]> git.sur5r.net Git - freertos/blobdiff - Source/queue.c
Update counting semaphore function prototype.
[freertos] / Source / queue.c
index ba0e893838164e9e721f1ccb19b23c627e2ea63d..2c6e34215716bf7cdcfc2511424b226b7d65dbd9 100644 (file)
@@ -1,5 +1,5 @@
 /*\r
-       FreeRTOS.org V4.6.1 - Copyright (C) 2003-2007 Richard Barry.\r
+       FreeRTOS.org V4.7.0 - Copyright (C) 2003-2007 Richard Barry.\r
 \r
        This file is part of the FreeRTOS.org distribution.\r
 \r
 /* Effectively make a union out of the xQUEUE structure. */\r
 #define pxMutexHolder                          pcTail\r
 #define uxQueueType                                    pcHead\r
+#define uxRecursiveCallCount           pcReadFrom\r
 #define queueQUEUE_IS_MUTEX                    NULL\r
 \r
 /* Semaphores do not actually store or copy data, so have an items size of\r
 zero. */\r
 #define queueSEMAPHORE_QUEUE_ITEM_LENGTH ( 0 )\r
 #define queueDONT_BLOCK                                         ( ( portTickType ) 0 )\r
-\r
+#define queueMUTEX_GIVE_BLOCK_TIME              ( ( portTickType ) 0 )\r
 /*\r
  * Definition of the queue used by the scheduler.\r
  * Items are queued by copy, not reference.\r
@@ -77,7 +78,7 @@ typedef struct QueueDefinition
        xList xTasksWaitingToSend;                              /*< List of tasks that are blocked waiting to post onto this queue.  Stored in priority order. */\r
        xList xTasksWaitingToReceive;                   /*< List of tasks that are blocked waiting to read from this queue.  Stored in priority order. */\r
 \r
-       unsigned portBASE_TYPE uxMessagesWaiting;/*< The number of items currently in the queue. */\r
+       volatile unsigned portBASE_TYPE uxMessagesWaiting;/*< The number of items currently in the queue. */\r
        unsigned portBASE_TYPE uxLength;                /*< The length of the queue defined as the number of items it will hold, not the number of bytes. */\r
        unsigned portBASE_TYPE uxItemSize;              /*< The size of each items that the queue will hold. */\r
 \r
@@ -107,6 +108,10 @@ signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, const void * co
 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, const void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken );\r
 xQueueHandle xQueueCreateMutex( void );\r
 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );\r
+portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle xMutex, portTickType xBlockTime );\r
+portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle xMutex );\r
+signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );\r
+signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, const void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );\r
 \r
 #if configUSE_CO_ROUTINES == 1\r
        signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );\r
@@ -259,6 +264,81 @@ size_t xQueueSizeInBytes;
 #endif /* configUSE_MUTEXES */\r
 /*-----------------------------------------------------------*/\r
 \r
+#if configUSE_RECURSIVE_MUTEXES == 1\r
+\r
+       portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle pxMutex )\r
+       {\r
+       portBASE_TYPE xReturn;\r
+\r
+               /* If this is the task that holds the mutex then pxMutexHolder will not \r
+               change outside of this task.  If this task does not hold the mutex then\r
+               pxMutexHolder can never coincidentally equal the tasks handle, and as\r
+               this is the only condition we are interested in it does not matter if\r
+               pxMutexHolder is accessed simultaneously by another task.  Therefore no\r
+               mutual exclusion is required to test the pxMutexHolder variable. */\r
+               if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
+               {\r
+                       /* uxRecursiveCallCount cannot be zero if pxMutexHolder is equal to\r
+                       the task handle, therefore no underflow check is required.  Also, \r
+                       uxRecursiveCallCount is only modified by the mutex holder, and as\r
+                       there can only be one, no mutual exclusion is required to modify the\r
+                       uxRecursiveCallCount member. */\r
+                       ( pxMutex->uxRecursiveCallCount )--;\r
+\r
+                       /* Have we unwound the call count? */\r
+                       if( pxMutex->uxRecursiveCallCount == 0 )\r
+                       {\r
+                               /* Return the mutex.  This will automatically unblock any other\r
+                               task that might be waiting to access the mutex. */\r
+                xQueueGenericSend( pxMutex, NULL, queueMUTEX_GIVE_BLOCK_TIME, queueSEND_TO_BACK );\r
+                       }\r
+\r
+                       xReturn = pdPASS;\r
+               }\r
+               else\r
+               {\r
+                       /* We cannot give the mutex because we are not the holder. */\r
+                       xReturn = pdFAIL;\r
+               }\r
+\r
+               return xReturn;\r
+       }\r
+\r
+#endif /* configUSE_RECURSIVE_MUTEXES */\r
+/*-----------------------------------------------------------*/\r
+\r
+#if configUSE_RECURSIVE_MUTEXES == 1\r
+\r
+       portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle pxMutex, portTickType xBlockTime )\r
+       {\r
+       portBASE_TYPE xReturn;\r
+\r
+               /* Comments regarding mutual exclusion as per those within \r
+               xQueueGiveMutexRecursive(). */\r
+\r
+               if( pxMutex->pxMutexHolder == xTaskGetCurrentTaskHandle() )\r
+               {\r
+                       ( pxMutex->uxRecursiveCallCount )++;\r
+                       xReturn = pdPASS;\r
+               }\r
+               else\r
+               {\r
+            xReturn = xQueueGenericReceive( pxMutex, NULL, xBlockTime, pdFALSE );\r
+\r
+                       /* pdPASS will only be returned if we successfully obtained the mutex,\r
+                       we may have blocked to reach here. */\r
+                       if( xReturn == pdPASS )\r
+                       {\r
+                               ( pxMutex->uxRecursiveCallCount )++;\r
+                       }\r
+               }\r
+\r
+               return xReturn;\r
