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

   1 /*\r
   2         FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section\r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26     ***************************************************************************\r
  27     ***************************************************************************\r
  28     *                                                                         *\r
  29     * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *\r
  30         *                                                                         *\r
  31         * This is a concise, step by step, 'hands on' guide that describes both   *\r
  32         * general multitasking concepts and FreeRTOS specifics. It presents and   *\r
  33         * explains numerous examples that are written using the FreeRTOS API.     *\r
  34         * Full source code for all the examples is provided in an accompanying    *\r
  35         * .zip file.                                                              *\r
  36     *                                                                         *\r
  37     ***************************************************************************\r
  38     ***************************************************************************\r
  39 \r
  40         Please ensure to read the configuration and relevant port sections of the\r
  41         online documentation.\r
  42 \r
  43         http://www.FreeRTOS.org - Documentation, latest information, license and\r
  44         contact details.\r
  45 \r
  46         http://www.SafeRTOS.com - A version that is certified for use in safety\r
  47         critical systems.\r
  48 \r
  49         http://www.OpenRTOS.com - Commercial support, development, porting,\r
  50         licensing and training services.\r
  51 */\r
  52 \r
  53 #include <stdlib.h>\r
  54 #include <string.h>\r
  55 #include "FreeRTOS.h"\r
  56 #include "task.h"\r
  57 #include "croutine.h"\r
  58 \r
  59 /*-----------------------------------------------------------\r
  60  * PUBLIC LIST API documented in list.h\r
  61  *----------------------------------------------------------*/\r
  62 \r
  63 /* Constants used with the cRxLock and cTxLock structure members. */\r
  64 #define queueUNLOCKED                                                   ( ( signed portBASE_TYPE ) -1 )\r
  65 #define queueLOCKED_UNMODIFIED                                  ( ( signed portBASE_TYPE ) 0 )\r
  66 \r
  67 #define queueERRONEOUS_UNBLOCK                                  ( -1 )\r
  68 \r
  69 /* For internal use only. */\r
  70 #define queueSEND_TO_BACK       ( 0 )\r
  71 #define queueSEND_TO_FRONT      ( 1 )\r
  72 \r
  73 /* Effectively make a union out of the xQUEUE structure. */\r
  74 #define pxMutexHolder                           pcTail\r
  75 #define uxQueueType                                     pcHead\r
  76 #define uxRecursiveCallCount            pcReadFrom\r
  77 #define queueQUEUE_IS_MUTEX                     NULL\r
  78 \r
  79 /* Semaphores do not actually store or copy data, so have an items size of\r
  80 zero. */\r
  81 #define queueSEMAPHORE_QUEUE_ITEM_LENGTH ( 0 )\r
  82 #define queueDONT_BLOCK                                  ( ( portTickType ) 0 )\r
  83 #define queueMUTEX_GIVE_BLOCK_TIME               ( ( portTickType ) 0 )\r
  84 \r
  85 /*\r
  86  * Definition of the queue used by the scheduler.\r
  87  * Items are queued by copy, not reference.\r
  88  */\r
  89 typedef struct QueueDefinition\r
  90 {\r
  91         signed portCHAR *pcHead;                                /*< Points to the beginning of the queue storage area. */\r
  92         signed portCHAR *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
  93 \r
  94         signed portCHAR *pcWriteTo;                             /*< Points to the free next place in the storage area. */\r
  95         signed portCHAR *pcReadFrom;                    /*< Points to the last place that a queued item was read from. */\r
  96 \r
  97         xList xTasksWaitingToSend;                              /*< List of tasks that are blocked waiting to post onto this queue.  Stored in priority order. */\r
  98         xList xTasksWaitingToReceive;                   /*< List of tasks that are blocked waiting to read from this queue.  Stored in priority order. */\r
  99 \r
 100         volatile unsigned portBASE_TYPE uxMessagesWaiting;/*< The number of items currently in the queue. */\r
 101         unsigned portBASE_TYPE uxLength;                /*< The length of the queue defined as the number of items it will hold, not the number of bytes. */\r
 102         unsigned portBASE_TYPE uxItemSize;              /*< The size of each items that the queue will hold. */\r
 103 \r
 104         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
 105         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
 106 \r
 107 } xQUEUE;\r
 108 /*-----------------------------------------------------------*/\r
 109 \r
 110 /*\r
 111  * Inside this file xQueueHandle is a pointer to a xQUEUE structure.\r
 112  * To keep the definition private the API header file defines it as a\r
 113  * pointer to void.\r
 114  */\r
 115 typedef xQUEUE * xQueueHandle;\r
 116 \r
 117 /*\r
 118  * Prototypes for public functions are included here so we don't have to\r
 119  * include the API header file (as it defines xQueueHandle differently).  These\r
 120  * functions are documented in the API header file.\r
 121  */\r
 122 xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize );\r
 123 signed portBASE_TYPE xQueueGenericSend( xQueueHandle xQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );\r
 124 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue );\r
 125 void vQueueDelete( xQueueHandle xQueue );\r
 126 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition );\r
 127 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );\r
 128 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken );\r
 129 xQueueHandle xQueueCreateMutex( void );\r
 130 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );\r
 131 portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle xMutex, portTickType xBlockTime );\r
 132 portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle xMutex );\r
 133 signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );\r
 134 signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );\r
 135 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue );\r
 136 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue );\r
 137 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue );\r
 138 \r
 139 /*\r
 140  * Co-routine queue functions differ from task queue functions.  Co-routines are\r
 141  * an optional component.\r
 142  */\r
 143 #if configUSE_CO_ROUTINES == 1\r
 144         signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );\r
 145         signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );\r
 146         signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );\r
 147         signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );\r
 148 #endif\r
 149 \r
 150 /*\r
 151  * The queue registry is just a means for kernel aware debuggers to locate\r
 152  * queue structures.  It has no other purpose so is an optional component.\r
 153  */\r
 154 #if configQUEUE_REGISTRY_SIZE > 0\r
 155 \r
 156         /* The type stored within the queue registry array.  This allows a name\r
 157         to be assigned to each queue making kernel aware debugging a little\r
 158         more user friendly. */\r
 159         typedef struct QUEUE_REGISTRY_ITEM\r
 160         {\r
 161                 signed portCHAR *pcQueueName;\r
 162                 xQueueHandle xHandle;\r
 163         } xQueueRegistryItem;\r
 164 \r
 165         /* The queue registry is simply an array of xQueueRegistryItem structures.\r
 166         The pcQueueName member of a structure being NULL is indicative of the\r
 167         array position being vacant. */\r
 168         xQueueRegistryItem xQueueRegistry[ configQUEUE_REGISTRY_SIZE ];\r
 169 \r
 170         /* Removes a queue from the registry by simply setting the pcQueueName\r
 171         member to NULL. */\r
 172         static void vQueueUnregisterQueue( xQueueHandle xQueue );\r
 173         void vQueueAddToRegistry( xQueueHandle xQueue, signed portCHAR *pcQueueName );\r
 174 #endif\r
 175 \r
 176 /*\r
 177  * Unlocks a queue locked by a call to prvLockQueue.  Locking a queue does not\r
 178  * prevent an ISR from adding or removing items to the queue, but does prevent\r
 179  * an ISR from removing tasks from the queue event lists.  If an ISR finds a\r
 180  * queue is locked it will instead increment the appropriate queue lock count\r
 181  * to indicate that a task may require unblocking.  When the queue in unlocked\r
 182  * these lock counts are inspected, and the appropriate action taken.\r
 183  */\r
 184 static void prvUnlockQueue( xQueueHandle pxQueue );\r
 185 \r
 186 /*\r
 187  * Uses a critical section to determine if there is any data in a queue.\r
