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uxTaskGetSystemState()
task.h
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| pxTaskStatusArray | A pointer to an array of TaskStatus_t structures. The array must contain at least one TaskStatus_t structure for each task that is under the control of the RTOS. The number of tasks under the control of the RTOS can be determined using the uxTaskGetNumberOfTasks() API function. |
| uxArraySize | The size of the array pointed to by the pxTaskStatusArray parameter. The size is specified as the number of indexes in the array (the number of TaskStatus_t structures contained in the array), not by the number of bytes in the array. |
| pulTotalRunTime | If configGENERATE_RUN_TIME_STATS is set to 1 in FreeRTOSConfig.h then *pulTotalRunTime is set by uxTaskGetSystemState() to the total run time (as defined by the run time stats clock) since the target booted. pulTotalRunTime can be set to NULL to omit the total run time value. |
- Returns:
- The number of TaskStatus_t structures that were populated by uxTaskGetSystemState(). This should equal the number returned by the uxTaskGetNumberOfTasks() API function, but will be zero if the value passed in the uxArraySize parameter was too small.
/* This example demonstrates how a human readable table of run time stats
information is generated from raw data provided by uxTaskGetSystemState().
The human readable table is written to pcWriteBuffer. (see the vTaskList()
API function which actually does just this). */
void vTaskGetRunTimeStats( signed char *pcWriteBuffer )
{
TaskStatus_t *pxTaskStatusArray;
volatile UBaseType_t uxArraySize, x;
unsigned long ulTotalRunTime, ulStatsAsPercentage;
/* 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 a TaskStatus_t structure for each task. An array could be
allocated statically at compile time. */
pxTaskStatusArray = pvPortMalloc( uxArraySize * sizeof( TaskStatus_t ) );
if( pxTaskStatusArray != NULL )
{
/* Generate raw status information about each task. */
uxArraySize = uxTaskGetSystemState( pxTaskStatusArray,
uxArraySize,
&ulTotalRunTime );
/* For percentage calculations. */
ulTotalRunTime /= 100UL;
/* Avoid divide by zero errors. */
if( ulTotalRunTime > 0 )
{
/* For each populated position in the pxTaskStatusArray array,
format the raw data as human readable ASCII 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 / ulTotalRunTime;
if( ulStatsAsPercentage > 0UL )
{
sprintf( pcWriteBuffer, "%s\t\t%lu\t\t%lu%%\r\n",
pxTaskStatusArray[ x ].pcTaskName,
pxTaskStatusArray[ x ].ulRunTimeCounter,
ulStatsAsPercentage );
}
else
{
/* If the percentage is zero here then the task has
consumed less than 1% of the total run time. */
sprintf( pcWriteBuffer, "%s\t\t%lu\t\t<1%%\r\n",
pxTaskStatusArray[ x ].pcTaskName,
pxTaskStatusArray[ x ].ulRunTimeCounter );
}
pcWriteBuffer += strlen( ( char * ) pcWriteBuffer );
}
}
/* The array is no longer needed, free the memory it consumes. */
vPortFree( pxTaskStatusArray );
}
}
The TaskStatus_t definition
typedef struct xTASK_STATUS
{
/* The handle of the task to which the rest of the information in the
structure relates. */
TaskHandle_t xHandle;
/* A pointer to the task's name. This value will be invalid if the task was
deleted since the structure was populated! */
const signed char *pcTaskName;
/* A number unique to the task. */
UBaseType_t xTaskNumber;
/* The state in which the task existed when the structure was populated. */
eTaskState eCurrentState;
/* The priority at which the task was running (may be inherited) when the
structure was populated. */
UBaseType_t uxCurrentPriority;
/* The priority to which the task will return if the task's current priority
has been inherited to avoid unbounded priority inversion when obtaining a
mutex. Only valid if configUSE_MUTEXES is defined as 1 in
FreeRTOSConfig.h. */
UBaseType_t uxBasePriority;
/* The total run time allocated to the task so far, as defined by the run
time stats clock. Only valid when configGENERATE_RUN_TIME_STATS is
defined as 1 in FreeRTOSConfig.h. */
unsigned long ulRunTimeCounter;
/* Points to the lowest address of the task's stack area. */
StackType_t *pxStackBase;
/* The minimum amount of stack space that has remained for the task since
the task was created. The closer this value is to zero the closer the task
has come to overflowing its stack. */
unsigned short usStackHighWaterMark;
} TaskStatus_t;
NXP tweet showing LPC5500 (ARMv8-M Cortex-M33) running FreeRTOS.
Meet Richard Barry and learn about running FreeRTOS on RISC-V at FOSDEM 2019
Version 10.1.1 of the FreeRTOS kernel is available for immediate download. MIT licensed.
View a recording of the "OTA Update Security and Reliability" webinar, presented by TI and AWS.
FreeRTOS and other embedded software careers at AWS.
