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tasks.c
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tasks.c
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/*
* 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
*
*/
/* Standard includes. */
#include <stdlib.h>
#include <string.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "timers.h"
#include "stack_macros.h"
/* Lint e9021, e961 and e750 are suppressed as a MISRA exception justified
* because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined
* for the header files above, but not in this file, in order to generate the
* correct privileged Vs unprivileged linkage and placement. */
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750 !e9021. */
/* Set configUSE_STATS_FORMATTING_FUNCTIONS to 2 to include the stats formatting
* functions but without including stdio.h here. */
#if ( configUSE_STATS_FORMATTING_FUNCTIONS == 1 )
/* At the bottom of this file are two optional functions that can be used
* to generate human readable text from the raw data generated by the
* uxTaskGetSystemState() function. Note the formatting functions are provided
* for convenience only, and are NOT considered part of the kernel. */
#include <stdio.h>
#endif /* configUSE_STATS_FORMATTING_FUNCTIONS == 1 ) */
#if ( configUSE_PREEMPTION == 0 )
/* If the cooperative scheduler is being used then a yield should not be
* performed just because a higher priority task has been woken. */
#define taskYIELD_IF_USING_PREEMPTION()
#else
#define taskYIELD_IF_USING_PREEMPTION() portYIELD_WITHIN_API()
#endif
/* Values that can be assigned to the ucNotifyState member of the TCB. */
#define taskNOT_WAITING_NOTIFICATION ( ( uint8_t ) 0 ) /* Must be zero as it is the initialised value. */
#define taskWAITING_NOTIFICATION ( ( uint8_t ) 1 )
#define taskNOTIFICATION_RECEIVED ( ( uint8_t ) 2 )
/*
* The value used to fill the stack of a task when the task is created. This
* is used purely for checking the high water mark for tasks.
*/
#define tskSTACK_FILL_BYTE ( 0xa5U )
/* Bits used to record how a task's stack and TCB were allocated. */
#define tskDYNAMICALLY_ALLOCATED_STACK_AND_TCB ( ( uint8_t ) 0 )
#define tskSTATICALLY_ALLOCATED_STACK_ONLY ( ( uint8_t ) 1 )
#define tskSTATICALLY_ALLOCATED_STACK_AND_TCB ( ( uint8_t ) 2 )
/* If any of the following are set then task stacks are filled with a known
* value so the high water mark can be determined. If none of the following are
* set then don't fill the stack so there is no unnecessary dependency on memset. */
#if ( ( configCHECK_FOR_STACK_OVERFLOW > 1 ) || ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark2 == 1 ) )
#define tskSET_NEW_STACKS_TO_KNOWN_VALUE 1
#else
#define tskSET_NEW_STACKS_TO_KNOWN_VALUE 0
#endif
/*
* Macros used by vListTask to indicate which state a task is in.
*/
#define tskRUNNING_CHAR ( 'X' )
#define tskBLOCKED_CHAR ( 'B' )
#define tskREADY_CHAR ( 'R' )
#define tskDELETED_CHAR ( 'D' )
#define tskSUSPENDED_CHAR ( 'S' )
/*
* Some kernel aware debuggers require the data the debugger needs access to to
* be global, rather than file scope.
*/
#ifdef portREMOVE_STATIC_QUALIFIER
#define static
#endif
/* The name allocated to the Idle task. This can be overridden by defining
* configIDLE_TASK_NAME in FreeRTOSConfig.h. */
#ifndef configIDLE_TASK_NAME
#define configIDLE_TASK_NAME "IDLE"
#endif
#if ( configUSE_PORT_OPTIMISED_TASK_SELECTION == 0 )
/* If configUSE_PORT_OPTIMISED_TASK_SELECTION is 0 then task selection is
* performed in a generic way that is not optimised to any particular
* microcontroller architecture. */
/* uxTopReadyPriority holds the priority of the highest priority ready
* state task. */
#define taskRECORD_READY_PRIORITY( uxPriority ) \
{ \
if( ( uxPriority ) > uxTopReadyPriority ) \
{ \
uxTopReadyPriority = ( uxPriority ); \
} \
} /* taskRECORD_READY_PRIORITY */
/*-----------------------------------------------------------*/
#define taskSELECT_HIGHEST_PRIORITY_TASK() \
{ \
UBaseType_t uxTopPriority = uxTopReadyPriority; \
\
/* Find the highest priority queue that contains ready tasks. */ \
while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopPriority ] ) ) ) \
{ \
configASSERT( uxTopPriority ); \
--uxTopPriority; \
} \
\
/* listGET_OWNER_OF_NEXT_ENTRY indexes through the list, so the tasks of \
* the same priority get an equal share of the processor time. */ \
listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopPriority ] ) ); \
uxTopReadyPriority = uxTopPriority; \
} /* taskSELECT_HIGHEST_PRIORITY_TASK */
/*-----------------------------------------------------------*/
