git.sur5r.net Git - freertos/blob - Source/queue.c

   1 /*\r
   2         FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd.\r
   3 \r
   4         This file is part of the FreeRTOS distribution.\r
   5 \r
   6         FreeRTOS is free software; you can redistribute it and/or modify it     under\r
   7         the terms of the GNU General Public License (version 2) as published by the\r
   8         Free Software Foundation and modified by the FreeRTOS exception.\r
   9         **NOTE** The exception to the GPL is included to allow you to distribute a\r
  10         combined work that includes FreeRTOS without being obliged to provide the\r
  11         source code for proprietary components outside of the FreeRTOS kernel.\r
  12         Alternative commercial license and support terms are also available upon\r
  13         request.  See the licensing section of http://www.FreeRTOS.org for full\r
  14         license details.\r
  15 \r
  16         FreeRTOS is distributed in the hope that it will be useful,     but WITHOUT\r
  17         ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or\r
  18         FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
  19         more details.\r
  20 \r
  21         You should have received a copy of the GNU General Public License along\r
  22         with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59\r
  23         Temple Place, Suite 330, Boston, MA  02111-1307  USA.\r
  24 \r
  25 \r
  26         ***************************************************************************\r
  27         *                                                                                                                                                *\r
  28         * Looking for a quick start?  Then check out the FreeRTOS eBook!                  *\r
  29         * See http://www.FreeRTOS.org/Documentation for details                            *\r
  30         *                                                                                                                                                *\r
  31         ***************************************************************************\r
  32 \r
  33         1 tab == 4 spaces!\r
  34 \r
  35         Please ensure to read the configuration and relevant port sections of the\r
  36         online documentation.\r
  37 \r
  38         http://www.FreeRTOS.org - Documentation, latest information, license and\r
  39         contact details.\r
  40 \r
  41         http://www.SafeRTOS.com - A version that is certified for use in safety\r
  42         critical systems.\r
  43 \r
  44         http://www.OpenRTOS.com - Commercial support, development, porting,\r
  45         licensing and training services.\r
  46 */\r
  47 \r
  48 #include <stdlib.h>\r
  49 #include <string.h>\r
  50 \r
  51 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining\r
  52 all the API functions to use the MPU wrappers.  That should only be done when\r
  53 task.h is included from an application file. */\r
  54 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE\r
  55 \r
  56 #include "FreeRTOS.h"\r
  57 #include "task.h"\r
  58 #include "croutine.h"\r
  59 \r
  60 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE\r
  61 \r
  62 /*-----------------------------------------------------------\r
  63  * PUBLIC LIST API documented in list.h\r
  64  *----------------------------------------------------------*/\r
  65 \r
  66 /* Constants used with the cRxLock and cTxLock structure members. */\r
  67 #define queueUNLOCKED                                   ( ( signed portBASE_TYPE ) -1 )\r
  68 #define queueLOCKED_UNMODIFIED                  ( ( signed portBASE_TYPE ) 0 )\r
  69 \r
  70 #define queueERRONEOUS_UNBLOCK                  ( -1 )\r
  71 \r
  72 /* For internal use only. */\r
  73 #define queueSEND_TO_BACK                               ( 0 )\r
  74 #define queueSEND_TO_FRONT                              ( 1 )\r
  75 \r
  76 /* Effectively make a union out of the xQUEUE structure. */\r
  77 #define pxMutexHolder                                   pcTail\r
  78 #define uxQueueType                                             pcHead\r
  79 #define uxRecursiveCallCount                    pcReadFrom\r
  80 #define queueQUEUE_IS_MUTEX                             NULL\r
  81 \r
  82 /* Semaphores do not actually store or copy data, so have an items size of\r
  83 zero. */\r
  84 #define queueSEMAPHORE_QUEUE_ITEM_LENGTH ( 0 )\r
  85 #define queueDONT_BLOCK                                  ( ( portTickType ) 0 )\r
  86 #define queueMUTEX_GIVE_BLOCK_TIME               ( ( portTickType ) 0 )\r
  87 \r
  88 /*\r
  89  * Definition of the queue used by the scheduler.\r
  90  * Items are queued by copy, not reference.\r
  91  */\r
  92 typedef struct QueueDefinition\r
  93 {\r
  94         signed char *pcHead;                            /*< Points to the beginning of the queue storage area. */\r
  95         signed char *pcTail;                            /*< Points to the byte at the end of the queue storage area.  Once more byte is allocated than necessary to store the queue items, this is used as a marker. */\r
  96 \r
  97         signed char *pcWriteTo;                         /*< Points to the free next place in the storage area. */\r
  98         signed char *pcReadFrom;                        /*< Points to the last place that a queued item was read from. */\r
  99 \r
 100         xList xTasksWaitingToSend;                              /*< List of tasks that are blocked waiting to post onto this queue.  Stored in priority order. */\r
 101         xList xTasksWaitingToReceive;                   /*< List of tasks that are blocked waiting to read from this queue.  Stored in priority order. */\r
 102 \r
 103         volatile unsigned portBASE_TYPE uxMessagesWaiting;/*< The number of items currently in the queue. */\r
 104         unsigned portBASE_TYPE uxLength;                /*< The length of the queue defined as the number of items it will hold, not the number of bytes. */\r
 105         unsigned portBASE_TYPE uxItemSize;              /*< The size of each items that the queue will hold. */\r
 106 \r
 107         signed portBASE_TYPE xRxLock;                   /*< Stores the number of items received from the queue (removed from the queue) while the queue was locked.  Set to queueUNLOCKED when the queue is not locked. */\r
 108         signed portBASE_TYPE xTxLock;                   /*< Stores the number of items transmitted to the queue (added to the queue) while the queue was locked.  Set to queueUNLOCKED when the queue is not locked. */\r
 109 \r
 110 } xQUEUE;\r
 111 /*-----------------------------------------------------------*/\r
 112 \r
 113 /*\r
 114  * Inside this file xQueueHandle is a pointer to a xQUEUE structure.\r
 115  * To keep the definition private the API header file defines it as a\r
 116  * pointer to void.\r
 117  */\r
 118 typedef xQUEUE * xQueueHandle;\r
 119 \r
 120 /*\r
 121  * Prototypes for public functions are included here so we don't have to\r
 122  * include the API header file (as it defines xQueueHandle differently).  These\r
 123  * functions are documented in the API header file.\r
 124  */\r
 125 xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize ) PRIVILEGED_FUNCTION;\r
 126 signed portBASE_TYPE xQueueGenericSend( xQueueHandle xQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition ) PRIVILEGED_FUNCTION;\r
 127 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 128 void vQueueDelete( xQueueHandle xQueue ) PRIVILEGED_FUNCTION;\r
 129 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition ) PRIVILEGED_FUNCTION;\r
 130 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking ) PRIVILEGED_FUNCTION;\r
 131 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken ) PRIVILEGED_FUNCTION;\r
 132 xQueueHandle xQueueCreateMutex( void ) PRIVILEGED_FUNCTION;\r
 133 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount ) PRIVILEGED_FUNCTION;\r
 134 portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle xMutex, portTickType xBlockTime ) PRIVILEGED_FUNCTION;\r
 135 portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle xMutex ) PRIVILEGED_FUNCTION;\r
 136 signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition ) PRIVILEGED_FUNCTION;\r
 137 signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking ) PRIVILEGED_FUNCTION;\r
 138 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 139 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 140 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 141 \r
 142 /*\r
 143  * Co-routine queue functions differ from task queue functions.  Co-routines are\r
 144  * an optional component.\r
 145  */\r
 146 #if configUSE_CO_ROUTINES == 1\r
 147         signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken ) PRIVILEGED_FUNCTION;\r
 148         signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken ) PRIVILEGED_FUNCTION;\r
 149         signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait ) PRIVILEGED_FUNCTION;\r
 150         signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait ) PRIVILEGED_FUNCTION;\r
 151 #endif\r
 152 \r
 153 /*\r
 154  * The queue registry is just a means for kernel aware debuggers to locate\r
 155  * queue structures.  It has no other purpose so is an optional component.\r
 156  */\r
 157 #if configQUEUE_REGISTRY_SIZE > 0\r
 158 \r
 159         /* The type stored within the queue registry array.  This allows a name\r