 188  *\r
 189  * @return pdTRUE if the queue contains no items, otherwise pdFALSE.\r
 190  */\r
 191 static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue );\r
 192 \r
 193 /*\r
 194  * Uses a critical section to determine if there is any space in a queue.\r
 195  *\r
 196  * @return pdTRUE if there is no space, otherwise pdFALSE;\r
 197  */\r
 198 static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue );\r
 199 \r
 200 /*\r
 201  * Copies an item into the queue, either at the front of the queue or the\r
 202  * back of the queue.\r
 203  */\r
 204 static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition );\r
 205 \r
 206 /*\r
 207  * Copies an item out of a queue.\r
 208  */\r
 209 static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer );\r
 210 /*-----------------------------------------------------------*/\r
 211 \r
 212 /*\r
 213  * Macro to mark a queue as locked.  Locking a queue prevents an ISR from\r
 214  * accessing the queue event lists.\r
 215  */\r
 216 #define prvLockQueue( pxQueue )                                                 \\r
 217 {                                                                                                               \\r
 218         taskENTER_CRITICAL();                                                           \\r
 219         {                                                                                                       \\r
 220                 if( pxQueue->xRxLock == queueUNLOCKED )                 \\r
 221                 {                                                                                               \\r
 222                         pxQueue->xRxLock = queueLOCKED_UNMODIFIED;      \\r
 223                 }                                                                                               \\r
 224                 if( pxQueue->xTxLock == queueUNLOCKED )                 \\r
 225                 {                                                                                               \\r
 226                         pxQueue->xTxLock = queueLOCKED_UNMODIFIED;      \\r
 227                 }                                                                                               \\r
 228         }                                                                                                       \\r
 229         taskEXIT_CRITICAL();                                                            \\r
 230 }\r
 231 /*-----------------------------------------------------------*/\r
 232 \r
 233 \r
 234 /*-----------------------------------------------------------\r
 235  * PUBLIC QUEUE MANAGEMENT API documented in queue.h\r
 236  *----------------------------------------------------------*/\r
 237 \r
 238 xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize )\r
 239 {\r
 240 xQUEUE *pxNewQueue;\r
 241 size_t xQueueSizeInBytes;\r
 242 \r
 243         /* Allocate the new queue structure. */\r
 244         if( uxQueueLength > ( unsigned portBASE_TYPE ) 0 )\r
 245         {\r
 246                 pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );\r
 247                 if( pxNewQueue != NULL )\r
 248                 {\r
 249                         /* Create the list of pointers to queue items.  The queue is one byte\r
 250                         longer than asked for to make wrap checking easier/faster. */\r
 251                         xQueueSizeInBytes = ( size_t ) ( uxQueueLength * uxItemSize ) + ( size_t ) 1;\r
 252 \r
 253                         pxNewQueue->pcHead = ( signed portCHAR * ) pvPortMalloc( xQueueSizeInBytes );\r
 254                         if( pxNewQueue->pcHead != NULL )\r
 255                         {\r
 256                                 /* Initialise the queue members as described above where the\r
 257                                 queue type is defined. */\r
 258                                 pxNewQueue->pcTail = pxNewQueue->pcHead + ( uxQueueLength * uxItemSize );\r
 259                                 pxNewQueue->uxMessagesWaiting = 0;\r
 260                                 pxNewQueue->pcWriteTo = pxNewQueue->pcHead;\r
 261                                 pxNewQueue->pcReadFrom = pxNewQueue->pcHead + ( ( uxQueueLength - 1 ) * uxItemSize );\r
 262                                 pxNewQueue->uxLength = uxQueueLength;\r
 263                                 pxNewQueue->uxItemSize = uxItemSize;\r
 264                                 pxNewQueue->xRxLock = queueUNLOCKED;\r
 265                                 pxNewQueue->xTxLock = queueUNLOCKED;\r
 266 \r
 267                                 /* Likewise ensure the event queues start with the correct state. */\r
 268                                 vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );\r
 269                                 vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );\r
 270 \r
 271                                 traceQUEUE_CREATE( pxNewQueue );\r
 272 \r
 273                                 return  pxNewQueue;\r
 274                         }\r
 275                         else\r
 276                         {\r
 277                                 traceQUEUE_CREATE_FAILED();\r
 278                                 vPortFree( pxNewQueue );\r
 279                         }\r
 280                 }\r
 281         }\r
 282 \r
 283         /* Will only reach here if we could not allocate enough memory or no memory\r
 284         was required. */\r
 285         return NULL;\r
 286 }\r
 287 /*-----------------------------------------------------------*/\r
 288 \r
 289 #if ( configUSE_MUTEXES == 1 )\r
 290 \r
 291         xQueueHandle xQueueCreateMutex( void )\r
 292         {\r
 293         xQUEUE *pxNewQueue;\r
 294 \r
 295                 /* Allocate the new queue structure. */\r
 296                 pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );\r
 297                 if( pxNewQueue != NULL )\r
 298                 {\r
 299                         /* Information required for priority inheritance. */\r
 300                         pxNewQueue->pxMutexHolder = NULL;\r
 301                         pxNewQueue->uxQueueType = queueQUEUE_IS_MUTEX;\r
 302 \r
 303                         /* Queues used as a mutex no data is actually copied into or out\r
 304                         of the queue. */\r
 305                         pxNewQueue->pcWriteTo = NULL;\r
 306                         pxNewQueue->pcReadFrom = NULL;\r
 307 \r
 308                         /* Each mutex has a length of 1 (like a binary semaphore) and\r
 309                         an item size of 0 as nothing is actually copied into or out\r
 310                         of the mutex. */\r
 311                         pxNewQueue->uxMessagesWaiting = 0;\r
 312                         pxNewQueue->uxLength = 1;\r
 313                         pxNewQueue->uxItemSize = 0;\r
 314                         pxNewQueue->xRxLock = queueUNLOCKED;\r
 315                         pxNewQueue->xTxLock = queueUNLOCKED;\r
 316 \r
 317                         /* Ensure the event queues start with the correct state. */\r
 318                         vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );\r
 319                         vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );\r
 320 \r
 321                         /* Start with the semaphore in the expected state. */\r
 322                         xQueueGenericSend( pxNewQueue, NULL, 0, queueSEND_TO_BACK );\r
 323 \r
 324                         traceCREATE_MUTEX( pxNewQueue );\r
 325                 }\r
 326                 else\r
 327                 {\r
 328                         traceCREATE_MUTEX_FAILED();\r
 329                 }\r
 330 \r
 331                 return pxNewQueue;\r
 332         }\r
 333 \r
 334 #endif /* configUSE_MUTEXES */\r
 335 /*-----------------------------------------------------------*/\r
 336 \r
 337 #if configUSE_RECURSIVE_MUTEXES == 1\r
 338 \r
 339         portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle pxMutex )\r
 340         {\r
 341         portBASE_TYPE xReturn;\r
 342 \r
 343                 /* If this is the task that holds the mutex then pxMutexHolder will not\r
 344                 change outside of this task.  If this task does not hold the mutex then\r
 345                 pxMutexHolder can never coincidentally equal the tasks handle, and as\r
 346                 this is the only condition we are interested in it does not matter if\r
 347                 pxMutexHolder is accessed simultaneously by another task.  Therefore no\r
 348                 mutual exclusion is required to test the pxMutexHolder variable. */\r
 349                 if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
 350                 {\r
 351                         traceGIVE_MUTEX_RECURSIVE( pxMutex );\r
 352 \r
 353                         /* uxRecursiveCallCount cannot be zero if pxMutexHolder is equal to\r
 354                         the task handle, therefore no underflow check is required.  Also,\r
 355                         uxRecursiveCallCount is only modified by the mutex holder, and as\r
