MacOS-获取CPU使用率

在MacApp Demo测试的，在iOS上应该也可以，需要修改相应参数

#import "ViewController.h"
#import <sys/sysctl.h>
#import <sys/types.h>
#import <mach/mach.h>
#import <mach/processor_info.h>
#import <mach/mach_host.h>

processor_info_array_t cpuInfo, prevCpuInfo;
mach_msg_type_number_t numCpuInfo, numPrevCpuInfo;
unsigned numCPUs;
NSTimer *updateTimer;
NSLock *CPUUsageLock;

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    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];
    updateTimer = [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(updateInfo:) userInfo:nil repeats:YES];
    [NSRunLoop.currentRunLoop addTimer:updateTimer forMode:NSRunLoopCommonModes];
}

- (void)updateInfo:(NSTimer *)timer {
    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) {
            float 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];
            }
            
            NSLog(@"Core: %u Usage: %f",i, inUse / total * 100.0);
        }
        [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 = NULL;
        numCpuInfo = 0U;
    } else {
        NSLog(@"Error!");
        [NSApp terminate:nil];
    }
}

@end