 160         to be assigned to each queue making kernel aware debugging a little\r
 161         more user friendly. */\r
 162         typedef struct QUEUE_REGISTRY_ITEM\r
 163         {\r
 164                 signed char *pcQueueName;\r
 165                 xQueueHandle xHandle;\r
 166         } xQueueRegistryItem;\r
 167 \r
 168         /* The queue registry is simply an array of xQueueRegistryItem structures.\r
 169         The pcQueueName member of a structure being NULL is indicative of the\r
 170         array position being vacant. */\r
 171         xQueueRegistryItem xQueueRegistry[ configQUEUE_REGISTRY_SIZE ];\r
 172 \r
 173         /* Removes a queue from the registry by simply setting the pcQueueName\r
 174         member to NULL. */\r
 175         static void vQueueUnregisterQueue( xQueueHandle xQueue ) PRIVILEGED_FUNCTION;\r
 176         void vQueueAddToRegistry( xQueueHandle xQueue, signed char *pcQueueName ) PRIVILEGED_FUNCTION;\r
 177 #endif\r
 178 \r
 179 /*\r
 180  * Unlocks a queue locked by a call to prvLockQueue.  Locking a queue does not\r
 181  * prevent an ISR from adding or removing items to the queue, but does prevent\r
 182  * an ISR from removing tasks from the queue event lists.  If an ISR finds a\r
 183  * queue is locked it will instead increment the appropriate queue lock count\r
 184  * to indicate that a task may require unblocking.  When the queue in unlocked\r
 185  * these lock counts are inspected, and the appropriate action taken.\r
 186  */\r
 187 static void prvUnlockQueue( xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 188 \r
 189 /*\r
 190  * Uses a critical section to determine if there is any data in a queue.\r
 191  *\r
 192  * @return pdTRUE if the queue contains no items, otherwise pdFALSE.\r
 193  */\r
 194 static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 195 \r
 196 /*\r
 197  * Uses a critical section to determine if there is any space in a queue.\r
 198  *\r
 199  * @return pdTRUE if there is no space, otherwise pdFALSE;\r
 200  */\r
 201 static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue ) PRIVILEGED_FUNCTION;\r
 202 \r
 203 /*\r
 204  * Copies an item into the queue, either at the front of the queue or the\r
 205  * back of the queue.\r
 206  */\r
 207 static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition ) PRIVILEGED_FUNCTION;\r
 208 \r
 209 /*\r
 210  * Copies an item out of a queue.\r
 211  */\r
 212 static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer ) PRIVILEGED_FUNCTION;\r
 213 /*-----------------------------------------------------------*/\r
 214 \r
 215 /*\r
 216  * Macro to mark a queue as locked.  Locking a queue prevents an ISR from\r
 217  * accessing the queue event lists.\r
 218  */\r
 219 #define prvLockQueue( pxQueue )                                                 \\r
 220 {                                                                                                               \\r
 221         taskENTER_CRITICAL();                                                           \\r
 222         {                                                                                                       \\r
 223                 if( pxQueue->xRxLock == queueUNLOCKED )                 \\r
 224                 {                                                                                               \\r
 225                         pxQueue->xRxLock = queueLOCKED_UNMODIFIED;      \\r
 226                 }                                                                                               \\r
 227                 if( pxQueue->xTxLock == queueUNLOCKED )                 \\r
 228                 {                                                                                               \\r
 229                         pxQueue->xTxLock = queueLOCKED_UNMODIFIED;      \\r
 230                 }                                                                                               \\r
 231         }                                                                                                       \\r
 232         taskEXIT_CRITICAL();                                                            \\r
 233 }\r
 234 /*-----------------------------------------------------------*/\r
 235 \r
 236 \r
 237 /*-----------------------------------------------------------\r
 238  * PUBLIC QUEUE MANAGEMENT API documented in queue.h\r
 239  *----------------------------------------------------------*/\r
 240 \r
 241 xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize )\r
 242 {\r
 243 xQUEUE *pxNewQueue;\r
 244 size_t xQueueSizeInBytes;\r
 245 \r
 246         /* Allocate the new queue structure. */\r
 247         if( uxQueueLength > ( unsigned portBASE_TYPE ) 0 )\r
 248         {\r
 249                 pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );\r
 250                 if( pxNewQueue != NULL )\r
 251                 {\r
 252                         /* Create the list of pointers to queue items.  The queue is one byte\r
 253                         longer than asked for to make wrap checking easier/faster. */\r
 254                         xQueueSizeInBytes = ( size_t ) ( uxQueueLength * uxItemSize ) + ( size_t ) 1;\r
 255 \r
 256                         pxNewQueue->pcHead = ( signed char * ) pvPortMalloc( xQueueSizeInBytes );\r
 257                         if( pxNewQueue->pcHead != NULL )\r
 258                         {\r
 259                                 /* Initialise the queue members as described above where the\r
 260                                 queue type is defined. */\r
 261                                 pxNewQueue->pcTail = pxNewQueue->pcHead + ( uxQueueLength * uxItemSize );\r
 262                                 pxNewQueue->uxMessagesWaiting = 0;\r
 263                                 pxNewQueue->pcWriteTo = pxNewQueue->pcHead;\r
 264                                 pxNewQueue->pcReadFrom = pxNewQueue->pcHead + ( ( uxQueueLength - 1 ) * uxItemSize );\r
 265                                 pxNewQueue->uxLength = uxQueueLength;\r
 266                                 pxNewQueue->uxItemSize = uxItemSize;\r
 267                                 pxNewQueue->xRxLock = queueUNLOCKED;\r
 268                                 pxNewQueue->xTxLock = queueUNLOCKED;\r
 269 \r
 270                                 /* Likewise ensure the event queues start with the correct state. */\r
 271                                 vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );\r
 272                                 vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );\r
 273 \r
 274                                 traceQUEUE_CREATE( pxNewQueue );\r
 275                                 return  pxNewQueue;\r
 276                         }\r
 277                         else\r
 278                         {\r
 279                                 traceQUEUE_CREATE_FAILED();\r
 280                                 vPortFree( pxNewQueue );\r
 281                         }\r
 282                 }\r
 283         }\r
 284 \r
 285         /* Will only reach here if we could not allocate enough memory or no memory\r
 286         was required. */\r
 287         return NULL;\r
 288 }\r
 289 /*-----------------------------------------------------------*/\r
 290 \r
 291 #if ( configUSE_MUTEXES == 1 )\r
 292 \r
 293         xQueueHandle xQueueCreateMutex( void )\r
 294         {\r
 295         xQUEUE *pxNewQueue;\r
 296 \r
 297                 /* Allocate the new queue structure. */\r
 298                 pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );\r
 299                 if( pxNewQueue != NULL )\r
 300                 {\r
 301                         /* Information required for priority inheritance. */\r
 302                         pxNewQueue->pxMutexHolder = NULL;\r
 303                         pxNewQueue->uxQueueType = queueQUEUE_IS_MUTEX;\r
 304 \r
 305                         /* Queues used as a mutex no data is actually copied into or out\r
 306                         of the queue. */\r
 307                         pxNewQueue->pcWriteTo = NULL;\r
 308                         pxNewQueue->pcReadFrom = NULL;\r
 309 \r
 310                         /* Each mutex has a length of 1 (like a binary semaphore) and\r
 311                         an item size of 0 as nothing is actually copied into or out\r
 312                         of the mutex. */\r
 313                         pxNewQueue->uxMessagesWaiting = 0;\r
 314                         pxNewQueue->uxLength = 1;\r
 315                         pxNewQueue->uxItemSize = 0;\r
 316                         pxNewQueue->xRxLock = queueUNLOCKED;\r
 317                         pxNewQueue->xTxLock = queueUNLOCKED;\r
 318 \r
 319                         /* Ensure the event queues start with the correct state. */\r
 320                         vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );\r
 321                         vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );\r
 322 \r
 323                         /* Start with the semaphore in the expected state. */\r
 324                         xQueueGenericSend( pxNewQueue, NULL, 0, queueSEND_TO_BACK );\r
 325 \r
 326                         traceCREATE_MUTEX( pxNewQueue );\r
 327                 }\r
 328                 else\r
 329                 {\r
 330                         traceCREATE_MUTEX_FAILED();\r
 331                 }\r