 356                         there can only be one, no mutual exclusion is required to modify the\r
 357                         uxRecursiveCallCount member. */\r
 358                         ( pxMutex->uxRecursiveCallCount )--;\r
 359 \r
 360                         /* Have we unwound the call count? */\r
 361                         if( pxMutex->uxRecursiveCallCount == 0 )\r
 362                         {\r
 363                                 /* Return the mutex.  This will automatically unblock any other\r
 364                                 task that might be waiting to access the mutex. */\r
 365                 xQueueGenericSend( pxMutex, NULL, queueMUTEX_GIVE_BLOCK_TIME, queueSEND_TO_BACK );\r
 366                         }\r
 367 \r
 368                         xReturn = pdPASS;\r
 369                 }\r
 370                 else\r
 371                 {\r
 372                         /* We cannot give the mutex because we are not the holder. */\r
 373                         xReturn = pdFAIL;\r
 374 \r
 375                         traceGIVE_MUTEX_RECURSIVE_FAILED( pxMutex );\r
 376                 }\r
 377 \r
 378                 return xReturn;\r
 379         }\r
 380 \r
 381 #endif /* configUSE_RECURSIVE_MUTEXES */\r
 382 /*-----------------------------------------------------------*/\r
 383 \r
 384 #if configUSE_RECURSIVE_MUTEXES == 1\r
 385 \r
 386         portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle pxMutex, portTickType xBlockTime )\r
 387         {\r
 388         portBASE_TYPE xReturn;\r
 389 \r
 390                 /* Comments regarding mutual exclusion as per those within\r
 391                 xQueueGiveMutexRecursive(). */\r
 392 \r
 393                 traceTAKE_MUTEX_RECURSIVE( pxMutex );\r
 394 \r
 395                 if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
 396                 {\r
 397                         ( pxMutex->uxRecursiveCallCount )++;\r
 398                         xReturn = pdPASS;\r
 399                 }\r
 400                 else\r
 401                 {\r
 402             xReturn = xQueueGenericReceive( pxMutex, NULL, xBlockTime, pdFALSE );\r
 403 \r
 404                         /* pdPASS will only be returned if we successfully obtained the mutex,\r
 405                         we may have blocked to reach here. */\r
 406                         if( xReturn == pdPASS )\r
 407                         {\r
 408                                 ( pxMutex->uxRecursiveCallCount )++;\r
 409                         }\r
 410                 }\r
 411 \r
 412                 return xReturn;\r
 413         }\r
 414 \r
 415 #endif /* configUSE_RECURSIVE_MUTEXES */\r
 416 /*-----------------------------------------------------------*/\r
 417 \r
 418 #if configUSE_COUNTING_SEMAPHORES == 1\r
 419 \r
 420         xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount )\r
 421         {\r
 422         xQueueHandle pxHandle;\r
 423 \r
 424                 pxHandle = xQueueCreate( ( unsigned portBASE_TYPE ) uxCountValue, queueSEMAPHORE_QUEUE_ITEM_LENGTH );\r
 425 \r
 426                 if( pxHandle != NULL )\r
 427                 {\r
 428                         pxHandle->uxMessagesWaiting = uxInitialCount;\r
 429 \r
 430                         traceCREATE_COUNTING_SEMAPHORE();\r
 431                 }\r
 432                 else\r
 433                 {\r
 434                         traceCREATE_COUNTING_SEMAPHORE_FAILED();\r
 435                 }\r
 436 \r
 437                 return pxHandle;\r
 438         }\r
 439 \r
 440 #endif /* configUSE_COUNTING_SEMAPHORES */\r
 441 /*-----------------------------------------------------------*/\r
 442 \r
 443 signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
 444 {\r
 445 signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 446 xTimeOutType xTimeOut;\r
 447 \r
 448         /* This function relaxes the coding standard somewhat to allow return\r
 449         statements within the function itself.  This is done in the interest\r
 450         of execution time efficiency. */\r
 451 \r
 452         for( ;; )\r
 453         {\r
 454                 taskENTER_CRITICAL();\r
 455                 {\r
 456                         /* Is there room on the queue now?  To be running we must be\r
 457                         the highest priority task wanting to access the queue. */\r
 458                         if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 459                         {\r
 460                                 traceQUEUE_SEND( pxQueue );\r
 461                                 prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 462 \r
 463                                 /* If there was a task waiting for data to arrive on the\r
 464                                 queue then unblock it now. */\r
 465                                 if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )\r
 466                                 {\r
 467                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )\r
 468                                         {\r
 469                                                 /* The unblocked task has a priority higher than\r
 470                                                 our own so yield immediately.  Yes it is ok to do\r
 471                                                 this from within the critical section - the kernel\r
 472                                                 takes care of that. */\r
 473                                                 taskYIELD();\r
 474                                         }\r
 475                                 }\r
 476 \r
 477                                 taskEXIT_CRITICAL();\r
 478                                 return pdPASS;\r
 479                         }\r
 480                         else\r
 481                         {\r
 482                                 if( xTicksToWait == ( portTickType ) 0 )\r
 483                                 {\r
 484                                         /* The queue was full and no block time is specified (or \r
 485                                         the block time has expired) so leave now. */\r
 486                                         taskEXIT_CRITICAL();\r
 487                                         return errQUEUE_FULL;\r
 488                                 }\r
 489                                 else if( xEntryTimeSet == pdFALSE )\r
 490                                 {\r
 491                                         /* The queue was full and a block time was specified so\r
 492                                         configure the timeout structure. */\r
 493                                         vTaskSetTimeOutState( &xTimeOut );\r
 494                                         xEntryTimeSet = pdTRUE;\r
 495                                 }\r
 496                         }\r
 497                 }\r
 498                 taskEXIT_CRITICAL();    \r
 499 \r
 500                 /* Interrupts and other tasks can send to and receive from the queue\r
 501                 now the critical section has been exited. */\r
 502 \r
 503                 vTaskSuspendAll();\r
 504                 prvLockQueue( pxQueue );\r
 505 \r
 506                 /* Update the timeout state to see if it has expired yet. */\r
 507                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 508                 {\r
 509                         if( prvIsQueueFull( pxQueue ) )\r
 510                         {               \r
 511                                 traceBLOCKING_ON_QUEUE_SEND( pxQueue );\r
 512                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );\r
 513 \r
 514                                 /* Unlocking the queue means queue events can effect the\r
 515                                 event list.  It is possible     that interrupts occurring now\r
 516                                 remove this task from the event list again - but as the\r
 517                                 scheduler is suspended the task will go onto the pending\r
 518                                 ready last instead of the actual ready list. */\r
 519                                 prvUnlockQueue( pxQueue );\r
 520 \r
 521                                 /* Resuming the scheduler will move tasks from the pending\r
 522                                 ready list into the ready list - so it is feasible that this\r
 523                                 task is already in a ready list before it yields - in which\r
 524                                 case the yield will not cause a context switch unless there\r
 525                                 is also a higher priority task in the pending ready list. */\r
 526                                 if( !xTaskResumeAll() )\r
 527                                 {\r
 528                                         taskYIELD();\r
 529                                 }\r
 530                         }\r
 531                         else\r
 532                         {\r
 533                                 /* Try again. */\r