/* Define away taskRESET_READY_PRIORITY() and portRESET_READY_PRIORITY() as
* they are only required when a port optimised method of task selection is
* being used. */
#define taskRESET_READY_PRIORITY( uxPriority )
#define portRESET_READY_PRIORITY( uxPriority, uxTopReadyPriority )
#else /* configUSE_PORT_OPTIMISED_TASK_SELECTION */
/* If configUSE_PORT_OPTIMISED_TASK_SELECTION is 1 then task selection is
* performed in a way that is tailored to the particular microcontroller
* architecture being used. */
/* A port optimised version is provided. Call the port defined macros. */
#define taskRECORD_READY_PRIORITY( uxPriority ) portRECORD_READY_PRIORITY( ( uxPriority ), uxTopReadyPriority )
/*-----------------------------------------------------------*/
#define taskSELECT_HIGHEST_PRIORITY_TASK() \
{ \
UBaseType_t uxTopPriority; \
\
/* Find the highest priority list that contains ready tasks. */ \
portGET_HIGHEST_PRIORITY( uxTopPriority, uxTopReadyPriority ); \
configASSERT( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ uxTopPriority ] ) ) > 0 ); \
listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopPriority ] ) ); \
} /* taskSELECT_HIGHEST_PRIORITY_TASK() */
/*-----------------------------------------------------------*/
/* A port optimised version is provided, call it only if the TCB being reset
* is being referenced from a ready list. If it is referenced from a delayed
* or suspended list then it won't be in a ready list. */
#define taskRESET_READY_PRIORITY( uxPriority ) \
{ \
if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ ( uxPriority ) ] ) ) == ( UBaseType_t ) 0 ) \
{ \
portRESET_READY_PRIORITY( ( uxPriority ), ( uxTopReadyPriority ) ); \
} \
}
#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */
/*-----------------------------------------------------------*/
/* pxDelayedTaskList and pxOverflowDelayedTaskList are switched when the tick
* count overflows. */
#define taskSWITCH_DELAYED_LISTS() \
{ \
List_t * pxTemp; \
\
/* The delayed tasks list should be empty when the lists are switched. */ \
configASSERT( ( listLIST_IS_EMPTY( pxDelayedTaskList ) ) ); \
\
pxTemp = pxDelayedTaskList; \
pxDelayedTaskList = pxOverflowDelayedTaskList; \
pxOverflowDelayedTaskList = pxTemp; \
xNumOfOverflows++; \
prvResetNextTaskUnblockTime(); \
}
/*-----------------------------------------------------------*/
/*
* Place the task represented by pxTCB into the appropriate ready list for
* the task. It is inserted at the end of the list.
*/
#define prvAddTaskToReadyList( pxTCB ) \
traceMOVED_TASK_TO_READY_STATE( pxTCB ); \
taskRECORD_READY_PRIORITY( ( pxTCB )->uxPriority ); \
listINSERT_END( &( pxReadyTasksLists[ ( pxTCB )->uxPriority ] ), &( ( pxTCB )->xStateListItem ) ); \
tracePOST_MOVED_TASK_TO_READY_STATE( pxTCB )
/*-----------------------------------------------------------*/
/*
* Several functions take a TaskHandle_t parameter that can optionally be NULL,
* where NULL is used to indicate that the handle of the currently executing
* task should be used in place of the parameter. This macro simply checks to
* see if the parameter is NULL and returns a pointer to the appropriate TCB.
*/
#define prvGetTCBFromHandle( pxHandle ) ( ( ( pxHandle ) == NULL ) ? pxCurrentTCB : ( pxHandle ) )
/* The item value of the event list item is normally used to hold the priority
* of the task to which it belongs (coded to allow it to be held in reverse
* priority order). However, it is occasionally borrowed for other purposes. It
* is important its value is not updated due to a task priority change while it is
* being used for another purpose. The following bit definition is used to inform
* the scheduler that the value should not be changed - in which case it is the
* responsibility of whichever module is using the value to ensure it gets set back
* to its original value when it is released. */
#if ( configUSE_16_BIT_TICKS == 1 )
#define taskEVENT_LIST_ITEM_VALUE_IN_USE 0x8000U
#else
#define taskEVENT_LIST_ITEM_VALUE_IN_USE 0x80000000UL
#endif
/*
* Task control block. A task control block (TCB) is allocated for each task,
* and stores task state information, including a pointer to the task's context
* (the task's run time environment, including register values)
*/
typedef struct tskTaskControlBlock /* The old naming convention is used to prevent breaking kernel aware debuggers. */
{
volatile StackType_t * pxTopOfStack; /*< Points to the location of the last item placed on the tasks stack. THIS MUST BE THE FIRST MEMBER OF THE TCB STRUCT. */
#if ( portUSING_MPU_WRAPPERS == 1 )
