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931 lines
32 KiB
C
931 lines
32 KiB
C
/*
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FreeRTOS.org V4.3.1 - Copyright (C) 2003-2007 Richard Barry.
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This file is part of the FreeRTOS.org distribution.
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FreeRTOS.org is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FreeRTOS.org is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FreeRTOS.org; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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A special exception to the GPL can be applied should you wish to distribute
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a combined work that includes FreeRTOS.org, without being obliged to provide
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the source code for any proprietary components. See the licensing section
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of http://www.FreeRTOS.org for full details of how and when the exception
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can be applied.
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***************************************************************************
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See http://www.FreeRTOS.org for documentation, latest information, license
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and contact details. Please ensure to read the configuration and relevant
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port sections of the online documentation.
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Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along
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with commercial development and support options.
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***************************************************************************
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*/
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/*
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Changes from V1.01
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+ More use of 8bit data types.
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+ Function name prefixes changed where the data type returned has changed.
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Changed from V2.0.0
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+ Added the queue locking mechanism and make more use of the scheduler
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suspension feature to minimise the time interrupts have to be disabled
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when accessing a queue.
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Changed from V2.2.0
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+ Explicit use of 'signed' qualifier on portCHAR types added.
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Changes from V3.0.0
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+ API changes as described on the FreeRTOS.org WEB site.
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Changes from V3.2.3
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+ Added the queue functions that can be used from co-routines.
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Changes from V4.0.5
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+ Added a loop within xQueueSend() and xQueueReceive() to prevent the
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functions exiting when a block time remains and the function has
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not completed.
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Changes from V4.1.2:
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+ BUG FIX: Removed the call to prvIsQueueEmpty from within xQueueCRReceive
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as it exited with interrupts enabled. Thanks Paul Katz.
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Changes from V4.1.3:
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+ Modified xQueueSend() and xQueueReceive() to handle the (very unlikely)
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case whereby a task unblocking due to a temporal event can remove/send an
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item from/to a queue when a higher priority task is still blocked on the
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queue. This modification is a result of the SafeRTOS testing.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include "FreeRTOS.h"
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#include "task.h"
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#include "croutine.h"
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/*-----------------------------------------------------------
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* PUBLIC LIST API documented in list.h
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*----------------------------------------------------------*/
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/* Constants used with the cRxLock and cTxLock structure members. */
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#define queueUNLOCKED ( ( signed portBASE_TYPE ) -1 )
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#define queueERRONEOUS_UNBLOCK ( -1 )
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/*
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* Definition of the queue used by the scheduler.
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* Items are queued by copy, not reference.
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*/
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typedef struct QueueDefinition
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{
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signed portCHAR *pcHead; /*< Points to the beginning of the queue storage area. */
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signed portCHAR *pcTail; /*< Points to the byte at the end of the queue storage area. Once more byte is allocated than necessary to store the queue items, this is used as a marker. */
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signed portCHAR *pcWriteTo; /*< Points to the free next place in the storage area. */
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signed portCHAR *pcReadFrom; /*< Points to the last place that a queued item was read from. */
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xList xTasksWaitingToSend; /*< List of tasks that are blocked waiting to post onto this queue. Stored in priority order. */
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xList xTasksWaitingToReceive; /*< List of tasks that are blocked waiting to read from this queue. Stored in priority order. */
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unsigned portBASE_TYPE uxMessagesWaiting;/*< The number of items currently in the queue. */
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unsigned portBASE_TYPE uxLength; /*< The length of the queue defined as the number of items it will hold, not the number of bytes. */
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unsigned portBASE_TYPE uxItemSize; /*< The size of each items that the queue will hold. */
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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. */
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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. */
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} xQUEUE;
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/*-----------------------------------------------------------*/
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/*
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* Inside this file xQueueHandle is a pointer to a xQUEUE structure.
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* To keep the definition private the API header file defines it as a
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* pointer to void.
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*/
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typedef xQUEUE * xQueueHandle;
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/*
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* Prototypes for public functions are included here so we don't have to
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* include the API header file (as it defines xQueueHandle differently). These
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* functions are documented in the API header file.