+       }\r
+\r
+#endif /* configUSE_RECURSIVE_MUTEXES */\r
+/*-----------------------------------------------------------*/\r
+\r
 #if configUSE_COUNTING_SEMAPHORES == 1\r
 \r
        xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount )\r
@@ -455,6 +535,198 @@ xTimeOutType xTimeOut;
 }\r
 /*-----------------------------------------------------------*/\r
 \r
+#if configUSE_ALTERNATIVE_API == 1\r
+\r
+       signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
+       {\r
+       signed portBASE_TYPE xReturn;\r
+       xTimeOutType xTimeOut;\r
+\r
+               /* The source code that implements the alternative (Alt) API is much \r
+               simpler because it executes everything from within a critical section.  \r
+               This is the approach taken by many other RTOSes, but FreeRTOS.org has the \r
+               preferred fully featured API too.  The fully featured API has more \r
+               complex code that takes longer to execute, but makes much less use of \r
+               critical sections.  Therefore the alternative API sacrifices interrupt \r
+               responsiveness to gain execution speed, whereas the fully featured API\r
+               sacrifices execution speed to ensure better interrupt responsiveness.  */\r
+\r
+               taskENTER_CRITICAL();\r
+               {\r
+                       /* Capture the current time status for future reference. */\r
+                       vTaskSetTimeOutState( &xTimeOut );\r
+\r
+                       /* If the queue is already full we may have to block. */\r
+                       do\r
+                       {\r
+                               if( pxQueue->uxMessagesWaiting == pxQueue->uxLength )\r
+                               {\r
+                                       /* The queue is full - do we want to block or just leave without\r
+                                       posting? */\r
+                                       if( xTicksToWait > ( portTickType ) 0 )\r
+                                       {\r
+                                               /* We are going to place ourselves on the xTasksWaitingToSend \r
+                                               event list, and will get woken should the delay expire, or \r
+                                               space become available on the queue. */\r
+                                               vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );\r
+                       \r
+                                               /* Force a context switch now as we are blocked.  We can do\r
+                                               this from within a critical section as the task we are\r
+                                               switching to has its own context.  When we return here (i.e.\r
+                                               we unblock) we will leave the critical section as normal. */\r
+                                               taskYIELD();\r
+                                       }\r
+                               }\r
+                                       \r
+                               if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
+                               {\r
+                                       /* There is room in the queue, copy the data into the queue. */                 \r
+                                       prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
+                                       xReturn = pdPASS;\r
+\r
+                                       if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
+                                       {\r
+                                               if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
+                                               {\r
+                                                       /* The task waiting has a higher priority. */\r
+                                                       taskYIELD();\r
+                                               }\r
+                                       }                       \r
+                               }\r
+                               else\r
+                               {\r
+                                       xReturn = errQUEUE_FULL;\r
+\r
+                                       if( xTicksToWait > 0 )\r
+                                       {                                       \r
+                                               if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
+                                               {\r
+                                                       /* Another task must have accessed the queue between \r
+                                                       this task unblocking and actually executing. */\r
+                                                       xReturn = queueERRONEOUS_UNBLOCK;\r
+                                               }\r
+                                       }\r
+                               }\r
+                       }\r
+                       while( xReturn == queueERRONEOUS_UNBLOCK );\r
+               }\r
+               taskEXIT_CRITICAL();\r
+\r
+               return xReturn;\r
+       }\r
+\r
+#endif /* configUSE_ALTERNATIVE_API */\r
+/*-----------------------------------------------------------*/\r
+\r
+#if configUSE_ALTERNATIVE_API == 1\r
+\r
+       signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, const void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )\r
+       {\r
+       signed portBASE_TYPE xReturn = pdTRUE;\r
+       xTimeOutType xTimeOut;\r
+       signed portCHAR *pcOriginalReadPosition;\r
+\r
+               /* The source code that implements the alternative (Alt) API is much \r
+               simpler because it executes everything from within a critical section.  \r
+               This is the approach taken by many other RTOSes, but FreeRTOS.org has the \r
+               preferred fully featured API too.  The fully featured API has more \r
+               complex code that takes longer to execute, but makes much less use of \r
+               critical sections.  Therefore the alternative API sacrifices interrupt \r
