cpu占用率

获得当前应用的cpu占用率

- (float)getCpuUsage
{
    kern_return_t           kr;
    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;
    }
    cpu_usage = 0;
    
    for (int i = 0; i < thread_count; i++)
    {
        thread_info_count = THREAD_INFO_MAX;
        kr = thread_info(thread_list[i], 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))
        {
            cpu_usage += basic_info_th->cpu_usage;
        }
    }
    
    cpu_usage = cpu_usage / (float)TH_USAGE_SCALE * 100.0;
    
    vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    
    return cpu_usage;
}

https://blog.csdn.net/qq_30513483/article/details/75085702
获得系统的cpu使用率

- (CGFloat)cpuUsageRate {
    processor_info_array_t _cpuInfo, _prevCPUInfo = nil;
    mach_msg_type_number_t _numCPUInfo, _numPrevCPUInfo = 0;
    unsigned _numCPUs;
    NSLock *_cpuUsageLock;
    
    int _mib[2U] = {CTL_HW, HW_NCPU};
    size_t _sizeOfNumCPUs = sizeof(_numCPUs);
    int _status = sysctl(_mib, 2U, &_numCPUs, &_sizeOfNumCPUs, NULL, 0U);
    if(_status) {
        _numCPUs = 1;
    }
    
    _cpuUsageLock = [[NSLock alloc] init];
    
    CGFloat used = 0;
    CGFloat total = 0;
    natural_t _numCPUsU = 0U;
    kern_return_t err = host_processor_info(mach_host_self(), PROCESSOR_CPU_LOAD_INFO, &_numCPUsU, &_cpuInfo, &_numCPUInfo);
    if(err == KERN_SUCCESS) {
        [_cpuUsageLock lock];
        
        for (unsigned i = 0U; i < _numCPUs; ++i) {
            Float32 _inUse, _total;
            if(_prevCPUInfo) {
                _inUse = (
                          (_cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_USER]   - _prevCPUInfo[(CPU_STATE_MAX * i) + CPU_STATE_USER])
                          + (_cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_SYSTEM] - _prevCPUInfo[(CPU_STATE_MAX * i) + CPU_STATE_SYSTEM])
                          + (_cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_NICE]   - _prevCPUInfo[(CPU_STATE_MAX * i) + CPU_STATE_NICE])
                          );
                
                _total = _inUse + (_cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_IDLE] - _prevCPUInfo[(CPU_STATE_MAX * i) + CPU_STATE_IDLE]);
            } else {
                _inUse = _cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_USER] + _cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_SYSTEM] + _cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_NICE];
                _total = _inUse + _cpuInfo[(CPU_STATE_MAX * i) + CPU_STATE_IDLE];
            }
            
            used += _inUse;
            total += _total;
        }
        
        [_cpuUsageLock unlock];
        
        if(_prevCPUInfo) {
            size_t prevCpuInfoSize = sizeof(integer_t) * _numPrevCPUInfo;
            vm_deallocate(mach_task_self(), (vm_address_t)_prevCPUInfo, prevCpuInfoSize);
        }
        
        _prevCPUInfo = _cpuInfo;
        _numPrevCPUInfo = _numCPUInfo;
        
        _cpuInfo = nil;
        _numCPUInfo = 0U;
        
    } else {
        NSLog(@"cpuUsage Error!");
    }
    
    return used/total*100;
}