变更记录

序号 录入时间 录入人 备注
1 2017-06-28 Alfred Jiang -

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

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//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

（无）

备注

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