What is the task application function of FreeRTOS real-time operating system

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1. Get task system status 1.1 function description UBaseType_t uxTaskGetSystemState (TaskStatus_t * constpxTaskStatusArray, const UBaseType_tuxArraySize, unsigned long * constpulTotalRunTime)

This function populates the TaskStatus_t structure with relevant information, and the information for each task in the system can be populated into the TaskStatus_t structure array, the size of which is specified by uxArraySize. The structure TaskStatus_t is defined as follows:

The typedef struct xTASK_STATUS {/ * task handle * / TaskHandle_t xHandle; / * pointer to the task name * / const signed char * pcTaskName; / * task ID is a unique number * / UBaseType_t xTaskNumber; / * when filling the structure, the task's current state (run, ready, pending, etc.) * / eTaskState eCurrentState; / * the priority of the task running (or inheriting) when filling the structure. * / UBaseType_t uxCurrentPriority; / * when the priority of a task is changed due to inheritance, this variable holds the original priority of the task. Valid only if configUSE_MUTEXES is defined as 1. The total elapsed time assigned to the task by * / UBaseType_t uxBasePriority; / *. Valid only when the macro configGENERATE_RUN_TIME_STATS is 1. * / unsigned long ulRunTimeCounter; / * the minimum number of stacks left since the task is created. The closer this value is to 0, the more likely the stack overflow is. * / unsigned short usStackHighWaterMark;} TaskStatus_t

Note that this function is for trial only, and calling this function suspends all tasks until the end of the function, so the task may be suspended for a long time. In the file FreeRTOSConfig.h, the macro configUSE _ TRACE_FACILITY must be set to 1 for this function to be valid.

1.2 Parameter description

PxTaskStatusArray: an array of structures pointing to the TaskStatus_t type. This array must contain at least 1 element. The number of tasks controlled by RTOS can be obtained using the API function uxTaskGetNumberOfTasks ().

UxArraySize: the size of the array that the parameter pxTaskStatusArray points to, that is, the number of indexes of the array.

PulTotalRunTime: if the macro configGENERATE _ RUN_TIME_STATS is set to 1 in the file FreeRTOSConfig.h, this function writes the total elapsed time to * pulTotalRunTime. PulTotalRunTime can be set to NULL, which means total elapsed time is ignored.

1.3 return value

The number of TaskStatus_t structures populated. This value should be equal to the value returned by calling the API function uxTaskGetNumberOfTasks (), but returns 0 if the value passed to the uxArraySize parameter is too small.

1.4 usage examples / * this example demonstrates how to use the uxTaskGetSystemState () function to obtain run-time information and convert it into a character format that is easier for programmers to recognize, and these converted characters are saved to pcWriteBuffer. * / void vTaskGetRunTimeStats (signed char * pcWriteBuffer) {TaskStatus_t*pxTaskStatusArray; volatileUBaseType_t uxArraySize, x; unsignedlong ulTotalRunTime, ulStatsAsPercentage; / * defensive code to ensure that the string has a reasonable end * / * pcWriteBuffer = 0x00; / * get the total number of tasks * / uxArraySize = uxTaskGetNumberOfTasks () / * allocate memory for the TaskStatus_t structure of each task, or statically allocate a sufficiently large array * / pxTaskStatusArray = pvPortMalloc (uxArraySize * sizeof (TaskStatus_t)); if (pxTaskStatusArray! = NULL) {/ * get the status information of each task * / uxArraySize = uxTaskGetSystemState (pxTaskStatusArray, uxArraySize,&ulTotalRunTime); / * percentage calculation * / ulTotalRunTime / = 100UL / * avoid zero division errors * / if (ulTotalRunTime > 0) {/ * convert each part of the task status information obtained into a string format easily recognized by the programmer * / for (x = 0; x

< uxArraySize; x++ ) { /* 计算任务运行时间与总运行时间的百分比。*/ ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter /ulTotalRunTime; if( ulStatsAsPercentage >

0UL) {sprintf (pcWriteBuffer, "% s\ t\ t%lu\ t\ t% Lu%\ r\ n", pxTaskStatusArray [x] .pcTaskName, pxTaskStatusArray [x] .ulRunTimeCounter, ulStatsAsPercentage) } else {/ * the task elapsed less than 1% of the total elapsed time (pcWriteBuffer, "% s\ t\ t%lu\ t\ t