/*\r
- FreeRTOS.org V4.4.0 - 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
#define queueUNLOCKED ( ( signed portBASE_TYPE ) -1 )\r
#define queueERRONEOUS_UNBLOCK ( -1 )\r
\r
+/* For internal use only. */\r
+#define queueSEND_TO_BACK ( 0 )\r
+#define queueSEND_TO_FRONT ( 1 )\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
+#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 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
- 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
+ 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
+ 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
} xQUEUE;\r
/*-----------------------------------------------------------*/\r
\r
* functions are documented in the API header file.\r
*/\r
xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize );\r
-signed portBASE_TYPE xQueueSend( xQueueHandle xQueue, const void * pvItemToQueue, portTickType xTicksToWait );\r
-unsigned portBASE_TYPE uxQueueMessagesWaiting( xQueueHandle pxQueue );\r
+signed portBASE_TYPE xQueueGenericSend( xQueueHandle xQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );\r
+unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue );\r
void vQueueDelete( xQueueHandle xQueue );\r
-signed portBASE_TYPE xQueueSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken );\r
-signed portBASE_TYPE xQueueReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );\r
-signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );\r
+signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken, portBASE_TYPE xCopyPosition );\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
static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue );\r
\r
/*\r
- * Macro that copies an item into the queue. This is done by copying the item\r
- * byte for byte, not by reference. Updates the queue state to ensure it's\r
- * integrity after the copy.\r
+ * Copies an item into the queue, either at the front of the queue or the\r
+ * back of the queue.\r
*/\r
-#define prvCopyQueueData( pxQueue, pvItemToQueue ) \\r
-{ \\r
- memcpy( ( void * ) pxQueue->pcWriteTo, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize ); \\r
- ++( pxQueue->uxMessagesWaiting ); \\r
- pxQueue->pcWriteTo += pxQueue->uxItemSize; \\r
- if( pxQueue->pcWriteTo >= pxQueue->pcTail ) \\r
- { \\r
- pxQueue->pcWriteTo = pxQueue->pcHead; \\r
- } \\r
-}\r
+static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition );\r
+\r
+/*\r
+ * Copies an item out of a queue.\r
+ */\r
+static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer );\r
/*-----------------------------------------------------------*/\r
\r
/*\r
}\r
/*-----------------------------------------------------------*/\r
\r
-signed portBASE_TYPE xQueueSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait )\r
+#if ( configUSE_MUTEXES == 1 )\r
+\r
+ xQueueHandle xQueueCreateMutex( void )\r
+ {\r
+ xQUEUE *pxNewQueue;\r
+ \r
+ /* Allocate the new queue structure. */\r
+ pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );\r
+ if( pxNewQueue != NULL )\r
+ {\r
+ /* Information required for priority inheritance. */\r
+ pxNewQueue->pxMutexHolder = NULL;\r
+ pxNewQueue->uxQueueType = queueQUEUE_IS_MUTEX;\r
+ \r
+ /* Queues used as a mutex no data is actually copied into or out\r
+ of the queue. */\r
+ pxNewQueue->pcWriteTo = NULL;\r
+ pxNewQueue->pcReadFrom = NULL;\r
+ \r
+ /* Each mutex has a length of 1 (like a binary semaphore) and\r
+ an item size of 0 as nothing is actually copied into or out\r
+ of the mutex. */\r
+ pxNewQueue->uxMessagesWaiting = 0;\r
+ pxNewQueue->uxLength = 1;\r
+ pxNewQueue->uxItemSize = 0;\r
+ pxNewQueue->xRxLock = queueUNLOCKED;\r
+ pxNewQueue->xTxLock = queueUNLOCKED;\r
+ \r
+ /* Ensure the event queues start with the correct state. */\r
+ vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );\r
+ vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );\r
+\r
+ /* Start with the semaphore in the expected state. */\r
+ xQueueGenericSend( pxNewQueue, NULL, 0, queueSEND_TO_BACK );\r
+ }\r
+ \r
+ return pxNewQueue;\r
+ }\r
+\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
xTimeOutType xTimeOut;\r
queue being modified here. Places where the event list is modified\r
include:\r
\r
- + xQueueSendFromISR(). This checks the lock on the queue to see if\r
- it has access. If the queue is locked then the Tx lock count is\r
+ + xQueueGenericSendFromISR(). This checks the lock on the queue to see\r
+ if it has access. If the queue is locked then the Tx lock count is\r
incremented to signify that a task waiting for data can be made ready\r
once the queue lock is removed. If the queue is not locked then\r
a task can be moved from the event list, but will not be removed\r
from the delayed list or placed in the ready list until the scheduler\r
is unlocked.\r
\r
