/* FreeRTOS V7.5.3 - Copyright (C) 2013 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that has become a de facto standard. * * * * Help yourself get started quickly and support the FreeRTOS * * project by purchasing a FreeRTOS tutorial book, reference * * manual, or both from: http://www.FreeRTOS.org/Documentation * * * * Thank you! * * * *************************************************************************** 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. Full license text is available from the following link: http://www.freertos.org/a00114.html 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, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and middleware. 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. 1 tab == 4 spaces! */ /* Standard includes. */ #include #include /* 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 "StackMacros.h" /* Lint 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. */ #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 #endif /* configUSE_STATS_FORMATTING_FUNCTIONS == 1 ) */ /* Sanity check the configuration. */ #if configUSE_TICKLESS_IDLE != 0 #if INCLUDE_vTaskSuspend != 1 #error INCLUDE_vTaskSuspend must be set to 1 if configUSE_TICKLESS_IDLE is not set to 0 #endif /* INCLUDE_vTaskSuspend */ #endif /* configUSE_TICKLESS_IDLE */ /* * Defines the size, in words, of the stack allocated to the idle task. */ #define tskIDLE_STACK_SIZE configMINIMAL_STACK_SIZE /* * 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 { volatile portSTACK_TYPE *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 xListItem xGenericListItem; /*< The list that the state list item of a task is reference from denotes the state of that task (Ready, Blocked, Suspended ). */ xListItem xEventListItem; /*< Used to reference a task from an event list. */ unsigned portBASE_TYPE uxPriority; /*< The priority of the task. 0 is the lowest priority. */ portSTACK_TYPE *pxStack; /*< Points to the start of the stack. */ signed char pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created. Facilitates debugging only. */ #if ( portSTACK_GROWTH > 0 ) portSTACK_TYPE *pxEndOfStack; /*< Points to the end of the stack on architectures where the stack grows up from low memory. */ #endif #if ( portCRITICAL_NESTING_IN_TCB == 1 ) unsigned portBASE_TYPE 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 ) unsigned portBASE_TYPE 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. */ unsigned portBASE_TYPE uxTaskNumber; /*< Stores a number specifically for use by third party trace code. */ #endif #if ( configUSE_MUTEXES == 1 ) unsigned portBASE_TYPE uxBasePriority; /*< The priority last assigned to the task - used by the priority inheritance mechanism. */ #endif #if ( configUSE_APPLICATION_TASK_TAG == 1 ) pdTASK_HOOK_CODE pxTaskTag; #endif #if ( configGENERATE_RUN_TIME_STATS == 1 ) unsigned long ulRunTimeCounter; /*< Stores the amount of time the task has spent in the Running state. */ #endif #if ( configUSE_NEWLIB_REENTRANT == 1 ) /* Allocate a Newlib reent structure that is specific to this task. Note Newlib support has been included by popular demand, but is not used by the FreeRTOS maintainers themselves. FreeRTOS is not responsible for resulting newlib operation. User must be familiar with newlib and must provide system-wide implementations of the necessary stubs. Be warned that (at the time of writing) the current newlib design implements a system-wide malloc() that must be provided with locks. */ struct _reent xNewLib_reent; #endif } tskTCB; /* * 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 /*lint -e956 A manual analysis and inspection has been used to determine which static variables must be declared volatile. */ PRIVILEGED_DATA tskTCB * volatile pxCurrentTCB = NULL; /* Lists for ready and blocked tasks. --------------------*/ PRIVILEGED_DATA static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */ PRIVILEGED_DATA static xList xDelayedTaskList1; /*< Delayed tasks. */ PRIVILEGED_DATA static xList xDelayedTaskList2; /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */ PRIVILEGED_DATA static xList * volatile pxDelayedTaskList; /*< Points to the delayed task list currently being used. */ PRIVILEGED_DATA static xList * volatile pxOverflowDelayedTaskList; /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */ PRIVILEGED_DATA static xList 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 xList xTasksWaitingTermination; /*< Tasks that have been deleted - but the their memory not yet freed. */ PRIVILEGED_DATA static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0U; #endif #if ( INCLUDE_vTaskSuspend == 1 ) PRIVILEGED_DATA static xList xSuspendedTaskList; /*< Tasks that are currently suspended. */ #endif #if ( INCLUDE_xTaskGetIdleTaskHandle == 1 ) PRIVILEGED_DATA static xTaskHandle xIdleTaskHandle = NULL; /*< Holds the handle of the idle task. The idle task is created automatically when the scheduler is started. */ #endif /* Other file private variables. --------------------------------*/ PRIVILEGED_DATA static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks = ( unsigned portBASE_TYPE ) 0U; PRIVILEGED_DATA static volatile portTickType xTickCount = ( portTickType ) 0U; PRIVILEGED_DATA static volatile unsigned portBASE_TYPE uxTopReadyPriority = tskIDLE_PRIORITY; PRIVILEGED_DATA static volatile signed portBASE_TYPE xSchedulerRunning = pdFALSE; PRIVILEGED_DATA static volatile unsigned portBASE_TYPE uxSchedulerSuspended = ( unsigned portBASE_TYPE ) pdFALSE; PRIVILEGED_DATA static volatile unsigned portBASE_TYPE uxPendedTicks = ( unsigned portBASE_TYPE ) 0U; PRIVILEGED_DATA static volatile portBASE_TYPE xYieldPending = pdFALSE; PRIVILEGED_DATA static volatile portBASE_TYPE xNumOfOverflows = ( portBASE_TYPE ) 0; PRIVILEGED_DATA static unsigned portBASE_TYPE uxTaskNumber = ( unsigned portBASE_TYPE ) 0U; PRIVILEGED_DATA static volatile portTickType xNextTaskUnblockTime = portMAX_DELAY; #if ( configGENERATE_RUN_TIME_STATS == 1 ) PRIVILEGED_DATA static unsigned long ulTaskSwitchedInTime = 0UL; /*< Holds the value of a timer/counter the last time a task was switched in. */ PRIVILEGED_DATA static unsigned long ulTotalRunTime = 0UL; /*< Holds the total amount of execution time as defined by the run time counter clock. */ #endif /*lint +e956 */ /* Debugging and trace facilities private variables and macros. ------------*/ /* * 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 ) /* * Macros used by vListTask to indicate which state a task is in. */ #define tskBLOCKED_CHAR ( ( signed char ) 'B' ) #define tskREADY_CHAR ( ( signed char ) 'R' ) #define tskDELETED_CHAR ( ( signed char ) 'D' ) #define tskSUSPENDED_CHAR ( ( signed char ) 'S' ) /*-----------------------------------------------------------*/ #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() \ { \ /* Find the highest priority queue that contains ready tasks. */ \ while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) ) \ { \ configASSERT( uxTopReadyPriority ); \ --uxTopReadyPriority; \ } \ \ /* 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[ uxTopReadyPriority ] ) ); \ } /* 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() \ { \ unsigned portBASE_TYPE uxTopPriority; \ \ /* Find the highest priority queue 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 ) ] ) ) == 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() \ { \ xList *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++; \ \ if( listLIST_IS_EMPTY( pxDelayedTaskList ) != pdFALSE ) \ { \ /* The new current delayed list is empty. Set \ xNextTaskUnblockTime to the maximum possible value so it is \ extremely unlikely that the \ if( xTickCount >= xNextTaskUnblockTime ) test will pass until \ there is an item in the delayed list. */ \ xNextTaskUnblockTime = portMAX_DELAY; \ } \ else \ { \ /* The new current delayed list is not empty, get the value of \ the item at the head of the delayed list. This is the time at \ which the task at the head of the delayed list should be removed \ from the Blocked state. */ \ pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ); \ xNextTaskUnblockTime = listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ); \ } \ } /*-----------------------------------------------------------*/ /* * 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 ); \ vListInsertEnd( &( pxReadyTasksLists[ ( pxTCB )->uxPriority ] ), &( ( pxTCB )->xGenericListItem ) ) /*-----------------------------------------------------------*/ /* * Several functions take an xTaskHandle 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 ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) ( pxHandle ) ) /* Callback function prototypes. --------------------------*/ extern void vApplicationStackOverflowHook( xTaskHandle xTask, signed char *pcTaskName ); extern void vApplicationTickHook( void ); /* File private functions. --------------------------------*/ /* * Utility to ready a TCB for a given task. Mainly just copies the parameters * into the TCB structure. */ static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed char * const pcName, unsigned portBASE_TYPE uxPriority, const xMemoryRegion * const xRegions, unsigned short usStackDepth ) PRIVILEGED_FUNCTION; /* * 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 ); /* * 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( tskTCB *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( portTickType xTimeToWake ) PRIVILEGED_FUNCTION; /* * Allocates memory from the heap for a TCB and associated stack. Checks the * allocation was successful. */ static tskTCB *prvAllocateTCBAndStack( unsigned short usStackDepth, portSTACK_TYPE *puxStackBuffer ) PRIVILEGED_FUNCTION; /* * Fills an xTaskStatusType 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 unsigned portBASE_TYPE prvListTaskWithinSingleList( xTaskStatusType *pxTaskStatusArray, xList *pxList, eTaskState eState ) 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 ) ) static unsigned short prvTaskCheckFreeStackSpace( const unsigned char * 