queue.h

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*/


#ifndef QUEUE_H
#define QUEUE_H

#ifndef INC_FREERTOS_H
    #error "include FreeRTOS.h" must appear in source files before "include queue.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif


typedef void * QueueHandle_t;

typedef void * QueueSetHandle_t;

typedef void * QueueSetMemberHandle_t;

/* For internal use only. */
#define queueSEND_TO_BACK       ( ( BaseType_t ) 0 )
#define queueSEND_TO_FRONT      ( ( BaseType_t ) 1 )
#define queueOVERWRITE          ( ( BaseType_t ) 2 )

/* For internal use only.  These definitions *must* match those in queue.c. */
#define queueQUEUE_TYPE_BASE                ( ( uint8_t ) 0U )
#define queueQUEUE_TYPE_SET                 ( ( uint8_t ) 0U )
#define queueQUEUE_TYPE_MUTEX               ( ( uint8_t ) 1U )
#define queueQUEUE_TYPE_COUNTING_SEMAPHORE  ( ( uint8_t ) 2U )
#define queueQUEUE_TYPE_BINARY_SEMAPHORE    ( ( uint8_t ) 3U )
#define queueQUEUE_TYPE_RECURSIVE_MUTEX     ( ( uint8_t ) 4U )

#define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( uxQueueLength, uxItemSize, queueQUEUE_TYPE_BASE )

#define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )

#define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )

#define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )

#define xQueueOverwrite( xQueue, pvItemToQueue ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), 0, queueOVERWRITE )


BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;

#define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )

BaseType_t xQueuePeekFromISR( QueueHandle_t xQueue, void * const pvBuffer ) PRIVILEGED_FUNCTION;

#define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )


BaseType_t xQueueGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, const BaseType_t xJustPeek ) PRIVILEGED_FUNCTION;

UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;

UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;

void vQueueDelete( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;

#define xQueueSendToFrontFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )


#define xQueueSendToBackFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )

#define xQueueOverwriteFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueOVERWRITE )

#define xQueueSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )

BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

BaseType_t xQueueReceiveFromISR( QueueHandle_t xQueue, void * const pvBuffer, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

/*
 * Utilities to query queues that are safe to use from an ISR.  These utilities
 * should be used only from witin an ISR, or within a critical section.
 */
BaseType_t xQueueIsQueueEmptyFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
UBaseType_t uxQueueMessagesWaitingFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;


/*
 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
 * Likewise xQueueAltGenericReceive() is an alternative version of
 * xQueueGenericReceive().
 *
 * The source code that implements the alternative (Alt) API is much
 * simpler  because it executes everything from within a critical section.
 * This is  the approach taken by many other RTOSes, but FreeRTOS.org has the
 * preferred fully featured API too.  The fully featured API has more
 * complex  code that takes longer to execute, but makes much less use of
 * critical sections.  Therefore the alternative API sacrifices interrupt
 * responsiveness to gain execution speed, whereas the fully featured API
 * sacrifices execution speed to ensure better interrupt responsiveness.
 */
BaseType_t xQueueAltGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
BaseType_t xQueueAltGenericReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait, BaseType_t xJustPeeking ) PRIVILEGED_FUNCTION;
#define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
#define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
#define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
#define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )

/*
 * The functions defined above are for passing data to and from tasks.  The
 * functions below are the equivalents for passing data to and from
 * co-routines.
 *
 * These functions are called from the co-routine macro implementation and
 * should not be called directly from application code.  Instead use the macro
 * wrappers defined within croutine.h.
 */
BaseType_t xQueueCRSendFromISR( QueueHandle_t xQueue, const void *pvItemToQueue, BaseType_t xCoRoutinePreviouslyWoken );
BaseType_t xQueueCRReceiveFromISR( QueueHandle_t xQueue, void *pvBuffer, BaseType_t *pxTaskWoken );
BaseType_t xQueueCRSend( QueueHandle_t xQueue, const void *pvItemToQueue, TickType_t xTicksToWait );
BaseType_t xQueueCRReceive( QueueHandle_t xQueue, void *pvBuffer, TickType_t xTicksToWait );

/*
 * For internal use only.  Use xSemaphoreCreateMutex(),
 * xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
 * these functions directly.
 */
QueueHandle_t xQueueCreateMutex( const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
QueueHandle_t xQueueCreateCountingSemaphore( const UBaseType_t uxMaxCount, const UBaseType_t uxInitialCount ) PRIVILEGED_FUNCTION;
void* xQueueGetMutexHolder( QueueHandle_t xSemaphore ) PRIVILEGED_FUNCTION;