- + xQueueReceiveFromISR(). As per xQueueSendFromISR().\r
+ + xQueueReceiveFromISR(). As per xQueueGenericSendFromISR().\r
*/\r
\r
/* If the queue is already full we may have to block. */\r
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
{\r
/* There is room in the queue, copy the data into the queue. */ \r
- prvCopyQueueData( pxQueue, pvItemToQueue ); \r
+ prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
xReturn = pdPASS;\r
\r
/* Update the TxLock count so prvUnlockQueue knows to check for\r
}\r
/*-----------------------------------------------------------*/\r
\r
-signed portBASE_TYPE xQueueSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken )\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 xQueueSend, except we don't block if there is no room in the\r
- queue. Also we don't directly wake a task that was blocked on a queue\r
- read, instead we return a flag to say whether a context switch is required\r
- or not (i.e. has a task with a higher priority than us been woken by this\r
- post). */\r
+ /* Similar to xQueueGenericSend, except we don't block if there is no room\r
+ in the queue. Also we don't directly wake a task that was blocked on a\r
+ queue read, instead we return a flag to say whether a context switch is\r
+ required or not (i.e. has a task with a higher priority than us been woken\r
+ by this post). */\r
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
{\r
- prvCopyQueueData( pxQueue, pvItemToQueue );\r
+ prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );\r
\r
/* If the queue is locked we do not alter the event list. This will\r
be done when the queue is unlocked later. */\r
}\r
/*-----------------------------------------------------------*/\r
\r
-signed portBASE_TYPE xQueueReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait )\r
+signed portBASE_TYPE xQueueGenericReceive( 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
- /* This function is very similar to xQueueSend(). See comments within\r
- xQueueSend() for a more detailed explanation.\r
+ /* This function is very similar to xQueueGenericSend(). See comments\r
+ within xQueueGenericSend() for a more detailed explanation.\r
\r
Make sure other tasks do not access the queue. */\r
vTaskSuspendAll();\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
+ portENTER_CRITICAL();\r
+ vTaskPriorityInherit( ( void * const ) pxQueue->pxMutexHolder );\r
+ portEXIT_CRITICAL();\r
+ }\r
+ }\r
+ #endif\r
+ \r
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );\r
taskENTER_CRITICAL();\r
{\r
{\r
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
{\r
- pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
- if( pxQueue->pcReadFrom >= pxQueue->pcTail )\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
- pxQueue->pcReadFrom = pxQueue->pcHead;\r
+ /* We are actually removing data. */\r
+ --( pxQueue->uxMessagesWaiting );\r
+ \r
+ /* Increment the lock count so prvUnlockQueue knows to check for\r
+ tasks waiting for space to become available on the queue. */\r
+ ++( pxQueue->xRxLock );\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
- --( pxQueue->uxMessagesWaiting );\r
- memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
- \r
- /* Increment the lock count so prvUnlockQueue knows to check for\r
- tasks waiting for space to become available on the queue. */\r
- ++( pxQueue->xRxLock );\r
- xReturn = pdPASS;\r
+ else\r
+ {\r
+ /* We are not removing the data, so reset our read\r
+ pointer. */\r
+ pxQueue->pcReadFrom = pcOriginalReadPosition;\r
+\r
+ /* The data is being left in the queue, so increment the\r
+ lock count so prvUnlockQueue knows to check for other\r
+ tasks waiting for the data to be available. */\r
+ ++( pxQueue->xTxLock ); \r
+ }\r
+ \r
+ xReturn = pdPASS; \r
}\r
else\r
{\r
}\r
/*-----------------------------------------------------------*/\r
\r
-signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken )\r
+signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, const void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken )\r
{\r
signed portBASE_TYPE xReturn;\r
\r
/* We cannot block from an ISR, so check there is data available. */\r
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )\r
{\r
- /* Copy the data from the queue. */\r
- pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
- if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
- {\r
- pxQueue->pcReadFrom = pxQueue->pcHead;\r
- }\r
+ prvCopyDataFromQueue( pxQueue, pvBuffer );\r
--( pxQueue->uxMessagesWaiting );\r
- memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
\r
/* If the queue is locked we will not modify the event list. Instead\r
we update the lock count so the task that unlocks the queue will know\r
}\r
/*-----------------------------------------------------------*/\r
\r
