedMemory; /*lint !e9087 !e826 Safe cast as allocated memory is aligned. */
}
#endif /* configSUPPORT_DYNAMIC_ALLOCATION */
/*-----------------------------------------------------------*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
StreamBufferHandle_t xStreamBufferGenericCreateStatic( size_t xBufferSizeBytes,
size_t xTriggerLevelBytes,
BaseType_t xIsMessageBuffer,
uint8_t * const pucStreamBufferStorageArea,
StaticStreamBuffer_t * const pxStaticStreamBuffer,
StreamBufferCallbackFunction_t pxSendCompletedCallback,
StreamBufferCallbackFunction_t pxReceiveCompletedCallback )
{
StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) pxStaticStreamBuffer; /*lint !e740 !e9087 Safe cast as StaticStreamBuffer_t is opaque Streambuffer_t. */
StreamBufferHandle_t xReturn;
uint8_t ucFlags;
configASSERT( pucStreamBufferStorageArea );
configASSERT( pxStaticStreamBuffer );
configASSERT( xTriggerLevelBytes <= xBufferSizeBytes );
/* A trigger level of 0 would cause a waiting task to unblock even when
* the buffer was empty. */
if( xTriggerLevelBytes == ( size_t ) 0 )
{
xTriggerLevelBytes = ( size_t ) 1;
}
if( xIsMessageBuffer != pdFALSE )
{
/* Statically allocated message buffer. */
ucFlags = sbFLAGS_IS_MESSAGE_BUFFER | sbFLAGS_IS_STATICALLY_ALLOCATED;
}
else
{
/* Statically allocated stream buffer. */
ucFlags = sbFLAGS_IS_STATICALLY_ALLOCATED;
}
/* In case the stream buffer is going to be used as a message buffer
* (that is, it will hold discrete messages with a little meta data that
* says how big the next message is) check the buffer will be large enough
* to hold at least one message. */
configASSERT( xBufferSizeBytes > sbBYTES_TO_STORE_MESSAGE_LENGTH );
#if ( configASSERT_DEFINED == 1 )
{
/* Sanity check that the size of the structure used to declare a
* variable of type StaticStreamBuffer_t equals the size of the real
* message buffer structure. */
volatile size_t xSize = sizeof( StaticStreamBuffer_t );
configASSERT( xSize == sizeof( StreamBuffer_t ) );
} /*lint !e529 xSize is referenced is configASSERT() is defined. */
#endif /* configASSERT_DEFINED */
if( ( pucStreamBufferStorageArea != NULL ) && ( pxStaticStreamBuffer != NULL ) )
{
prvInitialiseNewStreamBuffer( pxStreamBuffer,
pucStreamBufferStorageArea,
xBufferSizeBytes,
xTriggerLevelBytes,
ucFlags,
pxSendCompletedCallback,
pxReceiveCompletedCallback );
/* Remember this was statically allocated in case it is ever deleted
* again. */
pxStreamBuffer->ucFlags |= sbFLAGS_IS_STATICALLY_ALLOCATED;
traceSTREAM_BUFFER_CREATE( pxStreamBuffer, xIsMessageBuffer );
xReturn = ( StreamBufferHandle_t ) pxStaticStreamBuffer; /*lint !e9087 Data hiding requires cast to opaque type. */
}
else
{
xReturn = NULL;
traceSTREAM_BUFFER_CREATE_STATIC_FAILED( xReturn, xIsMessageBuffer );
}
return xReturn;
}
#endif /* ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
/*-----------------------------------------------------------*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
BaseType_t xStreamBufferGetStaticBuffers( StreamBufferHandle_t xStreamBuffer,
uint8_t ** ppucStreamBufferStorageArea,
StaticStreamBuffer_t ** ppxStaticStreamBuffer )
{
BaseType_t xReturn;
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
configASSERT( pxStreamBuffer );
configASSERT( ppucStreamBufferStorageArea );
configASSERT( ppxStaticStreamBuffer );
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_STATICALLY_ALLOCATED ) != ( uint8_t ) 0 )
{
*ppucStreamBufferStorageArea = pxStreamBuffer->pucBuffer;
*ppxStaticStreamBuffer = ( StaticStreamBuffer_t * ) pxStreamBuffer;
xReturn = pdTRUE;
}
else
{
xReturn = pdFALSE;
}
return xReturn;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
void vStreamBufferDelete( StreamBufferHandle_t xStreamBuffer )
{
StreamBuffer_t * pxStreamBuffer = xStreamBuffer;
configASSERT( pxStreamBuffer );
traceSTREAM_BUFFER_DELETE( xStreamBuffer );
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_STATICALLY_ALLOCATED ) == ( uint8_t ) pdFALSE )
{
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
{
/* Both the structure and the buffer were allocated using a single call
* to pvPortMalloc(), hence only one call to vPortFree() is required. */
vPortFree( ( void * ) pxStreamBuffer ); /*lint !e9087 Standard free() semantics require void *, plus pxStreamBuffer was allocated by pvPortMalloc(). */
}
#else
{
/* Should not be possible to get here, ucFlags must be corrupt.
