/*\r
- FreeRTOS.org V4.6.0 - 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
and contact details. Please ensure to read the configuration and relevant\r
port sections of the online documentation.\r
\r
- Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along\r
- with commercial development and support options.\r
+ Also see http://www.SafeRTOS.com a version that has been certified for use\r
+ in safety critical systems, plus commercial licensing, development and\r
+ support options.\r
***************************************************************************\r
*/\r
\r
-/*\r
-Changes from V1.01\r
-\r
- + More use of 8bit data types.\r
- + Function name prefixes changed where the data type returned has changed.\r
-\r
-Changed from V2.0.0\r
-\r
- + Added the queue locking mechanism and make more use of the scheduler\r
- suspension feature to minimise the time interrupts have to be disabled\r
- when accessing a queue.\r
-\r
-Changed from V2.2.0\r
-\r
- + Explicit use of 'signed' qualifier on portCHAR types added.\r
-\r
-Changes from V3.0.0\r
-\r
- + API changes as described on the FreeRTOS.org WEB site.\r
-\r
-Changes from V3.2.3\r
-\r
- + Added the queue functions that can be used from co-routines.\r
-\r
-Changes from V4.0.5\r
-\r
- + Added a loop within xQueueSend() and xQueueReceive() to prevent the\r
- functions exiting when a block time remains and the function has\r
- not completed.\r
-\r
-Changes from V4.1.2:\r
-\r
- + BUG FIX: Removed the call to prvIsQueueEmpty from within xQueueCRReceive\r
- as it exited with interrupts enabled. Thanks Paul Katz.\r
-\r
-Changes from V4.1.3:\r
-\r
- + Modified xQueueSend() and xQueueReceive() to handle the (very unlikely)\r
- case whereby a task unblocking due to a temporal event can remove/send an\r
- item from/to a queue when a higher priority task is still blocked on the\r
- queue. This modification is a result of the SafeRTOS testing.\r
-*/\r
-\r
#include <stdlib.h>\r
#include <string.h>\r
#include "FreeRTOS.h"\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
+#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
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
signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, const void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );\r
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
#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
+ {\r
+ xQueueHandle pxHandle;\r
+ \r
+ pxHandle = xQueueCreate( ( unsigned portBASE_TYPE ) uxCountValue, queueSEMAPHORE_QUEUE_ITEM_LENGTH );\r
+\r
+ if( pxHandle != NULL )\r
+ {\r
+ pxHandle->uxMessagesWaiting = uxInitialCount;\r
+ }\r
+\r
+ return pxHandle;\r
+ }\r
+\r
+#endif /* configUSE_COUNTING_SEMAPHORES */\r
+/*-----------------------------------------------------------*/\r
+\r
signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )\r
{\r
signed portBASE_TYPE xReturn = pdPASS;\r
}\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
{\r
/* The mutex is no longer being held. */\r
vTaskPriorityDisinherit( ( void * const ) pxQueue->pxMutexHolder );\r
+ pxQueue->pxMutexHolder = NULL;\r
}\r
}\r
#endif\r
projects / freertos / blobdiff