390 lines
15 KiB
C
390 lines
15 KiB
C
/*
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FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.
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FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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***************************************************************************
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* *
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* FreeRTOS tutorial books are available in pdf and paperback. *
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* Complete, revised, and edited pdf reference manuals are also *
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* available. *
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* *
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* Purchasing FreeRTOS documentation will not only help you, by *
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* ensuring you get running as quickly as possible and with an *
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* in-depth knowledge of how to use FreeRTOS, it will also help *
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* the FreeRTOS project to continue with its mission of providing *
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* professional grade, cross platform, de facto standard solutions *
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* for microcontrollers - completely free of charge! *
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* *
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* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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* *
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* Thank you for using FreeRTOS, and thank you for your support! *
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* *
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***************************************************************************
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This file is part of the FreeRTOS distribution.
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FreeRTOS is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License (version 2) as published by the
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Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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>>>NOTE<<< The modification to the GPL is included to allow you to
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distribute a combined work that includes FreeRTOS without being obliged to
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provide the source code for proprietary components outside of the FreeRTOS
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kernel. FreeRTOS is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details. You should have received a copy of the GNU General Public
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License and the FreeRTOS license exception along with FreeRTOS; if not it
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can be viewed here: http://www.freertos.org/a00114.html and also obtained
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by writing to Richard Barry, contact details for whom are available on the
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FreeRTOS WEB site.
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1 tab == 4 spaces!
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***************************************************************************
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* *
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* Having a problem? Start by reading the FAQ "My application does *
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* not run, what could be wrong?" *
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* *
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* http://www.FreeRTOS.org/FAQHelp.html *
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* *
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***************************************************************************
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http://www.FreeRTOS.org - Documentation, training, latest versions, license
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and contact details.
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http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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including FreeRTOS+Trace - an indispensable productivity tool.
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Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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the code with commercial support, indemnification, and middleware, under
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the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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provide a safety engineered and independently SIL3 certified version under
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the SafeRTOS brand: http://www.SafeRTOS.com.
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*/
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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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* Some kernel aware debuggers require data to be viewed to be global, rather
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* than file scope.
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*/
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#ifdef portREMOVE_STATIC_QUALIFIER
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#define static
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#endif
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/* Lists for ready and blocked co-routines. --------------------*/
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static xList pxReadyCoRoutineLists[ configMAX_CO_ROUTINE_PRIORITIES ]; /*< Prioritised ready co-routines. */
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static xList xDelayedCoRoutineList1; /*< Delayed co-routines. */
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static xList xDelayedCoRoutineList2; /*< Delayed co-routines (two lists are used - one for delays that have overflowed the current tick count. */
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static xList * pxDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used. */
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static xList * pxOverflowDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used to hold co-routines that have overflowed the current tick count. */
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static xList xPendingReadyCoRoutineList; /*< Holds co-routines that have been readied by an external event. They cannot be added directly to the ready lists as the ready lists cannot be accessed by interrupts. */
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/* Other file private variables. --------------------------------*/
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corCRCB * pxCurrentCoRoutine = NULL;
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static unsigned portBASE_TYPE uxTopCoRoutineReadyPriority = 0;
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static portTickType xCoRoutineTickCount = 0, xLastTickCount = 0, xPassedTicks = 0;
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/* The initial state of the co-routine when it is created. */
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#define corINITIAL_STATE ( 0 )
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/*
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* Place the co-routine represented by pxCRCB into the appropriate ready queue
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* for the priority. It is inserted at the end of the list.
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*
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* This macro accesses the co-routine ready lists and therefore must not be
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* used from within an ISR.
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*/
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#define prvAddCoRoutineToReadyQueue( pxCRCB ) \
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{ \
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if( pxCRCB->uxPriority > uxTopCoRoutineReadyPriority ) \
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{ \
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uxTopCoRoutineReadyPriority = pxCRCB->uxPriority; \
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} \
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vListInsertEnd( ( xList * ) &( pxReadyCoRoutineLists[ pxCRCB->uxPriority ] ), &( pxCRCB->xGenericListItem ) ); \
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}
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/*
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* Utility to ready all the lists used by the scheduler. This is called
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* automatically upon the creation of the first co-routine.
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*/
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static void prvInitialiseCoRoutineLists( void );
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/*
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* Co-routines that are readied by an interrupt cannot be placed directly into
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* the ready lists (there is no mutual exclusion). Instead they are placed in
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* in the pending ready list in order that they can later be moved to the ready
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* list by the co-routine scheduler.