-unsigned portBASE_TYPE uxQueueMessagesWaiting( xQueueHandle pxQueue )\r
+unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle pxQueue )\r
{\r
unsigned portBASE_TYPE uxReturn;\r
\r
}\r
/*-----------------------------------------------------------*/\r
\r
+static void prvCopyDataToQueue( xQUEUE *pxQueue, const void *pvItemToQueue, portBASE_TYPE xPosition )\r
+{\r
+ if( pxQueue->uxItemSize == 0 )\r
+ {\r
+ #if ( configUSE_MUTEXES == 1 )\r
+ {\r
+ if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )\r
+ {\r
+ /* The mutex is no longer being held. */\r
+ vTaskPriorityDisinherit( ( void * const ) pxQueue->pxMutexHolder );\r
+ pxQueue->pxMutexHolder = NULL;\r
+ }\r
+ }\r
+ #endif\r
+ }\r
+ else if( xPosition == queueSEND_TO_BACK )\r
+ {\r
+ memcpy( ( void * ) pxQueue->pcWriteTo, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
+ pxQueue->pcWriteTo += pxQueue->uxItemSize;\r
+ if( pxQueue->pcWriteTo >= pxQueue->pcTail )\r
+ {\r
+ pxQueue->pcWriteTo = pxQueue->pcHead;\r
+ }\r
+ }\r
+ else\r
+ {\r
+ memcpy( ( void * ) pxQueue->pcReadFrom, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize );\r
+ pxQueue->pcReadFrom -= pxQueue->uxItemSize;\r
+ if( pxQueue->pcReadFrom < pxQueue->pcHead )\r
+ {\r
+ pxQueue->pcReadFrom = ( pxQueue->pcTail - pxQueue->uxItemSize );\r
+ } \r
+ }\r
+\r
+ ++( pxQueue->uxMessagesWaiting );\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+static void prvCopyDataFromQueue( xQUEUE * const pxQueue, const void *pvBuffer )\r
+{\r
+ if( pxQueue->uxQueueType != queueQUEUE_IS_MUTEX )\r
+ {\r
+ pxQueue->pcReadFrom += pxQueue->uxItemSize;\r
+ if( pxQueue->pcReadFrom >= pxQueue->pcTail )\r
+ {\r
+ pxQueue->pcReadFrom = pxQueue->pcHead;\r
+ }\r
+ memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );\r
+ } \r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
static void prvUnlockQueue( xQueueHandle pxQueue )\r
{\r
/* THIS FUNCTION MUST BE CALLED WITH THE SCHEDULER SUSPENDED. */\r
signed portBASE_TYPE xReturn;\r
\r
/* If the queue is already full we may have to block. A critical section\r
- is required to prevent an interrupt removing something from the queue \r
+ is required to prevent an interrupt removing something from the queue\r
between the check to see if the queue is full and blocking on the queue. */\r
portDISABLE_INTERRUPTS();\r
{\r
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
{\r
/* There is room in the queue, copy the data into the queue. */ \r
- prvCopyQueueData( pxQueue, pvItemToQueue ); \r
+ prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
xReturn = pdPASS;\r
\r
/* Were any co-routines waiting for data to become available? */\r
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )\r
{\r
- /* In this instance the co-routine could be placed directly \r
- into the ready list as we are within a critical section. \r
- Instead the same pending ready list mechansim is used as if\r
+ /* In this instance the co-routine could be placed directly\r
+ into the ready list as we are within a critical section.\r
+ Instead the same pending ready list mechanism is used as if\r
the event were caused from within an interrupt. */\r
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )\r
{\r
- /* The co-routine waiting has a higher priority so record \r
+ /* The co-routine waiting has a higher priority so record\r
that a yield might be appropriate. */\r
xReturn = errQUEUE_YIELD;\r
}\r
signed portBASE_TYPE xReturn;\r
\r
/* If the queue is already empty we may have to block. A critical section\r
- is required to prevent an interrupt adding something to the queue \r
+ is required to prevent an interrupt adding something to the queue\r
between the check to see if the queue is empty and blocking on the queue. */\r
portDISABLE_INTERRUPTS();\r
{\r
/* Were any co-routines waiting for space to become available? */\r
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )\r
{\r
- /* In this instance the co-routine could be placed directly \r
- into the ready list as we are within a critical section. \r
- Instead the same pending ready list mechansim is used as if\r
+ /* In this instance the co-routine could be placed directly\r
+ into the ready list as we are within a critical section.\r
+ Instead the same pending ready list mechanism is used as if\r
the event were caused from within an interrupt. */\r
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )\r
{\r
exit without doing anything. */\r
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )\r
{\r
- prvCopyQueueData( pxQueue, pvItemToQueue );\r
+ prvCopyDataToQueue( pxQueue, pvItemToQueue, queueSEND_TO_BACK );\r
\r
- /* We only want to wake one co-routine per ISR, so check that a \r
+ /* We only want to wake one co-routine per ISR, so check that a\r
co-routine has not already been woken. */\r
if( !xCoRoutinePreviouslyWoken ) \r
{\r
projects / freertos / blobdiff