* Force an assert. */
configASSERT( xStreamBuffer == ( StreamBufferHandle_t ) ~0 );
}
#endif
}
else
{
/* The structure and buffer were not allocated dynamically and cannot be
* freed - just scrub the structure so future use will assert. */
( void ) memset( pxStreamBuffer, 0x00, sizeof( StreamBuffer_t ) );
}
}
/*-----------------------------------------------------------*/
BaseType_t xStreamBufferReset( StreamBufferHandle_t xStreamBuffer )
{
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
BaseType_t xReturn = pdFAIL;
StreamBufferCallbackFunction_t pxSendCallback = NULL, pxReceiveCallback = NULL;
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxStreamBufferNumber;
#endif
configASSERT( pxStreamBuffer );
#if ( configUSE_TRACE_FACILITY == 1 )
{
/* Store the stream buffer number so it can be restored after the
* reset. */
uxStreamBufferNumber = pxStreamBuffer->uxStreamBufferNumber;
}
#endif
/* Can only reset a message buffer if there are no tasks blocked on it. */
taskENTER_CRITICAL();
{
if( ( pxStreamBuffer->xTaskWaitingToReceive == NULL ) && ( pxStreamBuffer->xTaskWaitingToSend == NULL ) )
{
#if ( configUSE_SB_COMPLETED_CALLBACK == 1 )
{
pxSendCallback = pxStreamBuffer->pxSendCompletedCallback;
pxReceiveCallback = pxStreamBuffer->pxReceiveCompletedCallback;
}
#endif
prvInitialiseNewStreamBuffer( pxStreamBuffer,
pxStreamBuffer->pucBuffer,
pxStreamBuffer->xLength,
pxStreamBuffer->xTriggerLevelBytes,
pxStreamBuffer->ucFlags,
pxSendCallback,
pxReceiveCallback );
#if ( configUSE_TRACE_FACILITY == 1 )
{
pxStreamBuffer->uxStreamBufferNumber = uxStreamBufferNumber;
}
#endif
traceSTREAM_BUFFER_RESET( xStreamBuffer );
xReturn = pdPASS;
}
}
taskEXIT_CRITICAL();
return xReturn;
}
/*-----------------------------------------------------------*/
BaseType_t xStreamBufferSetTriggerLevel( StreamBufferHandle_t xStreamBuffer,
size_t xTriggerLevel )
{
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
BaseType_t xReturn;
configASSERT( pxStreamBuffer );
/* It is not valid for the trigger level to be 0. */
if( xTriggerLevel == ( size_t ) 0 )
{
xTriggerLevel = ( size_t ) 1;
}
/* The trigger level is the number of bytes that must be in the stream
* buffer before a task that is waiting for data is unblocked. */
if( xTriggerLevel < pxStreamBuffer->xLength )
{
pxStreamBuffer->xTriggerLevelBytes = xTriggerLevel;
xReturn = pdPASS;
}
else
{
xReturn = pdFALSE;
}
return xReturn;
}
/*-----------------------------------------------------------*/
size_t xStreamBufferSpacesAvailable( StreamBufferHandle_t xStreamBuffer )
{
const StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xSpace;
size_t xOriginalTail;
configASSERT( pxStreamBuffer );
/* The code below reads xTail and then xHead. This is safe if the stream
* buffer is updated once between the two reads - but not if the stream buffer
* is updated more than once between the two reads - hence the loop. */
do
{
xOriginalTail = pxStreamBuffer->xTail;
xSpace = pxStreamBuffer->xLength + pxStreamBuffer->xTail;
xSpace -= pxStreamBuffer->xHead;
} while( xOriginalTail != pxStreamBuffer->xTail );
xSpace -= ( size_t ) 1;
if( xSpace >= pxStreamBuffer->xLength )
{
xSpace -= pxStreamBuffer->xLength;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
return xSpace;
}
/*-----------------------------------------------------------*/
size_t xStreamBufferBytesAvailable( StreamBufferHandle_t xStreamBuffer )
{
const StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xReturn;
configASSERT( pxStreamBuffer );
xReturn = prvBytesInBuffer( pxStreamBuffer );
return xReturn;
}
/*-----------------------------------------------------------*/
size_t xStreamBufferSend( StreamBufferHandle_t xStreamBuffer,
const void * pvTxData,
size_t xDataLengthBytes,
TickType_t xTicksToWait )
{
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xReturn, xSpace = 0;
size_t xRequiredSpace = xDataLengthBytes;
TimeOut_t xTimeOut;
size_t xMaxReportedSpace = 0;
configASSERT( pvTxData );
configASSERT( pxStreamBuffer );
/* The maximum amount of space a stream buffer will ever report is its length
* minus 1. */
xMaxReportedSpace = pxStreamBuffer->xLength - ( size_t ) 1;