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*/
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static void prvCheckPendingReadyList( void );
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/*
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* Macro that looks at the list of co-routines that are currently delayed to
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* see if any require waking.
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*
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* Co-routines are stored in the queue in the order of their wake time -
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* meaning once one co-routine has been found whose timer has not expired
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* we need not look any further down the list.
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*/
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static void prvCheckDelayedList( void );
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, unsigned portBASE_TYPE uxPriority, unsigned portBASE_TYPE uxIndex )
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{
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signed portBASE_TYPE xReturn;
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corCRCB *pxCoRoutine;
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/* Allocate the memory that will store the co-routine control block. */
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pxCoRoutine = ( corCRCB * ) pvPortMalloc( sizeof( corCRCB ) );
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if( pxCoRoutine )
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{
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/* If pxCurrentCoRoutine is NULL then this is the first co-routine to
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be created and the co-routine data structures need initialising. */
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if( pxCurrentCoRoutine == NULL )
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{
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pxCurrentCoRoutine = pxCoRoutine;
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prvInitialiseCoRoutineLists();
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}
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/* Check the priority is within limits. */
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if( uxPriority >= configMAX_CO_ROUTINE_PRIORITIES )
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{
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uxPriority = configMAX_CO_ROUTINE_PRIORITIES - 1;
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}
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/* Fill out the co-routine control block from the function parameters. */
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pxCoRoutine->uxState = corINITIAL_STATE;
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pxCoRoutine->uxPriority = uxPriority;
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pxCoRoutine->uxIndex = uxIndex;
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pxCoRoutine->pxCoRoutineFunction = pxCoRoutineCode;
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/* Initialise all the other co-routine control block parameters. */
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vListInitialiseItem( &( pxCoRoutine->xGenericListItem ) );
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vListInitialiseItem( &( pxCoRoutine->xEventListItem ) );
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/* Set the co-routine control block as a link back from the xListItem.
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This is so we can get back to the containing CRCB from a generic item
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in a list. */
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listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xGenericListItem ), pxCoRoutine );
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listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xEventListItem ), pxCoRoutine );
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/* Event lists are always in priority order. */
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listSET_LIST_ITEM_VALUE( &( pxCoRoutine->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );
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/* Now the co-routine has been initialised it can be added to the ready
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list at the correct priority. */
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prvAddCoRoutineToReadyQueue( pxCoRoutine );
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xReturn = pdPASS;
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}
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else
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{
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xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
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}
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return xReturn;
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}
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/*-----------------------------------------------------------*/
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void vCoRoutineAddToDelayedList( portTickType xTicksToDelay, xList *pxEventList )
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{
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portTickType xTimeToWake;
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/* Calculate the time to wake - this may overflow but this is
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not a problem. */
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xTimeToWake = xCoRoutineTickCount + xTicksToDelay;
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/* We must remove ourselves from the ready list before adding
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ourselves to the blocked list as the same list item is used for
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both lists. */
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uxListRemove( ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) );
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/* The list item will be inserted in wake time order. */
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listSET_LIST_ITEM_VALUE( &( pxCurrentCoRoutine->xGenericListItem ), xTimeToWake );
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if( xTimeToWake < xCoRoutineTickCount )
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{
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/* Wake time has overflowed. Place this item in the
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overflow list. */
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vListInsert( ( xList * ) pxOverflowDelayedCoRoutineList, ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) );
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}
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else
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{
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/* The wake time has not overflowed, so we can use the
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current block list. */
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vListInsert( ( xList * ) pxDelayedCoRoutineList, ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) );
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}
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if( pxEventList )
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{
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/* Also add the co-routine to an event list. If this is done then the
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function must be called with interrupts disabled. */
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vListInsert( pxEventList, &( pxCurrentCoRoutine->xEventListItem ) );
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}
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}
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/*-----------------------------------------------------------*/
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static void prvCheckPendingReadyList( void )
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{
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/* Are there any co-routines waiting to get moved to the ready list? These
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are co-routines that have been readied by an ISR. The ISR cannot access
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the ready lists itself. */
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while( listLIST_IS_EMPTY( &xPendingReadyCoRoutineList ) == pdFALSE )
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{
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corCRCB *pxUnblockedCRCB;
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/* The pending ready list can be accessed by an ISR. */
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portDISABLE_INTERRUPTS();
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{
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pxUnblockedCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( (&xPendingReadyCoRoutineList) );
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uxListRemove( &( pxUnblockedCRCB->xEventListItem ) );
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}
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portENABLE_INTERRUPTS();
