| /* | |
| * FreeRTOS Kernel <DEVELOPMENT BRANCH> | |
| * 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 */ |