/*
 * For internal use only.  Use xSemaphoreTakeMutexRecursive() or
 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
 */
BaseType_t xQueueTakeMutexRecursive( QueueHandle_t xMutex, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
BaseType_t xQueueGiveMutexRecursive( QueueHandle_t pxMutex ) PRIVILEGED_FUNCTION;

/*
 * Reset a queue back to its original empty state.  The return value is now
 * obsolete and is always set to pdPASS.
 */
#define xQueueReset( xQueue ) xQueueGenericReset( xQueue, pdFALSE )

/*
 * The registry is provided as a means for kernel aware debuggers to
 * locate queues, semaphores and mutexes.  Call vQueueAddToRegistry() add
 * a queue, semaphore or mutex handle to the registry if you want the handle
 * to be available to a kernel aware debugger.  If you are not using a kernel
 * aware debugger then this function can be ignored.
 *
 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
 * registry can hold.  configQUEUE_REGISTRY_SIZE must be greater than 0
 * within FreeRTOSConfig.h for the registry to be available.  Its value
 * does not effect the number of queues, semaphores and mutexes that can be
 * created - just the number that the registry can hold.
 *
 * @param xQueue The handle of the queue being added to the registry.  This
 * is the handle returned by a call to xQueueCreate().  Semaphore and mutex
 * handles can also be passed in here.
 *
 * @param pcName The name to be associated with the handle.  This is the
 * name that the kernel aware debugger will display.  The queue registry only
 * stores a pointer to the string - so the string must be persistent (global or
 * preferably in ROM/Flash), not on the stack.
 */
#if configQUEUE_REGISTRY_SIZE > 0
    void vQueueAddToRegistry( QueueHandle_t xQueue, const char *pcName ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
#endif

/*
 * The registry is provided as a means for kernel aware debuggers to
 * locate queues, semaphores and mutexes.  Call vQueueAddToRegistry() add
 * a queue, semaphore or mutex handle to the registry if you want the handle
 * to be available to a kernel aware debugger, and vQueueUnregisterQueue() to
 * remove the queue, semaphore or mutex from the register.  If you are not using
 * a kernel aware debugger then this function can be ignored.
 *
 * @param xQueue The handle of the queue being removed from the registry.
 */
#if configQUEUE_REGISTRY_SIZE > 0
    void vQueueUnregisterQueue( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
#endif

/*
 * Generic version of the queue creation function, which is in turn called by
 * any queue, semaphore or mutex creation function or macro.
 */
QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength, const UBaseType_t uxItemSize, const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;

/*
 * Queue sets provide a mechanism to allow a task to block (pend) on a read
 * operation from multiple queues or semaphores simultaneously.
 *
 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
 * function.
 *
 * A queue set must be explicitly created using a call to xQueueCreateSet()
 * before it can be used.  Once created, standard FreeRTOS queues and semaphores
 * can be added to the set using calls to xQueueAddToSet().
 * xQueueSelectFromSet() is then used to determine which, if any, of the queues
 * or semaphores contained in the set is in a state where a queue read or
 * semaphore take operation would be successful.
 *
 * Note 1:  See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
 * for reasons why queue sets are very rarely needed in practice as there are
 * simpler methods of blocking on multiple objects.
 *
 * Note 2:  Blocking on a queue set that contains a mutex will not cause the
 * mutex holder to inherit the priority of the blocked task.
 *
 * Note 3:  An additional 4 bytes of RAM is required for each space in a every
 * queue added to a queue set.  Therefore counting semaphores that have a high
 * maximum count value should not be added to a queue set.
 *
 * Note 4:  A receive (in the case of a queue) or take (in the case of a
 * semaphore) operation must not be performed on a member of a queue set unless
 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
 *
 * @param uxEventQueueLength Queue sets store events that occur on
 * the queues and semaphores contained in the set.  uxEventQueueLength specifies
 * the maximum number of events that can be queued at once.  To be absolutely
 * certain that events are not lost uxEventQueueLength should be set to the
 * total sum of the length of the queues added to the set, where binary
 * semaphores and mutexes have a length of 1, and counting semaphores have a
 * length set by their maximum count value.  Examples:
 *  + If a queue set is to hold a queue of length 5, another queue of length 12,
 *    and a binary semaphore, then uxEventQueueLength should be set to
 *    (5 + 12 + 1), or 18.
 *  + If a queue set is to hold three binary semaphores then uxEventQueueLength
 *    should be set to (1 + 1 + 1 ), or 3.
 *  + If a queue set is to hold a counting semaphore that has a maximum count of
 *    5, and a counting semaphore that has a maximum count of 3, then
 *    uxEventQueueLength should be set to (5 + 3), or 8.
 *
 * @return If the queue set is created successfully then a handle to the created
 * queue set is returned.  Otherwise NULL is returned.
 */
QueueSetHandle_t xQueueCreateSet( const UBaseType_t uxEventQueueLength ) PRIVILEGED_FUNCTION;

