queue.h

ARM7(LPC2131) + FreeRTOS, 基于 Codesourcery gcc, 共10个任务, 仅占 2k RAM

        // the return value back into cTaskWokenByPost so xQueueSendFromISR
        // knows not to wake any task the next iteration of the loop.
        xTaskWokenByPost = xQueueSendToFrontFromISR( xRxQueue, &cIn, cTaskWokenByPost );

    } while( portINPUT_BYTE( BUFFER_COUNT ) );

    // Now the buffer is empty we can switch context if necessary.
    if( cTaskWokenByPost )
    {
        taskYIELD ();
    }
 }
 </pre>
 *
 * \defgroup xQueueSendFromISR xQueueSendFromISR
 * \ingroup QueueManagement
 */
#define xQueueSendToFrontFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken, queueSEND_TO_FRONT )


/**
 * queue. h
 * <pre>
 portBASE_TYPE xQueueSendToBackFromISR(
                                         xQueueHandle pxQueue,
                                         const void *pvItemToQueue,
                                         portBASE_TYPE xTaskPreviouslyWoken
                                      );
 </pre>
 *
 * This is a macro that calls xQueueGenericSendFromISR().
 *
 * Post an item to the back of a queue.  It is safe to use this macro from
 * within an interrupt service routine.
 *
 * Items are queued by copy not reference so it is preferable to only
 * queue small items, especially when called from an ISR.  In most cases
 * it would be preferable to store a pointer to the item being queued.
 *
 * @param xQueue The handle to the queue on which the item is to be posted.
 *
 * @param pvItemToQueue A pointer to the item that is to be placed on the
 * queue.  The size of the items the queue will hold was defined when the
 * queue was created, so this many bytes will be copied from pvItemToQueue
 * into the queue storage area.
 *
 * @param cTaskPreviouslyWoken This is included so an ISR can post onto
 * the same queue multiple times from a single interrupt.  The first call
 * should always pass in pdFALSE.  Subsequent calls should pass in
 * the value returned from the previous call.  See the file serial .c in the
 * PC port for a good example of this mechanism.
 *
 * @return pdTRUE if a task was woken by posting onto the queue.  This is
 * used by the ISR to determine if a context switch may be required following
 * the ISR.
 *
 * Example usage for buffered IO (where the ISR can obtain more than one value
 * per call):
   <pre>
 void vBufferISR( void )
 {
 portCHAR cIn;
 portBASE_TYPE xTaskWokenByPost;

    // We have not woken a task at the start of the ISR.
    cTaskWokenByPost = pdFALSE;

    // Loop until the buffer is empty.
    do
    {
        // Obtain a byte from the buffer.
        cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );						

        // Post the byte.  The first time round the loop cTaskWokenByPost
        // will be pdFALSE.  If the queue send causes a task to wake we do
        // not want the task to run until we have finished the ISR, so
        // xQueueSendFromISR does not cause a context switch.  Also we
        // don't want subsequent posts to wake any other tasks, so we store
        // the return value back into cTaskWokenByPost so xQueueSendFromISR
        // knows not to wake any task the next iteration of the loop.
        xTaskWokenByPost = xQueueSendToBackFromISR( xRxQueue, &cIn, cTaskWokenByPost );

    } while( portINPUT_BYTE( BUFFER_COUNT ) );

    // Now the buffer is empty we can switch context if necessary.
    if( cTaskWokenByPost )
    {
        taskYIELD ();
    }
 }
 </pre>
 *
 * \defgroup xQueueSendFromISR xQueueSendFromISR
 * \ingroup QueueManagement
 */
#define xQueueSendToBackFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken, queueSEND_TO_BACK )