 332 \r
 333                 return pxNewQueue;\r
 334         }\r
 335 \r
 336 #endif /* configUSE_MUTEXES */\r
 337 /*-----------------------------------------------------------*/\r
 338 \r
 339 #if configUSE_RECURSIVE_MUTEXES == 1\r
 340 \r
 341         portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle pxMutex )\r
 342         {\r
 343         portBASE_TYPE xReturn;\r
 344 \r
 345                 /* If this is the task that holds the mutex then pxMutexHolder will not\r
 346                 change outside of this task.  If this task does not hold the mutex then\r
 347                 pxMutexHolder can never coincidentally equal the tasks handle, and as\r
 348                 this is the only condition we are interested in it does not matter if\r
 349                 pxMutexHolder is accessed simultaneously by another task.  Therefore no\r
 350                 mutual exclusion is required to test the pxMutexHolder variable. */\r
 351                 if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
 352                 {\r
 353                         traceGIVE_MUTEX_RECURSIVE( pxMutex );\r
 354 \r
 355                         /* uxRecursiveCallCount cannot be zero if pxMutexHolder is equal to\r
 356                         the task handle, therefore no underflow check is required.  Also,\r
 357                         uxRecursiveCallCount is only modified by the mutex holder, and as\r
 358                         there can only be one, no mutual exclusion is required to modify the\r
 359                         uxRecursiveCallCount member. */\r
 360                         ( pxMutex->uxRecursiveCallCount )--;\r
 361 \r
 362                         /* Have we unwound the call count? */\r
 363                         if( pxMutex->uxRecursiveCallCount == 0 )\r
 364                         {\r
 365                                 /* Return the mutex.  This will automatically unblock any other\r
 366                                 task that might be waiting to access the mutex. */\r
 367                                 xQueueGenericSend( pxMutex, NULL, queueMUTEX_GIVE_BLOCK_TIME, queueSEND_TO_BACK );\r
 368                         }\r
 369 \r
 370                         xReturn = pdPASS;\r
 371                 }\r
 372                 else\r
 373                 {\r
 374                         /* We cannot give the mutex because we are not the holder. */\r
 375                         xReturn = pdFAIL;\r
 376 \r
 377                         traceGIVE_MUTEX_RECURSIVE_FAILED( pxMutex );\r
 378                 }\r
 379 \r
 380                 return xReturn;\r
 381         }\r
 382 \r
 383 #endif /* configUSE_RECURSIVE_MUTEXES */\r
 384 /*-----------------------------------------------------------*/\r
 385 \r
 386 #if configUSE_RECURSIVE_MUTEXES == 1\r
 387 \r
 388         portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle pxMutex, portTickType xBlockTime )\r
 389         {\r
 390         portBASE_TYPE xReturn;\r
 391 \r
 392                 /* Comments regarding mutual exclusion as per those within\r
 393                 xQueueGiveMutexRecursive(). */\r
 394 \r
 395                 traceTAKE_MUTEX_RECURSIVE( pxMutex );\r
 396 \r
 397                 if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
 398                 {\r
 399                         ( pxMutex->uxRecursiveCallCount )++;\r
 400                         xReturn = pdPASS;\r
 401                 }\r
 402                 else\r
 403                 {\r
 404                         xReturn = xQueueGenericReceive( pxMutex, NULL, xBlockTime, pdFALSE );\r
 405 \r
 406                         /* pdPASS will only be returned if we successfully obtained the mutex,\r
 407                         we may have blocked to reach here. */\r
 408                         if( xReturn == pdPASS )\r
 409                         {\r
 410                                 ( pxMutex->uxRecursiveCallCount )++;\r
 411                         }\r
 412                 }\r
 413 \r
 414                 return xReturn;\r
 415         }\r
 416 \r
 417 #endif /* configUSE_RECURSIVE_MUTEXES */\r
 418 /*-----------------------------------------------------------*/\r
 419 \r
 420 #if configUSE_COUNTING_SEMAPHORES == 1\r
 421 \r
 422         xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount )\r
 423         {\r
 424         xQueueHandle pxHandle;\r
 425 \r
 426                 pxHandle = xQueueCreate( ( unsigned portBASE_TYPE ) uxCountValue, queueSEMAPHORE_QUEUE_ITEM_LENGTH );\r
 427 \r
 428                 if( pxHandle != NULL )\r
 429                 {\r
 430                         pxHandle->uxMessagesWaiting = uxInitialCount;\r
 431 \r
 432                         traceCREATE_COUNTING_SEMAPHORE();\r
 433                 }\r
 434                 else\r
 435                 {\r
 436                         traceCREATE_COUNTING_SEMAPHORE_FAILED();\r
 437                 }\r
 438 \r
 439                 return pxHandle;\r
 440         }\r
 441 \r
 442 #endif /* configUSE_COUNTING_SEMAPHORES */\r
 443 /*-----------------------------------------------------------*/\r
 444 \r
 445 signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
 446 {\r
 447 signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 448 xTimeOutType xTimeOut;\r
 449 \r
 450         /* This function relaxes the coding standard somewhat to allow return\r
 451         statements within the function itself.  This is done in the interest\r
 452         of execution time efficiency. */\r
 453         for( ;; )\r
 454         {\r
 455                 taskENTER_CRITICAL();\r
 456                 {\r
 457                         /* Is there room on the queue now?  To be running we must be\r
 458                         the highest priority task wanting to access the queue. */\r
 459                         if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 460                         {\r
 461                                 traceQUEUE_SEND( pxQueue );\r
 462                                 prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 463 \r
 464                                 /* If there was a task waiting for data to arrive on the\r
 465                                 queue then unblock it now. */\r
 466                                 if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )\r
 467                                 {\r
 468                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )\r
 469                                         {\r
 470                                                 /* The unblocked task has a priority higher than\r
 471                                                 our own so yield immediately.  Yes it is ok to do\r
 472                                                 this from within the critical section - the kernel\r
 473                                                 takes care of that. */\r
 474                                                 portYIELD_WITHIN_API();\r
 475                                         }\r
 476                                 }\r
 477 \r
 478                                 taskEXIT_CRITICAL();\r
 479 \r
 480                                 /* Return to the original privilege level before exiting the\r
 481                                 function. */\r
 482                                 return pdPASS;\r
 483                         }\r
 484                         else\r
 485                         {\r
 486                                 if( xTicksToWait == ( portTickType ) 0 )\r
 487                                 {\r
 488                                         /* The queue was full and no block time is specified (or\r
 489                                         the block time has expired) so leave now. */\r
 490                                         taskEXIT_CRITICAL();\r
 491 \r
 492                                         /* Return to the original privilege level before exiting\r
 493                                         the function. */\r
 494                                         traceQUEUE_SEND_FAILED( pxQueue );\r
 495                                         return errQUEUE_FULL;\r
 496                                 }\r
 497                                 else if( xEntryTimeSet == pdFALSE )\r
 498                                 {\r
 499                                         /* The queue was full and a block time was specified so\r
 500                                         configure the timeout structure. */\r
 501                                         vTaskSetTimeOutState( &xTimeOut );\r
 502                                         xEntryTimeSet = pdTRUE;\r
 503                                 }\r
 504                         }\r
 505                 }\r
 506                 taskEXIT_CRITICAL();\r
 507 \r
 508                 /* Interrupts and other tasks can send to and receive from the queue\r
 509                 now the critical section has been exited. */\r
 510 \r
 511                 vTaskSuspendAll();\r
 512                 prvLockQueue( pxQueue );\r
 513 \r
 514                 /* Update the timeout state to see if it has expired yet. */\r
 515                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 516                 {\r
 517                         if( prvIsQueueFull( pxQueue ) )\r
 518                         {\r
 519                                 traceBLOCKING_ON_QUEUE_SEND( pxQueue );\r