 534                                 prvUnlockQueue( pxQueue );\r
 535                                 ( void ) xTaskResumeAll();                      \r
 536                         }\r
 537                 }\r
 538                 else\r
 539                 {\r
 540                         /* The timeout has expired. */\r
 541                         prvUnlockQueue( pxQueue );\r
 542                         ( void ) xTaskResumeAll();\r
 543                         return errQUEUE_FULL;\r
 544                 }\r
 545         }\r
 546 }\r
 547 /*-----------------------------------------------------------*/\r
 548 \r
 549 #if configUSE_ALTERNATIVE_API == 1\r
 550 \r
 551         signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
 552         {\r
 553         signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 554         xTimeOutType xTimeOut;\r
 555 \r
 556                 for( ;; )\r
 557                 {\r
 558                         taskENTER_CRITICAL();\r
 559                         {\r
 560                                 /* Is there room on the queue now?  To be running we must be\r
 561                                 the highest priority task wanting to access the queue. */\r
 562                                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 563                                 {\r
 564                                         traceQUEUE_SEND( pxQueue );\r
 565                                         prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 566 \r
 567                                         /* If there was a task waiting for data to arrive on the\r
 568                                         queue then unblock it now. */\r
 569                                         if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )\r
 570                                         {\r
 571                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )\r
 572                                                 {\r
 573                                                         /* The unblocked task has a priority higher than\r
 574                                                         our own so yield immediately. */\r
 575                                                         taskYIELD();\r
 576                                                 }\r
 577                                         }\r
 578 \r
 579                                         taskEXIT_CRITICAL();\r
 580                                         return pdPASS;\r
 581                                 }\r
 582                                 else\r
 583                                 {\r
 584                                         if( xTicksToWait == ( portTickType ) 0 )\r
 585                                         {\r
 586                                                 taskEXIT_CRITICAL();\r
 587                                                 return errQUEUE_FULL;\r
 588                                         }\r
 589                                         else if( xEntryTimeSet == pdFALSE )\r
 590                                         {\r
 591                                                 vTaskSetTimeOutState( &xTimeOut );\r
 592                                                 xEntryTimeSet = pdTRUE;\r
 593                                         }\r
 594                                 }\r
 595                         }\r
 596                         taskEXIT_CRITICAL();    \r
 597 \r
 598                         taskENTER_CRITICAL();\r
 599                         {\r
 600                                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 601                                 {\r
 602                                         if( prvIsQueueFull( pxQueue ) )\r
 603                                         {                               \r
 604                                                 traceBLOCKING_ON_QUEUE_SEND( pxQueue );\r
 605                                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );\r
 606                                                 taskYIELD();\r
 607                                         }\r
 608                                 }\r
 609                                 else\r
 610                                 {\r
 611                                         taskEXIT_CRITICAL();\r
 612                                         return errQUEUE_FULL;\r
 613                                 }\r
 614                         }\r
 615                         taskEXIT_CRITICAL();\r
 616                 }\r
 617         }\r
 618 \r
 619 #endif /* configUSE_ALTERNATIVE_API */\r
 620 /*-----------------------------------------------------------*/\r
 621 \r
 622 #if configUSE_ALTERNATIVE_API == 1\r
 623 \r
 624         signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )\r
 625         {\r
 626         signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 627         xTimeOutType xTimeOut;\r
 628         signed portCHAR *pcOriginalReadPosition;\r
 629 \r
 630                 for( ;; )\r
 631                 {\r
 632                         taskENTER_CRITICAL();\r
 633                         {\r
 634                                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 635                                 {\r
 636                                         /* Remember our read position in case we are just peeking. */\r
 637                                         pcOriginalReadPosition = pxQueue->pcReadFrom;\r
 638 \r
 639                                         prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 640 \r
 641                                         if( xJustPeeking == pdFALSE )\r
 642                                         {\r
 643                                                 traceQUEUE_RECEIVE( pxQueue );\r
 644 \r
 645                                                 /* We are actually removing data. */\r
 646                                                 --( pxQueue->uxMessagesWaiting );\r
 647 \r
 648                                                 #if ( configUSE_MUTEXES == 1 )\r
 649                                                 {\r
 650                                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 651                                                         {\r
 652                                                                 /* Record the information required to implement\r
 653                                                                 priority inheritance should it become necessary. */\r
 654                                                                 pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();\r
 655                                                         }\r
 656                                                 }\r
 657                                                 #endif\r
 658 \r
 659                                                 if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )\r
 660                                                 {\r
 661                                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )\r
 662                                                         {\r
 663                                                                 taskYIELD();\r
 664                                                         }\r
 665                                                 }\r
 666                                         }\r
 667                                         else\r
 668                                         {\r
 669                                                 traceQUEUE_PEEK( pxQueue );\r
 670 \r
 671                                                 /* We are not removing the data, so reset our read\r
 672                                                 pointer. */\r
 673                                                 pxQueue->pcReadFrom = pcOriginalReadPosition;\r
 674 \r
 675                                                 /* The data is being left in the queue, so see if there are\r
 676                                                 any other tasks waiting for the data. */\r
 677                                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 678                                                 {\r
 679                                                         /* Tasks that are removed from the event list will get added to\r
 680                                                         the pending ready list as the scheduler is still suspended. */\r
 681                                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 682                                                         {\r
 683                                                                 /* The task waiting has a higher priority than this task. */\r
 684                                                                 taskYIELD();\r
 685                                                         }\r
 686                                                 }\r
 687 \r