xMPU_SETTINGS xMPUSettings; /*< The MPU settings are defined as part of the port layer. THIS MUST BE THE SECOND MEMBER OF THE TCB STRUCT. */
#endif
ListItem_t xStateListItem; /*< The list that the state list item of a task is reference from denotes the state of that task (Ready, Blocked, Suspended ). */
ListItem_t xEventListItem; /*< Used to reference a task from an event list. */
UBaseType_t uxPriority; /*< The priority of the task. 0 is the lowest priority. */
StackType_t * pxStack; /*< Points to the start of the stack. */
char pcTaskName[ configMAX_TASK_NAME_LEN ]; /*< Descriptive name given to the task when created. Facilitates debugging only. */ /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
#if ( ( portSTACK_GROWTH > 0 ) || ( configRECORD_STACK_HIGH_ADDRESS == 1 ) )
StackType_t * pxEndOfStack; /*< Points to the highest valid address for the stack. */
#endif
#if ( portCRITICAL_NESTING_IN_TCB == 1 )
UBaseType_t uxCriticalNesting; /*< Holds the critical section nesting depth for ports that do not maintain their own count in the port layer. */
#endif
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxTCBNumber; /*< Stores a number that increments each time a TCB is created. It allows debuggers to determine when a task has been deleted and then recreated. */
UBaseType_t uxTaskNumber; /*< Stores a number specifically for use by third party trace code. */
#endif
#if ( configUSE_MUTEXES == 1 )
UBaseType_t uxBasePriority; /*< The priority last assigned to the task - used by the priority inheritance mechanism. */
UBaseType_t uxMutexesHeld;
#endif
#if ( configUSE_APPLICATION_TASK_TAG == 1 )
TaskHookFunction_t pxTaskTag;
#endif
#if ( configNUM_THREAD_LOCAL_STORAGE_POINTERS > 0 )
void * pvThreadLocalStoragePointers[ configNUM_THREAD_LOCAL_STORAGE_POINTERS ];
#endif
#if ( configGENERATE_RUN_TIME_STATS == 1 )
configRUN_TIME_COUNTER_TYPE ulRunTimeCounter; /*< Stores the amount of time the task has spent in the Running state. */
#endif
#if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
configTLS_BLOCK_TYPE xTLSBlock; /*< Memory block used as Thread Local Storage (TLS) Block for the task. */
#endif
#if ( configUSE_TASK_NOTIFICATIONS == 1 )
volatile uint32_t ulNotifiedValue[ configTASK_NOTIFICATION_ARRAY_ENTRIES ];
volatile uint8_t ucNotifyState[ configTASK_NOTIFICATION_ARRAY_ENTRIES ];
#endif
/* See the comments in FreeRTOS.h with the definition of
* tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE. */
#if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 ) /*lint !e731 !e9029 Macro has been consolidated for readability reasons. */
uint8_t ucStaticallyAllocated; /*< Set to pdTRUE if the task is a statically allocated to ensure no attempt is made to free the memory. */
#endif
#if ( INCLUDE_xTaskAbortDelay == 1 )
uint8_t ucDelayAborted;
#endif
#if ( configUSE_POSIX_ERRNO == 1 )
int iTaskErrno;
#endif
} tskTCB;
/* The old tskTCB name is maintained above then typedefed to the new TCB_t name
* below to enable the use of older kernel aware debuggers. */
typedef tskTCB TCB_t;
/*lint -save -e956 A manual analysis and inspection has been used to determine
* which static variables must be declared volatile. */
portDONT_DISCARD PRIVILEGED_DATA TCB_t * volatile pxCurrentTCB = NULL;
/* Lists for ready and blocked tasks. --------------------
* xDelayedTaskList1 and xDelayedTaskList2 could be moved to function scope but
* doing so breaks some kernel aware debuggers and debuggers that rely on removing
* the static qualifier. */
PRIVILEGED_DATA static List_t pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */
PRIVILEGED_DATA static List_t xDelayedTaskList1; /*< Delayed tasks. */
PRIVILEGED_DATA static List_t xDelayedTaskList2; /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */
PRIVILEGED_DATA static List_t * volatile pxDelayedTaskList; /*< Points to the delayed task list currently being used. */
PRIVILEGED_DATA static List_t * volatile pxOverflowDelayedTaskList; /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */
PRIVILEGED_DATA static List_t xPendingReadyList; /*< Tasks that have been readied while the scheduler was suspended. They will be moved to the ready list when the scheduler is resumed. */
#if ( INCLUDE_vTaskDelete == 1 )
PRIVILEGED_DATA static List_t xTasksWaitingTermination; /*< Tasks that have been deleted - but their memory not yet freed. */
PRIVILEGED_DATA static volatile UBaseType_t uxDeletedTasksWaitingCleanUp = ( UBaseType_t ) 0U;
#endif
#if ( INCLUDE_vTaskSuspend == 1 )
PRIVILEGED_DATA static List_t xSuspendedTaskList; /*< Tasks that are currently suspended. */
#endif
/* Global POSIX errno. Its value is changed upon context switching to match