 520                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );\r
 521 \r
 522                                 /* Unlocking the queue means queue events can effect the\r
 523                                 event list.  It is possible     that interrupts occurring now\r
 524                                 remove this task from the event list again - but as the\r
 525                                 scheduler is suspended the task will go onto the pending\r
 526                                 ready last instead of the actual ready list. */\r
 527                                 prvUnlockQueue( pxQueue );\r
 528 \r
 529                                 /* Resuming the scheduler will move tasks from the pending\r
 530                                 ready list into the ready list - so it is feasible that this\r
 531                                 task is already in a ready list before it yields - in which\r
 532                                 case the yield will not cause a context switch unless there\r
 533                                 is also a higher priority task in the pending ready list. */\r
 534                                 if( !xTaskResumeAll() )\r
 535                                 {\r
 536                                         portYIELD_WITHIN_API();\r
 537                                 }\r
 538                         }\r
 539                         else\r
 540                         {\r
 541                                 /* Try again. */\r
 542                                 prvUnlockQueue( pxQueue );\r
 543                                 ( void ) xTaskResumeAll();\r
 544                         }\r
 545                 }\r
 546                 else\r
 547                 {\r
 548                         /* The timeout has expired. */\r
 549                         prvUnlockQueue( pxQueue );\r
 550                         ( void ) xTaskResumeAll();\r
 551 \r
 552                         /* Return to the original privilege level before exiting the\r
 553                         function. */\r
 554                         traceQUEUE_SEND_FAILED( pxQueue );\r
 555                         return errQUEUE_FULL;\r
 556                 }\r
 557         }\r
 558 }\r
 559 /*-----------------------------------------------------------*/\r
 560 \r
 561 #if configUSE_ALTERNATIVE_API == 1\r
 562 \r
 563         signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
 564         {\r
 565         signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 566         xTimeOutType xTimeOut;\r
 567 \r
 568                 for( ;; )\r
 569                 {\r
 570                         taskENTER_CRITICAL();\r
 571                         {\r
 572                                 /* Is there room on the queue now?  To be running we must be\r
 573                                 the highest priority task wanting to access the queue. */\r
 574                                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 575                                 {\r
 576                                         traceQUEUE_SEND( pxQueue );\r
 577                                         prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 578 \r
 579                                         /* If there was a task waiting for data to arrive on the\r
 580                                         queue then unblock it now. */\r
 581                                         if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )\r
 582                                         {\r
 583                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )\r
 584                                                 {\r
 585                                                         /* The unblocked task has a priority higher than\r
 586                                                         our own so yield immediately. */\r
 587                                                         portYIELD_WITHIN_API();\r
 588                                                 }\r
 589                                         }\r
 590 \r
 591                                         taskEXIT_CRITICAL();\r
 592                                         return pdPASS;\r
 593                                 }\r
 594                                 else\r
 595                                 {\r
 596                                         if( xTicksToWait == ( portTickType ) 0 )\r
 597                                         {\r
 598                                                 taskEXIT_CRITICAL();\r
 599                                                 return errQUEUE_FULL;\r
 600                                         }\r
 601                                         else if( xEntryTimeSet == pdFALSE )\r
 602                                         {\r
 603                                                 vTaskSetTimeOutState( &xTimeOut );\r
 604                                                 xEntryTimeSet = pdTRUE;\r
 605                                         }\r
 606                                 }\r
 607                         }\r
 608                         taskEXIT_CRITICAL();\r
 609 \r
 610                         taskENTER_CRITICAL();\r
 611                         {\r
 612                                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 613                                 {\r
 614                                         if( prvIsQueueFull( pxQueue ) )\r
 615                                         {\r
 616                                                 traceBLOCKING_ON_QUEUE_SEND( pxQueue );\r
 617                                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );\r
 618                                                 portYIELD_WITHIN_API();\r
 619                                         }\r
 620                                 }\r
 621                                 else\r
 622                                 {\r
 623                                         taskEXIT_CRITICAL();\r
 624                                         traceQUEUE_SEND_FAILED( pxQueue );\r
 625                                         return errQUEUE_FULL;\r
 626                                 }\r
 627                         }\r
 628                         taskEXIT_CRITICAL();\r
 629                 }\r
 630         }\r
 631 \r
 632 #endif /* configUSE_ALTERNATIVE_API */\r
 633 /*-----------------------------------------------------------*/\r
 634 \r
 635 #if configUSE_ALTERNATIVE_API == 1\r
 636 \r
 637         signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )\r
 638         {\r
 639         signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 640         xTimeOutType xTimeOut;\r
 641         signed char *pcOriginalReadPosition;\r
 642 \r
 643                 for( ;; )\r
 644                 {\r
 645                         taskENTER_CRITICAL();\r
 646                         {\r
 647                                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 648                                 {\r
 649                                         /* Remember our read position in case we are just peeking. */\r
 650                                         pcOriginalReadPosition = pxQueue->pcReadFrom;\r
 651 \r
 652                                         prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 653 \r
 654                                         if( xJustPeeking == pdFALSE )\r
 655                                         {\r
 656                                                 traceQUEUE_RECEIVE( pxQueue );\r
 657 \r
 658                                                 /* We are actually removing data. */\r
 659                                                 --( pxQueue->uxMessagesWaiting );\r
 660 \r
 661                                                 #if ( configUSE_MUTEXES == 1 )\r
 662                                                 {\r
 663                                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 664                                                         {\r
 665                                                                 /* Record the information required to implement\r
 666                                                                 priority inheritance should it become necessary. */\r
 667                                                                 pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();\r
 668                                                         }\r
 669                                                 }\r
 670                                                 #endif\r
 671 \r
 672                                                 if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )\r
 673                                                 {\r
 674                                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )\r
 675                                                         {\r
 676                                                                 portYIELD_WITHIN_API();\r
 677                                                         }\r
 678                                                 }\r
 679                                         }\r
 680                                         else\r
 681                                         {\r
 682                                                 traceQUEUE_PEEK( pxQueue );\r
 683 \r
 684                                                 /* We are not removing the data, so reset our read\r
