git.sur5r.net Git - freertos/blob - FreeRTOS/Source/stream_buffer.c

   1 /*\r
   2  * FreeRTOS Kernel V10.0.1\r
   3  * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
   4  *\r
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
   6  * this software and associated documentation files (the "Software"), to deal in\r
   7  * the Software without restriction, including without limitation the rights to\r
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
   9  * the Software, and to permit persons to whom the Software is furnished to do so,\r
  10  * subject to the following conditions:\r
  11  *\r
  12  * The above copyright notice and this permission notice shall be included in all\r
  13  * copies or substantial portions of the Software.\r
  14  *\r
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
  17  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
  18  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
  19  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
  20  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  21  *\r
  22  * http://www.FreeRTOS.org\r
  23  * http://aws.amazon.com/freertos\r
  24  *\r
  25  * 1 tab == 4 spaces!\r
  26  */\r
  27 \r
  28 /* Standard includes. */\r
  29 #include <stdint.h>\r
  30 #include <string.h>\r
  31 \r
  32 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining\r
  33 all the API functions to use the MPU wrappers.  That should only be done when\r
  34 task.h is included from an application file. */\r
  35 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE\r
  36 \r
  37 /* FreeRTOS includes. */\r
  38 #include "FreeRTOS.h"\r
  39 #include "task.h"\r
  40 #include "stream_buffer.h"\r
  41 \r
  42 #if( configUSE_TASK_NOTIFICATIONS != 1 )\r
  43         #error configUSE_TASK_NOTIFICATIONS must be set to 1 to build stream_buffer.c\r
  44 #endif\r
  45 \r
  46 /* Lint e961 and e750 are suppressed as a MISRA exception justified because the\r
  47 MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined for the\r
  48 header files above, but not in this file, in order to generate the correct\r
  49 privileged Vs unprivileged linkage and placement. */\r
  50 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750. */\r
  51 \r
  52 /* If the user has not provided application specific Rx notification macros,\r
  53 or #defined the notification macros away, them provide default implementations\r
  54 that uses task notifications. */\r
  55 /*lint -save -e9026 Function like macros allowed and needed here so they can be overidden. */\r
  56 #ifndef sbRECEIVE_COMPLETED\r
  57         #define sbRECEIVE_COMPLETED( pxStreamBuffer )                                                                           \\r
  58                 vTaskSuspendAll();                                                                                                                              \\r
  59                 {                                                                                                                                                               \\r
  60                         if( ( pxStreamBuffer )->xTaskWaitingToSend != NULL )                                            \\r
  61                         {                                                                                                                                                       \\r
  62                                 ( void ) xTaskNotify( ( pxStreamBuffer )->xTaskWaitingToSend,                   \\r
  63                                                                           ( uint32_t ) 0,                                                                       \\r
  64                                                                           eNoAction );                                                                          \\r
  65                                 ( pxStreamBuffer )->xTaskWaitingToSend = NULL;                                                  \\r
  66                         }                                                                                                                                                       \\r
  67                 }                                                                                                                                                               \\r
  68                 ( void ) xTaskResumeAll();\r
  69 #endif /* sbRECEIVE_COMPLETED */\r
  70 \r
  71 #ifndef sbRECEIVE_COMPLETED_FROM_ISR\r
  72         #define sbRECEIVE_COMPLETED_FROM_ISR( pxStreamBuffer,                                                           \\r
  73                                                                                   pxHigherPriorityTaskWoken )                                   \\r
  74         {                                                                                                                                                                       \\r
  75         UBaseType_t uxSavedInterruptStatus;                                                                                                     \\r
  76                                                                                                                                                                                 \\r
  77                 uxSavedInterruptStatus = ( UBaseType_t ) portSET_INTERRUPT_MASK_FROM_ISR();             \\r
  78                 {                                                                                                                                                               \\r
  79                         if( ( pxStreamBuffer )->xTaskWaitingToSend != NULL )                                            \\r
  80                         {                                                                                                                                                       \\r
  81                                 ( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToSend,    \\r
  82                                                                                          ( uint32_t ) 0,                                                        \\r
  83                                                                                          eNoAction,                                                                     \\r
  84                                                                                          pxHigherPriorityTaskWoken );                           \\r
  85                                 ( pxStreamBuffer )->xTaskWaitingToSend = NULL;                                                  \\r
  86                         }                                                                                                                                                       \\r
  87                 }                                                                                                                                                               \\r
  88                 portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );                                    \\r
  89         }\r
  90 #endif /* sbRECEIVE_COMPLETED_FROM_ISR */\r
  91 \r
  92 /* If the user has not provided an application specific Tx notification macro,\r
  93 or #defined the notification macro away, them provide a default implementation\r
  94 that uses task notifications. */\r
  95 #ifndef sbSEND_COMPLETED\r
  96         #define sbSEND_COMPLETED( pxStreamBuffer )                                                                                      \\r
  97                 vTaskSuspendAll();                                                                                                                              \\r
  98                 {                                                                                                                                                               \\r
  99                         if( ( pxStreamBuffer )->xTaskWaitingToReceive != NULL )                                         \\r
 100                         {                                                                                                                                                       \\r
 101                                 ( void ) xTaskNotify( ( pxStreamBuffer )->xTaskWaitingToReceive,                \\r
 102                                                                           ( uint32_t ) 0,                                                                       \\r