/**
 * queue. h
 * <pre>
 portBASE_TYPE xQueueSendFromISR(
                                     xQueueHandle pxQueue,
                                     const void *pvItemToQueue,
                                     portBASE_TYPE xTaskPreviouslyWoken
                                );
 </pre>
 *
 * This is a macro that calls xQueueGenericSendFromISR().  It is included
 * for backward compatibility with versions of FreeRTOS.org that did not
 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
 * macros.
 *
 * Post an item to the back of a queue.  It is safe to use this function from
 * within an interrupt service routine.
 *
 * Items are queued by copy not reference so it is preferable to only
 * queue small items, especially when called from an ISR.  In most cases
 * it would be preferable to store a pointer to the item being queued.
 *
 * @param xQueue The handle to the queue on which the item is to be posted.
 *
 * @param pvItemToQueue A pointer to the item that is to be placed on the
 * queue.  The size of the items the queue will hold was defined when the
 * queue was created, so this many bytes will be copied from pvItemToQueue
 * into the queue storage area.
 *
 * @param cTaskPreviouslyWoken This is included so an ISR can post onto
 * the same queue multiple times from a single interrupt.  The first call
 * should always pass in pdFALSE.  Subsequent calls should pass in
 * the value returned from the previous call.  See the file serial .c in the
 * PC port for a good example of this mechanism.
 *
 * @return pdTRUE if a task was woken by posting onto the queue.  This is
 * used by the ISR to determine if a context switch may be required following
 * the ISR.
 *
 * Example usage for buffered IO (where the ISR can obtain more than one value
 * per call):
   <pre>
 void vBufferISR( void )
 {
 portCHAR cIn;
 portBASE_TYPE xTaskWokenByPost;

    // We have not woken a task at the start of the ISR.
    cTaskWokenByPost = pdFALSE;

    // Loop until the buffer is empty.
    do
    {
        // Obtain a byte from the buffer.
        cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );						

        // Post the byte.  The first time round the loop cTaskWokenByPost
        // will be pdFALSE.  If the queue send causes a task to wake we do
        // not want the task to run until we have finished the ISR, so
        // xQueueSendFromISR does not cause a context switch.  Also we
        // don't want subsequent posts to wake any other tasks, so we store
        // the return value back into cTaskWokenByPost so xQueueSendFromISR
        // knows not to wake any task the next iteration of the loop.
        xTaskWokenByPost = xQueueSendFromISR( xRxQueue, &cIn, cTaskWokenByPost );

    } while( portINPUT_BYTE( BUFFER_COUNT ) );

    // Now the buffer is empty we can switch context if necessary.
    if( cTaskWokenByPost )
    {
        taskYIELD ();
    }
 }
 </pre>
 *
 * \defgroup xQueueSendFromISR xQueueSendFromISR
 * \ingroup QueueManagement
 */
#define xQueueSendFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken ) xQueueGenericSendFromISR( pxQueue, pvItemToQueue, xTaskPreviouslyWoken, queueSEND_TO_BACK )

/**
 * queue. h
 * <pre>
 portBASE_TYPE xQueueGenericSendFromISR(
                                           xQueueHandle pxQueue,
                                           const void *pvItemToQueue,
                                           portBASE_TYPE xTaskPreviouslyWoken
										   portBASE_TYPE xCopyPosition
                                       );
 </pre>
 *
 * It is preferred that the macros xQueueSendFromISR(),
 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
 * of calling this function directly.
 *
 * Post an item on a queue.  It is safe to use this function from within an
 * interrupt service routine.
 *
 * Items are queued by copy not reference so it is preferable to only
 * queue small items, especially when called from an ISR.  In most cases
 * it would be preferable to store a pointer to the item being queued.
 *
 * @param xQueue The handle to the queue on which the item is to be posted.
 *
 * @param pvItemToQueue A pointer to the item that is to be placed on the
 * queue.  The size of the items the queue will hold was defined when the
 * queue was created, so this many bytes will be copied from pvItemToQueue
 * into the queue storage area.
 *
 * @param cTaskPreviouslyWoken This is included so an ISR can post onto
 * the same queue multiple times from a single interrupt.  The first call
 * should always pass in pdFALSE.  Subsequent calls should pass in
 * the value returned from the previous call.  See the file serial .c in the
 * PC port for a good example of this mechanism.
 *
 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
 * at the front of the queue (for high priority messages).
 *
 * @return pdTRUE if a task was woken by posting onto the queue.  This is
 * used by the ISR to determine if a context switch may be required following
 * the ISR.
 *
 * Example usage for buffered IO (where the ISR can obtain more than one value
 * per call):
   <pre>
 void vBufferISR( void )
 {
 portCHAR cIn;
 portBASE_TYPE xTaskWokenByPost;