 685                                                 pointer. */\r
 686                                                 pxQueue->pcReadFrom = pcOriginalReadPosition;\r
 687 \r
 688                                                 /* The data is being left in the queue, so see if there are\r
 689                                                 any other tasks waiting for the data. */\r
 690                                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 691                                                 {\r
 692                                                         /* Tasks that are removed from the event list will get added to\r
 693                                                         the pending ready list as the scheduler is still suspended. */\r
 694                                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 695                                                         {\r
 696                                                                 /* The task waiting has a higher priority than this task. */\r
 697                                                                 portYIELD_WITHIN_API();\r
 698                                                         }\r
 699                                                 }\r
 700 \r
 701                                         }\r
 702 \r
 703                                         taskEXIT_CRITICAL();\r
 704                                         return pdPASS;\r
 705                                 }\r
 706                                 else\r
 707                                 {\r
 708                                         if( xTicksToWait == ( portTickType ) 0 )\r
 709                                         {\r
 710                                                 taskEXIT_CRITICAL();\r
 711                                                 traceQUEUE_RECEIVE_FAILED( pxQueue );\r
 712                                                 return errQUEUE_EMPTY;\r
 713                                         }\r
 714                                         else if( xEntryTimeSet == pdFALSE )\r
 715                                         {\r
 716                                                 vTaskSetTimeOutState( &xTimeOut );\r
 717                                                 xEntryTimeSet = pdTRUE;\r
 718                                         }\r
 719                                 }\r
 720                         }\r
 721                         taskEXIT_CRITICAL();\r
 722 \r
 723                         taskENTER_CRITICAL();\r
 724                         {\r
 725                                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 726                                 {\r
 727                                         if( prvIsQueueEmpty( pxQueue ) )\r
 728                                         {\r
 729                                                 traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );\r
 730 \r
 731                                                 #if ( configUSE_MUTEXES == 1 )\r
 732                                                 {\r
 733                                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 734                                                         {\r
 735                                                                 portENTER_CRITICAL();\r
 736                                                                         vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );\r
 737                                                                 portEXIT_CRITICAL();\r
 738                                                         }\r
 739                                                 }\r
 740                                                 #endif\r
 741 \r
 742                                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
 743                                                 portYIELD_WITHIN_API();\r
 744                                         }\r
 745                                 }\r
 746                                 else\r
 747                                 {\r
 748                                         taskEXIT_CRITICAL();\r
 749                                         traceQUEUE_RECEIVE_FAILED( pxQueue );\r
 750                                         return errQUEUE_EMPTY;\r
 751                                 }\r
 752                         }\r
 753                         taskEXIT_CRITICAL();\r
 754                 }\r
 755         }\r
 756 \r
 757 \r
 758 #endif /* configUSE_ALTERNATIVE_API */\r
 759 /*-----------------------------------------------------------*/\r
 760 \r
 761 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition )\r
 762 {\r
 763 signed portBASE_TYPE xReturn;\r
 764 unsigned portBASE_TYPE uxSavedInterruptStatus;\r
 765 \r
 766         /* Similar to xQueueGenericSend, except we don't block if there is no room\r
 767         in the queue.  Also we don't directly wake a task that was blocked on a\r
 768         queue read, instead we return a flag to say whether a context switch is\r
 769         required or not (i.e. has a task with a higher priority than us been woken\r
 770         by this post). */\r
 771         uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();\r
 772         {\r
 773                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 774                 {\r
 775                         traceQUEUE_SEND_FROM_ISR( pxQueue );\r
 776 \r
 777                         prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 778 \r
 779                         /* If the queue is locked we do not alter the event list.  This will\r
 780                         be done when the queue is unlocked later. */\r
 781                         if( pxQueue->xTxLock == queueUNLOCKED )\r
 782                         {\r
 783                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 784                                 {\r
 785                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 786                                         {\r
 787                                                 /* The task waiting has a higher priority so record that a\r
 788                                                 context switch is required. */\r
 789                                                 *pxHigherPriorityTaskWoken = pdTRUE;\r
 790                                         }\r
 791                                 }\r
 792                         }\r
 793                         else\r
 794                         {\r
 795                                 /* Increment the lock count so the task that unlocks the queue\r
 796                                 knows that data was posted while it was locked. */\r
 797                                 ++( pxQueue->xTxLock );\r
 798                         }\r
 799 \r
 800                         xReturn = pdPASS;\r
 801                 }\r
 802                 else\r
 803                 {\r
 804                         traceQUEUE_SEND_FROM_ISR_FAILED( pxQueue );\r
 805                         xReturn = errQUEUE_FULL;\r
 806                 }\r
 807         }\r
 808         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
 809 \r
 810         return xReturn;\r
 811 }\r
 812 /*-----------------------------------------------------------*/\r
 813 \r
 814 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )\r
 815 {\r
 816 signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 817 xTimeOutType xTimeOut;\r
 818 signed char *pcOriginalReadPosition;\r
 819 \r
 820         /* This function relaxes the coding standard somewhat to allow return\r
 821         statements within the function itself.  This is done in the interest\r
 822         of execution time efficiency. */\r
 823 \r
 824         for( ;; )\r
 825         {\r
 826                 taskENTER_CRITICAL();\r
 827                 {\r
 828                         /* Is there data in the queue now?  To be running we must be\r
 829                         the highest priority task wanting to access the queue. */\r
 830                         if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 831                         {\r
 832                                 /* Remember our read position in case we are just peeking. */\r
 833                                 pcOriginalReadPosition = pxQueue->pcReadFrom;\r
 834 \r
 835                                 prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 836 \r
 837                                 if( xJustPeeking == pdFALSE )\r
 838                                 {\r
 839                                         traceQUEUE_RECEIVE( pxQueue );\r
 840 \r
 841                                         /* We are actually removing data. */\r
 842                                         --( pxQueue->uxMessagesWaiting );\r
 843 \r
 844                                         #if ( configUSE_MUTEXES == 1 )\r
 845                                         {\r
 846                                                 if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 847                                                 {\r
 848                                                         /* Record the information required to implement\r
 849                                                         priority inheritance should it become necessary. */\r