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*/
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xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize );
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signed portBASE_TYPE xQueueSend( xQueueHandle xQueue, const void * pvItemToQueue, portTickType xTicksToWait );
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unsigned portBASE_TYPE uxQueueMessagesWaiting( xQueueHandle pxQueue );
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void vQueueDelete( xQueueHandle xQueue );
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signed portBASE_TYPE xQueueSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken );
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signed portBASE_TYPE xQueueReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );
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signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
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#if configUSE_CO_ROUTINES == 1
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signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );
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signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
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signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );
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signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );
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#endif
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/*
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* Unlocks a queue locked by a call to prvLockQueue. Locking a queue does not
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* prevent an ISR from adding or removing items to the queue, but does prevent
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* an ISR from removing tasks from the queue event lists. If an ISR finds a
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* queue is locked it will instead increment the appropriate queue lock count
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* to indicate that a task may require unblocking. When the queue in unlocked
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* these lock counts are inspected, and the appropriate action taken.
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*/
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static void prvUnlockQueue( xQueueHandle pxQueue );
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/*
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* Uses a critical section to determine if there is any data in a queue.
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*
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* @return pdTRUE if the queue contains no items, otherwise pdFALSE.
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*/
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static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue );
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/*
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* Uses a critical section to determine if there is any space in a queue.
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*
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* @return pdTRUE if there is no space, otherwise pdFALSE;
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*/
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static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue );
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/*
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* Macro that copies an item into the queue. This is done by copying the item
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* byte for byte, not by reference. Updates the queue state to ensure it's
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* integrity after the copy.
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*/
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#define prvCopyQueueData( pxQueue, pvItemToQueue ) \
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{ \
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memcpy( ( void * ) pxQueue->pcWriteTo, pvItemToQueue, ( unsigned ) pxQueue->uxItemSize ); \
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++( pxQueue->uxMessagesWaiting ); \
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pxQueue->pcWriteTo += pxQueue->uxItemSize; \
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if( pxQueue->pcWriteTo >= pxQueue->pcTail ) \
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{ \
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pxQueue->pcWriteTo = pxQueue->pcHead; \
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} \
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}
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/*-----------------------------------------------------------*/
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/*
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* Macro to mark a queue as locked. Locking a queue prevents an ISR from
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* accessing the queue event lists.
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*/
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#define prvLockQueue( pxQueue ) \
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{ \
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taskENTER_CRITICAL(); \
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++( pxQueue->xRxLock ); \
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++( pxQueue->xTxLock ); \
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taskEXIT_CRITICAL(); \
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}
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/*-----------------------------------------------------------*/
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/*-----------------------------------------------------------
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* PUBLIC QUEUE MANAGEMENT API documented in queue.h
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*----------------------------------------------------------*/
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xQueueHandle xQueueCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize )
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{
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xQUEUE *pxNewQueue;
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size_t xQueueSizeInBytes;
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/* Allocate the new queue structure. */
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if( uxQueueLength > ( unsigned portBASE_TYPE ) 0 )
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{
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pxNewQueue = ( xQUEUE * ) pvPortMalloc( sizeof( xQUEUE ) );
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if( pxNewQueue != NULL )
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{
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/* Create the list of pointers to queue items. The queue is one byte
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longer than asked for to make wrap checking easier/faster. */
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xQueueSizeInBytes = ( size_t ) ( uxQueueLength * uxItemSize ) + ( size_t ) 1;
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pxNewQueue->pcHead = ( signed portCHAR * ) pvPortMalloc( xQueueSizeInBytes );
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if( pxNewQueue->pcHead != NULL )
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{
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/* Initialise the queue members as described above where the
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queue type is defined. */
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pxNewQueue->pcTail = pxNewQueue->pcHead + ( uxQueueLength * uxItemSize );
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pxNewQueue->uxMessagesWaiting = 0;
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pxNewQueue->pcWriteTo = pxNewQueue->pcHead;
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pxNewQueue->pcReadFrom = pxNewQueue->pcHead + ( ( uxQueueLength - 1 ) * uxItemSize );
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pxNewQueue->uxLength = uxQueueLength;
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pxNewQueue->uxItemSize = uxItemSize;
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pxNewQueue->xRxLock = queueUNLOCKED;
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pxNewQueue->xTxLock = queueUNLOCKED;
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/* Likewise ensure the event queues start with the correct state. */
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vListInitialise( &( pxNewQueue->xTasksWaitingToSend ) );
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vListInitialise( &( pxNewQueue->xTasksWaitingToReceive ) );
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return pxNewQueue;
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}
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else
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{
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vPortFree( pxNewQueue );
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}
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}
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}
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/* Will only reach here if we could not allocate enough memory or no memory
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was required. */
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return NULL;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xQueueSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait )
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{
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signed portBASE_TYPE xReturn = pdPASS;
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xTimeOutType xTimeOut;
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/* Make sure other tasks do not access the queue. */
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vTaskSuspendAll();
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/* Capture the current time status for future reference. */
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vTaskSetTimeOutState( &xTimeOut );
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/* It is important that this is the only thread/ISR that modifies the
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ready or delayed lists until xTaskResumeAll() is called. Places where
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the ready/delayed lists are modified include:
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+ vTaskDelay() - Nothing can call vTaskDelay as the scheduler is
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suspended, vTaskDelay() cannot be called from an ISR.