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 portTickType prvGetExpectedIdleTime( void ) PRIVILEGED_FUNCTION; #endif signed portBASE_TYPE xTaskGenericCreate( pdTASK_CODE pxTaskCode, const signed char * const pcName, unsigned short usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask, portSTACK_TYPE *puxStackBuffer, const xMemoryRegion * const xRegions ) { signed portBASE_TYPE xReturn; tskTCB * pxNewTCB; configASSERT( pxTaskCode ); configASSERT( ( ( uxPriority & ( ~portPRIVILEGE_BIT ) ) < configMAX_PRIORITIES ) ); /* Allocate the memory required by the TCB and stack for the new task, checking that the allocation was successful. */ pxNewTCB = prvAllocateTCBAndStack( usStackDepth, puxStackBuffer ); if( pxNewTCB != NULL ) { portSTACK_TYPE *pxTopOfStack; #if( portUSING_MPU_WRAPPERS == 1 ) /* Should the task be created in privileged mode? */ portBASE_TYPE xRunPrivileged; if( ( uxPriority & portPRIVILEGE_BIT ) != 0U ) { xRunPrivileged = pdTRUE; } else { xRunPrivileged = pdFALSE; } uxPriority &= ~portPRIVILEGE_BIT; #endif /* portUSING_MPU_WRAPPERS == 1 */ /* Calculate the top of stack address. This depends on whether the stack grows from high memory to low (as per the 80x86) or visa versa. portSTACK_GROWTH is used to make the result positive or negative as required by the port. */ #if( portSTACK_GROWTH < 0 ) { pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - ( unsigned short ) 1 ); pxTopOfStack = ( portSTACK_TYPE * ) ( ( ( portPOINTER_SIZE_TYPE ) pxTopOfStack ) & ( ( portPOINTER_SIZE_TYPE ) ~portBYTE_ALIGNMENT_MASK ) ); /*lint !e923 MISRA exception. Avoiding casts between pointers and integers is not practical. Size differences accounted for using portPOINTER_SIZE_TYPE type. */ /* Check the alignment of the calculated top of stack is correct. */ configASSERT( ( ( ( unsigned long ) pxTopOfStack & ( unsigned long ) portBYTE_ALIGNMENT_MASK ) == 0UL ) ); } #else /* portSTACK_GROWTH */ { pxTopOfStack = pxNewTCB->pxStack; /* Check the alignment of the stack buffer is correct. */ configASSERT( ( ( ( unsigned long ) pxNewTCB->pxStack & ( unsigned long ) portBYTE_ALIGNMENT_MASK ) == 0UL ) ); /* If we want to use stack checking on architectures that use a positive stack growth direction then we also need to store the other extreme of the stack space. */ pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 ); } #endif /* portSTACK_GROWTH */ /* Setup the newly allocated TCB with the initial state of the task. */ prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority, xRegions, usStackDepth ); /* 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 ) { pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxTaskCode, pvParameters, xRunPrivileged ); } #else /* portUSING_MPU_WRAPPERS */ { pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pxTaskCode, pvParameters ); } #endif /* portUSING_MPU_WRAPPERS */ if( ( void * ) pxCreatedTask != NULL ) { /* Pass the TCB out - in an anonymous way. The calling function/ task can use this as a handle to delete the task later if required.*/ *pxCreatedTask = ( xTaskHandle ) pxNewTCB; } /* Ensure interrupts don't access the task lists while they are being updated. */ taskENTER_CRITICAL(); { uxCurrentNumberOfTasks++; if( pxCurrentTCB == NULL ) { /* There are no other tasks, or all the other tasks are in the suspended state - make this the current task. */ pxCurrentTCB = pxNewTCB; if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 ) { /* This is the first task to be created so do the preliminary initialisation required. We will not recover if this call fails, but we will report the failure. */ prvInitialiseTaskLists(); } } else { /* If the scheduler is not already running, make this task the current task if it is the highest priority task to be created so far. */ if( xSchedulerRunning == pdFALSE ) { if( pxCurrentTCB->uxPriority <= uxPriority ) { pxCurrentTCB = pxNewTCB; } } } uxTaskNumber++; #if ( configUSE_TRACE_FACILITY == 1 ) { /* Add a counter into the TCB for tracing only. */ pxNewTCB->uxTCBNumber = uxTaskNumber; } #endif /* configUSE_TRACE_FACILITY */ traceTASK_CREATE( pxNewTCB ); prvAddTaskToReadyList( pxNewTCB ); xReturn = pdPASS; portSETUP_TCB( pxNewTCB ); } taskEXIT_CRITICAL(); } else { xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY; traceTASK_CREATE_FAILED(); } if( xReturn == pdPASS ) { if( xSchedulerRunning != pdFALSE ) { /* If the created task is of a higher priority than the current task then it should run now. */ if( pxCurrentTCB->uxPriority < uxPriority ) { portYIELD_WITHIN_API(); } } } return xReturn; } /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskDelete == 1 ) void vTaskDelete( xTaskHandle xTaskToDelete ) { tskTCB *pxTCB; taskENTER_CRITICAL(); { /* If null is passed in here then we are deleting ourselves. */ pxTCB = prvGetTCBFromHandle( xTaskToDelete ); /* Remove task from the ready list and place in the termination list. This will stop the task from be scheduled. The idle task will check the termination list and free up any memory allocated by the scheduler for the TCB and stack. */ if( uxListRemove( &( pxTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { taskRESET_READY_PRIORITY( pxTCB->uxPriority ); } /* Is the task waiting on an event also? */ if( listLIST_ITEM_CONTAINER( &( pxTCB->xEventListItem ) ) != NULL ) { ( void ) uxListRemove( &( pxTCB->xEventListItem ) ); } vListInsertEnd( &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) ); /* Increment the ucTasksDeleted variable so the idle task knows there is a task that has been deleted and that it should therefore check the xTasksWaitingTermination list. */ ++uxTasksDeleted; /* Increment the uxTaskNumberVariable also so kernel aware debuggers can detect that the task lists need re-generating. */ uxTaskNumber++; traceTASK_DELETE( pxTCB ); } taskEXIT_CRITICAL(); /* Force a reschedule if we have just deleted the current task. */ if( xSchedulerRunning != pdFALSE ) { if( pxTCB == pxCurrentTCB ) { portYIELD_WITHIN_API(); } } } #endif /* INCLUDE_vTaskDelete */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskDelayUntil == 1 ) void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement ) { portTickType xTimeToWake; portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE; configASSERT( pxPreviousWakeTime ); configASSERT( ( xTimeIncrement > 0U ) ); vTaskSuspendAll(); { /* Minor optimisation. The tick count cannot change in this block. */ const portTickType xConstTickCount = xTickCount; /* Generate the tick time at which the task wants to wake. */ xTimeToWake = *pxPreviousWakeTime + xTimeIncrement; if( xConstTickCount < *pxPreviousWakeTime ) { /* The tick count has overflowed since this function was lasted called. In this case the only time we should ever actually delay is if the wake time has also overflowed, and the wake time is greater than the tick time. When this is the case it is as if neither time had overflowed. */ if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xConstTickCount ) ) { xShouldDelay = pdTRUE; } } else { /* The tick time has not overflowed. In this case we will delay if either the wake time has overflowed, and/or the tick time is less than the wake time. */ if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xConstTickCount ) ) { xShouldDelay = pdTRUE; } } /* Update the wake time ready for the next call. */ *pxPreviousWakeTime = xTimeToWake; if( xShouldDelay != pdFALSE ) { traceTASK_DELAY_UNTIL(); /* 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. */ if( uxListRemove( &( pxCurrentTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { /* The current task must be in a ready list, so there is no need to check, and the port reset macro can be called directly. */ portRESET_READY_PRIORITY( pxCurrentTCB->uxPriority, uxTopReadyPriority ); } prvAddCurrentTaskToDelayedList( xTimeToWake ); } } xAlreadyYielded = xTaskResumeAll(); /* Force a reschedule if xTaskResumeAll has not already done so, we may have put ourselves to sleep. */ if( xAlreadyYielded == pdFALSE ) { portYIELD_WITHIN_API(); } } #endif /* INCLUDE_vTaskDelayUntil */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskDelay == 1 ) void vTaskDelay( portTickType xTicksToDelay ) { portTickType xTimeToWake; signed portBASE_TYPE xAlreadyYielded = pdFALSE; /* A delay time of zero just forces a reschedule. */ if( xTicksToDelay > ( portTickType ) 0U ) { vTaskSuspendAll(); { traceTASK_DELAY(); /* A task that is removed from the event list while the scheduler is suspended will not get placed in the ready list or removed from the blocked list until the scheduler is resumed. This task cannot be in an event list as it is the currently executing task. */ /* Calculate the time to wake - this may overflow but this is not a problem. */ xTimeToWake = xTickCount + 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. */ if( uxListRemove( &( pxCurrentTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { /* The current task must be in a ready list, so there is no need to check, and the port reset macro can be called directly. */ portRESET_READY_PRIORITY( pxCurrentTCB->uxPriority, uxTopReadyPriority ); } prvAddCurrentTaskToDelayedList( xTimeToWake ); } xAlreadyYielded = xTaskResumeAll(); } /* Force a reschedule if xTaskResumeAll has not already done so, we may have put ourselves to sleep. */ if( xAlreadyYielded == pdFALSE ) { portYIELD_WITHIN_API(); } } #endif /* INCLUDE_vTaskDelay */ /*-----------------------------------------------------------*/ #if ( INCLUDE_eTaskGetState == 1 ) eTaskState eTaskGetState( xTaskHandle xTask ) { eTaskState eReturn; xList *pxStateList; const tskTCB * const pxTCB = ( tskTCB * ) xTask; if( pxTCB == pxCurrentTCB ) { /* The task calling this function is querying its own state. */ eReturn = eRunning; } else { taskENTER_CRITICAL(); { pxStateList = ( xList * ) listLIST_ITEM_CONTAINER( &( pxTCB->xGenericListItem ) ); } taskEXIT_CRITICAL(); if( ( pxStateList == pxDelayedTaskList ) || ( pxStateList == pxOverflowDelayedTaskList ) ) { /* The task being queried is referenced from one of the Blocked lists. */ eReturn = eBlocked; } #if ( INCLUDE_vTaskSuspend == 1 ) else if( pxStateList == &xSuspendedTaskList ) { /* The task being queried is referenced from the suspended list. */ eReturn = eSuspended; } #endif #if ( INCLUDE_vTaskDelete == 1 ) else if( pxStateList == &xTasksWaitingTermination ) { /* The task being queried is referenced from the deleted tasks list. */ eReturn = eDeleted; } #endif else { /* If the task is not in any other state, it must be in the Ready (including pending ready) state. */ eReturn = eReady; } } return eReturn; } #endif /* INCLUDE_eTaskGetState */ /*-----------------------------------------------------------*/ #if ( INCLUDE_uxTaskPriorityGet == 1 ) unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle xTask ) { tskTCB *pxTCB; unsigned portBASE_TYPE uxReturn; taskENTER_CRITICAL(); { /* If null is passed in here then we are changing the priority of the calling function. */ pxTCB = prvGetTCBFromHandle( xTask ); uxReturn = pxTCB->uxPriority; } taskEXIT_CRITICAL(); return uxReturn; } #endif /* INCLUDE_uxTaskPriorityGet */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskPrioritySet == 1 ) void vTaskPrioritySet( xTaskHandle xTask, unsigned portBASE_TYPE uxNewPriority ) { tskTCB *pxTCB; unsigned portBASE_TYPE uxCurrentBasePriority, uxPriorityUsedOnEntry; portBASE_TYPE xYieldRequired = pdFALSE; configASSERT( ( uxNewPriority < configMAX_PRIORITIES ) ); /* Ensure the new priority is valid. */ if( uxNewPriority >= ( unsigned portBASE_TYPE ) configMAX_PRIORITIES ) { uxNewPriority = ( unsigned portBASE_TYPE ) configMAX_PRIORITIES - ( unsigned portBASE_TYPE ) 1U; } taskENTER_CRITICAL(); { /* If null is passed in here then it is the priority of the calling task that is being changed. */ pxTCB = prvGetTCBFromHandle( xTask ); traceTASK_PRIORITY_SET( pxTCB, uxNewPriority ); #if ( configUSE_MUTEXES == 1 ) { uxCurrentBasePriority = pxTCB->uxBasePriority; } #else { uxCurrentBasePriority = pxTCB->uxPriority; } #endif if( uxCurrentBasePriority != uxNewPriority ) { /* The priority change may have readied a task of higher priority than the calling task. */ if( uxNewPriority > uxCurrentBasePriority ) { if( pxTCB != pxCurrentTCB ) { /* The priority of a task other than the currently running task is being raised. Is the priority being raised above that of the running task? */ if( uxNewPriority >= pxCurrentTCB->uxPriority ) { xYieldRequired = pdTRUE; } } else { /* The priority of the running task is being raised, but the running task must already be the highest priority task able to run so no yield is required. */ } } else if( pxTCB == pxCurrentTCB ) { /* Setting the priority of the running task down means there may now be another task of higher priority that is ready to execute. */ xYieldRequired = pdTRUE; } else { /* Setting the priority of any other task down does not require a yield as the running task must be above the new priority of the task being modified. */ } /* Remember the ready list the task might be referenced from before its uxPriority member is changed so the taskRESET_READY_PRIORITY() macro can function correctly. */ uxPriorityUsedOnEntry = pxTCB->uxPriority; #if ( configUSE_MUTEXES == 1 ) { /* Only change the priority being used if the task is not currently using an inherited priority. */ if( pxTCB->uxBasePriority == pxTCB->uxPriority ) { pxTCB->uxPriority = uxNewPriority; } /* The base priority gets set whatever. */ pxTCB->uxBasePriority = uxNewPriority; } #else { pxTCB->uxPriority = uxNewPriority; } #endif listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( ( portTickType ) configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */ /* If the task is in the blocked or suspended list we need do nothing more than change it's priority variable. However, if the task is in a ready list it needs to be removed and placed in the list appropriate to its new priority. */ if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxPriorityUsedOnEntry ] ), &( pxTCB->xGenericListItem ) ) != pdFALSE ) { /* The task is currently in its ready list - remove before adding it to it's new ready list. As we are in a critical section we can do this even if the scheduler is suspended. */ if( uxListRemove( &( pxTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { /* It is known that the task is in its ready list so there is no need to check again and the port level reset macro can be called directly. */ portRESET_READY_PRIORITY( uxPriorityUsedOnEntry, uxTopReadyPriority ); } prvAddTaskToReadyList( pxTCB ); } if( xYieldRequired == pdTRUE ) { portYIELD_WITHIN_API(); } /* Remove compiler warning about unused variables when the port optimised task selection is not being used. */ ( void ) uxPriorityUsedOnEntry; } } taskEXIT_CRITICAL(); } #endif /* INCLUDE_vTaskPrioritySet */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskSuspend == 1 ) void vTaskSuspend( xTaskHandle xTaskToSuspend ) { tskTCB *pxTCB; taskENTER_CRITICAL(); { /* If null is passed in here then it is the running task that is being suspended. */ pxTCB = prvGetTCBFromHandle( xTaskToSuspend ); traceTASK_SUSPEND( pxTCB ); /* Remove task from the ready/delayed list and place in the suspended list. */ if( uxListRemove( &( pxTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { taskRESET_READY_PRIORITY( pxTCB->uxPriority ); } /* Is the task waiting on an event also? */ if( listLIST_ITEM_CONTAINER( &( pxTCB->xEventListItem ) ) != NULL ) { ( void ) uxListRemove( &( pxTCB->xEventListItem ) ); } vListInsertEnd( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ); } taskEXIT_CRITICAL(); if( pxTCB == pxCurrentTCB ) { if( xSchedulerRunning != pdFALSE ) { /* The current task has just been suspended. */ portYIELD_WITHIN_API(); } else { /* The scheduler is not running, but the task that was pointed to by pxCurrentTCB has just been suspended and pxCurrentTCB must be adjusted to point to a different task. */ if( listCURRENT_LIST_LENGTH( &xSuspendedTaskList ) == uxCurrentNumberOfTasks ) { /* No other tasks are ready, so set pxCurrentTCB back to NULL so when the next task is created pxCurrentTCB will be set to point to it no matter what its relative priority is. */ pxCurrentTCB = NULL; } else { vTaskSwitchContext(); } } } } #endif /* INCLUDE_vTaskSuspend */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskSuspend == 1 ) signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask ) { portBASE_TYPE xReturn = pdFALSE; const tskTCB * const pxTCB = ( tskTCB * ) xTask; /* It does not make sense to check if the calling task is suspended. */ configASSERT( xTask ); /* Is the task we are attempting to resume actually in the suspended list? */ if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE ) { /* Has the task already been resumed from within an ISR? */ if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) == pdFALSE ) { /* Is it in the suspended list because it is in the Suspended state? It is possible to be in the suspended list because it is blocked on a task with no timeout specified. */ if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) != pdFALSE ) { xReturn = pdTRUE; } } } return xReturn; } /*lint !e818 xTask cannot be a pointer to const because it is a typedef. */ #endif /* INCLUDE_vTaskSuspend */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskSuspend == 1 ) void vTaskResume( xTaskHandle xTaskToResume ) { tskTCB * const pxTCB = ( tskTCB * ) xTaskToResume; /* It does not make sense to resume the calling task. */ configASSERT( xTaskToResume ); /* The parameter cannot be NULL as it is impossible to resume the currently executing task. */ if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) ) { taskENTER_CRITICAL(); { if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE ) { traceTASK_RESUME( pxTCB ); /* As we are in a critical section we can access the ready lists even if the scheduler is suspended. */ ( void ) uxListRemove( &( pxTCB->xGenericListItem ) ); prvAddTaskToReadyList( pxTCB ); /* We may have just resumed a higher priority task. */ if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority ) { /* This yield may not cause the task just resumed to run, but will leave the lists in the correct state for the next yield. */ portYIELD_WITHIN_API(); } } } taskEXIT_CRITICAL(); } } #endif /* INCLUDE_vTaskSuspend */ /*-----------------------------------------------------------*/ #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) ) portBASE_TYPE xTaskResumeFromISR( xTaskHandle xTaskToResume ) { portBASE_TYPE xYieldRequired = pdFALSE; tskTCB * const pxTCB = ( tskTCB * ) xTaskToResume; unsigned portBASE_TYPE uxSavedInterruptStatus; configASSERT( xTaskToResume ); /* RTOS ports that support interrupt nesting have the concept of a maximum system call (or maximum API call) interrupt priority. Interrupts that are above the maximum system call priority are keep permanently enabled, even when the RTOS kernel is in a critical section, but cannot make any calls to FreeRTOS API functions. If configASSERT() is defined in FreeRTOSConfig.h then portASSERT_IF_INTERRUPT_PRIORITY_INVALID() will result in an assertion failure if a FreeRTOS API function is called from an interrupt that has been assigned a priority above the configured maximum system call priority. Only FreeRTOS functions that end in FromISR can be called from interrupts that have been assigned a priority at or (logically) below the maximum system call interrupt priority. FreeRTOS maintains a separate interrupt safe API to ensure interrupt entry is as fast and as simple as possible. More information (albeit Cortex-M specific) is provided on the following link: http://www.freertos.org/RTOS-Cortex-M3-M4.html */ portASSERT_IF_INTERRUPT_PRIORITY_INVALID(); uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR(); { if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE ) { traceTASK_RESUME_FROM_ISR( pxTCB ); if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE ) { if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority ) { xYieldRequired = pdTRUE; } ( void ) uxListRemove( &( pxTCB->xGenericListItem ) ); prvAddTaskToReadyList( pxTCB ); } else { /* We cannot access the delayed or ready lists, so will hold this task pending until the scheduler is resumed, at which point a yield will be performed if necessary. */ vListInsertEnd( &( xPendingReadyList ), &( pxTCB->xEventListItem ) ); } } } portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ); return xYieldRequired; } #endif /* ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) ) */ /*-----------------------------------------------------------*/ void vTaskStartScheduler( void ) { portBASE_TYPE xReturn; /* Add the idle task at the lowest priority. */ #if ( INCLUDE_xTaskGetIdleTaskHandle == 1 ) { /* Create the idle task, storing its handle in xIdleTaskHandle so it can be returned by the xTaskGetIdleTaskHandle() function. */ xReturn = xTaskCreate( prvIdleTask, ( signed char * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, ( tskIDLE_PRIORITY | portPRIVILEGE_BIT ), &xIdleTaskHandle ); /*lint !e961 MISRA exception, justified as it is not a redundant explicit cast to all supported compilers. */ } #else { /* Create the idle task without storing its handle. */ xReturn = xTaskCreate( prvIdleTask, ( signed char * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, ( tskIDLE_PRIORITY | portPRIVILEGE_BIT ), NULL ); /*lint !e961 MISRA exception, justified as it is not a redundant explicit cast to all supported compilers. */ } #endif /* INCLUDE_xTaskGetIdleTaskHandle */ #if ( configUSE_TIMERS == 1 ) { if( xReturn == pdPASS ) { xReturn = xTimerCreateTimerTask(); } } #endif /* configUSE_TIMERS */ if( xReturn == pdPASS ) { /* Interrupts are turned off here, to ensure a tick does not occur before or during the call to xPortStartScheduler(). The stacks of the created tasks contain a status word with interrupts switched on so interrupts will automatically get re-enabled when the first task starts to run. */ portDISABLE_INTERRUPTS(); #if ( configUSE_NEWLIB_REENTRANT == 1 ) { /* Switch Newlib's _impure_ptr variable to point to the _reent structure specific to the task that will run first. */ _impure_ptr = &( pxCurrentTCB->xNewLib_reent ); } #endif /* configUSE_NEWLIB_REENTRANT */ xSchedulerRunning = pdTRUE; xTickCount = ( portTickType ) 0U; /* If configGENERATE_RUN_TIME_STATS is defined then the following macro must be defined to configure the timer/counter used to generate the run time counter time base. */ portCONFIGURE_TIMER_FOR_RUN_TIME_STATS(); /* Setting up the timer tick is hardware specific and thus in the portable interface. */ if( xPortStartScheduler() != pdFALSE ) { /* Should not reach here as if the scheduler is running the function will not return. */ } else { /* Should only reach here if a task calls xTaskEndScheduler(). */ } } else { /* This line will only be reached if the kernel could not be started, because there was not enough FreeRTOS heap to create the idle task or the timer task. */ configASSERT( xReturn ); } } /*-----------------------------------------------------------*/ void vTaskEndScheduler( void ) { /* Stop the scheduler interrupts and call the portable scheduler end routine so the original ISRs can be restored if necessary. The port layer must ensure interrupts enable bit is left in the correct state. */ portDISABLE_INTERRUPTS(); xSchedulerRunning = pdFALSE; vPortEndScheduler(); } /*----------------------------------------------------------*/ void vTaskSuspendAll( void ) { /* A critical section is not required as the variable is of type portBASE_TYPE. */ ++uxSchedulerSuspended; } /*----------------------------------------------------------*/ #if ( configUSE_TICKLESS_IDLE != 0 ) static portTickType prvGetExpectedIdleTime( void ) { portTickType xReturn; if( pxCurrentTCB->uxPriority > tskIDLE_PRIORITY ) { xReturn = 0; } else if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > 1 ) { /* There are other idle priority tasks in the ready state. If time slicing is used then the very next tick interrupt must be processed. */ xReturn = 0; } else { xReturn = xNextTaskUnblockTime - xTickCount; } return xReturn; } #endif /* configUSE_TICKLESS_IDLE */ /*----------------------------------------------------------*/ signed portBASE_TYPE xTaskResumeAll( void ) { tskTCB *pxTCB; portBASE_TYPE xAlreadyYielded = pdFALSE; /* If uxSchedulerSuspended is zero then this function does not match a previous call to vTaskSuspendAll(). */ configASSERT( uxSchedulerSuspended ); /* It is possible that an ISR caused a task to be removed from an event list while the scheduler was suspended. If this was the case then the removed task will have been added to the xPendingReadyList. Once the scheduler has been resumed it is safe to move all the pending ready tasks from this list into their appropriate ready list. */ taskENTER_CRITICAL(); { --uxSchedulerSuspended; if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE ) { if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0U ) { /* Move any readied tasks from the pending list into the appropriate ready list. */ while( listLIST_IS_EMPTY( &xPendingReadyList ) == pdFALSE ) { pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( &xPendingReadyList ) ); ( void ) uxListRemove( &( pxTCB->xEventListItem ) ); ( void ) uxListRemove( &( pxTCB->xGenericListItem ) ); prvAddTaskToReadyList( pxTCB ); /* If we have moved a task that has a priority higher than the current task then we should yield. */ if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority ) { xYieldPending = pdTRUE; } } /* If any ticks occurred while the scheduler was suspended then they should be processed now. This ensures the tick count does not slip, and that any delayed tasks are resumed at the correct time. */ if( uxPendedTicks > ( unsigned portBASE_TYPE ) 0U ) { while( uxPendedTicks > ( unsigned portBASE_TYPE ) 0U ) { if( xTaskIncrementTick() != pdFALSE ) { xYieldPending = pdTRUE; } --uxPendedTicks; } } if( xYieldPending == pdTRUE ) { xAlreadyYielded = pdTRUE; portYIELD_WITHIN_API(); } } } } taskEXIT_CRITICAL(); return xAlreadyYielded; } /*-----------------------------------------------------------*/ portTickType xTaskGetTickCount( void ) { portTickType xTicks; /* Critical section required if running on a 16 bit processor. */ taskENTER_CRITICAL(); { xTicks = xTickCount; } taskEXIT_CRITICAL(); return xTicks; } /*-----------------------------------------------------------*/ portTickType xTaskGetTickCountFromISR( void ) { portTickType xReturn; unsigned portBASE_TYPE uxSavedInterruptStatus; /* RTOS ports that support interrupt nesting have the concept of a maximum system call (or maximum API call) interrupt priority. Interrupts that are above the maximum system call priority are keep permanently enabled, even when the RTOS kernel is in a critical section, but cannot make any calls to FreeRTOS API functions. If configASSERT() is defined in FreeRTOSConfig.h then portASSERT_IF_INTERRUPT_PRIORITY_INVALID() will result in an assertion failure if a FreeRTOS API function is called from an interrupt that has been assigned a priority above the configured maximum system call priority. Only FreeRTOS functions that end in FromISR can be called from interrupts that have been assigned a priority at or (logically) below the maximum system call interrupt priority. FreeRTOS maintains a separate interrupt safe API to ensure interrupt entry is as fast and as simple as possible. More information (albeit Cortex-M specific) is provided on the following link: http://www.freertos.org/RTOS-Cortex-M3-M4.html */ portASSERT_IF_INTERRUPT_PRIORITY_INVALID(); uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR(); xReturn = xTickCount; portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ); return xReturn; } /*-----------------------------------------------------------*/ unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void ) { /* A critical section is not required because the variables are of type portBASE_TYPE. */ return uxCurrentNumberOfTasks; } /*-----------------------------------------------------------*/ #if ( INCLUDE_pcTaskGetTaskName == 1 ) signed char *pcTaskGetTaskName( xTaskHandle xTaskToQuery ) { tskTCB *pxTCB; /* If null is passed in here then the name of the calling task is being queried. */ pxTCB = prvGetTCBFromHandle( xTaskToQuery ); configASSERT( pxTCB ); return &( pxTCB->pcTaskName[ 0 ] ); } #endif /* INCLUDE_pcTaskGetTaskName */ /*-----------------------------------------------------------*/ #if ( configUSE_TRACE_FACILITY == 1 ) unsigned portBASE_TYPE uxTaskGetSystemState( xTaskStatusType *pxTaskStatusArray, unsigned portBASE_TYPE uxArraySize, unsigned long *pulTotalRunTime ) { unsigned portBASE_TYPE uxTask = 0, uxQueue = configMAX_PRIORITIES; vTaskSuspendAll(); { /* Is there a space in the array for each task in the system? */ if( uxArraySize >= uxCurrentNumberOfTasks ) { /* Fill in an xTaskStatusType structure with information on each task in the Ready state. */ do { uxQueue--; uxTask += prvListTaskWithinSingleList( &( pxTaskStatusArray[ uxTask ] ), &( pxReadyTasksLists[ uxQueue ] ), eReady ); } while( uxQueue > ( unsigned portBASE_TYPE ) tskIDLE_PRIORITY ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */ /* Fill in an xTaskStatusType structure with information on each task in the Blocked state. */ uxTask += prvListTaskWithinSingleList( &( pxTaskStatusArray[ uxTask ] ), ( xList * ) pxDelayedTaskList, eBlocked ); uxTask += prvListTaskWithinSingleList( &( pxTaskStatusArray[ uxTask ] ), ( xList * ) pxOverflowDelayedTaskList, eBlocked ); #if( INCLUDE_vTaskDelete == 1 ) { /* Fill in an xTaskStatusType structure with information on each task that has been deleted but not yet cleaned up. */ uxTask += prvListTaskWithinSingleList( &( pxTaskStatusArray[ uxTask ] ), &xTasksWaitingTermination, eDeleted ); } #endif #if ( INCLUDE_vTaskSuspend == 1 ) { /* Fill in an xTaskStatusType structure with information on each task in the Suspended state. */ uxTask += prvListTaskWithinSingleList( &( pxTaskStatusArray[ uxTask ] ), &xSuspendedTaskList, eSuspended ); } #endif #if ( configGENERATE_RUN_TIME_STATS == 1) { if( pulTotalRunTime != NULL ) { #ifdef portALT_GET_RUN_TIME_COUNTER_VALUE