 688                                         }\r
 689 \r
 690                                         taskEXIT_CRITICAL();\r
 691                                         return pdPASS;\r
 692                                 }\r
 693                                 else\r
 694                                 {\r
 695                                         if( xTicksToWait == ( portTickType ) 0 )\r
 696                                         {\r
 697                                                 taskEXIT_CRITICAL();\r
 698                                                 return errQUEUE_EMPTY;\r
 699                                         }\r
 700                                         else if( xEntryTimeSet == pdFALSE )\r
 701                                         {\r
 702                                                 vTaskSetTimeOutState( &xTimeOut );\r
 703                                                 xEntryTimeSet = pdTRUE;\r
 704                                         }\r
 705                                 }\r
 706                         }\r
 707                         taskEXIT_CRITICAL();\r
 708 \r
 709                         taskENTER_CRITICAL();\r
 710                         {\r
 711                                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 712                                 {\r
 713                                         if( prvIsQueueEmpty( pxQueue ) )\r
 714                                         {                               \r
 715                                                 traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );\r
 716 \r
 717                                                 #if ( configUSE_MUTEXES == 1 )\r
 718                                                 {\r
 719                                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 720                                                         {\r
 721                                                                 portENTER_CRITICAL();\r
 722                                                                         vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );\r
 723                                                                 portEXIT_CRITICAL();\r
 724                                                         }\r
 725                                                 }\r
 726                                                 #endif\r
 727 \r
 728                                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
 729                                                 taskYIELD();\r
 730                                         }\r
 731                                 }\r
 732                                 else\r
 733                                 {\r
 734                                         taskEXIT_CRITICAL();\r
 735                                         return errQUEUE_EMPTY;\r
 736                                 }\r
 737                         }\r
 738                         taskEXIT_CRITICAL();\r
 739                 }\r
 740         }\r
 741 \r
 742 \r
 743 #endif /* configUSE_ALTERNATIVE_API */\r
 744 /*-----------------------------------------------------------*/\r
 745 \r
 746 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition )\r
 747 {\r
 748 signed portBASE_TYPE xReturn;\r
 749 unsigned portBASE_TYPE uxSavedInterruptStatus;\r
 750 \r
 751         /* Similar to xQueueGenericSend, except we don't block if there is no room\r
 752         in the queue.  Also we don't directly wake a task that was blocked on a\r
 753         queue read, instead we return a flag to say whether a context switch is\r
 754         required or not (i.e. has a task with a higher priority than us been woken\r
 755         by this post). */\r
 756         uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();\r
 757         {\r
 758                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
 759                 {\r
 760                         traceQUEUE_SEND_FROM_ISR( pxQueue );\r
 761 \r
 762                         prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
 763 \r
 764                         /* If the queue is locked we do not alter the event list.  This will\r
 765                         be done when the queue is unlocked later. */\r
 766                         if( pxQueue->xTxLock == queueUNLOCKED )\r
 767                         {\r
 768                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 769                                 {\r
 770                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 771                                         {\r
 772                                                 /* The task waiting has a higher priority so record that a\r
 773                                                 context switch is required. */\r
 774                                                 *pxHigherPriorityTaskWoken = pdTRUE;\r
 775                                         }\r
 776                                 }\r
 777                         }\r
 778                         else\r
 779                         {\r
 780                                 /* Increment the lock count so the task that unlocks the queue\r
 781                                 knows that data was posted while it was locked. */\r
 782                                 ++( pxQueue->xTxLock );\r
 783                         }\r
 784 \r
 785                         xReturn = pdPASS;\r
 786                 }\r
 787                 else\r
 788                 {\r
 789                         traceQUEUE_SEND_FROM_ISR_FAILED( pxQueue );\r
 790                         xReturn = errQUEUE_FULL;\r
 791                 }\r
 792         }\r
 793         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
 794 \r
 795         return xReturn;\r
 796 }\r
 797 /*-----------------------------------------------------------*/\r
 798 \r
 799 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )\r
 800 {\r
 801 signed portBASE_TYPE xEntryTimeSet = pdFALSE;\r
 802 xTimeOutType xTimeOut;\r
 803 signed portCHAR *pcOriginalReadPosition;\r
 804 \r
 805         /* This function relaxes the coding standard somewhat to allow return\r
 806         statements within the function itself.  This is done in the interest\r
 807         of execution time efficiency. */\r
 808 \r
 809         for( ;; )\r
 810         {\r
 811                 taskENTER_CRITICAL();\r
 812                 {\r
 813                         /* Is there space on the queue now?  To be running we must be\r
 814                         the highest priority task wanting to access the queue. */               \r
 815                         if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 816                         {\r
 817                                 /* Remember our read position in case we are just peeking. */\r
 818                                 pcOriginalReadPosition = pxQueue->pcReadFrom;\r
 819 \r
 820                                 prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 821 \r
 822                                 if( xJustPeeking == pdFALSE )\r
 823                                 {\r
 824                                         traceQUEUE_RECEIVE( pxQueue );\r
 825 \r
 826                                         /* We are actually removing data. */\r
 827                                         --( pxQueue->uxMessagesWaiting );\r
 828 \r
 829                                         #if ( configUSE_MUTEXES == 1 )\r
 830                                         {\r
 831                                                 if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 832                                                 {\r
 833                                                         /* Record the information required to implement\r
 834                                                         priority inheritance should it become necessary. */\r
 835                                                         pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();\r
 836                                                 }\r
 837                                         }\r
 838                                         #endif\r
 839 \r
 840                                         if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )\r
 841                                         {\r
 842                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )\r
 843                                                 {\r
 844                                                         taskYIELD();\r
 845                                                 }\r
 846                                         }\r
 847                                 }\r
 848                                 else\r
 849                                 {\r
 850                                         traceQUEUE_PEEK( pxQueue );\r
 851 \r
 852                                         /* We are not removing the data, so reset our read\r
 853                                         pointer. */\r
