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方案名称

能耗 - 检测应用 CPU 的使用率

关键字

能耗 \ CPU \ 使用率

需求场景

1. 用于判断某些逻辑是否为资源密集型逻辑时

参考链接

1. 《高性能 iOS 应用开发》

详细内容

通过以下函数可以获得应用对 CPU 的利用率

//Adapted from: http://stackoverflow.com/questions/8223348/ios-get-cpu-usage-from-application

#import <mach/mach.h>
#import <assert.h>

-(float)appCPUUsage
{
    kern_return_t kr;
    task_info_data_t tinfo;
    mach_msg_type_number_t task_info_count;

    task_info_count = TASK_INFO_MAX;
    kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }

    thread_array_t thread_list;
    mach_msg_type_number_t thread_count;

    thread_info_data_t thinfo;
    mach_msg_type_number_t thread_info_count;

    thread_basic_info_t basic_info_th;

    kr = task_threads(mach_task_self(), &thread_list, &thread_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }

    float tot_cpu = 0;
    int j;

    for (j = 0; j < thread_count; j++)
    {
        thread_info_count = THREAD_INFO_MAX;
        kr = thread_info(thread_list[j], THREAD_BASIC_INFO,
                         (thread_info_t)thinfo, &thread_info_count);
        if (kr != KERN_SUCCESS) {
            return -1;
        }

        basic_info_th = (thread_basic_info_t)thinfo;

        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {
            tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0;
        }
    }

    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    assert(kr == KERN_SUCCESS);

    return tot_cpu;
}

效果图

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备注

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