/* | |
FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd. | |
FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT | |
http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
*************************************************************************** | |
* * | |
* 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 * | |
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* 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 | |
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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 | |
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1 tab == 4 spaces! | |
*************************************************************************** | |
* * | |
* Having a problem? Start by reading the FAQ "My application does * | |
* not run, what could be wrong?" * | |
* * | |
* http://www.FreeRTOS.org/FAQHelp.html * | |
* * | |
*************************************************************************** | |
http://www.FreeRTOS.org - Documentation, books, training, latest versions, | |
license and Real Time Engineers Ltd. contact details. | |
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
including FreeRTOS+Trace - an indispensable productivity tool, and our new | |
fully thread aware and reentrant UDP/IP stack. | |
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High | |
Integrity Systems, who sell the code with commercial support, | |
indemnification and middleware, under the OpenRTOS brand. | |
http://www.SafeRTOS.com - High Integrity Systems also provide a safety | |
engineered and independently SIL3 certified version for use in safety and | |
mission critical applications that require provable dependability. | |
*/ | |
#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. */ | |
uxListRemove( ( 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) ); | |
uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); | |
} | |
portENABLE_INTERRUPTS(); | |
uxListRemove( &( 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. */ | |
uxListRemove( &( pxCRCB->xGenericListItem ) ); | |
/* Is the co-routine waiting on an event also? */ | |
if( pxCRCB->xEventListItem.pvContainer ) | |
{ | |
uxListRemove( &( 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 ); | |
uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); | |
vListInsertEnd( ( xList * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) ); | |
if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) | |
{ | |
xReturn = pdTRUE; | |
} | |
else | |
{ | |
xReturn = pdFALSE; | |
} | |
return xReturn; | |
} | |