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+ vTaskPrioritySet() - Has a critical section around the access.
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+ vTaskSwitchContext() - This will not get executed while the scheduler
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is suspended.
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+ prvCheckDelayedTasks() - This will not get executed while the
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scheduler is suspended.
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+ xTaskCreate() - Has a critical section around the access.
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+ vTaskResume() - Has a critical section around the access.
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+ xTaskResumeAll() - Has a critical section around the access.
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+ xTaskRemoveFromEventList - Checks to see if the scheduler is
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suspended. If so then the TCB being removed from the event is
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removed from the event and added to the xPendingReadyList.
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*/
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/* Make sure interrupts do not access the queue event list. */
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prvLockQueue( pxQueue );
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/* It is important that interrupts to not access the event list of the
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queue being modified here. Places where the event list is modified
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include:
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+ xQueueSendFromISR(). This checks the lock on the queue to see if
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it has access. If the queue is locked then the Tx lock count is
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incremented to signify that a task waiting for data can be made ready
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once the queue lock is removed. If the queue is not locked then
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a task can be moved from the event list, but will not be removed
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from the delayed list or placed in the ready list until the scheduler
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is unlocked.
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+ xQueueReceiveFromISR(). As per xQueueSendFromISR().
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*/
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/* If the queue is already full we may have to block. */
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do
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{
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if( prvIsQueueFull( pxQueue ) )
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{
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/* The queue is full - do we want to block or just leave without
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posting? */
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if( xTicksToWait > ( portTickType ) 0 )
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{
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/* We are going to place ourselves on the xTasksWaitingToSend event
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list, and will get woken should the delay expire, or space become
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available on the queue.
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As detailed above we do not require mutual exclusion on the event
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list as nothing else can modify it or the ready lists while we
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have the scheduler suspended and queue locked.
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It is possible that an ISR has removed data from the queue since we
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checked if any was available. If this is the case then the data
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will have been copied from the queue, and the queue variables
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updated, but the event list will not yet have been checked to see if
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anything is waiting as the queue is locked. */
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vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );
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/* Force a context switch now as we are blocked. We can do
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this from within a critical section as the task we are
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switching to has its own context. When we return here (i.e. we
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unblock) we will leave the critical section as normal.
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It is possible that an ISR has caused an event on an unrelated and
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unlocked queue. If this was the case then the event list for that
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queue will have been updated but the ready lists left unchanged -
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instead the readied task will have been added to the pending ready
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list. */
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taskENTER_CRITICAL();
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{
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/* We can safely unlock the queue and scheduler here as
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interrupts are disabled. We must not yield with anything
|
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locked, but we can yield from within a critical section.