portALT_GET_RUN_TIME_COUNTER_VALUE( ( *pulTotalRunTime ) ); #else *pulTotalRunTime = portGET_RUN_TIME_COUNTER_VALUE(); #endif } } #else { if( pulTotalRunTime != NULL ) { *pulTotalRunTime = 0; } } #endif } } ( void ) xTaskResumeAll(); return uxTask; } #endif /* configUSE_TRACE_FACILITY */ /*----------------------------------------------------------*/ #if ( INCLUDE_xTaskGetIdleTaskHandle == 1 ) xTaskHandle xTaskGetIdleTaskHandle( void ) { /* If xTaskGetIdleTaskHandle() is called before the scheduler has been started, then xIdleTaskHandle will be NULL. */ configASSERT( ( xIdleTaskHandle != NULL ) ); return xIdleTaskHandle; } #endif /* INCLUDE_xTaskGetIdleTaskHandle */ /*----------------------------------------------------------*/ /* This conditional compilation should use inequality to 0, not equality to 1. This is to ensure vTaskStepTick() is available 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 ) void vTaskStepTick( portTickType xTicksToJump ) { /* Correct the tick count value after a period during which the tick was suppressed. Note this does *not* call the tick hook function for each stepped tick. */ configASSERT( ( xTickCount + xTicksToJump ) <= xNextTaskUnblockTime ); xTickCount += xTicksToJump; traceINCREASE_TICK_COUNT( xTicksToJump ); } #endif /* configUSE_TICKLESS_IDLE */ /*----------------------------------------------------------*/ portBASE_TYPE xTaskIncrementTick( void ) { tskTCB * pxTCB; portTickType xItemValue; portBASE_TYPE xSwitchRequired = pdFALSE; /* Called by the portable layer each time a tick interrupt occurs. Increments the tick then checks to see if the new tick value will cause any tasks to be unblocked. */ traceTASK_INCREMENT_TICK( xTickCount ); if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE ) { /* Increment the RTOS tick, switching the delayed and overflowed delayed lists if it wraps to 0. */ ++xTickCount; { /* Minor optimisation. The tick count cannot change in this block. */ const portTickType xConstTickCount = xTickCount; if( xConstTickCount == ( portTickType ) 0U ) { taskSWITCH_DELAYED_LISTS(); } /* See if this tick has made a timeout expire. Tasks are stored in the queue in the order of their wake time - meaning once one tasks has been found whose block time has not expired there is no need not look any further down the list. */ if( xConstTickCount >= xNextTaskUnblockTime ) { for( ;; ) { if( listLIST_IS_EMPTY( pxDelayedTaskList ) != pdFALSE ) { /* The delayed list is empty. Set xNextTaskUnblockTime to the maximum possible value so it is extremely unlikely that the if( xTickCount >= xNextTaskUnblockTime ) test will pass next time through. */ xNextTaskUnblockTime = portMAX_DELAY; break; } else { /* The delayed list is not empty, get the value of the item at the head of the delayed list. This is the time at which the task at the head of the delayed list must be removed from the Blocked state. */ pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ); xItemValue = listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ); if( xConstTickCount < xItemValue ) { /* It is not time to unblock this item yet, but the item value is the time at which the task at the head of the blocked list must be removed from the Blocked state - so record the item value in xNextTaskUnblockTime. */ xNextTaskUnblockTime = xItemValue; break; } /* It is time to remove the item from the Blocked state. */ ( void ) uxListRemove( &( pxTCB->xGenericListItem ) ); /* Is the task waiting on an event also? If so remove it from the event list. */ if( listLIST_ITEM_CONTAINER( &( pxTCB->xEventListItem ) ) != NULL ) { ( void ) uxListRemove( &( pxTCB->xEventListItem ) ); } /* Place the unblocked task into the appropriate ready list. */ prvAddTaskToReadyList( pxTCB ); /* A task being unblocked cannot cause an immediate context switch if preemption is turned off. */ #if ( configUSE_PREEMPTION == 1 ) { /* Preemption is on, but a context switch should only be performed if the unblocked task has a priority that is equal to or higher than the currently executing task. */ if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority ) { xSwitchRequired = pdTRUE; } } #endif /* configUSE_PREEMPTION */ } } } } /* Tasks of equal priority to the currently running task will share processing time (time slice) if preemption is on, and the application writer has not explicitly turned time slicing off. */ #if ( ( configUSE_PREEMPTION == 1 ) && ( configUSE_TIME_SLICING == 1 ) ) { if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ pxCurrentTCB->uxPriority ] ) ) > ( unsigned portBASE_TYPE ) 1 ) { xSwitchRequired = pdTRUE; } } #endif /* ( ( configUSE_PREEMPTION == 1 ) && ( configUSE_TIME_SLICING == 1 ) ) */ #if ( configUSE_TICK_HOOK == 1 ) { /* Guard against the tick hook being called when the pended tick count is being unwound (when the scheduler is being unlocked). */ if( uxPendedTicks == ( unsigned portBASE_TYPE ) 0U ) { vApplicationTickHook(); } } #endif /* configUSE_TICK_HOOK */ } else { ++uxPendedTicks; /* The tick hook gets called at regular intervals, even if the scheduler is locked. */ #if ( configUSE_TICK_HOOK == 1 ) { vApplicationTickHook(); } #endif } #if ( configUSE_PREEMPTION == 1 ) { if( xYieldPending != pdFALSE ) { xSwitchRequired = pdTRUE; } } #endif /* configUSE_PREEMPTION */ return xSwitchRequired; } /*-----------------------------------------------------------*/ #if ( configUSE_APPLICATION_TASK_TAG == 1 ) void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxHookFunction ) { tskTCB *xTCB; /* If xTask is NULL then we are setting our own task hook. */ if( xTask == NULL ) { xTCB = ( tskTCB * ) pxCurrentTCB; } else { xTCB = ( tskTCB * ) xTask; } /* Save the hook function in the TCB. A critical section is required as the value can be accessed from an interrupt. */ taskENTER_CRITICAL(); xTCB->pxTaskTag = pxHookFunction; taskEXIT_CRITICAL(); } #endif /* configUSE_APPLICATION_TASK_TAG */ /*-----------------------------------------------------------*/ #if ( configUSE_APPLICATION_TASK_TAG == 1 ) pdTASK_HOOK_CODE xTaskGetApplicationTaskTag( xTaskHandle xTask ) { tskTCB *xTCB; pdTASK_HOOK_CODE xReturn; /* If xTask is NULL then we are setting our own task hook. */ if( xTask == NULL ) { xTCB = ( tskTCB * ) pxCurrentTCB; } else { xTCB = ( tskTCB * ) xTask; } /* Save the hook function in the TCB. A critical section is required as the value can be accessed from an interrupt. */ taskENTER_CRITICAL(); xReturn = xTCB->pxTaskTag; taskEXIT_CRITICAL(); return xReturn; } #endif /* configUSE_APPLICATION_TASK_TAG */ /*-----------------------------------------------------------*/ #if ( configUSE_APPLICATION_TASK_TAG == 1 ) portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter ) { tskTCB *xTCB; portBASE_TYPE xReturn; /* If xTask is NULL then we are calling our own task hook. */ if( xTask == NULL ) { xTCB = ( tskTCB * ) pxCurrentTCB; } else { xTCB = ( tskTCB * ) xTask; } if( xTCB->pxTaskTag != NULL ) { xReturn = xTCB->pxTaskTag( pvParameter ); } else { xReturn = pdFAIL; } return xReturn; } #endif /* configUSE_APPLICATION_TASK_TAG */ /*-----------------------------------------------------------*/ void vTaskSwitchContext( void ) { if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE ) { /* The scheduler is currently suspended - do not allow a context switch. */ xYieldPending = pdTRUE; } else { xYieldPending = pdFALSE; traceTASK_SWITCHED_OUT(); #if ( configGENERATE_RUN_TIME_STATS == 1 ) { #ifdef portALT_GET_RUN_TIME_COUNTER_VALUE portALT_GET_RUN_TIME_COUNTER_VALUE( ulTotalRunTime ); #else ulTotalRunTime = portGET_RUN_TIME_COUNTER_VALUE(); #endif /* Add the amount of time the task has been running to the accumulated time so far. The time the task started running was stored in ulTaskSwitchedInTime. Note that there is no overflow protection here so count values are only valid until the timer overflows. The guard against negative values is to protect against suspect run time stat counter implementations - which are provided by the application, not the kernel. */ if( ulTotalRunTime > ulTaskSwitchedInTime ) { pxCurrentTCB->ulRunTimeCounter += ( ulTotalRunTime - ulTaskSwitchedInTime ); } ulTaskSwitchedInTime = ulTotalRunTime; } #endif /* configGENERATE_RUN_TIME_STATS */ taskFIRST_CHECK_FOR_STACK_OVERFLOW(); taskSECOND_CHECK_FOR_STACK_OVERFLOW(); taskSELECT_HIGHEST_PRIORITY_TASK(); traceTASK_SWITCHED_IN(); #if ( configUSE_NEWLIB_REENTRANT == 1 ) { /* Switch Newlib's _impure_ptr variable to point to the _reent structure specific to this task. */ _impure_ptr = &( pxCurrentTCB->xNewLib_reent ); } #endif /* configUSE_NEWLIB_REENTRANT */ } } /*-----------------------------------------------------------*/ void vTaskPlaceOnEventList( xList * const pxEventList, portTickType xTicksToWait ) { portTickType xTimeToWake; configASSERT( pxEventList ); /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE SCHEDULER SUSPENDED. */ /* Place the event list item of the TCB in the appropriate event list. This is placed in the list in priority order so the highest priority task is the first to be woken by the event. */ vListInsert( pxEventList, &( pxCurrentTCB->xEventListItem ) ); /* 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. We have exclusive access to the ready lists as the scheduler is locked. */ if( uxListRemove( &( pxCurrentTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { /* The current task must be in a ready list, so there is no need to check, and the port reset macro can be called directly. */ portRESET_READY_PRIORITY( pxCurrentTCB->uxPriority, uxTopReadyPriority ); } #if ( INCLUDE_vTaskSuspend == 1 ) { if( xTicksToWait == portMAX_DELAY ) { /* Add ourselves to the suspended task list instead of a delayed task list to ensure we are not woken by a timing event. We will block indefinitely. */ vListInsertEnd( &xSuspendedTaskList, &( pxCurrentTCB->xGenericListItem ) ); } else { /* Calculate the time at which the task should be woken if the event does not occur. This may overflow but this doesn't matter. */ xTimeToWake = xTickCount + xTicksToWait; prvAddCurrentTaskToDelayedList( xTimeToWake ); } } #else /* INCLUDE_vTaskSuspend */ { /* Calculate the time at which the task should be woken if the event does not occur. This may overflow but this doesn't matter. */ xTimeToWake = xTickCount + xTicksToWait; prvAddCurrentTaskToDelayedList( xTimeToWake ); } #endif /* INCLUDE_vTaskSuspend */ } /*-----------------------------------------------------------*/ #if configUSE_TIMERS == 1 void vTaskPlaceOnEventListRestricted( xList * const pxEventList, portTickType xTicksToWait ) { portTickType xTimeToWake; configASSERT( pxEventList ); /* This function should not be called by application code hence the 'Restricted' in its name. It is not part of the public API. It is designed for use by kernel code, and has special calling requirements - it should be called from a critical section. */ /* Place the event list item of the TCB in the appropriate event list. In this case it is assume that this is the only task that is going to be waiting on this event list, so the faster vListInsertEnd() function can be used in place of vListInsert. */ vListInsertEnd( pxEventList, &( pxCurrentTCB->xEventListItem ) ); /* We must remove this task from the ready list before adding it to the blocked list as the same list item is used for both lists. This function is called form a critical section. */ if( uxListRemove( &( pxCurrentTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { /* The current task must be in a ready list, so there is no need to check, and the port reset macro can be called directly. */ portRESET_READY_PRIORITY( pxCurrentTCB->uxPriority, uxTopReadyPriority ); } /* Calculate the time at which the task should be woken if the event does not occur. This may overflow but this doesn't matter. */ xTimeToWake = xTickCount + xTicksToWait; traceTASK_DELAY_UNTIL(); prvAddCurrentTaskToDelayedList( xTimeToWake ); } #endif /* configUSE_TIMERS */ /*-----------------------------------------------------------*/ signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList ) { tskTCB *pxUnblockedTCB; portBASE_TYPE xReturn; /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE SCHEDULER SUSPENDED. It can also be called from within an ISR. */ /* The event list is sorted in priority order, so we can remove the first in the list, remove the TCB from the delayed list, and add it to the ready list. If an event is for a queue that is locked then this function will never get called - the lock count on the queue will get modified instead. This means we can always expect exclusive access to the event list here. This function assumes that a check has already been made to ensure that pxEventList is not empty. */ pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); configASSERT( pxUnblockedTCB ); ( void ) uxListRemove( &( pxUnblockedTCB->xEventListItem ) ); if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE ) { ( void ) uxListRemove( &( pxUnblockedTCB->xGenericListItem ) ); prvAddTaskToReadyList( pxUnblockedTCB ); } else { /* We cannot access the delayed or ready lists, so will hold this task pending until the scheduler is resumed. */ vListInsertEnd( &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) ); } if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority ) { /* Return true if the task removed from the event list has a higher priority than the calling task. This allows the calling task to know if it should force a context switch now. */ xReturn = pdTRUE; /* Mark that a yield is pending in case the user is not using the "xHigherPriorityTaskWoken" parameter to an ISR safe FreeRTOS function. */ xYieldPending = pdTRUE; } else { xReturn = pdFALSE; } return xReturn; } /*-----------------------------------------------------------*/ void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut ) { configASSERT( pxTimeOut ); pxTimeOut->xOverflowCount = xNumOfOverflows; pxTimeOut->xTimeOnEntering = xTickCount; } /*-----------------------------------------------------------*/ portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait ) { portBASE_TYPE xReturn; configASSERT( pxTimeOut ); configASSERT( pxTicksToWait ); taskENTER_CRITICAL(); { /* Minor optimisation. The tick count cannot change in this block. */ const portTickType xConstTickCount = xTickCount; #if ( INCLUDE_vTaskSuspend == 1 ) /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is the maximum block time then the task should block indefinitely, and therefore never time out. */ if( *pxTicksToWait == portMAX_DELAY ) { xReturn = pdFALSE; } else /* We are not blocking indefinitely, perform the checks below. */ #endif if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xConstTickCount >= pxTimeOut->xTimeOnEntering ) ) /*lint !e525 Indentation preferred as is to make code within pre-processor directives clearer. */ { /* The tick count is greater than the time at which vTaskSetTimeout() was called, but has also overflowed since vTaskSetTimeOut() was called. It must have wrapped all the way around and gone past us again. This passed since vTaskSetTimeout() was called. */ xReturn = pdTRUE; } else if( ( xConstTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait ) { /* Not a genuine timeout. Adjust parameters for time remaining. */ *pxTicksToWait -= ( xConstTickCount - pxTimeOut->xTimeOnEntering ); vTaskSetTimeOutState( pxTimeOut ); xReturn = pdFALSE; } else { xReturn = pdTRUE; } } taskEXIT_CRITICAL(); return xReturn; } /*-----------------------------------------------------------*/ void vTaskMissedYield( void ) { xYieldPending = pdTRUE; } /*-----------------------------------------------------------*/ #if ( configUSE_TRACE_FACILITY == 1 ) unsigned portBASE_TYPE uxTaskGetTaskNumber( xTaskHandle xTask ) { unsigned portBASE_TYPE uxReturn; tskTCB *pxTCB; if( xTask != NULL ) { pxTCB = ( tskTCB * ) xTask; uxReturn = pxTCB->uxTaskNumber; } else { uxReturn = 0U; } return uxReturn; } #endif /* configUSE_TRACE_FACILITY */ /*-----------------------------------------------------------*/ #if ( configUSE_TRACE_FACILITY == 1 ) void vTaskSetTaskNumber( xTaskHandle xTask, unsigned portBASE_TYPE uxHandle ) { tskTCB *pxTCB; if( xTask != NULL ) { pxTCB = ( tskTCB * ) xTask; pxTCB->uxTaskNumber = uxHandle; } } #endif /* configUSE_TRACE_FACILITY */ /* * ----------------------------------------------------------- * The Idle task. * ---------------------------------------------------------- * * The portTASK_FUNCTION() macro is used to allow port/compiler specific * language extensions. The equivalent prototype for this function is: * * void prvIdleTask( void *pvParameters ); * */ static portTASK_FUNCTION( prvIdleTask, pvParameters ) { /* Stop warnings. */ ( void ) pvParameters; for( ;; ) { /* See if any tasks have been deleted. */ prvCheckTasksWaitingTermination(); #if ( configUSE_PREEMPTION == 0 ) { /* If we are not using preemption we keep forcing a task switch to see if any other task has become available. If we are using preemption we don't need to do this as any task becoming available will automatically get the processor anyway. */ taskYIELD(); } #endif /* configUSE_PREEMPTION */ #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) ) { /* When using preemption tasks of equal priority will be timesliced. If a task that is sharing the idle priority is ready to run then the idle task should yield before the end of the timeslice. A critical region is not required here as we are just reading from the list, and an occasional incorrect value will not matter. If the ready list at the idle priority contains more than one task then a task other than the idle task is ready to execute. */ if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 ) { taskYIELD(); } } #endif /* ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) ) */ #if ( configUSE_IDLE_HOOK == 1 ) { extern void vApplicationIdleHook( void ); /* Call the user defined function from within the idle task. This allows the application designer to add background functionality without the overhead of a separate task. NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES, CALL A FUNCTION THAT MIGHT BLOCK. */ vApplicationIdleHook(); } #endif /* configUSE_IDLE_HOOK */ /* This conditional compilation should use inequality to 0, not equality to 1. This is to ensure portSUPPRESS_TICKS_AND_SLEEP() is 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 ) { portTickType xExpectedIdleTime; /* It is not desirable to suspend then resume the scheduler on each iteration of the idle task. Therefore, a preliminary test of the expected idle time is performed without the scheduler suspended. The result here is not necessarily valid. */ xExpectedIdleTime = prvGetExpectedIdleTime(); if( xExpectedIdleTime >= configEXPECTED_IDLE_TIME_BEFORE_SLEEP ) { vTaskSuspendAll(); { /* Now the scheduler is suspended, the expected idle time can be sampled again, and this time its value can be used. */ configASSERT( xNextTaskUnblockTime >= xTickCount ); xExpectedIdleTime = prvGetExpectedIdleTime(); if( xExpectedIdleTime >= configEXPECTED_IDLE_TIME_BEFORE_SLEEP ) { traceLOW_POWER_IDLE_BEGIN(); portSUPPRESS_TICKS_AND_SLEEP( xExpectedIdleTime ); traceLOW_POWER_IDLE_END(); } } ( void ) xTaskResumeAll(); } } #endif /* configUSE_TICKLESS_IDLE */ } } /*-----------------------------------------------------------*/ #if configUSE_TICKLESS_IDLE != 0 eSleepModeStatus eTaskConfirmSleepModeStatus( void ) { eSleepModeStatus eReturn = eStandardSleep; if( listCURRENT_LIST_LENGTH( &xPendingReadyList ) != 0 ) { /* A task was made ready while the scheduler was suspended. */ eReturn = eAbortSleep; } else if( xYieldPending != pdFALSE ) { /* A yield was pended while the scheduler was suspended. */ eReturn = eAbortSleep; } else { #if configUSE_TIMERS == 0 { /* The idle task exists in addition to the application tasks. */ const unsigned portBASE_TYPE uxNonApplicationTasks = 1; /* If timers are not being used and all the tasks are in the suspended list (which might mean they have an infinite block time rather than actually being suspended) then it is safe to turn all clocks off and just wait for external interrupts. */ if( listCURRENT_LIST_LENGTH( &xSuspendedTaskList ) == ( uxCurrentNumberOfTasks - uxNonApplicationTasks ) ) { eReturn = eNoTasksWaitingTimeout; } } #endif /* configUSE_TIMERS */ } return eReturn; } #endif /* configUSE_TICKLESS_IDLE */ /*-----------------------------------------------------------*/ static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed char * const pcName, unsigned portBASE_TYPE uxPriority, const xMemoryRegion * const xRegions, unsigned short usStackDepth ) { unsigned portBASE_TYPE x; /* Store the task name in the TCB. */ for( x = ( unsigned portBASE_TYPE ) 0; x < ( unsigned portBASE_TYPE ) configMAX_TASK_NAME_LEN; x++ ) { pxTCB->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 ] == 0x00 ) { break; } } /* Ensure the name string is terminated in the case that the string length was greater or equal to configMAX_TASK_NAME_LEN. */ pxTCB->pcTaskName[ configMAX_TASK_NAME_LEN - 1 ] = ( signed char ) '\0'; /* This is used as an array index so must ensure it's not too large. First remove the privilege bit if one is present. */ if( uxPriority >= ( unsigned portBASE_TYPE ) configMAX_PRIORITIES ) { uxPriority = ( unsigned portBASE_TYPE ) configMAX_PRIORITIES - ( unsigned portBASE_TYPE ) 1U; } pxTCB->uxPriority = uxPriority; #if ( configUSE_MUTEXES == 1 ) { pxTCB->uxBasePriority = uxPriority; } #endif /* configUSE_MUTEXES */ vListInitialiseItem( &( pxTCB->xGenericListItem ) ); vListInitialiseItem( &( pxTCB->xEventListItem ) ); /* Set the pxTCB as a link back from the xListItem. This is so we can get back to the containing TCB from a generic item in a list. */ listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB ); /* Event lists are always in priority order. */ listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( portTickType ) configMAX_PRIORITIES - ( portTickType ) uxPriority ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */ listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB ); #if ( portCRITICAL_NESTING_IN_TCB == 1 ) { pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0U; } #endif /* portCRITICAL_NESTING_IN_TCB */ #if ( configUSE_APPLICATION_TASK_TAG == 1 ) { pxTCB->pxTaskTag = NULL; } #endif /* configUSE_APPLICATION_TASK_TAG */ #if ( configGENERATE_RUN_TIME_STATS == 1 ) { pxTCB->ulRunTimeCounter = 0UL; } #endif /* configGENERATE_RUN_TIME_STATS */ #if ( portUSING_MPU_WRAPPERS == 1 ) { vPortStoreTaskMPUSettings( &( pxTCB->xMPUSettings ), xRegions, pxTCB->pxStack, usStackDepth ); } #else /* portUSING_MPU_WRAPPERS */ { ( void ) xRegions; ( void ) usStackDepth; } #endif /* portUSING_MPU_WRAPPERS */ #if ( configUSE_NEWLIB_REENTRANT == 1 ) { /* Initialise this task's Newlib reent structure. */ _REENT_INIT_PTR( ( &( pxTCB->xNewLib_reent ) ) ); } #endif /* configUSE_NEWLIB_REENTRANT */ } /*-----------------------------------------------------------*/ #if ( portUSING_MPU_WRAPPERS == 1 ) void vTaskAllocateMPURegions( xTaskHandle xTaskToModify, const xMemoryRegion * const xRegions ) { tskTCB *pxTCB; /* If null is passed in here then we are deleting ourselves. */ pxTCB = prvGetTCBFromHandle( xTaskToModify ); vPortStoreTaskMPUSettings( &( pxTCB->xMPUSettings ), xRegions, NULL, 0 ); } #endif /* portUSING_MPU_WRAPPERS */ /*-----------------------------------------------------------*/ static void prvInitialiseTaskLists( void ) { unsigned portBASE_TYPE uxPriority; for( uxPriority = ( unsigned portBASE_TYPE ) 0U; uxPriority < ( unsigned portBASE_TYPE ) configMAX_PRIORITIES; uxPriority++ ) { vListInitialise( &( pxReadyTasksLists[ uxPriority ] ) ); } vListInitialise( &xDelayedTaskList1 ); vListInitialise( &xDelayedTaskList2 ); vListInitialise( &xPendingReadyList ); #if ( INCLUDE_vTaskDelete == 1 ) { vListInitialise( &xTasksWaitingTermination ); } #endif /* INCLUDE_vTaskDelete */ #if ( INCLUDE_vTaskSuspend == 1 ) { vListInitialise( &xSuspendedTaskList ); } #endif /* INCLUDE_vTaskSuspend */ /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList using list2. */ pxDelayedTaskList = &xDelayedTaskList1; pxOverflowDelayedTaskList = &xDelayedTaskList2; } /*-----------------------------------------------------------*/ static void prvCheckTasksWaitingTermination( void ) { #if ( INCLUDE_vTaskDelete == 1 ) { portBASE_TYPE xListIsEmpty; /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called too often in the idle task. */ while( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0U ) { vTaskSuspendAll(); xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination ); ( void ) xTaskResumeAll(); if( xListIsEmpty == pdFALSE ) { tskTCB *pxTCB; taskENTER_CRITICAL(); { pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( &xTasksWaitingTermination ) ); ( void ) uxListRemove( &( pxTCB->xGenericListItem ) ); --uxCurrentNumberOfTasks; --uxTasksDeleted; } taskEXIT_CRITICAL(); prvDeleteTCB( pxTCB ); } } } #endif /* vTaskDelete */ } /*-----------------------------------------------------------*/ static void prvAddCurrentTaskToDelayedList( portTickType xTimeToWake ) { /* The list item will be inserted in wake time order. */ listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake ); if( xTimeToWake < xTickCount ) { /* Wake time has overflowed. Place this item in the overflow list. */ vListInsert( pxOverflowDelayedTaskList, &( pxCurrentTCB->xGenericListItem ) ); } else { /* The wake time has not overflowed, so we can use the current block list. */ vListInsert( pxDelayedTaskList, &( pxCurrentTCB->xGenericListItem ) ); /* If the task entering the blocked state was placed at the head of the list of blocked tasks then xNextTaskUnblockTime needs to be updated too. */ if( xTimeToWake < xNextTaskUnblockTime ) { xNextTaskUnblockTime = xTimeToWake; } } } /*-----------------------------------------------------------*/ static tskTCB *prvAllocateTCBAndStack( unsigned short usStackDepth, portSTACK_TYPE *puxStackBuffer ) { tskTCB *pxNewTCB; /* Allocate space for the TCB. Where the memory comes from depends on the implementation of the port malloc function. */ pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) ); if( pxNewTCB != NULL ) { /* 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 = ( portSTACK_TYPE * ) pvPortMallocAligned( ( ( ( size_t ) usStackDepth ) * sizeof( portSTACK_TYPE ) ), puxStackBuffer ); /*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 { /* Just to help debugging. */ ( void ) memset( pxNewTCB->pxStack, ( int ) tskSTACK_FILL_BYTE, ( size_t ) usStackDepth * sizeof( portSTACK_TYPE ) ); } } return pxNewTCB; } /*-----------------------------------------------------------*/ #if ( configUSE_TRACE_FACILITY == 1 ) static unsigned portBASE_TYPE prvListTaskWithinSingleList( xTaskStatusType *pxTaskStatusArray, xList *pxList, eTaskState eState ) { volatile tskTCB *pxNextTCB, *pxFirstTCB; unsigned portBASE_TYPE uxTask = 0; if( listCURRENT_LIST_LENGTH( pxList ) > ( unsigned portBASE_TYPE ) 0 ) { listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList ); /* Populate an xTaskStatusType structure within the pxTaskStatusArray array for each task that is referenced from pxList. See the definition of xTaskStatusType in task.h for the meaning of each xTaskStatusType structure member. */ do { listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList ); pxTaskStatusArray[ uxTask ].xHandle = ( xTaskHandle ) pxNextTCB; pxTaskStatusArray[ uxTask ].pcTaskName = ( const signed char * ) &( pxNextTCB->pcTaskName [ 0 ] ); pxTaskStatusArray[ uxTask ].xTaskNumber = pxNextTCB->uxTCBNumber; pxTaskStatusArray[ uxTask ].eCurrentState = eState; pxTaskStatusArray[ uxTask ].uxCurrentPriority = pxNextTCB->uxPriority; #if ( configUSE_MUTEXES == 1 ) { pxTaskStatusArray[ uxTask ].uxBasePriority = pxNextTCB->uxBasePriority; } #else { pxTaskStatusArray[ uxTask ].uxBasePriority = 0; } #endif #if ( configGENERATE_RUN_TIME_STATS == 1 ) { pxTaskStatusArray[ uxTask ].ulRunTimeCounter = pxNextTCB->ulRunTimeCounter; } #else { pxTaskStatusArray[ uxTask ].ulRunTimeCounter = 0; } #endif #if ( portSTACK_GROWTH > 0 ) { ppxTaskStatusArray[ uxTask ].usStackHighWaterMark = prvTaskCheckFreeStackSpace( ( unsigned char * ) pxNextTCB->pxEndOfStack ); } #else { pxTaskStatusArray[ uxTask ].usStackHighWaterMark = prvTaskCheckFreeStackSpace( ( unsigned char * ) pxNextTCB->pxStack ); } #endif uxTask++; } while( pxNextTCB != pxFirstTCB ); } return uxTask; } #endif /* configUSE_TRACE_FACILITY */ /*-----------------------------------------------------------*/ #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) ) static unsigned short prvTaskCheckFreeStackSpace( const unsigned char * pucStackByte ) { unsigned short usCount = 0U; while( *pucStackByte == tskSTACK_FILL_BYTE ) { pucStackByte -= portSTACK_GROWTH; usCount++; } usCount /= sizeof( portSTACK_TYPE ); return usCount; } #endif /* ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) ) */ /*-----------------------------------------------------------*/ #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask ) { tskTCB *pxTCB; unsigned char *pcEndOfStack; unsigned portBASE_TYPE uxReturn; pxTCB = prvGetTCBFromHandle( xTask ); #if portSTACK_GROWTH < 0 { pcEndOfStack = ( unsigned char * ) pxTCB->pxStack; } #else { pcEndOfStack = ( unsigned char * ) pxTCB->pxEndOfStack; } #endif uxReturn = ( unsigned portBASE_TYPE ) prvTaskCheckFreeStackSpace( pcEndOfStack ); return uxReturn; } #endif /* INCLUDE_uxTaskGetStackHighWaterMark */ /*-----------------------------------------------------------*/ #if ( INCLUDE_vTaskDelete == 1 ) static void prvDeleteTCB( tskTCB *pxTCB ) { /* This call is required specifically for the TriCore port. It must be above the vPortFree() calls. The call is also used by ports/demos that want to allocate and clean RAM statically. */ portCLEAN_UP_TCB( pxTCB ); /* Free up the memory allocated by the scheduler for the task. It is up to the task to free any memory allocated at the application level. */ vPortFreeAligned( pxTCB->pxStack ); vPortFree( pxTCB ); } #endif /* INCLUDE_vTaskDelete */ /*-----------------------------------------------------------*/ #if ( ( INCLUDE_xTaskGetCurrentTaskHandle == 1 ) || ( configUSE_MUTEXES == 1 ) ) xTaskHandle xTaskGetCurrentTaskHandle( void ) { xTaskHandle xReturn; /* A critical section is not required as this is not called from an interrupt and the current TCB will always be the same for any individual execution thread. */ xReturn = pxCurrentTCB; return xReturn; } #endif /* ( ( INCLUDE_xTaskGetCurrentTaskHandle == 1 ) || ( configUSE_MUTEXES == 1 ) ) */ /*-----------------------------------------------------------*/ #if ( ( INCLUDE_xTaskGetSchedulerState == 1 ) || ( configUSE_TIMERS == 1 ) ) portBASE_TYPE xTaskGetSchedulerState( void ) { portBASE_TYPE xReturn; if( xSchedulerRunning == pdFALSE ) { xReturn = taskSCHEDULER_NOT_STARTED; } else { if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE ) { xReturn = taskSCHEDULER_RUNNING; } else { xReturn = taskSCHEDULER_SUSPENDED; } } return xReturn; } #endif /* ( ( INCLUDE_xTaskGetSchedulerState == 1 ) || ( configUSE_TIMERS == 1 ) ) */ /*-----------------------------------------------------------*/ #if ( configUSE_MUTEXES == 1 ) void vTaskPriorityInherit( xTaskHandle const pxMutexHolder ) { tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder; /* If the mutex was given back by an interrupt while the queue was locked then the mutex holder might now be NULL. */ if( pxMutexHolder != NULL ) { if( pxTCB->uxPriority < pxCurrentTCB->uxPriority ) { /* Adjust the mutex holder state to account for its new priority. */ listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( portTickType ) configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */ /* If the task being modified is in the ready state it will need to be moved into a new list. */ if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) != pdFALSE ) { if( uxListRemove( &( pxTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { taskRESET_READY_PRIORITY( pxTCB->uxPriority ); } /* Inherit the priority before being moved into the new list. */ pxTCB->uxPriority = pxCurrentTCB->uxPriority; prvAddTaskToReadyList( pxTCB ); } else { /* Just inherit the priority. */ pxTCB->uxPriority = pxCurrentTCB->uxPriority; } traceTASK_PRIORITY_INHERIT( pxTCB, pxCurrentTCB->uxPriority ); } } } #endif /* configUSE_MUTEXES */ /*-----------------------------------------------------------*/ #if ( configUSE_MUTEXES == 1 ) void vTaskPriorityDisinherit( xTaskHandle const pxMutexHolder ) { tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder; if( pxMutexHolder != NULL ) { if( pxTCB->uxPriority != pxTCB->uxBasePriority ) { /* We must be the running task to be able to give the mutex back. Remove ourselves from the ready list we currently appear in. */ if( uxListRemove( &( pxTCB->xGenericListItem ) ) == ( unsigned portBASE_TYPE ) 0 ) { taskRESET_READY_PRIORITY( pxTCB->uxPriority ); } /* Disinherit the priority before adding the task into the new ready list. */ traceTASK_PRIORITY_DISINHERIT( pxTCB, pxTCB->uxBasePriority ); pxTCB->uxPriority = pxTCB->uxBasePriority; listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( portTickType ) configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */ prvAddTaskToReadyList( pxTCB ); } } } #endif /* configUSE_MUTEXES */ /*-----------------------------------------------------------*/ #if ( portCRITICAL_NESTING_IN_TCB == 1 ) void vTaskEnterCritical( void ) { portDISABLE_INTERRUPTS(); if( xSchedulerRunning != pdFALSE ) { ( pxCurrentTCB->uxCriticalNesting )++; } } #endif /* portCRITICAL_NESTING_IN_TCB */ /*-----------------------------------------------------------*/ #if ( portCRITICAL_NESTING_IN_TCB == 1 ) void vTaskExitCritical( void ) { if( xSchedulerRunning != pdFALSE ) { if( pxCurrentTCB->uxCriticalNesting > 0U ) { ( pxCurrentTCB->uxCriticalNesting )--; if( pxCurrentTCB->uxCriticalNesting == 0U ) { portENABLE_INTERRUPTS(); } } } } #endif /* portCRITICAL_NESTING_IN_TCB */ /*-----------------------------------------------------------*/ #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( configUSE_STATS_FORMATTING_FUNCTIONS == 1 ) ) void vTaskList( signed char *pcWriteBuffer ) { xTaskStatusType *pxTaskStatusArray; volatile unsigned portBASE_TYPE uxArraySize, x; char cStatus; /* * PLEASE NOTE: * * This function is provided for convenience only, and is used by many * of the demo applications. Do not consider it to be part of the * scheduler. * * vTaskList() calls uxTaskGetSystemState(), then formats part of the * uxTaskGetSystemState() output into a human readable table that * displays task names, states and stack usage. * * vTaskList() has a dependency on the sprintf() C library function that * might bloat the code size, use a lot of stack, and provide different * results on different platforms. An alternative, tiny, third party, * and limited functionality implementation of sprintf() is provided in * many of the FreeRTOS/Demo sub-directories in a file called * printf-stdarg.c (note printf-stdarg.c does not provide a full * snprintf() implementation!). * * It is recommended that production systems call uxTaskGetSystemState() * directly to get access to raw stats data, rather than indirectly * through a call to vTaskList(). */ /* Make sure the write buffer does not contain a string. */ *pcWriteBuffer = 0x00; /* Take a snapshot of the number of tasks in case it changes while this function is executing. */ uxArraySize = uxCurrentNumberOfTasks; /* Allocate an array index for each task. */ pxTaskStatusArray = pvPortMalloc( uxCurrentNumberOfTasks * sizeof( xTaskStatusType ) ); if( pxTaskStatusArray != NULL ) { /* Generate the (binary) data. */ uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, NULL ); /* Create a human readable table from the binary data. */ for( x = 0; x < uxArraySize; x++ ) { switch( pxTaskStatusArray[ x ].eCurrentState ) { case eReady: cStatus = tskREADY_CHAR; break; case eBlocked: cStatus = tskBLOCKED_CHAR; break; case eSuspended: cStatus = tskSUSPENDED_CHAR; break; case eDeleted: cStatus = tskDELETED_CHAR; break; default: /* Should not get here, but it is included to prevent static checking errors. */ cStatus = 0x00; break; } sprintf( ( char * ) pcWriteBuffer, ( char * ) "%s\t\t%c\t%u\t%u\t%u\r\n", pxTaskStatusArray[ x ].pcTaskName, cStatus, ( unsigned int ) pxTaskStatusArray[ x ].uxCurrentPriority, ( unsigned int ) pxTaskStatusArray[ x ].usStackHighWaterMark, ( unsigned int ) pxTaskStatusArray[ x ].xTaskNumber ); pcWriteBuffer += strlen( ( char * ) pcWriteBuffer ); } /* Free the array again. */ vPortFree( pxTaskStatusArray ); } } #endif /* configUSE_TRACE_FACILITY */ /*----------------------------------------------------------*/ #if ( ( configGENERATE_RUN_TIME_STATS == 1 ) && ( configUSE_STATS_FORMATTING_FUNCTIONS == 1 ) ) void vTaskGetRunTimeStats( signed char *pcWriteBuffer ) { xTaskStatusType *pxTaskStatusArray; volatile unsigned portBASE_TYPE uxArraySize, x; unsigned long ulTotalTime, ulStatsAsPercentage; /* * PLEASE NOTE: * * This function is provided for convenience only, and is used by many * of the demo applications. Do not consider it to be part of the * scheduler. * * vTaskGetRunTimeStats() calls uxTaskGetSystemState(), then formats part * of the uxTaskGetSystemState() output into a human readable table that * displays the amount of time each task has spent in the Running state * in both absolute and percentage terms. * * vTaskGetRunTimeStats() has a dependency on the sprintf() C library * function that might bloat the code size, use a lot of stack, and * provide different results on different platforms. An alternative, * tiny, third party, and limited functionality implementation of * sprintf() is provided in many of the FreeRTOS/Demo sub-directories in * a file called printf-stdarg.c (note printf-stdarg.c does not provide * a full snprintf() implementation!). * * It is recommended that production systems call uxTaskGetSystemState() * directly to get access to raw stats data, rather than indirectly * through a call to vTaskGetRunTimeStats(). */ /* Make sure the write buffer does not contain a string. */ *pcWriteBuffer = 0x00; /* Take a snapshot of the number of tasks in case it changes while this function is executing. */ uxArraySize = uxCurrentNumberOfTasks; /* Allocate an array index for each task. */ pxTaskStatusArray = pvPortMalloc( uxCurrentNumberOfTasks * sizeof( xTaskStatusType ) ); if( pxTaskStatusArray != NULL ) { /* Generate the (binary) data. */ uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, &ulTotalTime ); /* For percentage calculations. */ ulTotalTime /= 100UL; /* Avoid divide by zero errors. */ if( ulTotalTime > 0 ) { /* Create a human readable table from the binary data. */ for( x = 0; x < uxArraySize; x++ ) { /* What percentage of the total run time has the task used? This will always be rounded down to the nearest integer. ulTotalRunTimeDiv100 has already been divided by 100. */ ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter / ulTotalTime; if( ulStatsAsPercentage > 0UL ) { #ifdef portLU_PRINTF_SPECIFIER_REQUIRED { sprintf( ( char * ) pcWriteBuffer, ( char * ) "%s\t\t%lu\t\t%lu%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter, ulStatsAsPercentage ); } #else { /* sizeof( int ) == sizeof( long ) so a smaller printf() library can be used. */ sprintf( ( char * ) pcWriteBuffer, ( char * ) "%s\t\t%u\t\t%u%%\r\n", pxTaskStatusArray[ x ].pcTaskName, ( unsigned int ) pxTaskStatusArray[ x ].ulRunTimeCounter, ( unsigned int ) ulStatsAsPercentage ); } #endif } else { /* If the percentage is zero here then the task has consumed less than 1% of the total run time. */ #ifdef portLU_PRINTF_SPECIFIER_REQUIRED { sprintf( ( char * ) pcWriteBuffer, ( char * ) "%s\t\t%lu\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter ); } #else { /* sizeof( int ) == sizeof( long ) so a smaller printf() library can be used. */ sprintf( ( char * ) pcWriteBuffer, ( char * ) "%s\t\t%u\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, ( unsigned int ) pxTaskStatusArray[ x ].ulRunTimeCounter ); } #endif } pcWriteBuffer += strlen( ( char * ) pcWriteBuffer ); } } /* Free the array again. */ vPortFree( pxTaskStatusArray ); } } #endif /* configGENERATE_RUN_TIME_STATS */