 850                                                         pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();\r
 851                                                 }\r
 852                                         }\r
 853                                         #endif\r
 854 \r
 855                                         if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )\r
 856                                         {\r
 857                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )\r
 858                                                 {\r
 859                                                         portYIELD_WITHIN_API();\r
 860                                                 }\r
 861                                         }\r
 862                                 }\r
 863                                 else\r
 864                                 {\r
 865                                         traceQUEUE_PEEK( pxQueue );\r
 866 \r
 867                                         /* We are not removing the data, so reset our read\r
 868                                         pointer. */\r
 869                                         pxQueue->pcReadFrom = pcOriginalReadPosition;\r
 870 \r
 871                                         /* The data is being left in the queue, so see if there are\r
 872                                         any other tasks waiting for the data. */\r
 873                                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 874                                         {\r
 875                                                 /* Tasks that are removed from the event list will get added to\r
 876                                                 the pending ready list as the scheduler is still suspended. */\r
 877                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 878                                                 {\r
 879                                                         /* The task waiting has a higher priority than this task. */\r
 880                                                         portYIELD_WITHIN_API();\r
 881                                                 }\r
 882                                         }\r
 883 \r
 884                                 }\r
 885 \r
 886                                 taskEXIT_CRITICAL();\r
 887                                 return pdPASS;\r
 888                         }\r
 889                         else\r
 890                         {\r
 891                                 if( xTicksToWait == ( portTickType ) 0 )\r
 892                                 {\r
 893                                         /* The queue was empty and no block time is specified (or\r
 894                                         the block time has expired) so leave now. */\r
 895                                         taskEXIT_CRITICAL();\r
 896                                         traceQUEUE_RECEIVE_FAILED( pxQueue );\r
 897                                         return errQUEUE_EMPTY;\r
 898                                 }\r
 899                                 else if( xEntryTimeSet == pdFALSE )\r
 900                                 {\r
 901                                         /* The queue was empty and a block time was specified so\r
 902                                         configure the timeout structure. */\r
 903                                         vTaskSetTimeOutState( &xTimeOut );\r
 904                                         xEntryTimeSet = pdTRUE;\r
 905                                 }\r
 906                         }\r
 907                 }\r
 908                 taskEXIT_CRITICAL();\r
 909 \r
 910                 /* Interrupts and other tasks can send to and receive from the queue\r
 911                 now the critical section has been exited. */\r
 912 \r
 913                 vTaskSuspendAll();\r
 914                 prvLockQueue( pxQueue );\r
 915 \r
 916                 /* Update the timeout state to see if it has expired yet. */\r
 917                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 918                 {\r
 919                         if( prvIsQueueEmpty( pxQueue ) )\r
 920                         {\r
 921                                 traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );\r
 922 \r
 923                                 #if ( configUSE_MUTEXES == 1 )\r
 924                                 {\r
 925                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 926                                         {\r
 927                                                 portENTER_CRITICAL();\r
 928                                                 {\r
 929                                                         vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );\r
 930                                                 }\r
 931                                                 portEXIT_CRITICAL();\r
 932                                         }\r
 933                                 }\r
 934                                 #endif\r
 935 \r
 936                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
 937                                 prvUnlockQueue( pxQueue );\r
 938                                 if( !xTaskResumeAll() )\r
 939                                 {\r
 940                                         portYIELD_WITHIN_API();\r
 941                                 }\r
 942                         }\r
 943                         else\r
 944                         {\r
 945                                 /* Try again. */\r
 946                                 prvUnlockQueue( pxQueue );\r
 947                                 ( void ) xTaskResumeAll();\r
 948                         }\r
 949                 }\r
 950                 else\r
 951                 {\r
 952                         prvUnlockQueue( pxQueue );\r
 953                         ( void ) xTaskResumeAll();\r
 954                         traceQUEUE_RECEIVE_FAILED( pxQueue );\r
 955                         return errQUEUE_EMPTY;\r
 956                 }\r
 957         }\r
 958 }\r
 959 /*-----------------------------------------------------------*/\r
 960 \r
 961 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken )\r
 962 {\r
 963 signed portBASE_TYPE xReturn;\r
 964 unsigned portBASE_TYPE uxSavedInterruptStatus;\r
 965 \r
 966         uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();\r
 967         {\r
 968                 /* We cannot block from an ISR, so check there is data available. */\r
 969                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 970                 {\r
 971                         traceQUEUE_RECEIVE_FROM_ISR( pxQueue );\r
 972 \r
 973                         prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 974                         --( pxQueue->uxMessagesWaiting );\r
 975 \r
 976                         /* If the queue is locked we will not modify the event list.  Instead\r
 977                         we update the lock count so the task that unlocks the queue will know\r
 978                         that an ISR has removed data while the queue was locked. */\r
 979                         if( pxQueue->xRxLock == queueUNLOCKED )\r
 980                         {\r
 981                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
 982                                 {\r
 983                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
 984                                         {\r
 985                                                 /* The task waiting has a higher priority than us so\r
 986                                                 force a context switch. */\r
 987                                                 *pxTaskWoken = pdTRUE;\r
 988                                         }\r
 989                                 }\r
 990                         }\r
 991                         else\r
 992                         {\r
 993                                 /* Increment the lock count so the task that unlocks the queue\r
 994                                 knows that data was removed while it was locked. */\r
 995                                 ++( pxQueue->xRxLock );\r
 996                         }\r
 997 \r
 998                         xReturn = pdPASS;\r
 999                 }\r
1000                 else\r
1001                 {\r
1002                         xReturn = pdFAIL;\r
1003                         traceQUEUE_RECEIVE_FROM_ISR_FAILED( pxQueue );\r
1004                 }\r
1005         }\r
1006         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
1007 \r
1008         return xReturn;\r
1009 }\r
1010 /*-----------------------------------------------------------*/\r
1011 \r
1012 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue )\r
1013 {\r
1014 unsigned portBASE_TYPE uxReturn;\r
1015 \r
1016         taskENTER_CRITICAL();\r
1017                 uxReturn = pxQueue->uxMessagesWaiting;\r
1018         taskEXIT_CRITICAL();\r
1019 \r
1020         return uxReturn;\r
1021 }\r
1022 /*-----------------------------------------------------------*/\r
1023 \r
1024 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue )\r
1025 {\r
1026 unsigned portBASE_TYPE uxReturn;\r
1027 \r
1028         uxReturn = pxQueue->uxMessagesWaiting;\r
1029 \r
1030         return uxReturn;\r
1031 }\r
1032 /*-----------------------------------------------------------*/\r