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uxListRemove( &( pxUnblockedCRCB->xGenericListItem ) );
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prvAddCoRoutineToReadyQueue( pxUnblockedCRCB );
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}
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}
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/*-----------------------------------------------------------*/
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static void prvCheckDelayedList( void )
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{
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corCRCB *pxCRCB;
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xPassedTicks = xTaskGetTickCount() - xLastTickCount;
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while( xPassedTicks )
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{
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xCoRoutineTickCount++;
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xPassedTicks--;
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/* If the tick count has overflowed we need to swap the ready lists. */
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if( xCoRoutineTickCount == 0 )
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{
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xList * pxTemp;
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/* Tick count has overflowed so we need to swap the delay lists. If there are
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any items in pxDelayedCoRoutineList here then there is an error! */
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pxTemp = pxDelayedCoRoutineList;
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pxDelayedCoRoutineList = pxOverflowDelayedCoRoutineList;
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pxOverflowDelayedCoRoutineList = pxTemp;
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}
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/* See if this tick has made a timeout expire. */
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while( listLIST_IS_EMPTY( pxDelayedCoRoutineList ) == pdFALSE )
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{
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pxCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedCoRoutineList );
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if( xCoRoutineTickCount < listGET_LIST_ITEM_VALUE( &( pxCRCB->xGenericListItem ) ) )
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{
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/* Timeout not yet expired. */
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break;
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}
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portDISABLE_INTERRUPTS();
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{
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/* The event could have occurred just before this critical
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section. If this is the case then the generic list item will
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have been moved to the pending ready list and the following
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line is still valid. Also the pvContainer parameter will have
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been set to NULL so the following lines are also valid. */
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uxListRemove( &( pxCRCB->xGenericListItem ) );
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/* Is the co-routine waiting on an event also? */
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if( pxCRCB->xEventListItem.pvContainer )
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{
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uxListRemove( &( pxCRCB->xEventListItem ) );
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}
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}
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portENABLE_INTERRUPTS();
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prvAddCoRoutineToReadyQueue( pxCRCB );
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}
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}
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xLastTickCount = xCoRoutineTickCount;
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}
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/*-----------------------------------------------------------*/
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void vCoRoutineSchedule( void )
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{
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/* See if any co-routines readied by events need moving to the ready lists. */
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prvCheckPendingReadyList();
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/* See if any delayed co-routines have timed out. */
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prvCheckDelayedList();
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/* Find the highest priority queue that contains ready co-routines. */
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while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) )
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{
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if( uxTopCoRoutineReadyPriority == 0 )
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{
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/* No more co-routines to check. */
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return;
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}
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--uxTopCoRoutineReadyPriority;
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}
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/* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines
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of the same priority get an equal share of the processor time. */
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listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) );
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/* Call the co-routine. */
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( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex );
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return;
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}
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/*-----------------------------------------------------------*/
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static void prvInitialiseCoRoutineLists( void )
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{
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unsigned portBASE_TYPE uxPriority;
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for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ )
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{
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vListInitialise( ( xList * ) &( pxReadyCoRoutineLists[ uxPriority ] ) );
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}
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vListInitialise( ( xList * ) &xDelayedCoRoutineList1 );
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vListInitialise( ( xList * ) &xDelayedCoRoutineList2 );
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vListInitialise( ( xList * ) &xPendingReadyCoRoutineList );
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/* Start with pxDelayedCoRoutineList using list1 and the
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pxOverflowDelayedCoRoutineList using list2. */
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pxDelayedCoRoutineList = &xDelayedCoRoutineList1;
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pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xCoRoutineRemoveFromEventList( const xList *pxEventList )
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{
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corCRCB *pxUnblockedCRCB;
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signed portBASE_TYPE xReturn;
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/* This function is called from within an interrupt. It can only access
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event lists and the pending ready list. This function assumes that a
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check has already been made to ensure pxEventList is not empty. */
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pxUnblockedCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );
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uxListRemove( &( pxUnblockedCRCB->xEventListItem ) );
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vListInsertEnd( ( xList * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) );
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if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority )
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{
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xReturn = pdTRUE;
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}
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else
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{
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xReturn = pdFALSE;
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}
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return xReturn;
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}
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