    // We have not woken a task at the start of the ISR.
    cTaskWokenByPost = pdFALSE;

    // Loop until the buffer is empty.
    do
    {
        // Obtain a byte from the buffer.
        cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );						

        // Post the byte.  The first time round the loop cTaskWokenByPost
        // will be pdFALSE.  If the queue send causes a task to wake we do
        // not want the task to run until we have finished the ISR, so
        // xQueueSendFromISR does not cause a context switch.  Also we
        // don't want subsequent posts to wake any other tasks, so we store
        // the return value back into cTaskWokenByPost so xQueueSendFromISR
        // knows not to wake any task the next iteration of the loop.
        xTaskWokenByPost = xQueueGenericSendFromISR( xRxQueue, &cIn, cTaskWokenByPost, queueSEND_TO_BACK );

    } while( portINPUT_BYTE( BUFFER_COUNT ) );

    // Now the buffer is empty we can switch context if necessary.
    if( cTaskWokenByPost )
    {
        taskYIELD ();
    }
 }
 </pre>
 *
 * \defgroup xQueueSendFromISR xQueueSendFromISR
 * \ingroup QueueManagement
 */
signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken, portBASE_TYPE xCopyPosition );

/**
 * queue. h
 * <pre>
 portBASE_TYPE xQueueReceiveFromISR(
                                       xQueueHandle pxQueue,
                                       void *pvBuffer,
                                       portBASE_TYPE *pxTaskWoken
                                   );
 * </pre>
 *
 * Receive an item from a queue.  It is safe to use this function from within an
 * interrupt service routine.
 *
 * @param pxQueue The handle to the queue from which the item is to be
 * received.
 *
 * @param pvBuffer Pointer to the buffer into which the received item will
 * be copied.
 *
 * @param pxTaskWoken A task may be blocked waiting for space to become
 * available on the queue.  If xQueueReceiveFromISR causes such a task to
 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
 * remain unchanged.
 *
 * @return pdTRUE if an item was successfully received from the queue,
 * otherwise pdFALSE.
 *
 * Example usage:
   <pre>

 xQueueHandle xQueue;

 // Function to create a queue and post some values.
 void vAFunction( void *pvParameters )
 {
 portCHAR cValueToPost;
 const portTickType xBlockTime = ( portTickType )0xff;

    // Create a queue capable of containing 10 characters.
    xQueue = xQueueCreate( 10, sizeof( portCHAR ) );
    if( xQueue == 0 )
    {
        // Failed to create the queue.
    }

    // ...

    // Post some characters that will be used within an ISR.  If the queue
    // is full then this task will block for xBlockTime ticks.
    cValueToPost = 'a';
    xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
    cValueToPost = 'b';
    xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );

    // ... keep posting characters ... this task may block when the queue
    // becomes full.

    cValueToPost = 'c';
    xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
 }

 // ISR that outputs all the characters received on the queue.
 void vISR_Routine( void )
 {
 portBASE_TYPE xTaskWokenByReceive = pdFALSE;
 portCHAR cRxedChar;

    while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
    {
        // A character was received.  Output the character now.
        vOutputCharacter( cRxedChar );

        // If removing the character from the queue woke the task that was
        // posting onto the queue cTaskWokenByReceive will have been set to
        // pdTRUE.  No matter how many times this loop iterates only one
        // task will be woken.
    }

    if( cTaskWokenByPost != ( portCHAR ) pdFALSE;
    {
        taskYIELD ();
    }
 }
 </pre>
 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
 * \ingroup QueueManagement
 */
signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, const void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken );

/* 
 * 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.
 */
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 );
#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.
 */
signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );
signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );
signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );

/*
 * For internal use only.  Use xSemaphoreCreateMutex() or
 * xSemaphoreCreateCounting() instead of calling these functions directly.
 */
xQueueHandle xQueueCreateMutex( void );
xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );

/*
 * For internal use only.  Use xSemaphoreTakeMutexRecursive() or
 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
 */
portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle xMutex, portTickType xBlockTime );
portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle xMutex );

#ifdef __cplusplus
}
#endif

#endif /* QUEUE_H */