 103                                                                           eNoAction );                                                                          \\r
 104                                 ( pxStreamBuffer )->xTaskWaitingToReceive = NULL;                                               \\r
 105                         }                                                                                                                                                       \\r
 106                 }                                                                                                                                                               \\r
 107                 ( void ) xTaskResumeAll();\r
 108 #endif /* sbSEND_COMPLETED */\r
 109 \r
 110 #ifndef sbSEND_COMPLETE_FROM_ISR\r
 111         #define sbSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken )           \\r
 112         {                                                                                                                                                                       \\r
 113         UBaseType_t uxSavedInterruptStatus;                                                                                                     \\r
 114                                                                                                                                                                                 \\r
 115                 uxSavedInterruptStatus = ( UBaseType_t ) portSET_INTERRUPT_MASK_FROM_ISR();             \\r
 116                 {                                                                                                                                                               \\r
 117                         if( ( pxStreamBuffer )->xTaskWaitingToReceive != NULL )                                         \\r
 118                         {                                                                                                                                                       \\r
 119                                 ( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToReceive, \\r
 120                                                                                          ( uint32_t ) 0,                                                        \\r
 121                                                                                          eNoAction,                                                                     \\r
 122                                                                                          pxHigherPriorityTaskWoken );                           \\r
 123                                 ( pxStreamBuffer )->xTaskWaitingToReceive = NULL;                                               \\r
 124                         }                                                                                                                                                       \\r
 125                 }                                                                                                                                                               \\r
 126                 portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );                                    \\r
 127         }\r
 128 #endif /* sbSEND_COMPLETE_FROM_ISR */\r
 129 /*lint -restore (9026) */\r
 130 \r
 131 /* The number of bytes used to hold the length of a message in the buffer. */\r
 132 #define sbBYTES_TO_STORE_MESSAGE_LENGTH ( sizeof( size_t ) )\r
 133 \r
 134 /* Bits stored in the ucFlags field of the stream buffer. */\r
 135 #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. */\r
 136 #define sbFLAGS_IS_STATICALLY_ALLOCATED ( ( uint8_t ) 2 ) /* Set if the stream buffer was created using statically allocated memory. */\r
 137 \r
 138 /*-----------------------------------------------------------*/\r
 139 \r
 140 /* Structure that hold state information on the buffer. */\r
 141 typedef struct xSTREAM_BUFFER /*lint !e9058 Style convention uses tag. */\r
 142 {\r
 143         volatile size_t xTail;                          /* Index to the next item to read within the buffer. */\r
 144         volatile size_t xHead;                          /* Index to the next item to write within the buffer. */\r
 145         size_t xLength;                                         /* The length of the buffer pointed to by pucBuffer. */\r
 146         size_t xTriggerLevelBytes;                      /* The number of bytes that must be in the stream buffer before a task that is waiting for data is unblocked. */\r
 147         volatile TaskHandle_t xTaskWaitingToReceive; /* Holds the handle of a task waiting for data, or NULL if no tasks are waiting. */\r
 148         volatile TaskHandle_t xTaskWaitingToSend;       /* Holds the handle of a task waiting to send data to a message buffer that is full. */\r
 149         uint8_t *pucBuffer;                                     /* Points to the buffer itself - that is - the RAM that stores the data passed through the buffer. */\r
 150         uint8_t ucFlags;\r
 151 \r
 152         #if ( configUSE_TRACE_FACILITY == 1 )\r
 153                 UBaseType_t uxStreamBufferNumber;               /* Used for tracing purposes. */\r
 154         #endif\r
 155 } StreamBuffer_t;\r
 156 \r
 157 /*\r
 158  * The number of bytes available to be read from the buffer.\r
 159  */\r
 160 static size_t prvBytesInBuffer( const StreamBuffer_t * const pxStreamBuffer ) PRIVILEGED_FUNCTION;\r
 161 \r
 162 /*\r
 163  * Add xCount bytes from pucData into the pxStreamBuffer message buffer.\r
 164  * Returns the number of bytes written, which will either equal xCount in the\r
 165  * success case, or 0 if there was not enough space in the buffer (in which case\r
 166  * no data is written into the buffer).\r
 167  */\r
 168 static size_t prvWriteBytesToBuffer( StreamBuffer_t * const pxStreamBuffer, const uint8_t *pucData, size_t xCount ) PRIVILEGED_FUNCTION;\r
 169 \r
 170 /*\r
 171  * If the stream buffer is being used as a message buffer, then reads an entire\r
 172  * message out of the buffer.  If the stream buffer is being used as a stream\r
 173  * buffer then read as many bytes as possible from the buffer.\r
 174  * prvReadBytesFromBuffer() is called to actually extract the bytes from the\r
 175  * buffer's data storage area.\r
 176  */\r
 177 static size_t prvReadMessageFromBuffer( StreamBuffer_t *pxStreamBuffer,\r
 178                                                                                 void *pvRxData,\r
 179                                                                                 size_t xBufferLengthBytes,\r
 180                                                                                 size_t xBytesAvailable,\r
 181                                                                                 size_t xBytesToStoreMessageLength ) PRIVILEGED_FUNCTION;\r
 182 \r
 183 /*\r
 184  * If the stream buffer is being used as a message buffer, then writes an entire\r
 185  * message to the buffer.  If the stream buffer is being used as a stream\r
 186  * buffer then write as many bytes as possible to the buffer.\r
 187  * prvWriteBytestoBuffer() is called to actually send the bytes to the buffer's\r
 188  * data storage area.\r
 189  */\r
 190 static size_t prvWriteMessageToBuffer(  StreamBuffer_t * const pxStreamBuffer,\r
 191                                                                                 const void * pvTxData,\r
 192                                                                                 size_t xDataLengthBytes,\r
 193                                                                                 size_t xSpace,\r
 194                                                                                 size_t xRequiredSpace ) PRIVILEGED_FUNCTION;\r
 195 \r
 196 /*\r
 197  * Read xMaxCount bytes from the pxStreamBuffer message buffer and write them\r
 198  * to pucData.\r
 199  */\r
 200 static size_t prvReadBytesFromBuffer( StreamBuffer_t *pxStreamBuffer,\r
 201                                                                           uint8_t *pucData,\r
 202                                                                           size_t xMaxCount,\r
 203                                                                           size_t xBytesAvailable ); PRIVILEGED_FUNCTION\r
 204 \r
 205 /*\r
 206  * Called by both pxStreamBufferCreate() and pxStreamBufferCreateStatic() to\r
 207  * initialise the members of the newly created stream buffer structure.\r
 208  */\r
 209 static void prvInitialiseNewStreamBuffer( StreamBuffer_t * const pxStreamBuffer,\r