* the errno of the currently running task. */
#if ( configUSE_POSIX_ERRNO == 1 )
int FreeRTOS_errno = 0;
#endif
/* Other file private variables. --------------------------------*/
PRIVILEGED_DATA static volatile UBaseType_t uxCurrentNumberOfTasks = ( UBaseType_t ) 0U;
PRIVILEGED_DATA static volatile TickType_t xTickCount = ( TickType_t ) configINITIAL_TICK_COUNT;
PRIVILEGED_DATA static volatile UBaseType_t uxTopReadyPriority = tskIDLE_PRIORITY;
PRIVILEGED_DATA static volatile BaseType_t xSchedulerRunning = pdFALSE;
PRIVILEGED_DATA static volatile TickType_t xPendedTicks = ( TickType_t ) 0U;
PRIVILEGED_DATA static volatile BaseType_t xYieldPending = pdFALSE;
PRIVILEGED_DATA static volatile BaseType_t xNumOfOverflows = ( BaseType_t ) 0;
PRIVILEGED_DATA static UBaseType_t uxTaskNumber = ( UBaseType_t ) 0U;
PRIVILEGED_DATA static volatile TickType_t xNextTaskUnblockTime = ( TickType_t ) 0U; /* Initialised to portMAX_DELAY before the scheduler starts. */
PRIVILEGED_DATA static TaskHandle_t xIdleTaskHandle = NULL; /*< Holds the handle of the idle task. The idle task is created automatically when the scheduler is started. */
/* Improve support for OpenOCD. The kernel tracks Ready tasks via priority lists.
* For tracking the state of remote threads, OpenOCD uses uxTopUsedPriority
* to determine the number of priority lists to read back from the remote target. */
const volatile UBaseType_t uxTopUsedPriority = configMAX_PRIORITIES - 1U;
/* Context switches are held pending while the scheduler is suspended. Also,
* interrupts must not manipulate the xStateListItem of a TCB, or any of the
* lists the xStateListItem can be referenced from, if the scheduler is suspended.
* If an interrupt needs to unblock a task while the scheduler is suspended then it
* moves the task's event list item into the xPendingReadyList, ready for the
* kernel to move the task from the pending ready list into the real ready list
* when the scheduler is unsuspended. The pending ready list itself can only be
* accessed from a critical section. */
PRIVILEGED_DATA static volatile UBaseType_t uxSchedulerSuspended = ( UBaseType_t ) pdFALSE;
#if ( configGENERATE_RUN_TIME_STATS == 1 )
/* Do not move these variables to function scope as doing so prevents the
* code working with debuggers that need to remove the static qualifier. */
PRIVILEGED_DATA static configRUN_TIME_COUNTER_TYPE ulTaskSwitchedInTime = 0UL; /*< Holds the value of a timer/counter the last time a task was switched in. */
PRIVILEGED_DATA static volatile configRUN_TIME_COUNTER_TYPE ulTotalRunTime = 0UL; /*< Holds the total amount of execution time as defined by the run time counter clock. */
#endif
/*lint -restore */
/*-----------------------------------------------------------*/
/* File private functions. --------------------------------*/
/**
* Utility task that simply returns pdTRUE if the task referenced by xTask is
* currently in the Suspended state, or pdFALSE if the task referenced by xTask
* is in any other state.
*/
#if ( INCLUDE_vTaskSuspend == 1 )
static BaseType_t prvTaskIsTaskSuspended( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
#endif /* INCLUDE_vTaskSuspend */
/*
* Utility to ready all the lists used by the scheduler. This is called
* automatically upon the creation of the first task.
*/
static void prvInitialiseTaskLists( void ) PRIVILEGED_FUNCTION;
/*
* The idle task, which as all tasks is implemented as a never ending loop.
* The idle task is automatically created and added to the ready lists upon
* creation of the first user task.
*
* The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific
* language extensions. The equivalent prototype for this function is:
*
* void prvIdleTask( void *pvParameters );
*
*/
static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters ) PRIVILEGED_FUNCTION;
/*
* Utility to free all memory allocated by the scheduler to hold a TCB,
* including the stack pointed to by the TCB.
*
* This does not free memory allocated by the task itself (i.e. memory
* allocated by calls to pvPortMalloc from within the tasks application code).
*/
#if ( INCLUDE_vTaskDelete == 1 )
static void prvDeleteTCB( TCB_t * pxTCB ) PRIVILEGED_FUNCTION;
#endif
/*
* Used only by the idle task. This checks to see if anything has been placed
* in the list of tasks waiting to be deleted. If so the task is cleaned up
* and its TCB deleted.
*/
static void prvCheckTasksWaitingTermination( void ) PRIVILEGED_FUNCTION;
/*
* The currently executing task is entering the Blocked state. Add the task to
* either the current or the overflow delayed task list.