/*
 * Adds a queue or semaphore to a queue set that was previously created by a
 * call to xQueueCreateSet().
 *
 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
 * function.
 *
 * Note 1:  A receive (in the case of a queue) or take (in the case of a
 * semaphore) operation must not be performed on a member of a queue set unless
 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
 *
 * @param xQueueOrSemaphore The handle of the queue or semaphore being added to
 * the queue set (cast to an QueueSetMemberHandle_t type).
 *
 * @param xQueueSet The handle of the queue set to which the queue or semaphore
 * is being added.
 *
 * @return If the queue or semaphore was successfully added to the queue set
 * then pdPASS is returned.  If the queue could not be successfully added to the
 * queue set because it is already a member of a different queue set then pdFAIL
 * is returned.
 */
BaseType_t xQueueAddToSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;

/*
 * Removes a queue or semaphore from a queue set.  A queue or semaphore can only
 * be removed from a set if the queue or semaphore is empty.
 *
 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
 * function.
 *
 * @param xQueueOrSemaphore The handle of the queue or semaphore being removed
 * from the queue set (cast to an QueueSetMemberHandle_t type).
 *
 * @param xQueueSet The handle of the queue set in which the queue or semaphore
 * is included.
 *
 * @return If the queue or semaphore was successfully removed from the queue set
 * then pdPASS is returned.  If the queue was not in the queue set, or the
 * queue (or semaphore) was not empty, then pdFAIL is returned.
 */
BaseType_t xQueueRemoveFromSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;

/*
 * xQueueSelectFromSet() selects from the members of a queue set a queue or
 * semaphore that either contains data (in the case of a queue) or is available
 * to take (in the case of a semaphore).  xQueueSelectFromSet() effectively
 * allows a task to block (pend) on a read operation on all the queues and
 * semaphores in a queue set simultaneously.
 *
 * See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
 * function.
 *
 * Note 1:  See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
 * for reasons why queue sets are very rarely needed in practice as there are
 * simpler methods of blocking on multiple objects.
 *
 * Note 2:  Blocking on a queue set that contains a mutex will not cause the
 * mutex holder to inherit the priority of the blocked task.
 *
 * Note 3:  A receive (in the case of a queue) or take (in the case of a
 * semaphore) operation must not be performed on a member of a queue set unless
 * a call to xQueueSelectFromSet() has first returned a handle to that set member.
 *
 * @param xQueueSet The queue set on which the task will (potentially) block.
 *
 * @param xTicksToWait The maximum time, in ticks, that the calling task will
 * remain in the Blocked state (with other tasks executing) to wait for a member
 * of the queue set to be ready for a successful queue read or semaphore take
 * operation.
 *
 * @return xQueueSelectFromSet() will return the handle of a queue (cast to
 * a QueueSetMemberHandle_t type) contained in the queue set that contains data,
 * or the handle of a semaphore (cast to a QueueSetMemberHandle_t type) contained
 * in the queue set that is available, or NULL if no such queue or semaphore
 * exists before before the specified block time expires.
 */
QueueSetMemberHandle_t xQueueSelectFromSet( QueueSetHandle_t xQueueSet, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

/*
 * A version of xQueueSelectFromSet() that can be used from an ISR.
 */
QueueSetMemberHandle_t xQueueSelectFromSetFromISR( QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;

/* Not public API functions. */
void vQueueWaitForMessageRestricted( QueueHandle_t xQueue, TickType_t xTicksToWait, const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
BaseType_t xQueueGenericReset( QueueHandle_t xQueue, BaseType_t xNewQueue ) PRIVILEGED_FUNCTION;
void vQueueSetQueueNumber( QueueHandle_t xQueue, UBaseType_t uxQueueNumber ) PRIVILEGED_FUNCTION;
UBaseType_t uxQueueGetQueueNumber( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
uint8_t ucQueueGetQueueType( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;


#ifdef __cplusplus
}
#endif

#endif /* QUEUE_H */