Task

Table of Contents

• Features Supported
• Features NOT Supported
• Important Usage Guidelines
• Example Usage
• API

Attention

This module is not applicable for NO RTOS environment

Features Supported

• APIs to create and destroy tasks
• APIs to yeild a task
• Ability to specify task priority, task entry function, stack pointer, stack size
• Ability to get task and CPU load

Features NOT Supported

NA

Important Usage Guidelines

• On R5F, and M4F, make sure memory provided as stack is 32b aligned and size is also multiple of 32b
• Stack and stack size MUST be provided by application and is not allocated internally

Example Usage

Include the below file to access the APIs,

#include <kernel/dpl/TaskP.h>

Example usage to define task objects and parameters

/* Task priority, stack, stack size and task objects, these MUST be global's */
#define MY_TASK_PRI         (8U)
#define MY_TASK_STACK_SIZE  (4*1024U)
uint8_t gMyTaskStack[MY_TASK_STACK_SIZE] __attribute__((aligned(32)));
TaskP_Object gMyTask;
 
/* Application specific task arguments */
typedef struct {
    uint32_t value;
} MyTask_Args;
 
MyTask_Args gMyTask_args;

Example task main function

/* Task entry point or main function for this task */
void myTaskMain(void *args)
{
    MyTask_Args *myArgs = (MyTask_Args*)args;
    DebugP_assert(myArgs != NULL);
 
    /* myArgs points to structure pointer passed during TaskP_construct */
 
    /* do something in the task */
 
    /* when done call below function, DO NOT 'return` from this function */
    TaskP_exit();
}

Example usage to create a task

    int32_t status;
    TaskP_Params myTaskParams; /* this need not be global variable */
 
    TaskP_Params_init(&myTaskParams);
    myTaskParams.name = "MY_TASK";
    myTaskParams.stackSize = MY_TASK_STACK_SIZE;
    myTaskParams.stack = gMyTaskStack;
    myTaskParams.priority = MY_TASK_PRI;
    myTaskParams.args = &gMyTask_args;
    myTaskParams.taskMain = myTaskMain;
 
    status = TaskP_construct(&gMyTask, &myTaskParams);
    DebugP_assert(status == SystemP_SUCCESS);

Example usage to get task and CPU load

    TaskP_Load taskLoad;
    uint32_t cpuLoad;
 
    cpuLoad = TaskP_loadGetTotalCpuLoad();
    DebugP_log(" LOAD: CPU  = %2d.%2d %%\r\n", cpuLoad/100, cpuLoad%100 );
 
    TaskP_loadGet(&gMyTask, &taskLoad);
    DebugP_log(" LOAD: %s = %2d.%2d %%\r\n", taskLoad.name, taskLoad.cpuLoad/100, taskLoad.cpuLoad%100 );

API

APIs for Task