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Diffstat (limited to 'libraries/FreeRTOS/utility/croutine.c')
| -rwxr-xr-x | libraries/FreeRTOS/utility/croutine.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/libraries/FreeRTOS/utility/croutine.c b/libraries/FreeRTOS/utility/croutine.c new file mode 100755 index 0000000..fe56730 --- /dev/null +++ b/libraries/FreeRTOS/utility/croutine.c @@ -0,0 +1,380 @@ +/* + FreeRTOS V7.0.1 - Copyright (C) 2011 Real Time Engineers Ltd. + + + FreeRTOS supports many tools and architectures. V7.0.0 is sponsored by: + Atollic AB - Atollic provides professional embedded systems development + tools for C/C++ development, code analysis and test automation. + See http://www.atollic.com + + + *************************************************************************** + * * + * FreeRTOS tutorial books are available in pdf and paperback. * + * Complete, revised, and edited pdf reference manuals are also * + * available. * + * * + * Purchasing FreeRTOS documentation will not only help you, by * + * ensuring you get running as quickly as possible and with an * + * in-depth knowledge of how to use FreeRTOS, it will also help * + * the FreeRTOS project to continue with its mission of providing * + * professional grade, cross platform, de facto standard solutions * + * for microcontrollers - completely free of charge! * + * * + * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * + * * + * Thank you for using FreeRTOS, and thank you for your support! * + * * + *************************************************************************** + + + This file is part of the FreeRTOS distribution. + + FreeRTOS is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License (version 2) as published by the + Free Software Foundation AND MODIFIED BY the FreeRTOS exception. + >>>NOTE<<< The modification to the GPL is included to allow you to + distribute a combined work that includes FreeRTOS without being obliged to + provide the source code for proprietary components outside of the FreeRTOS + kernel. FreeRTOS is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. You should have received a copy of the GNU General Public + License and the FreeRTOS license exception along with FreeRTOS; if not it + can be viewed here: http://www.freertos.org/a00114.html and also obtained + by writing to Richard Barry, contact details for whom are available on the + FreeRTOS WEB site. + + 1 tab == 4 spaces! + + http://www.FreeRTOS.org - Documentation, latest information, license and + contact details. + + http://www.SafeRTOS.com - A version that is certified for use in safety + critical systems. + + http://www.OpenRTOS.com - Commercial support, development, porting, + licensing and training services. +*/ + +#include "FreeRTOS.h" +#include "task.h" +#include "croutine.h" + +/* + * Some kernel aware debuggers require data to be viewed to be global, rather + * than file scope. + */ +#ifdef portREMOVE_STATIC_QUALIFIER + #define static +#endif + + +/* Lists for ready and blocked co-routines. --------------------*/ +static xList pxReadyCoRoutineLists[ configMAX_CO_ROUTINE_PRIORITIES ]; /*< Prioritised ready co-routines. */ +static xList xDelayedCoRoutineList1; /*< Delayed co-routines. */ +static xList xDelayedCoRoutineList2; /*< Delayed co-routines (two lists are used - one for delays that have overflowed the current tick count. */ +static xList * pxDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used. */ +static xList * pxOverflowDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used to hold co-routines that have overflowed the current tick count. */ +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. */ + +/* Other file private variables. --------------------------------*/ +corCRCB * pxCurrentCoRoutine = NULL; +static unsigned portBASE_TYPE uxTopCoRoutineReadyPriority = 0; +static portTickType xCoRoutineTickCount = 0, xLastTickCount = 0, xPassedTicks = 0; + +/* The initial state of the co-routine when it is created. */ +#define corINITIAL_STATE ( 0 ) + +/* + * Place the co-routine represented by pxCRCB into the appropriate ready queue + * for the priority. It is inserted at the end of the list. + * + * This macro accesses the co-routine ready lists and therefore must not be + * used from within an ISR. + */ +#define prvAddCoRoutineToReadyQueue( pxCRCB ) \ +{ \ + if( pxCRCB->uxPriority > uxTopCoRoutineReadyPriority ) \ + { \ + uxTopCoRoutineReadyPriority = pxCRCB->uxPriority; \ + } \ + vListInsertEnd( ( xList * ) &( pxReadyCoRoutineLists[ pxCRCB->uxPriority ] ), &( pxCRCB->xGenericListItem ) ); \ +} + +/* + * Utility to ready all the lists used by the scheduler. This is called + * automatically upon the creation of the first co-routine. + */ +static void prvInitialiseCoRoutineLists( void ); + +/* + * Co-routines that are readied by an interrupt cannot be placed directly into + * the ready lists (there is no mutual exclusion). Instead they are placed in + * in the pending ready list in order that they can later be moved to the ready + * list by the co-routine scheduler. + */ +static void prvCheckPendingReadyList( void ); + +/* + * Macro that looks at the list of co-routines that are currently delayed to + * see if any require waking. + * + * Co-routines are stored in the queue in the order of their wake time - + * meaning once one co-routine has been found whose timer has not expired + * we need not look any further down the list. + */ +static void prvCheckDelayedList( void ); + +/*-----------------------------------------------------------*/ + +signed portBASE_TYPE xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, unsigned portBASE_TYPE uxPriority, unsigned portBASE_TYPE uxIndex ) +{ +signed portBASE_TYPE xReturn; +corCRCB *pxCoRoutine; + + /* Allocate the memory that will store the co-routine control block. */ + pxCoRoutine = ( corCRCB * ) pvPortMalloc( sizeof( corCRCB ) ); + if( pxCoRoutine ) + { + /* If pxCurrentCoRoutine is NULL then this is the first co-routine to + be created and the co-routine data structures need initialising. */ + if( pxCurrentCoRoutine == NULL ) + { + pxCurrentCoRoutine = pxCoRoutine; + prvInitialiseCoRoutineLists(); + } + + /* Check the priority is within limits. */ + if( uxPriority >= configMAX_CO_ROUTINE_PRIORITIES ) + { + uxPriority = configMAX_CO_ROUTINE_PRIORITIES - 1; + } + + /* Fill out the co-routine control block from the function parameters. */ + pxCoRoutine->uxState = corINITIAL_STATE; + pxCoRoutine->uxPriority = uxPriority; + pxCoRoutine->uxIndex = uxIndex; + pxCoRoutine->pxCoRoutineFunction = pxCoRoutineCode; + + /* Initialise all the other co-routine control block parameters. */ + vListInitialiseItem( &( pxCoRoutine->xGenericListItem ) ); + vListInitialiseItem( &( pxCoRoutine->xEventListItem ) ); + + /* Set the co-routine control block as a link back from the xListItem. + This is so we can get back to the containing CRCB from a generic item + in a list. */ + listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xGenericListItem ), pxCoRoutine ); + listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xEventListItem ), pxCoRoutine ); + + /* Event lists are always in priority order. */ + listSET_LIST_ITEM_VALUE( &( pxCoRoutine->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority ); + + /* Now the co-routine has been initialised it can be added to the ready + list at the correct priority. */ + prvAddCoRoutineToReadyQueue( pxCoRoutine ); + + xReturn = pdPASS; + } + else + { + xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY; + } + + return xReturn; +} +/*-----------------------------------------------------------*/ + +void vCoRoutineAddToDelayedList( portTickType xTicksToDelay, xList *pxEventList ) +{ +portTickType xTimeToWake; + + /* Calculate the time to wake - this may overflow but this is + not a problem. */ + xTimeToWake = xCoRoutineTickCount + xTicksToDelay; + + /* We must remove ourselves from the ready list before adding + ourselves to the blocked list as the same list item is used for + both lists. */ + vListRemove( ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) ); + + /* The list item will be inserted in wake time order. */ + listSET_LIST_ITEM_VALUE( &( pxCurrentCoRoutine->xGenericListItem ), xTimeToWake ); + + if( xTimeToWake < xCoRoutineTickCount ) + { + /* Wake time has overflowed. Place this item in the + overflow list. */ + vListInsert( ( xList * ) pxOverflowDelayedCoRoutineList, ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) ); + } + else + { + /* The wake time has not overflowed, so we can use the + current block list. */ + vListInsert( ( xList * ) pxDelayedCoRoutineList, ( xListItem * ) &( pxCurrentCoRoutine->xGenericListItem ) ); + } + + if( pxEventList ) + { + /* Also add the co-routine to an event list. If this is done then the + function must be called with interrupts disabled. */ + vListInsert( pxEventList, &( pxCurrentCoRoutine->xEventListItem ) ); + } +} +/*-----------------------------------------------------------*/ + +static void prvCheckPendingReadyList( void ) +{ + /* Are there any co-routines waiting to get moved to the ready list? These + are co-routines that have been readied by an ISR. The ISR cannot