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Tasks that have been placed on the pending ready list cannot
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be tasks that are waiting for events on this queue. See
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in comment xTaskRemoveFromEventList(). */
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prvUnlockQueue( pxQueue );
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/* Resuming the scheduler may cause a yield. If so then there
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is no point yielding again here. */
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if( !xTaskResumeAll() )
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{
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taskYIELD();
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}
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/* We want to check to see if the queue is still full
|
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before leaving the critical section. This is to prevent
|
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this task placing an item into the queue due to an
|
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interrupt making space on the queue between critical
|
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sections (when there might be a higher priority task
|
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blocked on the queue that cannot run yet because the
|
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scheduler gets suspended). */
|
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if( pxQueue->uxMessagesWaiting == pxQueue->uxLength )
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{
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/* We unblocked but there is no space in the queue,
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we probably timed out. */
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xReturn = errQUEUE_FULL;
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}
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/* Before leaving the critical section we have to ensure
|
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exclusive access again. */
|
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vTaskSuspendAll();
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prvLockQueue( pxQueue );
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}
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taskEXIT_CRITICAL();
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}
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}
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/* If xReturn is errQUEUE_FULL then we unblocked when the queue
|
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was still full. Don't check it again now as it is possible that
|
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an interrupt has removed an item from the queue since we left the
|
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critical section and we don't want to write to the queue in case
|
|
there is a task of higher priority blocked waiting for space to
|
|
be available on the queue. If this is the case the higher priority
|
|
task will execute when the scheduler is unsupended. */
|
|
if( xReturn != errQUEUE_FULL )
|
|
{
|
|
/* When we are here it is possible that we unblocked as space became
|
|
available on the queue. It is also possible that an ISR posted to the
|
|
queue since we left the critical section, so it may be that again there
|
|
is no space. This would only happen if a task and ISR post onto the
|
|
same queue. */
|
|
taskENTER_CRITICAL();
|
|
{
|
|
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
|
|
{
|
|
/* There is room in the queue, copy the data into the queue. */
|
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prvCopyQueueData( pxQueue, pvItemToQueue );
|
|
xReturn = pdPASS;
|
|
|
|
/* Update the TxLock count so prvUnlockQueue knows to check for
|
|
tasks waiting for data to become available in the queue. */
|
|
++( pxQueue->xTxLock );
|
|
}
|
|
else
|
|
{
|
|
xReturn = errQUEUE_FULL;
|
|
}
|
|
}
|
|
taskEXIT_CRITICAL();
|
|
}
|
|
|
|
if( xReturn == errQUEUE_FULL )
|
|
{
|
|
if( xTicksToWait > 0 )
|
|
{
|
|
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
|
|
{
|
|
xReturn = queueERRONEOUS_UNBLOCK;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
while( xReturn == queueERRONEOUS_UNBLOCK );
|
|
|
|
prvUnlockQueue( pxQueue );
|
|
xTaskResumeAll();
|
|
|
|
return xReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
signed portBASE_TYPE xQueueSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken )
|
|
{
|
|
/* Similar to xQueueSend, except we don't block if there is no room in the
|
|
queue. Also we don't directly wake a task that was blocked on a queue
|
|
read, instead we return a flag to say whether a context switch is required
|
|
or not (i.e. has a task with a higher priority than us been woken by this
|
|
post). */
|
|
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
|
|
{
|
|
prvCopyQueueData( pxQueue, pvItemToQueue );
|
|
|
|
/* If the queue is locked we do not alter the event list. This will
|
|
be done when the queue is unlocked later. */
|
|
if( pxQueue->xTxLock == queueUNLOCKED )
|
|
{
|
|
/* We only want to wake one task per ISR, so check that a task has
|
|
not already been woken. */
|
|
if( !xTaskPreviouslyWoken )
|
|
{
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
|
|
{
|
|
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
|
|
{
|
|
/* The task waiting has a higher priority so record that a
|
|
context switch is required. */
|
|
return pdTRUE;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Increment the lock count so the task that unlocks the queue
|
|
knows that data was posted while it was locked. */
|
|
++( pxQueue->xTxLock );
|
|
}
|
|
}
|
|
|
|
return xTaskPreviouslyWoken;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
signed portBASE_TYPE xQueueReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait )
|
|
{
|
|
signed portBASE_TYPE xReturn = pdTRUE;
|
|
xTimeOutType xTimeOut;
|
|
|
|
/* This function is very similar to xQueueSend(). See comments within
|
|
xQueueSend() for a more detailed explanation.