 210                                                                                   uint8_t * const pucBuffer,\r
 211                                                                                   size_t xBufferSizeBytes,\r
 212                                                                                   size_t xTriggerLevelBytes,\r
 213                                                                                   BaseType_t xIsMessageBuffer ) PRIVILEGED_FUNCTION;\r
 214 \r
 215 /*-----------------------------------------------------------*/\r
 216 \r
 217 #if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )\r
 218 \r
 219         StreamBufferHandle_t xStreamBufferGenericCreate( size_t xBufferSizeBytes, size_t xTriggerLevelBytes, BaseType_t xIsMessageBuffer )\r
 220         {\r
 221         uint8_t *pucAllocatedMemory;\r
 222 \r
 223                 /* In case the stream buffer is going to be used as a message buffer\r
 224                 (that is, it will hold discrete messages with a little meta data that\r
 225                 says how big the next message is) check the buffer will be large enough\r
 226                 to hold at least one message. */\r
 227                 configASSERT( xBufferSizeBytes > sbBYTES_TO_STORE_MESSAGE_LENGTH );\r
 228                 configASSERT( xTriggerLevelBytes <= xBufferSizeBytes );\r
 229 \r
 230                 /* A trigger level of 0 would cause a waiting task to unblock even when\r
 231                 the buffer was empty. */\r
 232                 if( xTriggerLevelBytes == ( size_t ) 0 )\r
 233                 {\r
 234                         xTriggerLevelBytes = ( size_t ) 1; /*lint !e9044 Parameter modified to ensure it doesn't have a dangerous value. */\r
 235                 }\r
 236 \r
 237                 /* A stream buffer requires a StreamBuffer_t structure and a buffer.\r
 238                 Both are allocated in a single call to pvPortMalloc().  The\r
 239                 StreamBuffer_t structure is placed at the start of the allocated memory\r
 240                 and the buffer follows immediately after.  The requested size is\r
 241                 incremented so the free space is returned as the user would expect -\r
 242                 this is a quirk of the implementation that means otherwise the free\r
 243                 space would be reported as one byte smaller than would be logically\r
 244                 expected. */\r
 245                 xBufferSizeBytes++;\r
 246                 pucAllocatedMemory = ( uint8_t * ) pvPortMalloc( xBufferSizeBytes + sizeof( StreamBuffer_t ) ); /*lint !e9079 malloc() only returns void*. */\r
 247 \r
 248                 if( pucAllocatedMemory != NULL )\r
 249                 {\r
 250                         prvInitialiseNewStreamBuffer( ( StreamBuffer_t * ) pucAllocatedMemory, /* 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. */\r
 251                                                                                    pucAllocatedMemory + sizeof( StreamBuffer_t ),  /* Storage area follows. */ /*lint !e9016 Indexing past structure valid for uint8_t pointer, also storage area has no alignment requirement. */\r
 252                                                                                    xBufferSizeBytes,\r
 253                                                                                    xTriggerLevelBytes,\r
 254                                                                                    xIsMessageBuffer );\r
 255 \r
 256                         traceSTREAM_BUFFER_CREATE( ( ( StreamBuffer_t * ) pucAllocatedMemory ), xIsMessageBuffer );\r
 257                 }\r
 258                 else\r
 259                 {\r
 260                         traceSTREAM_BUFFER_CREATE_FAILED( xIsMessageBuffer );\r
 261                 }\r
 262 \r
 263                 return ( StreamBufferHandle_t * ) pucAllocatedMemory; /*lint !e9087 !e826 Safe cast as allocated memory is aligned. */\r
 264         }\r
 265 \r
 266 #endif /* configSUPPORT_DYNAMIC_ALLOCATION */\r
 267 /*-----------------------------------------------------------*/\r
 268 \r
 269 #if( configSUPPORT_STATIC_ALLOCATION == 1 )\r
 270 \r
 271         StreamBufferHandle_t xStreamBufferGenericCreateStatic( size_t xBufferSizeBytes,\r
 272                                                                                                                    size_t xTriggerLevelBytes,\r
 273                                                                                                                    BaseType_t xIsMessageBuffer,\r
 274                                                                                                                    uint8_t * const pucStreamBufferStorageArea,\r
 275                                                                                                                    StaticStreamBuffer_t * const pxStaticStreamBuffer )\r
 276         {\r
 277         StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) pxStaticStreamBuffer; /*lint !e740 !e9087 Safe cast as StaticStreamBuffer_t is opaque Streambuffer_t. */\r
 278         StreamBufferHandle_t xReturn;\r
 279 \r
 280                 configASSERT( pucStreamBufferStorageArea );\r
 281                 configASSERT( pxStaticStreamBuffer );\r
 282                 configASSERT( xTriggerLevelBytes <= xBufferSizeBytes );\r
 283 \r
 284                 /* A trigger level of 0 would cause a waiting task to unblock even when\r
 285                 the buffer was empty. */\r
 286                 if( xTriggerLevelBytes == ( size_t ) 0 )\r
 287                 {\r
 288                         xTriggerLevelBytes = ( size_t ) 1; /*lint !e9044 Function parameter deliberately modified to ensure it is in range. */\r
 289                 }\r
 290 \r
 291                 /* In case the stream buffer is going to be used as a message buffer\r
 292                 (that is, it will hold discrete messages with a little meta data that\r
 293                 says how big the next message is) check the buffer will be large enough\r
 294                 to hold at least one message. */\r
 295                 configASSERT( xBufferSizeBytes > sbBYTES_TO_STORE_MESSAGE_LENGTH );\r
 296 \r
 297                 #if( configASSERT_DEFINED == 1 )\r
 298                 {\r
 299                         /* Sanity check that the size of the structure used to declare a\r
 300                         variable of type StaticStreamBuffer_t equals the size of the real\r
 301                         message buffer structure. */\r
 302                         volatile size_t xSize = sizeof( StaticStreamBuffer_t );\r
 303                         configASSERT( xSize == sizeof( StreamBuffer_t ) );\r
 304                 }\r
 305                 #endif /* configASSERT_DEFINED */\r
 306 \r
 307                 if( ( pucStreamBufferStorageArea != NULL ) && ( pxStaticStreamBuffer != NULL ) )\r
 308                 {\r
 309                         prvInitialiseNewStreamBuffer( pxStreamBuffer,\r
 310                                                                                   pucStreamBufferStorageArea,\r
 311                                                                                   xBufferSizeBytes,\r
 312                                                                                   xTriggerLevelBytes,\r
 313                                                                                   xIsMessageBuffer );\r
 314 \r
 315                         /* Remember this was statically allocated in case it is ever deleted\r
 316                         again. */\r
 317                         pxStreamBuffer->ucFlags |= sbFLAGS_IS_STATICALLY_ALLOCATED;\r
 318 \r
 319                         traceSTREAM_BUFFER_CREATE( pxStreamBuffer, xIsMessageBuffer );\r
 320 \r
 321                         xReturn = ( StreamBufferHandle_t ) pxStaticStreamBuffer; /*lint !e9087 Data hiding requires cast to opaque type. */\r
 322                 }\r
 323                 else\r
 324                 {\r
 325                         xReturn = NULL;\r
 326                         traceSTREAM_BUFFER_CREATE_STATIC_FAILED( xReturn, xIsMessageBuffer );\r
 327                 }\r
 328 \r
 329                 return xReturn;\r
 330         }\r
 331 \r
 332 #endif /* ( configSUPPORT_STATIC_ALLOCATION == 1 ) */\r
 333 /*-----------------------------------------------------------*/\r
 334 \r
 335 void vStreamBufferDelete( StreamBufferHandle_t xStreamBuffer )\r
 336 {\r
 337 StreamBuffer_t * pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 338 \r
