取得系统资源信息

【内存使用率】 

float CHWMSchedule::GetMemUsedRate()
{
    unsigned long long ullFreePhyMem = 0;
    unsigned long long ullUsedPhyMem = 0;
    unsigned long long ullTotalPhyMem = 0;
    perfstat_memory_total_t minfo;
    if(perfstat_memory_total(NULL, &minfo, sizeof(perfstat_memory_total_t), 1) != 1)
    {
        printf("Get System Memory Fail");
        return 0.0;
    }
    //minfo.real_free的单位是4kb
    ullFreePhyMem = minfo.real_free;
    ullTotalPhyMem = minfo.real_total;
    ullUsedPhyMem = ullTotalPhyMem - ullFreePhyMem;
    
    return (float)ullUsedPhyMem/ullTotalPhyMem;  
}

【cpu使用率】

 float CHWMSchedule::GetCpuUsedRate()

{
    //perfstat_cpu_total_t结构定义了cpu信息，具体可以看头文件libperfstat.h
    static perfstat_cpu_total_t t1,t2;
    double total_cpu;

    //为了准确增加查询次数
    int nOffset = 10;
    total_cpu = 0;
    int nCpuSys = 0;
    int nCpuWait = 0;
    int nCpuUser = 0;
    int nCpuIdle = 0;

    if (t1.psys == 0)
    {
        //获取当前值的函数，具体定义可以参考头文件
        if (perfstat_cpu_total(NULL,&t1,sizeof(perfstat_cpu_total_t),1) < 0)
        {
            return 0.0;
        }
        usleep(100000);
    }

    // 这里为什么要取10次，因为psys等变量记录的是CPU当前跳数，因此需要统计当前的值减去上次的值，
    // 因此 static perfstat_cpu_total_t t1,t2定义成static
    for(int i=0; i<nOffset; i++)
    {
        t2 = t1;
        if (perfstat_cpu_total(NULL,&t1,sizeof(perfstat_cpu_total_t),1) < 0)
        {
            return 0.0;
        }
        
        total_cpu = (t1.psys+t1.puser+t1.pidle+t1.pwait-(t2.psys+t2.puser+t2.pidle+t2.pwait));
        nCpuSys    += (int)((t1.psys-t2.psys)*10000/total_cpu);
        nCpuWait   += (int)((t1.pwait-t2.pwait)*10000/total_cpu);
        nCpuUser   += (int)((t1.puser-t2.puser)*10000/total_cpu);
        nCpuIdle   += (int)((t1.pidle-t2.pidle)*10000/total_cpu);
        
        usleep(1000);
    }
    
    nCpuSys = nCpuSys/nOffset;
    nCpuWait = nCpuWait/nOffset;
    nCpuUser = nCpuUser/nOffset;
    nCpuIdle = nCpuIdle/nOffset;
    
//    ZX_TRACK_0(LOG_TRACK_CODE, "系统占用：%.3f, 用户占用:%.3f, 等待：%.3f, 空闲：%.3f\n", 
//                nCpuSys/100.0, nCpuUser/100.0, nCpuWait/100.0, nCpuIdle/100.0);
                
    return (nCpuSys/100.0 + nCpuUser/100.0 + nCpuWait/100.0);
}