 854                                         pxQueue->pcReadFrom = pcOriginalReadPosition;\r
 855 \r
 856                                         /* The data is being left in the queue, so see if there are\r
 857                                         any other tasks waiting for the data. */\r
 858                                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
 859                                         {\r
 860                                                 /* Tasks that are removed from the event list will get added to\r
 861                                                 the pending ready list as the scheduler is still suspended. */\r
 862                                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
 863                                                 {\r
 864                                                         /* The task waiting has a higher priority than this task. */\r
 865                                                         taskYIELD();\r
 866                                                 }\r
 867                                         }\r
 868 \r
 869                                 }\r
 870 \r
 871                                 taskEXIT_CRITICAL();\r
 872                                 return pdPASS;\r
 873                         }\r
 874                         else\r
 875                         {\r
 876                                 if( xTicksToWait == ( portTickType ) 0 )\r
 877                                 {\r
 878                                         /* The queue was empty and no block time is specified (or \r
 879                                         the block time has expired) so leave now. */                            \r
 880                                         taskEXIT_CRITICAL();\r
 881                                         return errQUEUE_EMPTY;\r
 882                                 }\r
 883                                 else if( xEntryTimeSet == pdFALSE )\r
 884                                 {\r
 885                                         /* The queue was empty and a block time was specified so\r
 886                                         configure the timeout structure. */                             \r
 887                                         vTaskSetTimeOutState( &xTimeOut );\r
 888                                         xEntryTimeSet = pdTRUE;\r
 889                                 }\r
 890                         }\r
 891                 }\r
 892                 taskEXIT_CRITICAL();\r
 893 \r
 894                 /* Interrupts and other tasks can send to and receive from the queue\r
 895                 now the critical section has been exited. */\r
 896 \r
 897                 vTaskSuspendAll();\r
 898                 prvLockQueue( pxQueue );\r
 899 \r
 900                 /* Update the timeout state to see if it has expired yet. */\r
 901                 if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
 902                 {\r
 903                         if( prvIsQueueEmpty( pxQueue ) )\r
 904                         {\r
 905                                 traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );\r
 906 \r
 907                                 #if ( configUSE_MUTEXES == 1 )\r
 908                                 {\r
 909                                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
 910                                         {\r
 911                                                 portENTER_CRITICAL();\r
 912                                                 {\r
 913                                                         vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );\r
 914                                                 }\r
 915                                                 portEXIT_CRITICAL();\r
 916                                         }\r
 917                                 }\r
 918                                 #endif\r
 919 \r
 920                                 vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
 921                                 prvUnlockQueue( pxQueue );\r
 922                                 if( !xTaskResumeAll() )\r
 923                                 {\r
 924                                         taskYIELD();\r
 925                                 }\r
 926                         }\r
 927                         else\r
 928                         {\r
 929                                 /* Try again. */\r
 930                                 prvUnlockQueue( pxQueue );\r
 931                                 ( void ) xTaskResumeAll();\r
 932                         }\r
 933                 }\r
 934                 else\r
 935                 {\r
 936                         prvUnlockQueue( pxQueue );\r
 937                         ( void ) xTaskResumeAll();\r
 938                         return errQUEUE_EMPTY;\r
 939                 }\r
 940         }\r
 941 }\r
 942 /*-----------------------------------------------------------*/\r
 943 \r
 944 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken )\r
 945 {\r
 946 signed portBASE_TYPE xReturn;\r
 947 unsigned portBASE_TYPE uxSavedInterruptStatus;\r
 948 \r
 949         uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();\r
 950         {\r
 951                 /* We cannot block from an ISR, so check there is data available. */\r
 952                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
 953                 {\r
 954                         traceQUEUE_RECEIVE_FROM_ISR( pxQueue );\r
 955 \r
 956                         prvCopyDataFromQueue( pxQueue, pvBuffer );\r
 957                         --( pxQueue->uxMessagesWaiting );\r
 958 \r
 959                         /* If the queue is locked we will not modify the event list.  Instead\r
 960                         we update the lock count so the task that unlocks the queue will know\r
 961                         that an ISR has removed data while the queue was locked. */\r
 962                         if( pxQueue->xRxLock == queueUNLOCKED )\r
 963                         {\r
 964                                 if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
 965                                 {\r
 966                                         if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
 967                                         {\r
 968                                                 /* The task waiting has a higher priority than us so\r
 969                                                 force a context switch. */\r
 970                                                 *pxTaskWoken = pdTRUE;\r
 971                                         }\r
 972                                 }\r
 973                         }\r
 974                         else\r
 975                         {\r
 976                                 /* Increment the lock count so the task that unlocks the queue\r
 977                                 knows that data was removed while it was locked. */\r
 978                                 ++( pxQueue->xRxLock );\r
 979                         }\r
 980 \r
 981                         xReturn = pdPASS;\r
 982                 }\r
 983                 else\r
 984                 {\r
 985                         xReturn = pdFAIL;\r
 986                         traceQUEUE_RECEIVE_FROM_ISR_FAILED( pxQueue );\r
 987                 }\r
 988         }\r
 989         portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );\r
 990 \r
 991         return xReturn;\r
 992 }\r
 993 /*-----------------------------------------------------------*/\r
 994 \r
 995 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue )\r
 996 {\r
 997 unsigned portBASE_TYPE uxReturn;\r
 998 \r
 999         taskENTER_CRITICAL();\r
1000                 uxReturn = pxQueue->uxMessagesWaiting;\r
1001         taskEXIT_CRITICAL();\r
1002 \r
1003         return uxReturn;\r
1004 }\r
1005 /*-----------------------------------------------------------*/\r
1006 \r
1007 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue )\r
1008 {\r
1009 unsigned portBASE_TYPE uxReturn;\r
1010 \r
1011         uxReturn = pxQueue->uxMessagesWaiting;\r
1012 \r
1013         return uxReturn;\r
1014 }\r
1015 /*-----------------------------------------------------------*/\r
1016 \r
1017 void vQueueDelete( xQueueHandle pxQueue )\r
1018 {\r
1019         traceQUEUE_DELETE( pxQueue );\r
1020         vQueueUnregisterQueue( pxQueue );\r
1021         vPortFree( pxQueue->pcHead );\r
1022         vPortFree( pxQueue );\r
1023 }\r
1024 /*-----------------------------------------------------------*/\r
1025 \r
1026 static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition )\r
1027 {\r
1028         if( pxQueue->uxItemSize == ( unsigned portBASE_TYPE ) 0 )\r
1029         {\r
1030                 #if ( configUSE_MUTEXES == 1 )\r
1031                 {\r
1032                         if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
1033                         {\r
1034                                 /* The mutex is no longer being held. */\r