*/
static void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
const BaseType_t xCanBlockIndefinitely ) PRIVILEGED_FUNCTION;
/*
* Fills an TaskStatus_t structure with information on each task that is
* referenced from the pxList list (which may be a ready list, a delayed list,
* a suspended list, etc.).
*
* THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM
* NORMAL APPLICATION CODE.
*/
#if ( configUSE_TRACE_FACILITY == 1 )
static UBaseType_t prvListTasksWithinSingleList( TaskStatus_t * pxTaskStatusArray,
List_t * pxList,
eTaskState eState ) PRIVILEGED_FUNCTION;
#endif
/*
* Searches pxList for a task with name pcNameToQuery - returning a handle to
* the task if it is found, or NULL if the task is not found.
*/
#if ( INCLUDE_xTaskGetHandle == 1 )
static TCB_t * prvSearchForNameWithinSingleList( List_t * pxList,
const char pcNameToQuery[] ) PRIVILEGED_FUNCTION;
#endif
/*
* When a task is created, the stack of the task is filled with a known value.
* This function determines the 'high water mark' of the task stack by
* determining how much of the stack remains at the original preset value.
*/
#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark2 == 1 ) )
static configSTACK_DEPTH_TYPE prvTaskCheckFreeStackSpace( const uint8_t * pucStackByte ) PRIVILEGED_FUNCTION;
#endif
/*
* Return the amount of time, in ticks, that will pass before the kernel will
* next move a task from the Blocked state to the Running state.
*
* This conditional compilation should use inequality to 0, not equality to 1.
* This is to ensure portSUPPRESS_TICKS_AND_SLEEP() can be called when user
* defined low power mode implementations require configUSE_TICKLESS_IDLE to be
* set to a value other than 1.
*/
#if ( configUSE_TICKLESS_IDLE != 0 )
static TickType_t prvGetExpectedIdleTime( void ) PRIVILEGED_FUNCTION;
#endif
/*
* Set xNextTaskUnblockTime to the time at which the next Blocked state task
* will exit the Blocked state.
*/
static void prvResetNextTaskUnblockTime( void ) PRIVILEGED_FUNCTION;
#if ( configUSE_STATS_FORMATTING_FUNCTIONS > 0 )
/*
* Helper function used to pad task names with spaces when printing out
* human readable tables of task information.
*/
static char * prvWriteNameToBuffer( char * pcBuffer,
const char * pcTaskName ) PRIVILEGED_FUNCTION;
#endif
/*
* Called after a Task_t structure has been allocated either statically or
* dynamically to fill in the structure's members.
*/
static void prvInitialiseNewTask( TaskFunction_t pxTaskCode,
const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const uint32_t ulStackDepth,
void * const pvParameters,
UBaseType_t uxPriority,
TaskHandle_t * const pxCreatedTask,
TCB_t * pxNewTCB,
const MemoryRegion_t * const xRegions ) PRIVILEGED_FUNCTION;
/*
* Called after a new task has been created and initialised to place the task
* under the control of the scheduler.
*/
static void prvAddNewTaskToReadyList( TCB_t * pxNewTCB ) PRIVILEGED_FUNCTION;
/*
* freertos_tasks_c_additions_init() should only be called if the user definable
* macro FREERTOS_TASKS_C_ADDITIONS_INIT() is defined, as that is the only macro
* called by the function.
*/
#ifdef FREERTOS_TASKS_C_ADDITIONS_INIT
static void freertos_tasks_c_additions_init( void ) PRIVILEGED_FUNCTION;
#endif
/*-----------------------------------------------------------*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const uint32_t ulStackDepth,
void * const pvParameters,
UBaseType_t uxPriority,
StackType_t * const puxStackBuffer,
StaticTask_t * const pxTaskBuffer )
{
TCB_t * pxNewTCB;
TaskHandle_t xReturn;
configASSERT( puxStackBuffer != NULL );
configASSERT( pxTaskBuffer != NULL );
#if ( configASSERT_DEFINED == 1 )
{
/* Sanity check that the size of the structure used to declare a
* variable of type StaticTask_t equals the size of the real task
* structure. */
volatile size_t xSize = sizeof( StaticTask_t );
configASSERT( xSize == sizeof( TCB_t ) );
( void ) xSize; /* Prevent lint warning when configASSERT() is not used. */
}
#endif /* configASSERT_DEFINED */
if( ( pxTaskBuffer != NULL ) && ( puxStackBuffer != NULL ) )
{
/* The memory used for the task's TCB and stack are passed into this
* function - use them. */
pxNewTCB = ( TCB_t * ) pxTaskBuffer; /*lint !e740 !e9087 Unusual cast is ok as the structures are designed to have the same alignment, and the size is checked by an assert. */
memset( ( void * ) pxNewTCB, 0x00, sizeof( TCB_t ) );
pxNewTCB->pxStack = ( StackType_t * ) puxStackBuffer;
#if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 ) /*lint !e731 !e9029 Macro has been consolidated for readability reasons. */
{
/* Tasks can be created statically or dynamically, so note this