 339         configASSERT( pxStreamBuffer );\r
 340 \r
 341         traceSTREAM_BUFFER_DELETE( xStreamBuffer );\r
 342 \r
 343         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_STATICALLY_ALLOCATED ) == ( uint8_t ) pdFALSE )\r
 344         {\r
 345                 #if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )\r
 346                 {\r
 347                         /* Both the structure and the buffer were allocated using a single call\r
 348                         to pvPortMalloc(), hence only one call to vPortFree() is required. */\r
 349                         vPortFree( ( void * ) pxStreamBuffer ); /*lint !e9087 Standard free() semantics require void *, plus pxStreamBuffer was allocated by pvPortMalloc(). */\r
 350                 }\r
 351                 #else\r
 352                 {\r
 353                         /* Should not be possible to get here, ucFlags must be corrupt.\r
 354                         Force an assert. */\r
 355                         configASSERT( xStreamBuffer == ( StreamBufferHandle_t ) ~0 );\r
 356                 }\r
 357                 #endif\r
 358         }\r
 359         else\r
 360         {\r
 361                 /* The structure and buffer were not allocated dynamically and cannot be\r
 362                 freed - just scrub the structure so future use will assert. */\r
 363                 memset( pxStreamBuffer, 0x00, sizeof( StreamBuffer_t ) );\r
 364         }\r
 365 }\r
 366 /*-----------------------------------------------------------*/\r
 367 \r
 368 BaseType_t xStreamBufferReset( StreamBufferHandle_t xStreamBuffer )\r
 369 {\r
 370 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 371 BaseType_t xReturn = pdFAIL, xIsMessageBuffer;\r
 372 \r
 373 #if( configUSE_TRACE_FACILITY == 1 )\r
 374         UBaseType_t uxStreamBufferNumber;\r
 375 #endif\r
 376 \r
 377         configASSERT( pxStreamBuffer );\r
 378 \r
 379         #if( configUSE_TRACE_FACILITY == 1 )\r
 380         {\r
 381                 /* Store the stream buffer number so it can be restored after the\r
 382                 reset. */\r
 383                 uxStreamBufferNumber = pxStreamBuffer->uxStreamBufferNumber;\r
 384         }\r
 385         #endif\r
 386 \r
 387         /* Can only reset a message buffer if there are no tasks blocked on it. */\r
 388         if( pxStreamBuffer->xTaskWaitingToReceive == NULL )\r
 389         {\r
 390                 if( pxStreamBuffer->xTaskWaitingToSend == NULL )\r
 391                 {\r
 392                         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 393                         {\r
 394                                 xIsMessageBuffer = pdTRUE;\r
 395                         }\r
 396                         else\r
 397                         {\r
 398                                 xIsMessageBuffer = pdFALSE;\r
 399                         }\r
 400 \r
 401                         prvInitialiseNewStreamBuffer( pxStreamBuffer,\r
 402                                                                                   pxStreamBuffer->pucBuffer,\r
 403                                                                                   pxStreamBuffer->xLength,\r
 404                                                                                   pxStreamBuffer->xTriggerLevelBytes,\r
 405                                                                                   xIsMessageBuffer );\r
 406                         xReturn = pdPASS;\r
 407 \r
 408                         #if( configUSE_TRACE_FACILITY == 1 )\r
 409                         {\r
 410                                 pxStreamBuffer->uxStreamBufferNumber = uxStreamBufferNumber;\r
 411                         }\r
 412                         #endif\r
 413 \r
 414                         traceSTREAM_BUFFER_RESET( xStreamBuffer );\r
 415                 }\r
 416         }\r
 417 \r
 418         return xReturn;\r
 419 }\r
 420 /*-----------------------------------------------------------*/\r
 421 \r
 422 BaseType_t xStreamBufferSetTriggerLevel( StreamBufferHandle_t xStreamBuffer, size_t xTriggerLevel )\r
 423 {\r
 424 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 425 BaseType_t xReturn;\r
 426 \r
 427         configASSERT( pxStreamBuffer );\r
 428 \r
 429         /* It is not valid for the trigger level to be 0. */\r
 430         if( xTriggerLevel == ( size_t ) 0 )\r
 431         {\r
 432                 xTriggerLevel = ( size_t ) 1; /*lint !e9044 Parameter modified to ensure it doesn't have a dangerous value. */\r
 433         }\r
 434 \r
 435         /* The trigger level is the number of bytes that must be in the stream\r
 436         buffer before a task that is waiting for data is unblocked. */\r
 437         if( xTriggerLevel <= pxStreamBuffer->xLength )\r
 438         {\r
 439                 pxStreamBuffer->xTriggerLevelBytes = xTriggerLevel;\r
 440                 xReturn = pdPASS;\r
 441         }\r
 442         else\r
 443         {\r
 444                 xReturn = pdFALSE;\r
 445         }\r
 446 \r
 447         return xReturn;\r
 448 }\r
 449 /*-----------------------------------------------------------*/\r
 450 \r
 451 size_t xStreamBufferSpacesAvailable( StreamBufferHandle_t xStreamBuffer )\r
 452 {\r
 453 const StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 454 size_t xSpace;\r
 455 \r
 456         configASSERT( pxStreamBuffer );\r
 457 \r
 458         xSpace = pxStreamBuffer->xLength + pxStreamBuffer->xTail;\r
 459         xSpace -= pxStreamBuffer->xHead;\r
 460         xSpace -= ( size_t ) 1;\r
 461 \r
 462         if( xSpace >= pxStreamBuffer->xLength )\r
 463         {\r
 464                 xSpace -= pxStreamBuffer->xLength;\r
 465         }\r
 466         else\r
 467         {\r
 468                 mtCOVERAGE_TEST_MARKER();\r
 469         }\r
 470 \r
 471         return xSpace;\r
 472 }\r
 473 /*-----------------------------------------------------------*/\r
 474 \r
 475 size_t xStreamBufferBytesAvailable( StreamBufferHandle_t xStreamBuffer )\r
 476 {\r
 477 const StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 478 size_t xReturn;\r
 479 \r
 480         configASSERT( pxStreamBuffer );\r
 481 \r
 482         xReturn = prvBytesInBuffer( pxStreamBuffer );\r
 483         return xReturn;\r
 484 }\r
 485 /*-----------------------------------------------------------*/\r
 486 \r
 487 size_t xStreamBufferSend( StreamBufferHandle_t xStreamBuffer,\r
 488                                                   const void *pvTxData,\r
 489                                                   size_t xDataLengthBytes,\r
 490                                                   TickType_t xTicksToWait )\r
 491 {\r
 492 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 493 size_t xReturn, xSpace = 0;\r
 494 size_t xRequiredSpace = xDataLengthBytes;\r
 495 TimeOut_t xTimeOut;\r
 496 \r
 497         configASSERT( pvTxData );\r
 498         configASSERT( pxStreamBuffer );\r
 499 \r
 500         /* This send function is used to write to both message buffers and stream\r
 501         buffers.  If this is a message buffer then the space needed must be\r
 502         increased by the amount of bytes needed to store the length of the\r
 503         message. */\r
 504         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 505         {\r
 506                 xRequiredSpace += sbBYTES_TO_STORE_MESSAGE_LENGTH;\r
 507         }\r
 508         else\r
 509         {\r
 510                 mtCOVERAGE_TEST_MARKER();\r
 511         }\r
 512 \r
 513         if( xTicksToWait != ( TickType_t ) 0 )\r
 514         {\r
 515                 vTaskSetTimeOutState( &xTimeOut );\r
 516 \r
 517                 do\r
 518                 {\r
 519                         /* Wait until the required number of bytes are free in the message\r
 520                         buffer. */\r
 521                         taskENTER_CRITICAL();\r
 522                         {\r
 523                                 xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );\r
 524 \r
 525                                 if( xSpace < xRequiredSpace )\r
 526                                 {\r
 527                                         /* Clear notification state as going to wait for space. */\r
 528                                         ( void ) xTaskNotifyStateClear( NULL );\r
 529 \r
 530                                         /* Should only be one writer. */\r
 531                                         configASSERT( pxStreamBuffer->xTaskWaitingToSend == NULL );\r