/* This send function is used to write to both message buffers and stream
* buffers. If this is a message buffer then the space needed must be
* increased by the amount of bytes needed to store the length of the
* message. */
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )
{
xRequiredSpace += sbBYTES_TO_STORE_MESSAGE_LENGTH;
/* Overflow? */
configASSERT( xRequiredSpace > xDataLengthBytes );
/* If this is a message buffer then it must be possible to write the
* whole message. */
if( xRequiredSpace > xMaxReportedSpace )
{
/* The message would not fit even if the entire buffer was empty,
* so don't wait for space. */
xTicksToWait = ( TickType_t ) 0;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
/* If this is a stream buffer then it is acceptable to write only part
* of the message to the buffer. Cap the length to the total length of
* the buffer. */
if( xRequiredSpace > xMaxReportedSpace )
{
xRequiredSpace = xMaxReportedSpace;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
if( xTicksToWait != ( TickType_t ) 0 )
{
vTaskSetTimeOutState( &xTimeOut );
do
{
/* Wait until the required number of bytes are free in the message
* buffer. */
taskENTER_CRITICAL();
{
xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );
if( xSpace < xRequiredSpace )
{
/* Clear notification state as going to wait for space. */
( void ) xTaskNotifyStateClear( NULL );
/* Should only be one writer. */
configASSERT( pxStreamBuffer->xTaskWaitingToSend == NULL );
pxStreamBuffer->xTaskWaitingToSend = xTaskGetCurrentTaskHandle();
}
else
{
taskEXIT_CRITICAL();
break;
}
}
taskEXIT_CRITICAL();
traceBLOCKING_ON_STREAM_BUFFER_SEND( xStreamBuffer );
( void ) xTaskNotifyWait( ( uint32_t ) 0, ( uint32_t ) 0, NULL, xTicksToWait );
pxStreamBuffer->xTaskWaitingToSend = NULL;
} while( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
if( xSpace == ( size_t ) 0 )
{
xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
xReturn = prvWriteMessageToBuffer( pxStreamBuffer, pvTxData, xDataLengthBytes, xSpace, xRequiredSpace );
if( xReturn > ( size_t ) 0 )
{
traceSTREAM_BUFFER_SEND( xStreamBuffer, xReturn );
/* Was a task waiting for the data? */
if( prvBytesInBuffer( pxStreamBuffer ) >= pxStreamBuffer->xTriggerLevelBytes )
{
prvSEND_COMPLETED( pxStreamBuffer );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
traceSTREAM_BUFFER_SEND_FAILED( xStreamBuffer );
}
return xReturn;
}
/*-----------------------------------------------------------*/
size_t xStreamBufferSendFromISR( StreamBufferHandle_t xStreamBuffer,
const void * pvTxData,
size_t xDataLengthBytes,
BaseType_t * const pxHigherPriorityTaskWoken )
{
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xReturn, xSpace;
size_t xRequiredSpace = xDataLengthBytes;
configASSERT( pvTxData );
configASSERT( pxStreamBuffer );
/* This send function is used to write to both message buffers and stream
* buffers. If this is a message buffer then the space needed must be
* increased by the amount of bytes needed to store the length of the
* message. */
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )
{
xRequiredSpace += sbBYTES_TO_STORE_MESSAGE_LENGTH;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );
xReturn = prvWriteMessageToBuffer( pxStreamBuffer, pvTxData, xDataLengthBytes, xSpace, xRequiredSpace );
if( xReturn > ( size_t ) 0 )
{
/* Was a task waiting for the data? */
if( prvBytesInBuffer( pxStreamBuffer ) >= pxStreamBuffer->xTriggerLevelBytes )
{
prvSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
traceSTREAM_BUFFER_SEND_FROM_ISR( xStreamBuffer, xReturn );
return xReturn;
}
/*-----------------------------------------------------------*/
static size_t prvWriteMessageToBuffer( StreamBuffer_t * const pxStreamBuffer,
const void * pvTxData,
size_t xDataLengthBytes,
size_t xSpace,
size_t xRequiredSpace )
{
size_t xNextHead = pxStreamBuffer->xHead;
configMESSAGE_BUFFER_LENGTH_TYPE xMessageLength;
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )
{
/* This is a message buffer, as opposed to a stream buffer. */
/* Convert xDataLengthBytes to the message length type. */
xMessageLength = ( configMESSAGE_BUFFER_LENGTH_TYPE ) xDataLengthBytes;