* task was created statically in case the task is later deleted. */
pxNewTCB->ucStaticallyAllocated = tskSTATICALLY_ALLOCATED_STACK_AND_TCB;
}
#endif /* tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE */
prvInitialiseNewTask( pxTaskCode, pcName, ulStackDepth, pvParameters, uxPriority, &xReturn, pxNewTCB, NULL );
prvAddNewTaskToReadyList( pxNewTCB );
}
else
{
xReturn = NULL;
}
return xReturn;
}
#endif /* SUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
#if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
BaseType_t xTaskCreateRestrictedStatic( const TaskParameters_t * const pxTaskDefinition,
TaskHandle_t * pxCreatedTask )
{
TCB_t * pxNewTCB;
BaseType_t xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
configASSERT( pxTaskDefinition->puxStackBuffer != NULL );
configASSERT( pxTaskDefinition->pxTaskBuffer != NULL );
if( ( pxTaskDefinition->puxStackBuffer != NULL ) && ( pxTaskDefinition->pxTaskBuffer != NULL ) )
{
/* Allocate space for the TCB. Where the memory comes from depends
* on the implementation of the port malloc function and whether or
* not static allocation is being used. */
pxNewTCB = ( TCB_t * ) pxTaskDefinition->pxTaskBuffer;
memset( ( void * ) pxNewTCB, 0x00, sizeof( TCB_t ) );
/* Store the stack location in the TCB. */
pxNewTCB->pxStack = pxTaskDefinition->puxStackBuffer;
#if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 )
{
/* Tasks can be created statically or dynamically, so note this
* task was created statically in case the task is later deleted. */
pxNewTCB->ucStaticallyAllocated = tskSTATICALLY_ALLOCATED_STACK_AND_TCB;
}
#endif /* tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE */
prvInitialiseNewTask( pxTaskDefinition->pvTaskCode,
pxTaskDefinition->pcName,
( uint32_t ) pxTaskDefinition->usStackDepth,
pxTaskDefinition->pvParameters,
pxTaskDefinition->uxPriority,
pxCreatedTask, pxNewTCB,
pxTaskDefinition->xRegions );
prvAddNewTaskToReadyList( pxNewTCB );
xReturn = pdPASS;
}
return xReturn;
}
#endif /* ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) */
/*-----------------------------------------------------------*/
#if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) )
BaseType_t xTaskCreateRestricted( const TaskParameters_t * const pxTaskDefinition,
TaskHandle_t * pxCreatedTask )
{
TCB_t * pxNewTCB;
BaseType_t xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
configASSERT( pxTaskDefinition->puxStackBuffer );
if( pxTaskDefinition->puxStackBuffer != NULL )
{
/* Allocate space for the TCB. Where the memory comes from depends
* on the implementation of the port malloc function and whether or
* not static allocation is being used. */
pxNewTCB = ( TCB_t * ) pvPortMalloc( sizeof( TCB_t ) );
if( pxNewTCB != NULL )
{
memset( ( void * ) pxNewTCB, 0x00, sizeof( TCB_t ) );
/* Store the stack location in the TCB. */
pxNewTCB->pxStack = pxTaskDefinition->puxStackBuffer;
#if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 )
{
/* Tasks can be created statically or dynamically, so note
* this task had a statically allocated stack in case it is
* later deleted. The TCB was allocated dynamically. */
pxNewTCB->ucStaticallyAllocated = tskSTATICALLY_ALLOCATED_STACK_ONLY;
}
#endif /* tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE */
prvInitialiseNewTask( pxTaskDefinition->pvTaskCode,
pxTaskDefinition->pcName,
( uint32_t ) pxTaskDefinition->usStackDepth,
pxTaskDefinition->pvParameters,
pxTaskDefinition->uxPriority,
pxCreatedTask, pxNewTCB,
pxTaskDefinition->xRegions );
prvAddNewTaskToReadyList( pxNewTCB );
xReturn = pdPASS;
}
}
return xReturn;
}
#endif /* portUSING_MPU_WRAPPERS */
/*-----------------------------------------------------------*/
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
BaseType_t xTaskCreate( TaskFunction_t pxTaskCode,
const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const configSTACK_DEPTH_TYPE usStackDepth,
void * const pvParameters,
UBaseType_t uxPriority,
TaskHandle_t * const pxCreatedTask )
{
TCB_t * pxNewTCB;
BaseType_t xReturn;
/* If the stack grows down then allocate the stack then the TCB so the stack
* does not grow into the TCB. Likewise if the stack grows up then allocate
* the TCB then the stack. */
#if ( portSTACK_GROWTH > 0 )
{
/* Allocate space for the TCB. Where the memory comes from depends on
* the implementation of the port malloc function and whether or not static
* allocation is being used. */
pxNewTCB = ( TCB_t * ) pvPortMalloc( sizeof( TCB_t ) );
if( pxNewTCB != NULL )
{
memset( ( void * ) pxNewTCB, 0x00, sizeof( TCB_t ) );
/* Allocate space for the stack used by the task being created.