 532                                         pxStreamBuffer->xTaskWaitingToSend = xTaskGetCurrentTaskHandle();\r
 533                                 }\r
 534                                 else\r
 535                                 {\r
 536                                         taskEXIT_CRITICAL();\r
 537                                         break;\r
 538                                 }\r
 539                         }\r
 540                         taskEXIT_CRITICAL();\r
 541 \r
 542                         traceBLOCKING_ON_STREAM_BUFFER_SEND( xStreamBuffer );\r
 543                         ( void ) xTaskNotifyWait( ( uint32_t ) 0, ( uint32_t ) 0, NULL, xTicksToWait );\r
 544                         pxStreamBuffer->xTaskWaitingToSend = NULL;\r
 545 \r
 546                 } while( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE );\r
 547         }\r
 548         else\r
 549         {\r
 550                 mtCOVERAGE_TEST_MARKER();\r
 551         }\r
 552 \r
 553         if( xSpace == ( size_t ) 0 )\r
 554         {\r
 555                 xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );\r
 556         }\r
 557         else\r
 558         {\r
 559                 mtCOVERAGE_TEST_MARKER();\r
 560         }\r
 561 \r
 562         xReturn = prvWriteMessageToBuffer( pxStreamBuffer, pvTxData, xDataLengthBytes, xSpace, xRequiredSpace );\r
 563 \r
 564         if( xReturn > ( size_t ) 0 )\r
 565         {\r
 566                 traceSTREAM_BUFFER_SEND( xStreamBuffer, xReturn );\r
 567 \r
 568                 /* Was a task waiting for the data? */\r
 569                 if( prvBytesInBuffer( pxStreamBuffer ) >= pxStreamBuffer->xTriggerLevelBytes )\r
 570                 {\r
 571                         sbSEND_COMPLETED( pxStreamBuffer );\r
 572                 }\r
 573                 else\r
 574                 {\r
 575                         mtCOVERAGE_TEST_MARKER();\r
 576                 }\r
 577         }\r
 578         else\r
 579         {\r
 580                 mtCOVERAGE_TEST_MARKER();\r
 581                 traceSTREAM_BUFFER_SEND_FAILED( xStreamBuffer );\r
 582         }\r
 583 \r
 584         return xReturn;\r
 585 }\r
 586 /*-----------------------------------------------------------*/\r
 587 \r
 588 size_t xStreamBufferSendFromISR( StreamBufferHandle_t xStreamBuffer,\r
 589                                                                  const void *pvTxData,\r
 590                                                                  size_t xDataLengthBytes,\r
 591                                                                  BaseType_t * const pxHigherPriorityTaskWoken )\r
 592 {\r
 593 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 594 size_t xReturn, xSpace;\r
 595 size_t xRequiredSpace = xDataLengthBytes;\r
 596 \r
 597         configASSERT( pvTxData );\r
 598         configASSERT( pxStreamBuffer );\r
 599 \r
 600         /* This send function is used to write to both message buffers and stream\r
 601         buffers.  If this is a message buffer then the space needed must be\r
 602         increased by the amount of bytes needed to store the length of the\r
 603         message. */\r
 604         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 605         {\r
 606                 xRequiredSpace += sbBYTES_TO_STORE_MESSAGE_LENGTH;\r
 607         }\r
 608         else\r
 609         {\r
 610                 mtCOVERAGE_TEST_MARKER();\r
 611         }\r
 612 \r
 613         xSpace = xStreamBufferSpacesAvailable( pxStreamBuffer );\r
 614         xReturn = prvWriteMessageToBuffer( pxStreamBuffer, pvTxData, xDataLengthBytes, xSpace, xRequiredSpace );\r
 615 \r
 616         if( xReturn > ( size_t ) 0 )\r
 617         {\r
 618                 /* Was a task waiting for the data? */\r
 619                 if( prvBytesInBuffer( pxStreamBuffer ) >= pxStreamBuffer->xTriggerLevelBytes )\r
 620                 {\r
 621                         sbSEND_COMPLETE_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken );\r
 622                 }\r
 623                 else\r
 624                 {\r
 625                         mtCOVERAGE_TEST_MARKER();\r
 626                 }\r
 627         }\r
 628         else\r
 629         {\r
 630                 mtCOVERAGE_TEST_MARKER();\r
 631         }\r
 632 \r
 633         traceSTREAM_BUFFER_SEND_FROM_ISR( xStreamBuffer, xReturn );\r
 634 \r
 635         return xReturn;\r
 636 }\r
 637 /*-----------------------------------------------------------*/\r
 638 \r
 639 static size_t prvWriteMessageToBuffer( StreamBuffer_t * const pxStreamBuffer,\r
 640                                                                            const void * pvTxData,\r
 641                                                                            size_t xDataLengthBytes,\r
 642                                                                            size_t xSpace,\r
 643                                                                            size_t xRequiredSpace )\r
 644 {\r
 645         BaseType_t xShouldWrite;\r
 646         size_t xReturn;\r
 647 \r
 648         if( xSpace == ( size_t ) 0 )\r
 649         {\r
 650                 /* Doesn't matter if this is a stream buffer or a message buffer, there\r
 651                 is no space to write. */\r
 652                 xShouldWrite = pdFALSE;\r
 653         }\r
 654         else if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) == ( uint8_t ) 0 )\r
 655         {\r
 656                 /* This is a stream buffer, as opposed to a message buffer, so writing a\r
 657                 stream of bytes rather than discrete messages.  Write as many bytes as\r
 658                 possible. */\r
 659                 xShouldWrite = pdTRUE;\r
 660                 xDataLengthBytes = configMIN( xDataLengthBytes, xSpace ); /*lint !e9044 Function parameter modified to ensure it is capped to available space. */\r
 661         }\r
 662         else if( xSpace >= xRequiredSpace )\r
 663         {\r
 664                 /* This is a message buffer, as opposed to a stream buffer, and there\r
 665                 is enough space to write both the message length and the message itself\r
 666                 into the buffer.  Start by writing the length of the data, the data\r
 667                 itself will be written later in this function. */\r
 668                 xShouldWrite = pdTRUE;\r
 669                 ( void ) prvWriteBytesToBuffer( pxStreamBuffer, ( const uint8_t * ) &( xDataLengthBytes ), sbBYTES_TO_STORE_MESSAGE_LENGTH );\r
 670         }\r
 671         else\r
 672         {\r
 673                 /* There is space available, but not enough space. */\r
 674                 xShouldWrite = pdFALSE;\r
 675         }\r
 676 \r
 677         if( xShouldWrite != pdFALSE )\r
 678         {\r
 679                 /* Writes the data itself. */\r
 680                 xReturn = prvWriteBytesToBuffer( pxStreamBuffer, ( const uint8_t * ) pvTxData, xDataLengthBytes ); /*lint !e9079 Storage buffer is implemented as uint8_t for ease of sizing, alighment and access. */\r
 681         }\r
 682         else\r
 683         {\r
 684                 xReturn = 0;\r
 685         }\r
 686 \r
 687         return xReturn;\r
 688 }\r
 689 /*-----------------------------------------------------------*/\r
 690 \r
 691 size_t xStreamBufferReceive( StreamBufferHandle_t xStreamBuffer,\r
 692                                                          void *pvRxData,\r
 693                                                          size_t xBufferLengthBytes,\r
 694                                                          TickType_t xTicksToWait )\r
 695 {\r
 696 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 697 size_t xReceivedLength = 0, xBytesAvailable, xBytesToStoreMessageLength;\r
 698 \r
 699         configASSERT( pvRxData );\r
 700         configASSERT( pxStreamBuffer );\r
 701 \r
 702         /* This receive function is used by both message buffers, which store\r
 703         discrete messages, and stream buffers, which store a continuous stream of\r
 704         bytes.  Discrete messages include an additional\r
 705         sbBYTES_TO_STORE_MESSAGE_LENGTH bytes that hold the length of the\r
 706         message. */\r
 707         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 708         {\r
 709                 xBytesToStoreMessageLength = sbBYTES_TO_STORE_MESSAGE_LENGTH;\r
 710         }\r
 711         else\r
 712         {\r
 713                 xBytesToStoreMessageLength = 0;\r
 714         }\r
 715 \r
 716         if( xTicksToWait != ( TickType_t ) 0 )\r