|
|
|
|
Make sure other tasks do not access the queue. */
|
|
vTaskSuspendAll();
|
|
|
|
/* Capture the current time status for future reference. */
|
|
vTaskSetTimeOutState( &xTimeOut );
|
|
|
|
/* Make sure interrupts do not access the queue. */
|
|
prvLockQueue( pxQueue );
|
|
|
|
do
|
|
{
|
|
/* If there are no messages in the queue we may have to block. */
|
|
if( prvIsQueueEmpty( pxQueue ) )
|
|
{
|
|
/* There are no messages in the queue, do we want to block or just
|
|
leave with nothing? */
|
|
if( xTicksToWait > ( portTickType ) 0 )
|
|
{
|
|
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );
|
|
taskENTER_CRITICAL();
|
|
{
|
|
prvUnlockQueue( pxQueue );
|
|
if( !xTaskResumeAll() )
|
|
{
|
|
taskYIELD();
|
|
}
|
|
|
|
if( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
/* We unblocked but the queue is empty. We probably
|
|
timed out. */
|
|
xReturn = errQUEUE_EMPTY;
|
|
}
|
|
|
|
vTaskSuspendAll();
|
|
prvLockQueue( pxQueue );
|
|
}
|
|
taskEXIT_CRITICAL();
|
|
}
|
|
}
|
|
|
|
if( xReturn != errQUEUE_EMPTY )
|
|
{
|
|
taskENTER_CRITICAL();
|
|
{
|
|
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
pxQueue->pcReadFrom += pxQueue->uxItemSize;
|
|
if( pxQueue->pcReadFrom >= pxQueue->pcTail )
|
|
{
|
|
pxQueue->pcReadFrom = pxQueue->pcHead;
|
|
}
|
|
--( pxQueue->uxMessagesWaiting );
|
|
memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );
|
|
|
|
/* Increment the lock count so prvUnlockQueue knows to check for
|
|
tasks waiting for space to become available on the queue. */
|
|
++( pxQueue->xRxLock );
|
|
xReturn = pdPASS;
|
|
}
|
|
else
|
|
{
|
|
xReturn = errQUEUE_EMPTY;
|
|
}
|
|
}
|
|
taskEXIT_CRITICAL();
|
|
}
|
|
|
|
if( xReturn == errQUEUE_EMPTY )
|
|
{
|
|
if( xTicksToWait > 0 )
|
|
{
|
|
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
|
|
{
|
|
xReturn = queueERRONEOUS_UNBLOCK;
|
|
}
|
|
}
|
|
}
|
|
} while( xReturn == queueERRONEOUS_UNBLOCK );
|
|
|
|
/* We no longer require exclusive access to the queue. */
|
|
prvUnlockQueue( pxQueue );
|
|
xTaskResumeAll();
|
|
|
|
return xReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
/* We cannot block from an ISR, so check there is data available. */
|
|
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
/* Copy the data from the queue. */
|
|
pxQueue->pcReadFrom += pxQueue->uxItemSize;
|
|
if( pxQueue->pcReadFrom >= pxQueue->pcTail )
|
|
{
|
|
pxQueue->pcReadFrom = pxQueue->pcHead;
|
|
}
|
|
--( pxQueue->uxMessagesWaiting );
|
|
memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );
|
|
|
|
/* If the queue is locked we will not modify the event list. Instead
|
|
we update the lock count so the task that unlocks the queue will know
|
|
that an ISR has removed data while the queue was locked. */
|
|
if( pxQueue->xRxLock == queueUNLOCKED )
|
|
{
|
|
/* We only want to wake one task per ISR, so check that a task has
|
|
not already been woken. */
|
|
if( !( *pxTaskWoken ) )
|
|
{
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
|
|
{
|
|
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
|
|
{
|
|
/* The task waiting has a higher priority than us so
|
|
force a context switch. */
|
|
*pxTaskWoken = pdTRUE;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Increment the lock count so the task that unlocks the queue
|
|
knows that data was removed while it was locked. */
|
|
++( pxQueue->xRxLock );
|
|
}
|
|
|
|
xReturn = pdPASS;
|
|
}
|
|
else
|
|
{
|
|
xReturn = pdFAIL;
|
|
}
|
|
|
|
return xReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
unsigned portBASE_TYPE uxQueueMessagesWaiting( xQueueHandle pxQueue )
|
|
{
|
|
unsigned portBASE_TYPE uxReturn;
|
|
|
|
taskENTER_CRITICAL();
|
|
uxReturn = pxQueue->uxMessagesWaiting;
|
|
taskEXIT_CRITICAL();
|
|
|
|
return uxReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vQueueDelete( xQueueHandle pxQueue )