1035                                 vTaskPriorityDisinherit( ( void * ) pxQueue->pxMutexHolder );\r
1036                 pxQueue->pxMutexHolder = NULL;\r
1037                         }\r
1038                 }\r
1039                 #endif\r
1040         }\r
1041         else if( xPosition == queueSEND_TO_BACK )\r
1042         {\r
1043                 memcpy( ( void * ) pxQueue->pcWriteTo, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
1044                 pxQueue->pcWriteTo += pxQueue->uxItemSize;\r
1045                 if( pxQueue->pcWriteTo >= pxQueue->pcTail )\r
1046                 {\r
1047                         pxQueue->pcWriteTo = pxQueue->pcHead;\r
1048                 }\r
1049         }\r
1050         else\r
1051         {\r
1052                 memcpy( ( void * ) pxQueue->pcReadFrom, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
1053                 pxQueue->pcReadFrom -= pxQueue->uxItemSize;\r
1054                 if( pxQueue->pcReadFrom < pxQueue->pcHead )\r
1055                 {\r
1056                         pxQueue->pcReadFrom = ( pxQueue->pcTail - pxQueue->uxItemSize );\r
1057                 }\r
1058         }\r
1059 \r
1060         ++( pxQueue->uxMessagesWaiting );\r
1061 }\r
1062 /*-----------------------------------------------------------*/\r
1063 \r
1064 static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer )\r
1065 {\r
1066         if( pxQueue->uxQueueType != queueQUEUE_IS_MUTEX )\r
1067         {\r
1068                 pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1069                 if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1070                 {\r
1071                         pxQueue->pcReadFrom = pxQueue->pcHead;\r
1072                 }\r
1073                 memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1074         }\r
1075 }\r
1076 /*-----------------------------------------------------------*/\r
1077 \r
1078 static void prvUnlockQueue( xQueueHandle pxQueue )\r
1079 {\r
1080         /* THIS FUNCTION MUST BE CALLED WITH THE SCHEDULER SUSPENDED. */\r
1081 \r
1082         /* The lock counts contains the number of extra data items placed or\r
1083         removed from the queue while the queue was locked.  When a queue is\r
1084         locked items can be added or removed, but the event lists cannot be\r
1085         updated. */\r
1086         taskENTER_CRITICAL();\r
1087         {\r
1088                 /* See if data was added to the queue while it was locked. */\r
1089                 while( pxQueue->xTxLock > queueLOCKED_UNMODIFIED )\r
1090                 {\r
1091                         /* Data was posted while the queue was locked.  Are any tasks\r
1092                         blocked waiting for data to become available? */\r
1093                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1094                         {\r
1095                                 /* Tasks that are removed from the event list will get added to\r
1096                                 the pending ready list as the scheduler is still suspended. */\r
1097                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1098                                 {\r
1099                                         /* The task waiting has a higher priority so record that a\r
1100                                         context switch is required. */\r
1101                                         vTaskMissedYield();\r
1102                                 }\r
1103 \r
1104                                 --( pxQueue->xTxLock );\r
1105                         }\r
1106                         else\r
1107                         {\r
1108                                 break;\r
1109                         }\r
1110                 }\r
1111 \r
1112                 pxQueue->xTxLock = queueUNLOCKED;\r
1113         }\r
1114         taskEXIT_CRITICAL();\r
1115 \r
1116         /* Do the same for the Rx lock. */\r
1117         taskENTER_CRITICAL();\r
1118         {\r
1119                 while( pxQueue->xRxLock > queueLOCKED_UNMODIFIED )\r
1120                 {\r
1121                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1122                         {\r
1123                                 if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1124                                 {\r
1125                                         vTaskMissedYield();\r
1126                                 }\r
1127 \r
1128                                 --( pxQueue->xRxLock );\r
1129                         }\r
1130                         else\r
1131                         {\r
1132                                 break;\r
1133                         }\r
1134                 }\r
1135 \r
1136                 pxQueue->xRxLock = queueUNLOCKED;\r
1137         }\r
1138         taskEXIT_CRITICAL();\r
1139 }\r
1140 /*-----------------------------------------------------------*/\r
1141 \r
1142 static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue )\r
1143 {\r
1144 signed portBASE_TYPE xReturn;\r
1145 \r
1146         taskENTER_CRITICAL();\r
1147                 xReturn = ( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 );\r
1148         taskEXIT_CRITICAL();\r
1149 \r
1150         return xReturn;\r
1151 }\r
1152 /*-----------------------------------------------------------*/\r
1153 \r
1154 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue )\r
1155 {\r
1156 signed portBASE_TYPE xReturn;\r
1157 \r
1158         xReturn = ( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 );\r
1159 \r
1160         return xReturn;\r
1161 }\r
1162 /*-----------------------------------------------------------*/\r
1163 \r
1164 static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue )\r
1165 {\r
1166 signed portBASE_TYPE xReturn;\r
1167 \r
1168         taskENTER_CRITICAL();\r
1169                 xReturn = ( pxQueue->uxMessagesWaiting == pxQueue->uxLength );\r
1170         taskEXIT_CRITICAL();\r
1171 \r
1172         return xReturn;\r
1173 }\r
1174 /*-----------------------------------------------------------*/\r
1175 \r
1176 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue )\r
1177 {\r
1178 signed portBASE_TYPE xReturn;\r
1179 \r
1180         xReturn = ( pxQueue->uxMessagesWaiting == pxQueue->uxLength );\r
1181 \r
1182         return xReturn;\r
1183 }\r
1184 /*-----------------------------------------------------------*/\r
1185 \r
1186 #if configUSE_CO_ROUTINES == 1\r
1187 signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait )\r
1188 {\r
1189 signed portBASE_TYPE xReturn;\r
1190 \r
1191         /* If the queue is already full we may have to block.  A critical section\r
1192         is required to prevent an interrupt removing something from the queue\r
1193         between the check to see if the queue is full and blocking on the queue. */\r
1194         portDISABLE_INTERRUPTS();\r
1195         {\r
1196                 if( prvIsQueueFull( pxQueue ) )\r
1197                 {\r
1198                         /* The queue is full - do we want to block or just leave without\r
1199                         posting? */\r
1200                         if( xTicksToWait > ( portTickType ) 0 )\r
1201                         {\r
1202                                 /* As this is called from a coroutine we cannot block directly, but\r
1203                                 return indicating that we need to block. */\r
1204                                 vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToSend ) );\r
1205                                 portENABLE_INTERRUPTS();\r
1206                                 return errQUEUE_BLOCKED;\r
1207                         }\r
1208                         else\r
1209                         {\r
1210                                 portENABLE_INTERRUPTS();\r
1211                                 return errQUEUE_FULL;\r
1212                         }\r
1213                 }\r
1214         }\r
1215         portENABLE_INTERRUPTS();\r
1216 \r
1217         portNOP();\r
1218 \r
1219         portDISABLE_INTERRUPTS();\r
1220         {\r
1221                 if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
1222                 {\r
1223                         /* There is room in the queue, copy the data into the queue. */\r
1224                         prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
1225                         xReturn = pdPASS;\r
1226 \r
1227                         /* Were any co-routines waiting for data to become available? */\r
1228                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1229                         {\r
1230                                 /* In this instance the co-routine could be placed directly\r
1231                                 into the ready list as we are within a critical section.\r
1232                                 Instead the same pending ready list mechanism is used as if\r
1233                                 the event were caused from within an interrupt. */\r
1234                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1235                                 {\r