* The base of the stack memory stored in the TCB so the task can
* be deleted later if required. */
pxNewTCB->pxStack = ( StackType_t * ) pvPortMallocStack( ( ( ( size_t ) usStackDepth ) * sizeof( StackType_t ) ) ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */
if( pxNewTCB->pxStack == NULL )
{
/* Could not allocate the stack. Delete the allocated TCB. */
vPortFree( pxNewTCB );
pxNewTCB = NULL;
}
}
}
#else /* portSTACK_GROWTH */
{
StackType_t * pxStack;
/* Allocate space for the stack used by the task being created. */
pxStack = pvPortMallocStack( ( ( ( size_t ) usStackDepth ) * sizeof( StackType_t ) ) ); /*lint !e9079 All values returned by pvPortMalloc() have at least the alignment required by the MCU's stack and this allocation is the stack. */
if( pxStack != NULL )
{
/* Allocate space for the TCB. */
pxNewTCB = ( TCB_t * ) pvPortMalloc( sizeof( TCB_t ) ); /*lint !e9087 !e9079 All values returned by pvPortMalloc() have at least the alignment required by the MCU's stack, and the first member of TCB_t is always a pointer to the task's stack. */
if( pxNewTCB != NULL )
{
memset( ( void * ) pxNewTCB, 0x00, sizeof( TCB_t ) );
/* Store the stack location in the TCB. */
pxNewTCB->pxStack = pxStack;
}
else
{
/* The stack cannot be used as the TCB was not created. Free
* it again. */
vPortFreeStack( pxStack );
}
}
else
{
pxNewTCB = NULL;
}
}
#endif /* portSTACK_GROWTH */
if( pxNewTCB != NULL )
{
#if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 ) /*lint !e9029 !e731 Macro has been consolidated for readability reasons. */
{
/* Tasks can be created statically or dynamically, so note this
* task was created dynamically in case it is later deleted. */
pxNewTCB->ucStaticallyAllocated = tskDYNAMICALLY_ALLOCATED_STACK_AND_TCB;
}
#endif /* tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE */
prvInitialiseNewTask( pxTaskCode, pcName, ( uint32_t ) usStackDepth, pvParameters, uxPriority, pxCreatedTask, pxNewTCB, NULL );
prvAddNewTaskToReadyList( pxNewTCB );
xReturn = pdPASS;
}
else
{
xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
}
return xReturn;
}
#endif /* configSUPPORT_DYNAMIC_ALLOCATION */
/*-----------------------------------------------------------*/
static void prvInitialiseNewTask( TaskFunction_t pxTaskCode,
const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
const uint32_t ulStackDepth,
void * const pvParameters,
UBaseType_t uxPriority,
TaskHandle_t * const pxCreatedTask,
TCB_t * pxNewTCB,
const MemoryRegion_t * const xRegions )
{
StackType_t * pxTopOfStack;
UBaseType_t x;
#if ( portUSING_MPU_WRAPPERS == 1 )
/* Should the task be created in privileged mode? */
BaseType_t xRunPrivileged;
if( ( uxPriority & portPRIVILEGE_BIT ) != 0U )
{
xRunPrivileged = pdTRUE;
}
else
{
xRunPrivileged = pdFALSE;
}
uxPriority &= ~portPRIVILEGE_BIT;
#endif /* portUSING_MPU_WRAPPERS == 1 */
/* Avoid dependency on memset() if it is not required. */
#if ( tskSET_NEW_STACKS_TO_KNOWN_VALUE == 1 )
{
/* Fill the stack with a known value to assist debugging. */
( void ) memset( pxNewTCB->pxStack, ( int ) tskSTACK_FILL_BYTE, ( size_t ) ulStackDepth * sizeof( StackType_t ) );
}
#endif /* tskSET_NEW_STACKS_TO_KNOWN_VALUE */
/* Calculate the top of stack address. This depends on whether the stack
* grows from high memory to low (as per the 80x86) or vice versa.