1033 \r
1034 void vQueueDelete( xQueueHandle pxQueue )\r
1035 {\r
1036         traceQUEUE_DELETE( pxQueue );\r
1037         vQueueUnregisterQueue( pxQueue );\r
1038         vPortFree( pxQueue->pcHead );\r
1039         vPortFree( pxQueue );\r
1040 }\r
1041 /*-----------------------------------------------------------*/\r
1042 \r
1043 static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition )\r
1044 {\r
1045         if( pxQueue->uxItemSize == ( unsigned portBASE_TYPE ) 0 )\r
1046         {\r
1047                 #if ( configUSE_MUTEXES == 1 )\r
1048                 {\r
1049                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
1050                         {\r
1051                                 /* The mutex is no longer being held. */\r
1052                                 vTaskPriorityDisinherit( ( void * ) pxQueue->pxMutexHolder );\r
1053                                 pxQueue->pxMutexHolder = NULL;\r
1054                         }\r
1055                 }\r
1056                 #endif\r
1057         }\r
1058         else if( xPosition == queueSEND_TO_BACK )\r
1059         {\r
1060                 memcpy( ( void * ) pxQueue->pcWriteTo, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
1061                 pxQueue->pcWriteTo += pxQueue->uxItemSize;\r
1062                 if( pxQueue->pcWriteTo >= pxQueue->pcTail )\r
1063                 {\r
1064                         pxQueue->pcWriteTo = pxQueue->pcHead;\r
1065                 }\r
1066         }\r
1067         else\r
1068         {\r
1069                 memcpy( ( void * ) pxQueue->pcReadFrom, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
1070                 pxQueue->pcReadFrom -= pxQueue->uxItemSize;\r
1071                 if( pxQueue->pcReadFrom < pxQueue->pcHead )\r
1072                 {\r
1073                         pxQueue->pcReadFrom = ( pxQueue->pcTail - pxQueue->uxItemSize );\r
1074                 }\r
1075         }\r
1076 \r
1077         ++( pxQueue->uxMessagesWaiting );\r
1078 }\r
1079 /*-----------------------------------------------------------*/\r
1080 \r
1081 static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer )\r
1082 {\r
1083         if( pxQueue->uxQueueType != queueQUEUE_IS_MUTEX )\r
1084         {\r
1085                 pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1086                 if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1087                 {\r
1088                         pxQueue->pcReadFrom = pxQueue->pcHead;\r
1089                 }\r
1090                 memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1091         }\r
1092 }\r
1093 /*-----------------------------------------------------------*/\r
1094 \r
1095 static void prvUnlockQueue( xQueueHandle pxQueue )\r
1096 {\r
1097         /* THIS FUNCTION MUST BE CALLED WITH THE SCHEDULER SUSPENDED. */\r
1098 \r
1099         /* The lock counts contains the number of extra data items placed or\r
1100         removed from the queue while the queue was locked.  When a queue is\r
1101         locked items can be added or removed, but the event lists cannot be\r
1102         updated. */\r
1103         taskENTER_CRITICAL();\r
1104         {\r
1105                 /* See if data was added to the queue while it was locked. */\r
1106                 while( pxQueue->xTxLock > queueLOCKED_UNMODIFIED )\r
1107                 {\r
1108                         /* Data was posted while the queue was locked.  Are any tasks\r
1109                         blocked waiting for data to become available? */\r
1110                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1111                         {\r
1112                                 /* Tasks that are removed from the event list will get added to\r
1113                                 the pending ready list as the scheduler is still suspended. */\r
1114                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1115                                 {\r
1116                                         /* The task waiting has a higher priority so record that a\r
1117                                         context switch is required. */\r
1118                                         vTaskMissedYield();\r
1119                                 }\r
1120 \r
1121                                 --( pxQueue->xTxLock );\r
1122                         }\r
1123                         else\r
1124                         {\r
1125                                 break;\r
1126                         }\r
1127                 }\r
1128 \r
1129                 pxQueue->xTxLock = queueUNLOCKED;\r
1130         }\r
1131         taskEXIT_CRITICAL();\r
1132 \r
1133         /* Do the same for the Rx lock. */\r
1134         taskENTER_CRITICAL();\r
1135         {\r
1136                 while( pxQueue->xRxLock > queueLOCKED_UNMODIFIED )\r
1137                 {\r
1138                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1139                         {\r
1140                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1141                                 {\r
1142                                         vTaskMissedYield();\r
1143                                 }\r
1144 \r
1145                                 --( pxQueue->xRxLock );\r
1146                         }\r
1147                         else\r
1148                         {\r
1149                                 break;\r
1150                         }\r
1151                 }\r
1152 \r
1153                 pxQueue->xRxLock = queueUNLOCKED;\r
1154         }\r
1155         taskEXIT_CRITICAL();\r
1156 }\r
1157 /*-----------------------------------------------------------*/\r
1158 \r
1159 static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue )\r
1160 {\r
1161 signed portBASE_TYPE xReturn;\r
1162 \r
1163         taskENTER_CRITICAL();\r
1164                 xReturn = ( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 );\r
1165         taskEXIT_CRITICAL();\r
1166 \r
1167         return xReturn;\r
1168 }\r
1169 /*-----------------------------------------------------------*/\r
1170 \r
1171 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue )\r
1172 {\r
1173 signed portBASE_TYPE xReturn;\r
1174 \r
1175         xReturn = ( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 );\r
1176 \r
1177         return xReturn;\r
1178 }\r
1179 /*-----------------------------------------------------------*/\r
1180 \r
1181 static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue )\r
1182 {\r
1183 signed portBASE_TYPE xReturn;\r
1184 \r
1185         taskENTER_CRITICAL();\r
1186                 xReturn = ( pxQueue->uxMessagesWaiting == pxQueue->uxLength );\r
1187         taskEXIT_CRITICAL();\r
1188 \r
1189         return xReturn;\r
1190 }\r
1191 /*-----------------------------------------------------------*/\r
1192 \r
1193 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue )\r
1194 {\r
1195 signed portBASE_TYPE xReturn;\r
1196 \r
1197         xReturn = ( pxQueue->uxMessagesWaiting == pxQueue->uxLength );\r
1198 \r
1199         return xReturn;\r
1200 }\r
1201 /*-----------------------------------------------------------*/\r
1202 \r
1203 #if configUSE_CO_ROUTINES == 1\r
1204 signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait )\r
1205 {\r
1206 signed portBASE_TYPE xReturn;\r
1207 \r
1208         /* If the queue is already full we may have to block.  A critical section\r
1209         is required to prevent an interrupt removing something from the queue\r
1210         between the check to see if the queue is full and blocking on the queue. */\r
1211         portDISABLE_INTERRUPTS();\r
1212         {\r
1213                 if( prvIsQueueFull( pxQueue ) )\r
1214                 {\r
1215                         /* The queue is full - do we want to block or just leave without\r
1216                         posting? */\r
1217                         if( xTicksToWait > ( portTickType ) 0 )\r
1218                         {\r
1219                                 /* As this is called from a coroutine we cannot block directly, but\r
1220                                 return indicating that we need to block. */\r
1221                                 vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToSend ) );\r
1222                                 portENABLE_INTERRUPTS();\r
1223                                 return errQUEUE_BLOCKED;\r
1224                         }\r
1225                         else\r
1226                         {\r
1227                                 portENABLE_INTERRUPTS();\r
1228                                 return errQUEUE_FULL;\r
1229                         }\r
1230                 }\r
1231         }\r
1232         portENABLE_INTERRUPTS();\r
1233 \r
1234         portNOP();\r
1235 \r
1236         portDISABLE_INTERRUPTS();\r
1237         {\r
1238                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
1239                 {\r
1240                         /* There is room in the queue, copy the data into the queue. */\r
1241                         prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
1242                         xReturn = pdPASS;\r
1243 \r
1244                         /* Were any co-routines waiting for data to become available? */\r
1245                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1246                         {\r
1247                                 /* In this instance the co-routine could be placed directly\r