|
|
{
|
|
vPortFree( pxQueue->pcHead );
|
|
vPortFree( pxQueue );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvUnlockQueue( xQueueHandle pxQueue )
|
|
{
|
|
/* THIS FUNCTION MUST BE CALLED WITH THE SCHEDULER SUSPENDED. */
|
|
|
|
/* The lock counts contains the number of extra data items placed or
|
|
removed from the queue while the queue was locked. When a queue is
|
|
locked items can be added or removed, but the event lists cannot be
|
|
updated. */
|
|
taskENTER_CRITICAL();
|
|
{
|
|
--( pxQueue->xTxLock );
|
|
|
|
/* See if data was added to the queue while it was locked. */
|
|
if( pxQueue->xTxLock > queueUNLOCKED )
|
|
{
|
|
pxQueue->xTxLock = queueUNLOCKED;
|
|
|
|
/* Data was posted while the queue was locked. Are any tasks
|
|
blocked waiting for data to become available? */
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
|
|
{
|
|
/* Tasks that are removed from the event list will get added to
|
|
the pending ready list as the scheduler is still suspended. */
|
|
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
|
|
{
|
|
/* The task waiting has a higher priority so record that a
|
|
context switch is required. */
|
|
vTaskMissedYield();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
taskEXIT_CRITICAL();
|
|
|
|
/* Do the same for the Rx lock. */
|
|
taskENTER_CRITICAL();
|
|
{
|
|
--( pxQueue->xRxLock );
|
|
|
|
if( pxQueue->xRxLock > queueUNLOCKED )
|
|
{
|
|
pxQueue->xRxLock = queueUNLOCKED;
|
|
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
|
|
{
|
|
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
|
|
{
|
|
vTaskMissedYield();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
taskEXIT_CRITICAL();
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static signed portBASE_TYPE prvIsQueueEmpty( const xQueueHandle pxQueue )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
taskENTER_CRITICAL();
|
|
xReturn = ( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 );
|
|
taskEXIT_CRITICAL();
|
|
|
|
return xReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static signed portBASE_TYPE prvIsQueueFull( const xQueueHandle pxQueue )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
taskENTER_CRITICAL();
|
|
xReturn = ( pxQueue->uxMessagesWaiting == pxQueue->uxLength );
|
|
taskEXIT_CRITICAL();
|
|
|
|
return xReturn;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if configUSE_CO_ROUTINES == 1
|
|
signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
/* If the queue is already full we may have to block. A critical section
|
|
is required to prevent an interrupt removing something from the queue
|
|
between the check to see if the queue is full and blocking on the queue. */
|
|
portDISABLE_INTERRUPTS();
|
|
{
|
|
if( prvIsQueueFull( pxQueue ) )
|
|
{
|
|
/* The queue is full - do we want to block or just leave without
|
|
posting? */
|
|
if( xTicksToWait > ( portTickType ) 0 )
|
|
{
|
|
/* As this is called from a coroutine we cannot block directly, but
|
|
return indicating that we need to block. */
|
|
vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToSend ) );
|
|
portENABLE_INTERRUPTS();
|
|
return errQUEUE_BLOCKED;
|
|
}
|
|
else
|
|
{
|
|
portENABLE_INTERRUPTS();
|
|
return errQUEUE_FULL;
|
|
}
|
|
}
|
|
}
|
|
portENABLE_INTERRUPTS();
|
|
|
|
portNOP();
|
|
|
|
portDISABLE_INTERRUPTS();
|
|
{
|
|
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
|
|
{
|
|
/* There is room in the queue, copy the data into the queue. */
|
|
prvCopyQueueData( pxQueue, pvItemToQueue );
|
|
xReturn = pdPASS;
|
|
|
|
/* Were any co-routines waiting for data to become available? */
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
|
|
{
|
|
/* In this instance the co-routine could be placed directly
|
|
into the ready list as we are within a critical section.