* portSTACK_GROWTH is used to make the result positive or negative as required
* by the port. */
#if ( portSTACK_GROWTH < 0 )
{
pxTopOfStack = &( pxNewTCB->pxStack[ ulStackDepth - ( uint32_t ) 1 ] );
pxTopOfStack = ( StackType_t * ) ( ( ( portPOINTER_SIZE_TYPE ) pxTopOfStack ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) ); /*lint !e923 !e9033 !e9078 MISRA exception. Avoiding casts between pointers and integers is not practical. Size differences accounted for using portPOINTER_SIZE_TYPE type. Checked by assert(). */
/* Check the alignment of the calculated top of stack is correct. */
configASSERT( ( ( ( portPOINTER_SIZE_TYPE ) pxTopOfStack & ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) == 0UL ) );
#if ( configRECORD_STACK_HIGH_ADDRESS == 1 )
{
/* Also record the stack's high address, which may assist
* debugging. */
pxNewTCB->pxEndOfStack = pxTopOfStack;
}
#endif /* configRECORD_STACK_HIGH_ADDRESS */
}
#else /* portSTACK_GROWTH */
{
pxTopOfStack = pxNewTCB->pxStack;
/* Check the alignment of the stack buffer is correct. */
configASSERT( ( ( ( portPOINTER_SIZE_TYPE ) pxNewTCB->pxStack & ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) == 0UL ) );
/* The other extreme of the stack space is required if stack checking is
* performed. */
pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( ulStackDepth - ( uint32_t ) 1 );
}
#endif /* portSTACK_GROWTH */
/* Store the task name in the TCB. */
if( pcName != NULL )
{
for( x = ( UBaseType_t ) 0; x < ( UBaseType_t ) configMAX_TASK_NAME_LEN; x++ )
{
pxNewTCB->pcTaskName[ x ] = pcName[ x ];
/* Don't copy all configMAX_TASK_NAME_LEN if the string is shorter than
* configMAX_TASK_NAME_LEN characters just in case the memory after the
* string is not accessible (extremely unlikely). */
if( pcName[ x ] == ( char ) 0x00 )
{
break;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
/* Ensure the name string is terminated in the case that the string length
* was greater or equal to configMAX_TASK_NAME_LEN. */
pxNewTCB->pcTaskName[ configMAX_TASK_NAME_LEN - 1 ] = '\0';
}
else
{
mtCOVERAGE_TEST_MARKER();
}
/* This is used as an array index so must ensure it's not too large. */
configASSERT( uxPriority < configMAX_PRIORITIES );
if( uxPriority >= ( UBaseType_t ) configMAX_PRIORITIES )
{
uxPriority = ( UBaseType_t ) configMAX_PRIORITIES - ( UBaseType_t ) 1U;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
pxNewTCB->uxPriority = uxPriority;
#if ( configUSE_MUTEXES == 1 )
{
pxNewTCB->uxBasePriority = uxPriority;
}
#endif /* configUSE_MUTEXES */
vListInitialiseItem( &( pxNewTCB->xStateListItem ) );
vListInitialiseItem( &( pxNewTCB->xEventListItem ) );
/* Set the pxNewTCB as a link back from the ListItem_t. This is so we can get
* back to the containing TCB from a generic item in a list. */
listSET_LIST_ITEM_OWNER( &( pxNewTCB->xStateListItem ), pxNewTCB );
/* Event lists are always in priority order. */
listSET_LIST_ITEM_VALUE( &( pxNewTCB->xEventListItem ), ( TickType_t ) configMAX_PRIORITIES - ( TickType_t ) uxPriority ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */
listSET_LIST_ITEM_OWNER( &( pxNewTCB->xEventListItem ), pxNewTCB );
#if ( portUSING_MPU_WRAPPERS == 1 )
{
vPortStoreTaskMPUSettings( &( pxNewTCB->xMPUSettings ), xRegions, pxNewTCB->pxStack, ulStackDepth );
}
#else
{
/* Avoid compiler warning about unreferenced parameter. */
( void ) xRegions;
}
#endif
#if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
{
/* Allocate and initialize memory for the task's TLS Block. */
configINIT_TLS_BLOCK( pxNewTCB->xTLSBlock );
}
#endif
/* Initialize the TCB stack to look as if the task was already running,
* but had been interrupted by the scheduler. The return address is set
* to the start of the task function. Once the stack has been initialised
* the top of stack variable is updated. */
#if ( portUSING_MPU_WRAPPERS == 1 )
{
/* If the port has capability to detect stack overflow,
* pass the stack end address to the stack initialization
* function as well. */
#if ( portHAS_STACK_OVERFLOW_CHECKING == 1 )
{
#if ( portSTACK_GROWTH < 0 )
{
pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxNewTCB->pxStack, pxTaskCode, pvParameters, xRunPrivileged );
}
#else /* portSTACK_GROWTH */
{
pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxNewTCB->pxEndOfStack, pxTaskCode, pvParameters, xRunPrivileged );
}
#endif /* portSTACK_GROWTH */
}
#else /* portHAS_STACK_OVERFLOW_CHECKING */
{
pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxTaskCode, pvParameters, xRunPrivileged );
}
#endif /* portHAS_STACK_OVERFLOW_CHECKING */
}
#else /* portUSING_MPU_WRAPPERS */
{
/* If the port has capability to detect stack overflow,
* pass the stack end address to the stack initialization
* function as well. */
#if ( portHAS_STACK_OVERFLOW_CHECKING == 1 )
{
#if ( portSTACK_GROWTH < 0 )
{
pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxNewTCB->pxStack, pxTaskCode, pvParameters );
}
#else /* portSTACK_GROWTH */
{