获取CPU使用百分比

Question

我是Objective-C的初学者，我决定尝试编写一些简单的应用程序，所以我试图制作一个可以测量CPU使用率等的应用程序。是否有一种简单的方法可以在Cocoa应用程序中使用Objective-C获取CPU百分比等信息？

我发现了这个问题Determine Process Info Programmatically in Darwin/OSX这是相似的，但不完全一样。主要的是，我希望整个系统的CPU百分比使用率，不仅仅是我的过程，而且我实际上更喜欢Objective-C解决方案，而在这个问题中，海报需要别的东西。

Answer 1

这里就是这样，我做到了：

* .h文件中：

#include <sys/sysctl.h> 
#include <sys/types.h> 
#include <mach/mach.h> 
#include <mach/processor_info.h> 
#include <mach/mach_host.h> 

的ivars：

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

* .m文件

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification 
{  
    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] retain];  
} 

- (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); 
     } 
     [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]; 
    } 
}