1236                                         /* The co-routine waiting has a higher priority so record\r
1237                                         that a yield might be appropriate. */\r
1238                                         xReturn = errQUEUE_YIELD;\r
1239                                 }\r
1240                         }\r
1241                 }\r
1242                 else\r
1243                 {\r
1244                         xReturn = errQUEUE_FULL;\r
1245                 }\r
1246         }\r
1247         portENABLE_INTERRUPTS();\r
1248 \r
1249         return xReturn;\r
1250 }\r
1251 #endif\r
1252 /*-----------------------------------------------------------*/\r
1253 \r
1254 #if configUSE_CO_ROUTINES == 1\r
1255 signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait )\r
1256 {\r
1257 signed portBASE_TYPE xReturn;\r
1258 \r
1259         /* If the queue is already empty we may have to block.  A critical section\r
1260         is required to prevent an interrupt adding something to the queue\r
1261         between the check to see if the queue is empty and blocking on the queue. */\r
1262         portDISABLE_INTERRUPTS();\r
1263         {\r
1264                 if( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 )\r
1265                 {\r
1266                         /* There are no messages in the queue, do we want to block or just\r
1267                         leave with nothing? */\r
1268                         if( xTicksToWait > ( portTickType ) 0 )\r
1269                         {\r
1270                                 /* As this is a co-routine we cannot block directly, but return\r
1271                                 indicating that we need to block. */\r
1272                                 vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToReceive ) );\r
1273                                 portENABLE_INTERRUPTS();\r
1274                                 return errQUEUE_BLOCKED;\r
1275                         }\r
1276                         else\r
1277                         {\r
1278                                 portENABLE_INTERRUPTS();\r
1279                                 return errQUEUE_FULL;\r
1280                         }\r
1281                 }\r
1282         }\r
1283         portENABLE_INTERRUPTS();\r
1284 \r
1285         portNOP();\r
1286 \r
1287         portDISABLE_INTERRUPTS();\r
1288         {\r
1289                 if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
1290                 {\r
1291                         /* Data is available from the queue. */\r
1292                         pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1293                         if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1294                         {\r
1295                                 pxQueue->pcReadFrom = pxQueue->pcHead;\r
1296                         }\r
1297                         --( pxQueue->uxMessagesWaiting );\r
1298                         memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1299 \r
1300                         xReturn = pdPASS;\r
1301 \r
1302                         /* Were any co-routines waiting for space to become available? */\r
1303                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1304                         {\r
1305                                 /* In this instance the co-routine could be placed directly\r
1306                                 into the ready list as we are within a critical section.\r
1307                                 Instead the same pending ready list mechanism is used as if\r
1308                                 the event were caused from within an interrupt. */\r
1309                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1310                                 {\r
1311                                         xReturn = errQUEUE_YIELD;\r
1312                                 }\r
1313                         }\r
1314                 }\r
1315                 else\r
1316                 {\r
1317                         xReturn = pdFAIL;\r
1318                 }\r
1319         }\r
1320         portENABLE_INTERRUPTS();\r
1321 \r
1322         return xReturn;\r
1323 }\r
1324 #endif\r
1325 /*-----------------------------------------------------------*/\r
1326 \r
1327 \r
1328 \r
1329 #if configUSE_CO_ROUTINES == 1\r
1330 signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken )\r
1331 {\r
1332         /* Cannot block within an ISR so if there is no space on the queue then\r
1333         exit without doing anything. */\r
1334         if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
1335         {\r
1336                 prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
1337 \r
1338                 /* We only want to wake one co-routine per ISR, so check that a\r
1339                 co-routine has not already been woken. */\r
1340                 if( !xCoRoutinePreviouslyWoken )\r
1341                 {\r
1342                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
1343                         {\r
1344                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
1345                                 {\r
1346                                         return pdTRUE;\r
1347                                 }\r
1348                         }\r
1349                 }\r
1350         }\r
1351 \r
1352         return xCoRoutinePreviouslyWoken;\r
1353 }\r
1354 #endif\r
1355 /*-----------------------------------------------------------*/\r
1356 \r
1357 #if configUSE_CO_ROUTINES == 1\r
1358 signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxCoRoutineWoken )\r
1359 {\r
1360 signed portBASE_TYPE xReturn;\r
1361 \r
1362         /* We cannot block from an ISR, so check there is data available. If\r
1363         not then just leave without doing anything. */\r
1364         if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
1365         {\r
1366                 /* Copy the data from the queue. */\r
1367                 pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
1368                 if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
1369                 {\r
1370                         pxQueue->pcReadFrom = pxQueue->pcHead;\r
1371                 }\r
1372                 --( pxQueue->uxMessagesWaiting );\r
1373                 memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
1374 \r
1375                 if( !( *pxCoRoutineWoken ) )\r
1376                 {\r
1377                         if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
1378                         {\r
1379                                 if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
1380                                 {\r
1381                                         *pxCoRoutineWoken = pdTRUE;\r
1382                                 }\r
1383                         }\r
1384                 }\r
1385 \r
1386                 xReturn = pdPASS;\r
1387         }\r
1388         else\r
1389         {\r
1390                 xReturn = pdFAIL;\r
1391         }\r
1392 \r
1393         return xReturn;\r
1394 }\r
1395 #endif\r
1396 /*-----------------------------------------------------------*/\r
1397 \r
1398 #if configQUEUE_REGISTRY_SIZE > 0\r
1399 \r
1400         void vQueueAddToRegistry( xQueueHandle xQueue, signed portCHAR *pcQueueName )\r
1401         {\r
1402         unsigned portBASE_TYPE ux;\r
1403 \r
1404                 /* See if there is an empty space in the registry.  A NULL name denotes\r
1405                 a free slot. */\r
1406                 for( ux = 0; ux < configQUEUE_REGISTRY_SIZE; ux++ )\r
1407                 {\r
1408                         if( xQueueRegistry[ ux ].pcQueueName == NULL )\r
1409                         {\r
1410                                 /* Store the information on this queue. */\r
1411                                 xQueueRegistry[ ux ].pcQueueName = pcQueueName;\r
1412                                 xQueueRegistry[ ux ].xHandle = xQueue;\r
1413                                 break;\r
1414                         }\r
1415                 }\r
1416         }\r
1417 \r
1418 #endif\r
1419         /*-----------------------------------------------------------*/\r
1420 \r
1421 #if configQUEUE_REGISTRY_SIZE > 0\r
1422 \r
1423         static void vQueueUnregisterQueue( xQueueHandle xQueue )\r
1424         {\r
1425         unsigned portBASE_TYPE ux;\r
1426 \r
1427                 /* See if the handle of the queue being unregistered in actually in the\r
1428                 registry. */\r
1429                 for( ux = 0; ux < configQUEUE_REGISTRY_SIZE; ux++ )\r
1430                 {\r
1431                         if( xQueueRegistry[ ux ].xHandle == xQueue )\r
1432                         {\r
1433                                 /* Set the name to NULL to show that this slot if free again. */\r
1434                                 xQueueRegistry[ ux ].pcQueueName = NULL;\r
1435                                 break;\r
1436                         }\r
1437                 }\r
1438         }\r
1439 \r
1440 #endif\r
1441 \r