Development Guidelines

• Available APIs
• How to Develop
• Development Example
  • Example Description
  • Sample Code
  • Verification

Available APIs

Table 1 Functions

How to Develop

The typical CPUP development process is as follows.

1. Call LOS_SysCpuUsage to obtain the system CPUP.

2. Call LOS_HistorySysCpuUsage to obtain the historical CPUP of the system.

3. Call LOS_TaskCpuUsage to obtain the CPUP of a specified task.

   • If the task has been created, disable interrupt, obtain the CPUP, and then enable interrupt.
   • If the task is not created, return an error code.

4. Call LOS_HistoryTaskCpuUsage to obtain the historical CPUP of a specified task.

   • If the task has been created, disable interrupt, obtain the CPUP in different modes, and then enable interrupt.
   • If the task is not created, return an error code.

5. Call LOS_AllCpuUsage to obtain the CPUP of all tasks.

   • If the CPUP is initialized, disable interrupt, obtain the CPUP in different modes, and then enable interrupt.
   • If CPUP is not initialized or has invalid input parameters, return an error code.

Development Example

Example Description

This example implements the following:

1. Create a task for the CPUP test.
2. Obtain the CPUP of the current system.
3. Obtain the historical system CPUP in different modes.
4. Obtain the CPUP of the created test task.
5. Obtain the CPUP of the created test task in different modes.

Sample Code

Prerequisites

In target_config.h, the LOSCFG_BASE_CORE_CPUP parameter is enabled.

The sample code is as follows:

#include "los_task.h"
#include "los_cpup.h" 
#define  MODE  4
UINT32 g_cpuTestTaskID;  
VOID ExampleCpup(VOID) 
{      
    printf("entry cpup test example\n");
    while(1) {
        usleep(100);
    }
}
UINT32 ItCpupTest(VOID) 
{     
    UINT32 ret;
    UINT32 cpupUse;
    TSK_INIT_PARAM_S cpupTestTask = { 0 };
    memset(&cpupTestTask, 0, sizeof(TSK_INIT_PARAM_S));
    cpupTestTask.pfnTaskEntry = (TSK_ENTRY_FUNC)ExampleCpup;
    cpupTestTask.pcName       = "TestCpupTsk"; 
    cpupTestTask.uwStackSize  = 0x800;
    cpupTestTask.usTaskPrio   = 5;
    ret = LOS_TaskCreate(&g_cpuTestTaskID, &cpupTestTask);
    if(ret != LOS_OK) {
        printf("cpupTestTask create failed .\n");
        return LOS_NOK;
    }

    usleep(100);

 /* Obtain the current CPUP of the system. */
    cpupUse = LOS_SysCpuUsage();
    printf("the current system cpu usage is: %u.%u\n",
            cpupUse / LOS_CPUP_PRECISION_MULT, cpupUse % LOS_CPUP_PRECISION_MULT); 

    cpupUse = LOS_HistorySysCpuUsage(CPU_LESS_THAN_1S);
 /* Obtain the CPUP of the specified task (cpupTestTask in this example).*/
    printf("the history system CPUP in all time: %u.%u\n",
           cpupUse / LOS_CPUP_PRECISION_MULT, cpupUse % LOS_CPUP_PRECISION_MULT);
    cpupUse = LOS_TaskCpuUsage(g_cpuTestTaskID);    
 /* Obtain the CPUP of the specified historical task (cpupTestTask in this example) since the system startup. */
    printf("cpu usage of the cpupTestTask:\n TaskID: %d\n usage: %u.%u\n",
           g_cpuTestTaskID, cpupUse / LOS_CPUP_PRECISION_MULT, cpupUse % LOS_CPUP_PRECISION_MULT); 
    cpupUse = LOS_HistoryTaskCpuUsage(g_cpuTestTaskID, CPU_LESS_THAN_1S);   
    printf("cpu usage of the cpupTestTask in all time:\n TaskID: %d\n usage: %u.%u\n",
           g_cpuTestTaskID, cpupUse / LOS_CPUP_PRECISION_MULT, cpupUse % LOS_CPUP_PRECISION_MULT);   
    return LOS_OK; 
}

Verification

The development is successful if the return result is as follows:

entry cpup test example 
the current system cpu usage is : 1.5
 the history system cpu usage in all time: 3.0
 cpu usage of the cpupTestTask: TaskID:10 usage: 0.0
 cpu usage of the cpupTestTask in all time: TaskID:10 usage: 0.0