access + the ready lists itself. */ + while( listLIST_IS_EMPTY( &xPendingReadyCoRoutineList ) == pdFALSE ) + { + corCRCB *pxUnblockedCRCB; + + /* The pending ready list can be accessed by an ISR. */ + portDISABLE_INTERRUPTS(); + { + pxUnblockedCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( (&xPendingReadyCoRoutineList) ); + vListRemove( &( pxUnblockedCRCB->xEventListItem ) ); + } + portENABLE_INTERRUPTS(); + + vListRemove( &( pxUnblockedCRCB->xGenericListItem ) ); + prvAddCoRoutineToReadyQueue( pxUnblockedCRCB ); + } +} +/*-----------------------------------------------------------*/ + +static void prvCheckDelayedList( void ) +{ +corCRCB *pxCRCB; + + xPassedTicks = xTaskGetTickCount() - xLastTickCount; + while( xPassedTicks ) + { + xCoRoutineTickCount++; + xPassedTicks--; + + /* If the tick count has overflowed we need to swap the ready lists. */ + if( xCoRoutineTickCount == 0 ) + { + xList * pxTemp; + + /* Tick count has overflowed so we need to swap the delay lists. If there are + any items in pxDelayedCoRoutineList here then there is an error! */ + pxTemp = pxDelayedCoRoutineList; + pxDelayedCoRoutineList = pxOverflowDelayedCoRoutineList; + pxOverflowDelayedCoRoutineList = pxTemp; + } + + /* See if this tick has made a timeout expire. */ + while( listLIST_IS_EMPTY( pxDelayedCoRoutineList ) == pdFALSE ) + { + pxCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedCoRoutineList ); + + if( xCoRoutineTickCount < listGET_LIST_ITEM_VALUE( &( pxCRCB->xGenericListItem ) ) ) + { + /* Timeout not yet expired. */ + break; + } + + portDISABLE_INTERRUPTS(); + { + /* The event could have occurred just before this critical + section. If this is the case then the generic list item will + have been moved to the pending ready list and the following + line is still valid. Also the pvContainer parameter will have + been set to NULL so the following lines are also valid. */ + vListRemove( &( pxCRCB->xGenericListItem ) ); + + /* Is the co-routine waiting on an event also? */ + if( pxCRCB->xEventListItem.pvContainer ) + { + vListRemove( &( pxCRCB->xEventListItem ) ); + } + } + portENABLE_INTERRUPTS(); + + prvAddCoRoutineToReadyQueue( pxCRCB ); + } + } + + xLastTickCount = xCoRoutineTickCount; +} +/*-----------------------------------------------------------*/ + +void vCoRoutineSchedule( void ) +{ + /* See if any co-routines readied by events need moving to the ready lists. */ + prvCheckPendingReadyList(); + + /* See if any delayed co-routines have timed out. */ + prvCheckDelayedList(); + + /* Find the highest priority queue that contains ready co-routines. */ + while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) ) + { + if( uxTopCoRoutineReadyPriority == 0 ) + { + /* No more co-routines to check. */ + return; + } + --uxTopCoRoutineReadyPriority; + } + + /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines + of the same priority get an equal share of the processor time. */ + listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ); + + /* Call the co-routine. */ + ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex ); + + return; +} +/*-----------------------------------------------------------*/ + +static void prvInitialiseCoRoutineLists( void ) +{ +unsigned portBASE_TYPE uxPriority; + + for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ ) + { + vListInitialise( ( xList * ) &( pxReadyCoRoutineLists[ uxPriority ] ) ); + } + + vListInitialise( ( xList * ) &xDelayedCoRoutineList1 ); + vListInitialise( ( xList * ) &xDelayedCoRoutineList2 ); + vListInitialise( ( xList * ) &xPendingReadyCoRoutineList ); + + /* Start with pxDelayedCoRoutineList using list1 and the + pxOverflowDelayedCoRoutineList using list2. */ + pxDelayedCoRoutineList = &xDelayedCoRoutineList1; + pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2; +} +/*-----------------------------------------------------------*/ + +signed portBASE_TYPE xCoRoutineRemoveFromEventList( const xList *pxEventList ) +{ +corCRCB *pxUnblockedCRCB; +signed portBASE_TYPE xReturn; + + /* This function is called from within an interrupt. It can only access + event lists and the pending ready list. This function assumes that a + check has already been made to ensure pxEventList is not empty. */ + pxUnblockedCRCB = ( corCRCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); + vListRemove( &( pxUnblockedCRCB->xEventListItem ) ); + vListInsertEnd( ( xList * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) ); + + if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) + { + xReturn = pdTRUE; + } + else + { + xReturn = pdFALSE; + } + + return xReturn; +} + |