1248                                 into the ready list as we are within a critical section.\r
1249                                 Instead the same pending ready list mechanism is used as if\r
1250                                 the event were caused from within an interrupt. */\r
1251                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1252                                 {\r
1253                                         /* The co-routine waiting has a higher priority so record\r
1254                                         that a yield might be appropriate. */\r
1255                                         xReturn = errQUEUE_YIELD;\r
1256                                 }\r
1257                         }\r
1258                 }\r
1259                 else\r
1260                 {\r
1261                         xReturn = errQUEUE_FULL;\r
1262                 }\r
1263         }\r
1264         portENABLE_INTERRUPTS();\r
1265 \r
1266         return xReturn;\r
1267 }\r
1268 #endif\r
1269 /*-----------------------------------------------------------*/\r
1270 \r
1271 #if configUSE_CO_ROUTINES == 1\r
1272 signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait )\r
1273 {\r
1274 signed portBASE_TYPE xReturn;\r
1275 \r
1276         /* If the queue is already empty we may have to block.  A critical section\r
1277         is required to prevent an interrupt adding something to the queue\r
1278         between the check to see if the queue is empty and blocking on the queue. */\r
1279         portDISABLE_INTERRUPTS();\r
1280         {\r
1281                 if( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 )\r
1282                 {\r
1283                         /* There are no messages in the queue, do we want to block or just\r
1284                         leave with nothing? */\r
1285                         if( xTicksToWait > ( portTickType ) 0 )\r
1286                         {\r
1287                                 /* As this is a co-routine we cannot block directly, but return\r
1288                                 indicating that we need to block. */\r
1289                                 vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToReceive ) );\r
1290                                 portENABLE_INTERRUPTS();\r
1291                                 return errQUEUE_BLOCKED;\r
1292                         }\r
1293                         else\r
1294                         {\r
1295                                 portENABLE_INTERRUPTS();\r
1296                                 return errQUEUE_FULL;\r
1297                         }\r
1298                 }\r
1299         }\r
1300         portENABLE_INTERRUPTS();\r
1301 \r
1302         portNOP();\r
1303 \r
1304         portDISABLE_INTERRUPTS();\r
1305         {\r
1306                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
1307                 {\r
1308                         /* Data is available from the queue. */\r
1309                         pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1310                         if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1311                         {\r
1312                                 pxQueue->pcReadFrom = pxQueue->pcHead;\r
1313                         }\r
1314                         --( pxQueue->uxMessagesWaiting );\r
1315                         memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1316 \r
1317                         xReturn = pdPASS;\r
1318 \r
1319                         /* Were any co-routines waiting for space to become available? */\r
1320                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1321                         {\r
1322                                 /* In this instance the co-routine could be placed directly\r
1323                                 into the ready list as we are within a critical section.\r
1324                                 Instead the same pending ready list mechanism is used as if\r
1325                                 the event were caused from within an interrupt. */\r
1326                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1327                                 {\r
1328                                         xReturn = errQUEUE_YIELD;\r
1329                                 }\r
1330                         }\r
1331                 }\r
1332                 else\r
1333                 {\r
1334                         xReturn = pdFAIL;\r
1335                 }\r
1336         }\r
1337         portENABLE_INTERRUPTS();\r
1338 \r
1339         return xReturn;\r
1340 }\r
1341 #endif\r
1342 /*-----------------------------------------------------------*/\r
1343 \r
1344 \r
1345 \r
1346 #if configUSE_CO_ROUTINES == 1\r
1347 signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken )\r
1348 {\r
1349         /* Cannot block within an ISR so if there is no space on the queue then\r
1350         exit without doing anything. */\r
1351         if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
1352         {\r
1353                 prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
1354 \r
1355                 /* We only want to wake one co-routine per ISR, so check that a\r
1356                 co-routine has not already been woken. */\r
1357                 if( !xCoRoutinePreviouslyWoken )\r
1358                 {\r
1359                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1360                         {\r
1361                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1362                                 {\r
1363                                         return pdTRUE;\r
1364                                 }\r
1365                         }\r
1366                 }\r
1367         }\r
1368 \r
1369         return xCoRoutinePreviouslyWoken;\r
1370 }\r
1371 #endif\r
1372 /*-----------------------------------------------------------*/\r
1373 \r
1374 #if configUSE_CO_ROUTINES == 1\r
1375 signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxCoRoutineWoken )\r
1376 {\r
1377 signed portBASE_TYPE xReturn;\r
1378 \r
1379         /* We cannot block from an ISR, so check there is data available. If\r
1380         not then just leave without doing anything. */\r
1381         if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
1382         {\r
1383                 /* Copy the data from the queue. */\r
1384                 pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1385                 if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1386                 {\r
1387                         pxQueue->pcReadFrom = pxQueue->pcHead;\r
1388                 }\r
1389                 --( pxQueue->uxMessagesWaiting );\r
1390                 memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1391 \r
1392                 if( !( *pxCoRoutineWoken ) )\r
1393                 {\r
1394                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1395                         {\r
1396                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1397                                 {\r
1398                                         *pxCoRoutineWoken = pdTRUE;\r
1399                                 }\r
1400                         }\r
1401                 }\r
1402 \r
1403                 xReturn = pdPASS;\r
1404         }\r
1405         else\r
1406         {\r
1407                 xReturn = pdFAIL;\r
1408         }\r
1409 \r
1410         return xReturn;\r
1411 }\r
1412 #endif\r
1413 /*-----------------------------------------------------------*/\r
1414 \r
1415 #if configQUEUE_REGISTRY_SIZE > 0\r
1416 \r
1417         void vQueueAddToRegistry( xQueueHandle xQueue, signed char *pcQueueName )\r
1418         {\r
1419         unsigned portBASE_TYPE ux;\r
1420 \r
1421                 /* See if there is an empty space in the registry.  A NULL name denotes\r
1422                 a free slot. */\r
1423                 for( ux = 0; ux < configQUEUE_REGISTRY_SIZE; ux++ )\r
1424                 {\r
1425                         if( xQueueRegistry[ ux ].pcQueueName == NULL )\r
1426                         {\r
1427                                 /* Store the information on this queue. */\r
1428                                 xQueueRegistry[ ux ].pcQueueName = pcQueueName;\r
1429                                 xQueueRegistry[ ux ].xHandle = xQueue;\r
1430                                 break;\r
1431                         }\r
1432                 }\r
1433         }\r
1434 \r
1435 #endif\r
1436         /*-----------------------------------------------------------*/\r
1437 \r
1438 #if configQUEUE_REGISTRY_SIZE > 0\r
1439 \r
1440         static void vQueueUnregisterQueue( xQueueHandle xQueue )\r
1441         {\r
1442         unsigned portBASE_TYPE ux;\r
1443 \r
1444                 /* See if the handle of the queue being unregistered in actually in the\r
1445                 registry. */\r
1446                 for( ux = 0; ux < configQUEUE_REGISTRY_SIZE; ux++ )\r
1447                 {\r
1448                         if( xQueueRegistry[ ux ].xHandle == xQueue )\r
1449                         {\r
1450                                 /* Set the name to NULL to show that this slot if free again. */\r
1451                                 xQueueRegistry[ ux ].pcQueueName = NULL;\r
1452                                 break;\r
1453                         }\r
1454                 }\r
1455 \r
1456         }\r
1457 \r
1458 #endif\r
1459 \r