/* Ensure the data length given fits within configMESSAGE_BUFFER_LENGTH_TYPE. */
configASSERT( ( size_t ) xMessageLength == xDataLengthBytes );
if( xSpace >= xRequiredSpace )
{
/* There is enough space to write both the message length and the message
* itself into the buffer. Start by writing the length of the data, the data
* itself will be written later in this function. */
xNextHead = prvWriteBytesToBuffer( pxStreamBuffer, ( const uint8_t * ) &( xMessageLength ), sbBYTES_TO_STORE_MESSAGE_LENGTH, xNextHead );
}
else
{
/* Not enough space, so do not write data to the buffer. */
xDataLengthBytes = 0;
}
}
else
{
/* This is a stream buffer, as opposed to a message buffer, so writing a
* stream of bytes rather than discrete messages. Plan to write as many
* bytes as possible. */
xDataLengthBytes = configMIN( xDataLengthBytes, xSpace );
}
if( xDataLengthBytes != ( size_t ) 0 )
{
/* Write the data to the buffer. */
pxStreamBuffer->xHead = prvWriteBytesToBuffer( pxStreamBuffer, ( const uint8_t * ) pvTxData, xDataLengthBytes, xNextHead ); /*lint !e9079 Storage buffer is implemented as uint8_t for ease of sizing, alignment and access. */
}
return xDataLengthBytes;
}
/*-----------------------------------------------------------*/
size_t xStreamBufferReceive( StreamBufferHandle_t xStreamBuffer,
void * pvRxData,
size_t xBufferLengthBytes,
TickType_t xTicksToWait )
{
StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
size_t xReceivedLength = 0, xBytesAvailable, xBytesToStoreMessageLength;
configASSERT( pvRxData );
configASSERT( pxStreamBuffer );
/* This receive function is used by both message buffers, which store
* discrete messages, and stream buffers, which store a continuous stream of
* bytes. Discrete messages include an additional
* sbBYTES_TO_STORE_MESSAGE_LENGTH bytes that hold the length of the
* message. */
if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )
{
xBytesToStoreMessageLength = sbBYTES_TO_STORE_MESSAGE_LENGTH;
}
else
{
xBytesToStoreMessageLength = 0;
}
if( xTicksToWait != ( TickType_t ) 0 )
{
/* Checking if there is data and clearing the notification state must be
* performed atomically. */
taskENTER_CRITICAL();
{
xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );
/* If this function was invoked by a message buffer read then
* xBytesToStoreMessageLength holds the number of bytes used to hold
* the length of the next discrete message. If this function was
* invoked by a stream buffer read then xBytesToStoreMessageLength will
* be 0. */
if( xBytesAvailable <= xBytesToStoreMessageLength )
{
/* Clear notification state as going to wait for data. */
( void ) xTaskNotifyStateClear( NULL );
/* Should only be one reader. */
configASSERT( pxStreamBuffer->xTaskWaitingToReceive == NULL );
pxStreamBuffer->xTaskWaitingToReceive = xTaskGetCurrentTaskHandle();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
taskEXIT_CRITICAL();
if( xBytesAvailable <= xBytesToStoreMessageLength )
{
/* Wait for data to be available. */
traceBLOCKING_ON_STREAM_BUFFER_RECEIVE( xStreamBuffer );
( void ) xTaskNotifyWait( ( uint32_t ) 0, ( uint32_t ) 0, NULL, xTicksToWait );
pxStreamBuffer->xTaskWaitingToReceive = NULL;
/* Recheck the data available after blocking. */
xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );
}
/* Whether receiving a discrete message (where xBytesToStoreMessageLength
* holds the number of bytes used to store the message length) or a stream of
* bytes (where xBytesToStoreMessageLength is zero), the number of bytes
* available must be greater than xBytesToStoreMessageLength to be able to
* read bytes from the buffer. */
if( xBytesAvailable > xBytesToStoreMessageLength )
{
xReceivedLength = prvReadMessageFromBuffer( pxStreamBuffer, pvRxData, xBufferLengthBytes, xBytesAvailable );
/* Was a task waiting for space in the buffer? */
if( xReceivedLength != ( size_t ) 0 )
{
traceSTREAM_BUFFER_RECEIVE( xStreamBuffer, xReceivedLength );
prvRECEIVE_COMPLETED( xStreamBuffer );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
traceSTREAM_BUFFER_RECEIVE_FAILED( xStreamBuffer );
mtCOVERAGE_TEST_MARKER();
}