 717         {\r
 718                 /* Checking if there is data and clearing the notification state must be\r
 719                 performed atomically. */\r
 720                 taskENTER_CRITICAL();\r
 721                 {\r
 722                         xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );\r
 723 \r
 724                         /* If this function was invoked by a message buffer read then\r
 725                         xBytesToStoreMessageLength holds the number of bytes used to hold\r
 726                         the length of the next discrete message.  If this function was\r
 727                         invoked by a stream buffer read then xBytesToStoreMessageLength will\r
 728                         be 0. */\r
 729                         if( xBytesAvailable <= xBytesToStoreMessageLength )\r
 730                         {\r
 731                                 /* Clear notification state as going to wait for data. */\r
 732                                 ( void ) xTaskNotifyStateClear( NULL );\r
 733 \r
 734                                 /* Should only be one reader. */\r
 735                                 configASSERT( pxStreamBuffer->xTaskWaitingToReceive == NULL );\r
 736                                 pxStreamBuffer->xTaskWaitingToReceive = xTaskGetCurrentTaskHandle();\r
 737                         }\r
 738                         else\r
 739                         {\r
 740                                 mtCOVERAGE_TEST_MARKER();\r
 741                         }\r
 742                 }\r
 743                 taskEXIT_CRITICAL();\r
 744 \r
 745                 if( xBytesAvailable <= xBytesToStoreMessageLength )\r
 746                 {\r
 747                         /* Wait for data to be available. */\r
 748                         traceBLOCKING_ON_STREAM_BUFFER_RECEIVE( xStreamBuffer );\r
 749                         ( void ) xTaskNotifyWait( ( uint32_t ) 0, ( uint32_t ) 0, NULL, xTicksToWait );\r
 750                         pxStreamBuffer->xTaskWaitingToReceive = NULL;\r
 751 \r
 752                         /* Recheck the data available after blocking. */\r
 753                         xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );\r
 754                 }\r
 755                 else\r
 756                 {\r
 757                         mtCOVERAGE_TEST_MARKER();\r
 758                 }\r
 759         }\r
 760         else\r
 761         {\r
 762                 xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );\r
 763         }\r
 764 \r
 765         /* Whether receiving a discrete message (where xBytesToStoreMessageLength\r
 766         holds the number of bytes used to store the message length) or a stream of\r
 767         bytes (where xBytesToStoreMessageLength is zero), the number of bytes\r
 768         available must be greater than xBytesToStoreMessageLength to be able to\r
 769         read bytes from the buffer. */\r
 770         if( xBytesAvailable > xBytesToStoreMessageLength )\r
 771         {\r
 772                 xReceivedLength = prvReadMessageFromBuffer( pxStreamBuffer, pvRxData, xBufferLengthBytes, xBytesAvailable, xBytesToStoreMessageLength );\r
 773 \r
 774                 /* Was a task waiting for space in the buffer? */\r
 775                 if( xReceivedLength != ( size_t ) 0 )\r
 776                 {\r
 777                         traceSTREAM_BUFFER_RECEIVE( xStreamBuffer, xReceivedLength );\r
 778                         sbRECEIVE_COMPLETED( pxStreamBuffer );\r
 779                 }\r
 780                 else\r
 781                 {\r
 782                         mtCOVERAGE_TEST_MARKER();\r
 783                 }\r
 784         }\r
 785         else\r
 786         {\r
 787                 traceSTREAM_BUFFER_RECEIVE_FAILED( xStreamBuffer );\r
 788                 mtCOVERAGE_TEST_MARKER();\r
 789         }\r
 790 \r
 791         return xReceivedLength;\r
 792 }\r
 793 /*-----------------------------------------------------------*/\r
 794 \r
 795 size_t xStreamBufferNextMessageLengthBytes( StreamBufferHandle_t xStreamBuffer )\r
 796 {\r
 797 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 798 size_t xReturn, xBytesAvailable, xOriginalTail;\r
 799 \r
 800         configASSERT( pxStreamBuffer );\r
 801 \r
 802         /* Ensure the stream buffer is being used as a message buffer. */\r
 803         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 804         {\r
 805                 xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );\r
 806                 if( xBytesAvailable > sbBYTES_TO_STORE_MESSAGE_LENGTH )\r
 807                 {\r
 808                         /* The number of bytes available is greater than the number of bytes\r
 809                         required to hold the length of the next message, so another message\r
 810                         is available.  Return its length without removing the length bytes\r
 811                         from the buffer.  A copy of the tail is stored so the buffer can be\r
 812                         returned to its prior state as the message is not actually being\r
 813                         removed from the buffer. */\r
 814                         xOriginalTail = pxStreamBuffer->xTail;\r
 815                         ( void ) prvReadBytesFromBuffer( pxStreamBuffer, ( uint8_t * ) &xReturn, sbBYTES_TO_STORE_MESSAGE_LENGTH, xBytesAvailable );\r
 816                         pxStreamBuffer->xTail = xOriginalTail;\r
 817                 }\r
 818                 else\r
 819                 {\r
 820                         /* The minimum amount of bytes in a message buffer is\r
 821                         ( sbBYTES_TO_STORE_MESSAGE_LENGTH + 1 ), so if xBytesAvailable is\r
 822                         less than sbBYTES_TO_STORE_MESSAGE_LENGTH the only other valid\r
 823                         value is 0. */\r
 824                         configASSERT( xBytesAvailable == 0 );\r
 825                         xReturn = 0;\r
 826                 }\r
 827         }\r
 828         else\r
 829         {\r
 830                 xReturn = 0;\r
 831         }\r
 832 \r
 833         return xReturn;\r
 834 }\r
 835 /*-----------------------------------------------------------*/\r
 836 \r
 837 size_t xStreamBufferReceiveFromISR( StreamBufferHandle_t xStreamBuffer,\r
 838                                                                         void *pvRxData,\r
 839                                                                         size_t xBufferLengthBytes,\r
 840                                                                         BaseType_t * const pxHigherPriorityTaskWoken )\r
 841 {\r
 842 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 843 size_t xReceivedLength = 0, xBytesAvailable, xBytesToStoreMessageLength;\r
 844 \r
 845         configASSERT( pvRxData );\r
 846         configASSERT( pxStreamBuffer );\r
 847 \r
 848         /* This receive function is used by both message buffers, which store\r
 849         discrete messages, and stream buffers, which store a continuous stream of\r
 850         bytes.  Discrete messages include an additional\r
 851         sbBYTES_TO_STORE_MESSAGE_LENGTH bytes that hold the length of the\r
 852         message. */\r
 853         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 854         {\r
 855                 xBytesToStoreMessageLength = sbBYTES_TO_STORE_MESSAGE_LENGTH;\r
 856         }\r
 857         else\r
 858         {\r
 859                 xBytesToStoreMessageLength = 0;\r
 860         }\r
 861 \r
 862         xBytesAvailable = prvBytesInBuffer( pxStreamBuffer );\r
 863 \r
 864         /* Whether receiving a discrete message (where xBytesToStoreMessageLength\r
 865         holds the number of bytes used to store the message length) or a stream of\r
 866         bytes (where xBytesToStoreMessageLength is zero), the number of bytes\r
 867         available must be greater than xBytesToStoreMessageLength to be able to\r
 868         read bytes from the buffer. */\r
 869         if( xBytesAvailable > xBytesToStoreMessageLength )\r
 870         {\r
 871                 xReceivedLength = prvReadMessageFromBuffer( pxStreamBuffer, pvRxData, xBufferLengthBytes, xBytesAvailable, xBytesToStoreMessageLength );\r
 872 \r
 873                 /* Was a task waiting for space in the buffer? */\r
 874                 if( xReceivedLength != ( size_t ) 0 )\r
 875                 {\r
 876                         sbRECEIVE_COMPLETED_FROM_ISR( pxStreamBuffer, pxHigherPriorityTaskWoken );\r
 877                 }\r
 878                 else\r
 879                 {\r