|
|
Instead the same pending ready list mechansim is used as if
|
|
the event were caused from within an interrupt. */
|
|
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
|
|
{
|
|
/* The co-routine waiting has a higher priority so record
|
|
that a yield might be appropriate. */
|
|
xReturn = errQUEUE_YIELD;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
xReturn = errQUEUE_FULL;
|
|
}
|
|
}
|
|
portENABLE_INTERRUPTS();
|
|
|
|
return xReturn;
|
|
}
|
|
#endif
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if configUSE_CO_ROUTINES == 1
|
|
signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
/* If the queue is already empty we may have to block. A critical section
|
|
is required to prevent an interrupt adding something to the queue
|
|
between the check to see if the queue is empty and blocking on the queue. */
|
|
portDISABLE_INTERRUPTS();
|
|
{
|
|
if( pxQueue->uxMessagesWaiting == ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
/* There are no messages in the queue, do we want to block or just
|
|
leave with nothing? */
|
|
if( xTicksToWait > ( portTickType ) 0 )
|
|
{
|
|
/* As this is a co-routine we cannot block directly, but return
|
|
indicating that we need to block. */
|
|
vCoRoutineAddToDelayedList( xTicksToWait, &( pxQueue->xTasksWaitingToReceive ) );
|
|
portENABLE_INTERRUPTS();
|
|
return errQUEUE_BLOCKED;
|
|
}
|
|
else
|
|
{
|
|
portENABLE_INTERRUPTS();
|
|
return errQUEUE_FULL;
|
|
}
|
|
}
|
|
}
|
|
portENABLE_INTERRUPTS();
|
|
|
|
portNOP();
|
|
|
|
portDISABLE_INTERRUPTS();
|
|
{
|
|
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
/* Data is available from the queue. */
|
|
pxQueue->pcReadFrom += pxQueue->uxItemSize;
|
|
if( pxQueue->pcReadFrom >= pxQueue->pcTail )
|
|
{
|
|
pxQueue->pcReadFrom = pxQueue->pcHead;
|
|
}
|
|
--( pxQueue->uxMessagesWaiting );
|
|
memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );
|
|
|
|
xReturn = pdPASS;
|
|
|
|
/* Were any co-routines waiting for space to become available? */
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
|
|
{
|
|
/* In this instance the co-routine could be placed directly
|
|
into the ready list as we are within a critical section.
|
|
Instead the same pending ready list mechansim is used as if
|
|
the event were caused from within an interrupt. */
|
|
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
|
|
{
|
|
xReturn = errQUEUE_YIELD;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
xReturn = pdFAIL;
|
|
}
|
|
}
|
|
portENABLE_INTERRUPTS();
|
|
|
|
return xReturn;
|
|
}
|
|
#endif
|
|
/*-----------------------------------------------------------*/
|
|
|
|
|
|
|
|
#if configUSE_CO_ROUTINES == 1
|
|
signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken )
|
|
{
|
|
/* Cannot block within an ISR so if there is no space on the queue then
|
|
exit without doing anything. */
|
|
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
|
|
{
|
|
prvCopyQueueData( pxQueue, pvItemToQueue );
|
|
|
|
/* We only want to wake one co-routine per ISR, so check that a
|
|
co-routine has not already been woken. */
|
|
if( !xCoRoutinePreviouslyWoken )
|
|
{
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
|
|
{
|
|
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
|
|
{
|
|
return pdTRUE;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return xCoRoutinePreviouslyWoken;
|
|
}
|
|
#endif
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if configUSE_CO_ROUTINES == 1
|
|
signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxCoRoutineWoken )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
/* We cannot block from an ISR, so check there is data available. If
|
|
not then just leave without doing anything. */
|
|
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
|
|
{
|
|
/* Copy the data from the queue. */
|
|
pxQueue->pcReadFrom += pxQueue->uxItemSize;
|
|
if( pxQueue->pcReadFrom >= pxQueue->pcTail )
|
|
{
|
|
pxQueue->pcReadFrom = pxQueue->pcHead;
|
|
}
|
|
--( pxQueue->uxMessagesWaiting );
|
|
memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );
|
|
|
|
if( !( *pxCoRoutineWoken ) )
|
|
{
|
|
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
|
|
{
|
|
if( xCoRoutineRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
|
|
{
|
|
*pxCoRoutineWoken = pdTRUE;
|
|
}
|
|
}
|
|
}
|
|
|
|
xReturn = pdPASS;
|
|
}
|
|
else
|
|
{
|
|
xReturn = pdFAIL;
|
|
}
|
|
|
|
return xReturn;
|
|
}
|
|
#endif
|
|
/*-----------------------------------------------------------*/
|
|
|