@ -55,13 +55,14 @@
/* Effectively make a union out of the xQUEUE structure. */
# define pxMutexHolder pcTail
# define uxQueueType pcHead
# define uxRecursiveCallCount pcReadFrom
# define queueQUEUE_IS_MUTEX NULL
/* Semaphores do not actually store or copy data, so have an items size of
zero . */
# define queueSEMAPHORE_QUEUE_ITEM_LENGTH ( 0 )
# define queueDONT_BLOCK ( ( portTickType ) 0 )
# define queueMUTEX_GIVE_BLOCK_TIME ( ( portTickType ) 0 )
/*
* Definition of the queue used by the scheduler .
* Items are queued by copy , not reference .
@ -107,6 +108,8 @@ signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, const void * co
signed portBASE_TYPE xQueueReceiveFromISR ( xQueueHandle pxQueue , const void * const pvBuffer , signed portBASE_TYPE * pxTaskWoken ) ;
xQueueHandle xQueueCreateMutex ( void ) ;
xQueueHandle xQueueCreateCountingSemaphore ( unsigned portBASE_TYPE uxCountValue , unsigned portBASE_TYPE uxInitialCount ) ;
portBASE_TYPE xQueueTakeMutexRecursive ( xQueueHandle xMutex , portTickType xBlockTime ) ;
portBASE_TYPE xQueueGiveMutexRecursive ( xQueueHandle xMutex ) ;
signed portBASE_TYPE xQueueAltGenericSend ( xQueueHandle pxQueue , const void * const pvItemToQueue , portTickType xTicksToWait , portBASE_TYPE xCopyPosition ) ;
signed portBASE_TYPE xQueueAltGenericReceive ( xQueueHandle pxQueue , const void * const pvBuffer , portTickType xTicksToWait , portBASE_TYPE xJustPeeking ) ;
@ -261,9 +264,84 @@ size_t xQueueSizeInBytes;
# endif /* configUSE_MUTEXES */
/*-----------------------------------------------------------*/
# if configUSE_RECURSIVE_MUTEXES == 1
portBASE_TYPE xQueueGiveMutexRecursive ( xQueueHandle pxMutex )
{
portBASE_TYPE xReturn ;
/* If this is the task that holds the mutex then pxMutexHolder will not
change outside of this task . If this task does not hold the mutex then
pxMutexHolder can never coincidentally equal the tasks handle , and as
this is the only condition we are interested in it does not matter if
pxMutexHolder is accessed simultaneously by another task . Therefore no
mutual exclusion is required to test the pxMutexHolder variable . */
if ( pxMutex - > pxMutexHolder = = xTaskGetCurrentTaskHandle ( ) )
{
/* uxRecursiveCallCount cannot be zero if pxMutexHolder is equal to
the task handle , therefore no underflow check is required . Also ,
uxRecursiveCallCount is only modified by the mutex holder , and as
there can only be one , no mutual exclusion is required to modify the
uxRecursiveCallCount member . */
( pxMutex - > uxRecursiveCallCount ) - - ;
/* Have we unwound the call count? */
if ( pxMutex - > uxRecursiveCallCount = = 0 )
{
/* Return the mutex. This will automatically unblock any other
task that might be waiting to access the mutex . */
xQueueGenericSend ( pxMutex , NULL , queueMUTEX_GIVE_BLOCK_TIME , queueSEND_TO_BACK ) ;
}
xReturn = pdPASS ;
}
else
{
/* We cannot give the mutex because we are not the holder. */
xReturn = pdFAIL ;
}
return xReturn ;
}
# endif /* configUSE_RECURSIVE_MUTEXES */
/*-----------------------------------------------------------*/
# if configUSE_RECURSIVE_MUTEXES == 1
portBASE_TYPE xQueueTakeMutexRecursive ( xQueueHandle pxMutex , portTickType xBlockTime )
{
portBASE_TYPE xReturn ;
/* Comments regarding mutual exclusion as per those within
xQueueGiveMutexRecursive ( ) . */
if ( pxMutex - > pxMutexHolder = = xTaskGetCurrentTaskHandle ( ) )
{
( pxMutex - > uxRecursiveCallCount ) + + ;
xReturn = pdPASS ;
}
else
{
xReturn = xQueueGenericReceive ( pxMutex , NULL , xBlockTime , pdFALSE ) ;
/* pdPASS will only be returned if we successfully obtained the mutex,
we may have blocked to reach here . */
if ( xReturn = = pdPASS )
{
( pxMutex - > uxRecursiveCallCount ) + + ;
}
}
return xReturn ;
}
# endif /* configUSE_RECURSIVE_MUTEXES */
/*-----------------------------------------------------------*/
# if configUSE_COUNTING_SEMAPHORES == 1
xQueueHandle xQueueCreateCountingSemaphore ( unsigned portBASE_TYPE uxCountValue , unsigned portBASE_TYPE uxInitialCount )
xQueueHandle xQueueCreateCountingSemaphore ( unsigned portBASE_TYPE uxCountValue , unsigned portBASE_TYPE uxInitialCount , portBASE_TYPE xIsRecursive )
{
xQueueHandle pxHandle ;
@ -902,6 +980,7 @@ static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, port
{
/* The mutex is no longer being held. */
vTaskPriorityDisinherit ( ( void * const ) pxQueue - > pxMutexHolder ) ;
pxQueue - > pxMutexHolder = NULL ;
}
}
# endif
Richard Barry
17 years ago