 880                         mtCOVERAGE_TEST_MARKER();\r
 881                 }\r
 882         }\r
 883         else\r
 884         {\r
 885                 mtCOVERAGE_TEST_MARKER();\r
 886         }\r
 887 \r
 888         traceSTREAM_BUFFER_RECEIVE_FROM_ISR( xStreamBuffer, xReceivedLength );\r
 889 \r
 890         return xReceivedLength;\r
 891 }\r
 892 /*-----------------------------------------------------------*/\r
 893 \r
 894 static size_t prvReadMessageFromBuffer( StreamBuffer_t *pxStreamBuffer,\r
 895                                                                                 void *pvRxData,\r
 896                                                                                 size_t xBufferLengthBytes,\r
 897                                                                                 size_t xBytesAvailable,\r
 898                                                                                 size_t xBytesToStoreMessageLength )\r
 899 {\r
 900 size_t xOriginalTail, xReceivedLength, xNextMessageLength;\r
 901 \r
 902         if( xBytesToStoreMessageLength != ( size_t ) 0 )\r
 903         {\r
 904                 /* A discrete message is being received.  First receive the length\r
 905                 of the message.  A copy of the tail is stored so the buffer can be\r
 906                 returned to its prior state if the length of the message is too\r
 907                 large for the provided buffer. */\r
 908                 xOriginalTail = pxStreamBuffer->xTail;\r
 909                 ( void ) prvReadBytesFromBuffer( pxStreamBuffer, ( uint8_t * ) &xNextMessageLength, xBytesToStoreMessageLength, xBytesAvailable );\r
 910 \r
 911                 /* Reduce the number of bytes available by the number of bytes just\r
 912                 read out. */\r
 913                 xBytesAvailable -= xBytesToStoreMessageLength;\r
 914 \r
 915                 /* Check there is enough space in the buffer provided by the\r
 916                 user. */\r
 917                 if( xNextMessageLength > xBufferLengthBytes )\r
 918                 {\r
 919                         /* The user has provided insufficient space to read the message\r
 920                         so return the buffer to its previous state (so the length of\r
 921                         the message is in the buffer again). */\r
 922                         pxStreamBuffer->xTail = xOriginalTail;\r
 923                         xNextMessageLength = 0;\r
 924                 }\r
 925                 else\r
 926                 {\r
 927                         mtCOVERAGE_TEST_MARKER();\r
 928                 }\r
 929         }\r
 930         else\r
 931         {\r
 932                 /* A stream of bytes is being received (as opposed to a discrete\r
 933                 message), so read as many bytes as possible. */\r
 934                 xNextMessageLength = xBufferLengthBytes;\r
 935         }\r
 936 \r
 937         /* Read the actual data. */\r
 938         xReceivedLength = prvReadBytesFromBuffer( pxStreamBuffer, ( uint8_t * ) pvRxData, xNextMessageLength, xBytesAvailable ); /*lint !e9079 Data storage area is implemented as uint8_t array for ease of sizing, indexing and alignment. */\r
 939 \r
 940         return xReceivedLength;\r
 941 }\r
 942 /*-----------------------------------------------------------*/\r
 943 \r
 944 BaseType_t xStreamBufferIsEmpty( StreamBufferHandle_t xStreamBuffer )\r
 945 {\r
 946 const StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 947 BaseType_t xReturn;\r
 948 size_t xTail;\r
 949 \r
 950         configASSERT( pxStreamBuffer );\r
 951 \r
 952         /* True if no bytes are available. */\r
 953         xTail = pxStreamBuffer->xTail;\r
 954         if( pxStreamBuffer->xHead == xTail )\r
 955         {\r
 956                 xReturn = pdTRUE;\r
 957         }\r
 958         else\r
 959         {\r
 960                 xReturn = pdFALSE;\r
 961         }\r
 962 \r
 963         return xReturn;\r
 964 }\r
 965 /*-----------------------------------------------------------*/\r
 966 \r
 967 BaseType_t xStreamBufferIsFull( StreamBufferHandle_t xStreamBuffer )\r
 968 {\r
 969 BaseType_t xReturn;\r
 970 size_t xBytesToStoreMessageLength;\r
 971 const StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
 972 \r
 973         configASSERT( pxStreamBuffer );\r
 974 \r
 975         /* This generic version of the receive function is used by both message\r
 976         buffers, which store discrete messages, and stream buffers, which store a\r
 977         continuous stream of bytes.  Discrete messages include an additional\r
 978         sbBYTES_TO_STORE_MESSAGE_LENGTH bytes that hold the length of the message. */\r
 979         if( ( pxStreamBuffer->ucFlags & sbFLAGS_IS_MESSAGE_BUFFER ) != ( uint8_t ) 0 )\r
 980         {\r
 981                 xBytesToStoreMessageLength = sbBYTES_TO_STORE_MESSAGE_LENGTH;\r
 982         }\r
 983         else\r
 984         {\r
 985                 xBytesToStoreMessageLength = 0;\r
 986         }\r
 987 \r
 988         /* True if the available space equals zero. */\r
 989         if( xStreamBufferSpacesAvailable( xStreamBuffer ) <= xBytesToStoreMessageLength )\r
 990         {\r
 991                 xReturn = pdTRUE;\r
 992         }\r
 993         else\r
 994         {\r
 995                 xReturn = pdFALSE;\r
 996         }\r
 997 \r
 998         return xReturn;\r
 999 }\r
1000 /*-----------------------------------------------------------*/\r
1001 \r
1002 BaseType_t xStreamBufferSendCompletedFromISR( StreamBufferHandle_t xStreamBuffer, BaseType_t *pxHigherPriorityTaskWoken )\r
1003 {\r
1004 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
1005 BaseType_t xReturn;\r
1006 UBaseType_t uxSavedInterruptStatus;\r
1007 \r
1008         configASSERT( pxStreamBuffer );\r
1009 \r
1010         uxSavedInterruptStatus = ( UBaseType_t ) portSET_INTERRUPT_MASK_FROM_ISR();\r
1011         {\r
1012                 if( ( pxStreamBuffer )->xTaskWaitingToReceive != NULL )\r
1013                 {\r
1014                         ( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToReceive,\r
1015                                                                                  ( uint32_t ) 0,\r
1016                                                                                  eNoAction,\r
1017                                                                                  pxHigherPriorityTaskWoken );\r
1018                         ( pxStreamBuffer )->xTaskWaitingToReceive = NULL;\r
1019                         xReturn = pdTRUE;\r
1020                 }\r
1021                 else\r
1022                 {\r
1023                         xReturn = pdFALSE;\r
1024                 }\r
1025         }\r
1026         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
1027 \r
1028         return xReturn;\r
1029 }\r
1030 /*-----------------------------------------------------------*/\r
1031 \r
1032 BaseType_t xStreamBufferReceiveCompletedFromISR( StreamBufferHandle_t xStreamBuffer, BaseType_t *pxHigherPriorityTaskWoken )\r
1033 {\r
1034 StreamBuffer_t * const pxStreamBuffer = ( StreamBuffer_t * ) xStreamBuffer; /*lint !e9087 !e9079 Safe cast as StreamBufferHandle_t is opaque Streambuffer_t. */\r
1035 BaseType_t xReturn;\r
1036 UBaseType_t uxSavedInterruptStatus;\r
1037 \r
1038         configASSERT( pxStreamBuffer );\r
1039 \r
1040         uxSavedInterruptStatus = ( UBaseType_t ) portSET_INTERRUPT_MASK_FROM_ISR();\r
1041         {\r
1042                 if( ( pxStreamBuffer )->xTaskWaitingToSend != NULL )\r
1043                 {\r
1044                         ( void ) xTaskNotifyFromISR( ( pxStreamBuffer )->xTaskWaitingToSend,\r
1045                                                                                  ( uint32_t ) 0,\r
1046                                                                                  eNoAction,\r
1047                                                                                  pxHigherPriorityTaskWoken );\r
1048                         ( pxStreamBuffer )->xTaskWaitingToSend = NULL;\r
1049                         xReturn = pdTRUE;\r
1050                 }\r
1051                 else\r
1052                 {\r
1053                         xReturn = pdFALSE;\r
1054                 }\r
1055         }\r
1056         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
1057 \r
1058         return xReturn;\r
1059 }\r
1060 /*-----------------------------------------------------------*/\r
1061 \r
1062 static size_t prvWriteBytesToBuffer( StreamBuffer_t * const pxStreamBuffer, const uint8_t *pucData, size_t xCount )\r
