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/*
* FreeRTOS Kernel V10.4.6 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * SPDX-License-Identifier: MIT * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * https://www.FreeRTOS.org
* https://github.com/FreeRTOS
* */
#include "FreeRTOS.h"
#include "task.h"
#include "croutine.h"
/* Remove the whole file is co-routines are not being used. */#if ( configUSE_CO_ROUTINES != 0 )
/*
* 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 List_t pxReadyCoRoutineLists[ configMAX_CO_ROUTINE_PRIORITIES ]; /*< Prioritised ready co-routines. */ static List_t xDelayedCoRoutineList1; /*< Delayed co-routines. */ static List_t xDelayedCoRoutineList2; /*< Delayed co-routines (two lists are used - one for delays that have overflowed the current tick count. */ static List_t * pxDelayedCoRoutineList = NULL; /*< Points to the delayed co-routine list currently being used. */ static List_t * pxOverflowDelayedCoRoutineList = NULL; /*< Points to the delayed co-routine list currently being used to hold co-routines that have overflowed the current tick count. */ static List_t 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. --------------------------------*/ CRCB_t * pxCurrentCoRoutine = NULL; static UBaseType_t uxTopCoRoutineReadyPriority = 0; static TickType_t 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( ( List_t * ) &( 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 );
/*-----------------------------------------------------------*/
BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, UBaseType_t uxPriority, UBaseType_t uxIndex ) { BaseType_t xReturn; CRCB_t * pxCoRoutine;
/* Allocate the memory that will store the co-routine control block. */ pxCoRoutine = ( CRCB_t * ) pvPortMalloc( sizeof( CRCB_t ) );
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 ListItem_t.
* 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 ), ( ( TickType_t ) configMAX_CO_ROUTINE_PRIORITIES - ( TickType_t ) 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( TickType_t xTicksToDelay, List_t * pxEventList ) { TickType_t 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. */ ( void ) uxListRemove( ( ListItem_t * ) &( 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( ( List_t * ) pxOverflowDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); } else { /* The wake time has not overflowed, so we can use the
* current block list. */ vListInsert( ( List_t * ) pxDelayedCoRoutineList, ( ListItem_t * ) &( 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 ) { CRCB_t * pxUnblockedCRCB;
/* The pending ready list can be accessed by an ISR. */ portDISABLE_INTERRUPTS(); { pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( ( &xPendingReadyCoRoutineList ) ); ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); } portENABLE_INTERRUPTS();
( void ) uxListRemove( &( pxUnblockedCRCB->xGenericListItem ) ); prvAddCoRoutineToReadyQueue( pxUnblockedCRCB ); } }/*-----------------------------------------------------------*/
static void prvCheckDelayedList( void ) { CRCB_t * pxCRCB;
xPassedTicks = xTaskGetTickCount() - xLastTickCount;
while( xPassedTicks ) { xCoRoutineTickCount++; xPassedTicks--;
/* If the tick count has overflowed we need to swap the ready lists. */ if( xCoRoutineTickCount == 0 ) { List_t * 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 = ( CRCB_t * ) 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. */ ( void ) uxListRemove( &( pxCRCB->xGenericListItem ) );
/* Is the co-routine waiting on an event also? */ if( pxCRCB->xEventListItem.pxContainer ) { ( void ) uxListRemove( &( pxCRCB->xEventListItem ) ); } } portENABLE_INTERRUPTS();
prvAddCoRoutineToReadyQueue( pxCRCB ); } }
xLastTickCount = xCoRoutineTickCount; }/*-----------------------------------------------------------*/
void vCoRoutineSchedule( void ) { /* Only run a co-routine after prvInitialiseCoRoutineLists() has been
* called. prvInitialiseCoRoutineLists() is called automatically when a * co-routine is created. */ if( pxDelayedCoRoutineList != NULL ) { /* 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 ); } }/*-----------------------------------------------------------*/
static void prvInitialiseCoRoutineLists( void ) { UBaseType_t uxPriority;
for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ ) { vListInitialise( ( List_t * ) &( pxReadyCoRoutineLists[ uxPriority ] ) ); }
vListInitialise( ( List_t * ) &xDelayedCoRoutineList1 ); vListInitialise( ( List_t * ) &xDelayedCoRoutineList2 ); vListInitialise( ( List_t * ) &xPendingReadyCoRoutineList );
/* Start with pxDelayedCoRoutineList using list1 and the
* pxOverflowDelayedCoRoutineList using list2. */ pxDelayedCoRoutineList = &xDelayedCoRoutineList1; pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2; }/*-----------------------------------------------------------*/
BaseType_t xCoRoutineRemoveFromEventList( const List_t * pxEventList ) { CRCB_t * pxUnblockedCRCB; BaseType_t 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 = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); vListInsertEnd( ( List_t * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) );
if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) { xReturn = pdTRUE; } else { xReturn = pdFALSE; }
return xReturn; }
#endif /* configUSE_CO_ROUTINES == 0 */
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