+               responsiveness to gain execution speed, whereas the fully featured API\r
+               sacrifices execution speed to ensure better interrupt responsiveness.  */\r
+\r
+               taskENTER_CRITICAL();\r
+               {\r
+                       /* Capture the current time status for future reference. */\r
+                       vTaskSetTimeOutState( &xTimeOut );\r
+\r
+                       do\r
+                       {\r
+                               /* If there are no messages in the queue we may have to block. */\r
+                               if( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 )\r
+                               {\r
+                                       /* There are no messages in the queue, do we want to block or just\r
+                                       leave with nothing? */                  \r
+                                       if( xTicksToWait > ( portTickType ) 0 )\r
+                                       {\r
+                                               #if ( configUSE_MUTEXES == 1 )\r
+                                               {\r
+                                                       if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
+                                                       {\r
+                                                               vTaskPriorityInherit( ( void * const ) pxQueue->pxMutexHolder );\r
+                                                       }\r
+                                               }\r
+                                               #endif\r
+                                               \r
+                                               vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
+                                               taskYIELD();\r
+                                       }\r
+                               }\r
+                       \r
+                               if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
+                               {\r
+                                       /* Remember our read position in case we are just peeking. */\r
+                                       pcOriginalReadPosition = pxQueue->pcReadFrom;\r
+\r
+                                       prvCopyDataFromQueue( pxQueue, pvBuffer );\r
+\r
+                                       if( xJustPeeking == pdFALSE )\r
+                                       {\r
+                                               /* We are actually removing data. */\r
+                                               --( pxQueue->uxMessagesWaiting );\r
+                                                       \r
+                                               #if ( configUSE_MUTEXES == 1 )\r
+                                               {\r
+                                                       if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
+                                                       {\r
+                                                               /* Record the information required to implement\r
+                                                               priority inheritance should it become necessary. */\r
+                                                               pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();\r
+                                                       }\r
+                                               }\r
+                                               #endif\r
+\r
+                                               if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
+                                               {\r
+                                                       if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
+                                                       {\r
+                                                               /* The task waiting has a higher priority. */\r
+                                                               taskYIELD();\r
+                                                       }\r
+                                               }\r
+                                       }\r
+                                       else\r
+                                       {\r
+                                               /* We are not removing the data, so reset our read\r
+                                               pointer. */\r
+                                               pxQueue->pcReadFrom = pcOriginalReadPosition;\r
+                                       }\r
+                                       \r
+                                       xReturn = pdPASS;                                       \r
+                               }\r
+                               else\r
+                               {\r
+                                       xReturn = errQUEUE_EMPTY;\r
+\r
+                                       if( xTicksToWait > 0 )\r
+                                       {\r
+                                               if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )\r
+                                               {\r
+                                                       xReturn = queueERRONEOUS_UNBLOCK;\r
+                                               }\r
+                                       }\r
+                               }\r
+\r
+                       } while( xReturn == queueERRONEOUS_UNBLOCK );\r
+               }\r
+               taskEXIT_CRITICAL();\r
+\r
+               return xReturn;\r
+       }\r
+\r
+#endif /* configUSE_ALTERNATIVE_API */\r
+/*-----------------------------------------------------------*/\r
+\r
 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken, portBASE_TYPE xCopyPosition )\r
 {\r
        /* Similar to xQueueGenericSend, except we don't block if there is no room\r
@@ -708,6 +980,7 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port
                        {\r
                                /* The mutex is no longer being held. */\r
                                vTaskPriorityDisinherit( ( void * const ) pxQueue->pxMutexHolder );\r
+                pxQueue->pxMutexHolder = NULL;\r
                        }\r
                }\r
                #endif\r