1063 {\r
1064 size_t xNextHead, xFirstLength;\r
1065 \r
1066         configASSERT( xCount > ( size_t ) 0 );\r
1067 \r
1068         xNextHead = pxStreamBuffer->xHead;\r
1069 \r
1070         /* Calculate the number of bytes that can be added in the first write -\r
1071         which may be less than the total number of bytes that need to be added if\r
1072         the buffer will wrap back to the beginning. */\r
1073         xFirstLength = configMIN( pxStreamBuffer->xLength - xNextHead, xCount );\r
1074 \r
1075         /* Write as many bytes as can be written in the first write. */\r
1076         configASSERT( ( xNextHead + xFirstLength ) <= pxStreamBuffer->xLength );\r
1077         memcpy( ( void* ) ( &( pxStreamBuffer->pucBuffer[ xNextHead ] ) ), ( const void * ) pucData, xFirstLength ); /*lint !e9087 memcpy() requires void *. */\r
1078 \r
1079         /* If the number of bytes written was less than the number that could be\r
1080         written in the first write... */\r
1081         if( xCount > xFirstLength )\r
1082         {\r
1083                 /* ...then write the remaining bytes to the start of the buffer. */\r
1084                 configASSERT( ( xCount - xFirstLength ) <= pxStreamBuffer->xLength );\r
1085                 memcpy( ( void * ) pxStreamBuffer->pucBuffer, ( const void * ) &( pucData[ xFirstLength ] ), xCount - xFirstLength ); /*lint !e9087 memcpy() requires void *. */\r
1086         }\r
1087         else\r
1088         {\r
1089                 mtCOVERAGE_TEST_MARKER();\r
1090         }\r
1091 \r
1092         xNextHead += xCount;\r
1093         if( xNextHead >= pxStreamBuffer->xLength )\r
1094         {\r
1095                 xNextHead -= pxStreamBuffer->xLength;\r
1096         }\r
1097         else\r
1098         {\r
1099                 mtCOVERAGE_TEST_MARKER();\r
1100         }\r
1101 \r
1102         pxStreamBuffer->xHead = xNextHead;\r
1103 \r
1104         return xCount;\r
1105 }\r
1106 /*-----------------------------------------------------------*/\r
1107 \r
1108 static size_t prvReadBytesFromBuffer( StreamBuffer_t *pxStreamBuffer, uint8_t *pucData, size_t xMaxCount, size_t xBytesAvailable )\r
1109 {\r
1110 size_t xCount, xFirstLength, xNextTail;\r
1111 \r
1112         /* Use the minimum of the wanted bytes and the available bytes. */\r
1113         xCount = configMIN( xBytesAvailable, xMaxCount );\r
1114 \r
1115         if( xCount > ( size_t ) 0 )\r
1116         {\r
1117                 xNextTail = pxStreamBuffer->xTail;\r
1118 \r
1119                 /* Calculate the number of bytes that can be read - which may be\r
1120                 less than the number wanted if the data wraps around to the start of\r
1121                 the buffer. */\r
1122                 xFirstLength = configMIN( pxStreamBuffer->xLength - xNextTail, xCount );\r
1123 \r
1124                 /* Obtain the number of bytes it is possible to obtain in the first\r
1125                 read.  Asserts check bounds of read and write. */\r
1126                 configASSERT( xFirstLength <= xMaxCount );\r
1127                 configASSERT( ( xNextTail + xFirstLength ) <= pxStreamBuffer->xLength );\r
1128                 memcpy( ( void * ) pucData, ( const void * ) &( pxStreamBuffer->pucBuffer[ xNextTail ] ), xFirstLength ); /*lint !e9087 memcpy() requires void *. */\r
1129 \r
1130                 /* If the total number of wanted bytes is greater than the number\r
1131                 that could be read in the first read... */\r
1132                 if( xCount > xFirstLength )\r
1133                 {\r
1134                         /*...then read the remaining bytes from the start of the buffer. */\r
1135                         configASSERT( xCount <= xMaxCount );\r
1136                         memcpy( ( void * ) &( pucData[ xFirstLength ] ), ( void * ) ( pxStreamBuffer->pucBuffer ), xCount - xFirstLength ); /*lint !e9087 memcpy() requires void *. */\r
1137                 }\r
1138                 else\r
1139                 {\r
1140                         mtCOVERAGE_TEST_MARKER();\r
1141                 }\r
1142 \r
1143                 /* Move the tail pointer to effectively remove the data read from\r
1144                 the buffer. */\r
1145                 xNextTail += xCount;\r
1146 \r
1147                 if( xNextTail >= pxStreamBuffer->xLength )\r
1148                 {\r
1149                         xNextTail -= pxStreamBuffer->xLength;\r
1150                 }\r
1151 \r
1152                 pxStreamBuffer->xTail = xNextTail;\r
1153         }\r
1154         else\r
1155         {\r
1156                 mtCOVERAGE_TEST_MARKER();\r
1157         }\r
1158 \r
1159         return xCount;\r
1160 }\r
1161 /*-----------------------------------------------------------*/\r
1162 \r
1163 static size_t prvBytesInBuffer( const StreamBuffer_t * const pxStreamBuffer )\r
1164 {\r
1165 /* Returns the distance between xTail and xHead. */\r
1166 size_t xCount;\r
1167 \r
1168         xCount = pxStreamBuffer->xLength + pxStreamBuffer->xHead;\r
1169         xCount -= pxStreamBuffer->xTail;\r
1170         if ( xCount >= pxStreamBuffer->xLength )\r
1171         {\r
1172                 xCount -= pxStreamBuffer->xLength;\r
1173         }\r
1174         else\r
1175         {\r
1176                 mtCOVERAGE_TEST_MARKER();\r
1177         }\r
1178 \r
1179         return xCount;\r
1180 }\r
1181 /*-----------------------------------------------------------*/\r
1182 \r
1183 static void prvInitialiseNewStreamBuffer( StreamBuffer_t * const pxStreamBuffer,\r
1184                                                                                   uint8_t * const pucBuffer,\r
1185                                                                                   size_t xBufferSizeBytes,\r
1186                                                                                   size_t xTriggerLevelBytes,\r
1187                                                                                   BaseType_t xIsMessageBuffer )\r
1188 {\r
1189         /* Assert here is deliberately writing to the entire buffer to ensure it can\r
1190         be written to without generating exceptions, and is setting the buffer to a\r
1191         known value to assist in development/debugging. */\r
1192         #if( configASSERT_DEFINED == 1 )\r
1193         {\r
1194                 /* The value written just has to be identifiable when looking at the\r
1195                 memory.  Don't use 0xA5 as that is the stack fill value and could\r
1196                 result in confusion as to what is actually being observed. */\r
1197                 const BaseType_t xWriteValue = 0x55;\r
1198                 configASSERT( memset( pucBuffer, ( int ) xWriteValue, xBufferSizeBytes ) == pucBuffer );\r
1199         }\r
1200         #endif\r
1201 \r
1202         memset( ( void * ) pxStreamBuffer, 0x00, sizeof( StreamBuffer_t ) ); /*lint !e9087 memset() requires void *. */\r
1203         pxStreamBuffer->pucBuffer = pucBuffer;\r
1204         pxStreamBuffer->xLength = xBufferSizeBytes;\r
1205         pxStreamBuffer->xTriggerLevelBytes = xTriggerLevelBytes;\r
1206 \r
1207         if( xIsMessageBuffer != pdFALSE )\r
1208         {\r
1209                 pxStreamBuffer->ucFlags |= sbFLAGS_IS_MESSAGE_BUFFER;\r
1210         }\r
1211 }\r
1212 \r
1213 #if ( configUSE_TRACE_FACILITY == 1 )\r
1214 \r
1215         UBaseType_t uxStreamBufferGetStreamBufferNumber( StreamBufferHandle_t xStreamBuffer )\r
1216         {\r
1217                 return ( ( StreamBuffer_t * ) xStreamBuffer )->uxStreamBufferNumber;\r
1218         }\r
1219 \r
1220 #endif /* configUSE_TRACE_FACILITY */\r
1221 /*-----------------------------------------------------------*/\r
1222 \r
1223 #if ( configUSE_TRACE_FACILITY == 1 )\r
1224 \r
1225         void vStreamBufferSetStreamBufferNumber( StreamBufferHandle_t xStreamBuffer, UBaseType_t uxStreamBufferNumber )\r
1226         {\r
1227                 ( ( StreamBuffer_t * ) xStreamBuffer )->uxStreamBufferNumber = uxStreamBufferNumber;\r
1228         }\r
1229 \r
1230 #endif /* configUSE_TRACE_FACILITY */\r
1231 /*-----------------------------------------------------------*/\r
1232 \r
1233 #if ( configUSE_TRACE_FACILITY == 1 )\r
1234 \r
1235         uint8_t ucStreamBufferGetStreamBufferType( StreamBufferHandle_t xStreamBuffer )\r
1236         {\r
1237                 return ( ( StreamBuffer_t * )xStreamBuffer )->ucFlags | sbFLAGS_IS_MESSAGE_BUFFER;\r
1238         }\r
1239 \r
1240 #endif /* configUSE_TRACE_FACILITY */\r
1241 /*-----------------------------------------------------------*/\r