iOS 获取APP的CPU、内存等信息

目标是开发一个SDK，嵌入到APP里面，用来统计当前APP的实时CPU、内存等信息

2015.11.17

http://stackoverflow.com/questions/12889422/ios-cpu-usage-for-each-process-using-sysctl

这是第一个找到，采用的是sysctl函数

但是出来的CPU数据和instrument、GT的数据对不上（后两者数据比较接近）

2015.11.19

https://github.com/TianJIANG/ios_monitor

从guithub上搜到的，利用的主要是#import <mach/mach.h> 里面的task_info 等，打开了一道新的大门，后续找到不少类似的方法

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

这个答案也是给的这个方法，末尾额外加了一行代码， vm_dealloc，解决leaking问题

补充几个相关的：

http://stackoverflow.com/questions/5182924/where-is-my-ipad-runtime-memory-going%E2%80%8C%E2%80%8B

http://blog.sina.com.cn/s/blog_693de6100101ffwm.html

http://www.zhihu.com/question/22992491

Github 搜 “Activity Monitor”

https://github.com/AndrewBarba/ActivityMonitor

https://github.com/vsnrain/ActivityMonitor

此算法是获取当前APP的CPU，数值与Instrument、GT接近

- (void)GetCpuUsage {
    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;
    }
    
    task_basic_info_t      basic_info;
    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;
    uint32_t stat_thread = 0; // Mach threads
    
    basic_info = (task_basic_info_t)tinfo;
    
    // get threads in the task
    kr = task_threads(mach_task_self(), &thread_list, &thread_count);
    if (kr != KERN_SUCCESS) {
        return;
    }
    if (thread_count > 0)
        stat_thread += thread_count;
    
    long tot_sec = 0;
    long tot_usec = 0;
    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;
        }
        
        basic_info_th = (thread_basic_info_t)thinfo;
        
        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {
            tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;
            tot_usec = tot_usec + basic_info_th->system_time.microseconds + basic_info_th->system_time.microseconds;
            tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0;
        }
        
    } // for each thread
    
    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    assert(kr == KERN_SUCCESS);
    
    NSLog(@"CPU Usage: %f 
", tot_cpu);
}

此算法是获取当前APP的内存，数值与GT的一致，与Instrument不一致

- (void)GetCurrentTaskUsedMemory {
    task_basic_info_data_t taskInfo;
    mach_msg_type_number_t infoCount = TASK_BASIC_INFO_COUNT;
    kern_return_t kernReturn = task_info(mach_task_self(),
                                         TASK_BASIC_INFO, (task_info_t)&taskInfo, &infoCount);
    
    if(kernReturn != KERN_SUCCESS) {
        return;
    }
    
    NSLog(@"Memory Usage: %f", taskInfo.resident_size / 1024.0 / 1024.0);
}

2015.11.20

XNU

https://en.wikipedia.org/wiki/XNU

MACH

https://en.wikipedia.org/wiki/Mach_(kernel)

Kernel Programming Guide

https://developer.apple.com/library/mac/documentation/Darwin/Conceptual/KernelProgramming/About/About.html

github 上搜 mach_msg_type_number_t

https://github.com/search?l=objective-c&q=mach_msg_type_number_t&type=Code&utf8=✓

2015.11.22

用VM Tracker查看内存，有那么几项

Resident Size｜Dirty Size｜Virtual Size

http://stackoverflow.com/questions/5176074/what-do-dirty-and-resident-mean-in-relation-to-virtual-memory

这篇解释了三者的差别，我理解我们应该跟踪的是Resident Size，但是数值上与VM Tracker上对不上 

- (void)GetMemoryStatistics {
    
    // Get Page Size
    int mib[2];
    int page_size;
    size_t len;
    
    mib[0] = CTL_HW;
    mib[1] = HW_PAGESIZE;
    len = sizeof(page_size);
    
//    // 方法一: 16384
//    int status = sysctl(mib, 2, &page_size, &len, NULL, 0);
//    if (status < 0) {
//        perror("Failed to get page size");
//    }
//    // 方法二: 16384
//    page_size = getpagesize();
    // 方法三: 4096
    if( host_page_size(mach_host_self(), &page_size)!= KERN_SUCCESS ){
        perror("Failed to get page size");
    }
    printf("Page size is %d bytes
", page_size);
    
    // Get Memory Size
    mib[0] = CTL_HW;
    mib[1] = HW_MEMSIZE;
    long ram;
    len = sizeof(ram);
    if (sysctl(mib, 2, &ram, &len, NULL, 0)) {
        perror("Failed to get ram size");
    }
    printf("Ram size is %f MB
", ram / (1024.0) / (1024.0));
    
    // Get Memory Statistics
//    vm_statistics_data_t vm_stats;
//    mach_msg_type_number_t info_count = HOST_VM_INFO_COUNT;
    vm_statistics64_data_t vm_stats;
    mach_msg_type_number_t info_count64 = HOST_VM_INFO64_COUNT;
//    kern_return_t kern_return = host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vm_stats, &info_count);
    kern_return_t kern_return = host_statistics64(mach_host_self(), HOST_VM_INFO64, (host_info64_t)&vm_stats, &info_count64);
    if (kern_return != KERN_SUCCESS) {
        printf("Failed to get VM statistics!");
    }
    
    double vm_total = vm_stats.wire_count + vm_stats.active_count + vm_stats.inactive_count + vm_stats.free_count;
    double vm_wire = vm_stats.wire_count;
    double vm_active = vm_stats.active_count;
    double vm_inactive = vm_stats.inactive_count;
    double vm_free = vm_stats.free_count;
    double unit = (1024.0) * (1024.0);
    
    NSLog(@"Total Memory: %f", vm_total * page_size / unit);
    NSLog(@"Wired Memory: %f", vm_wire * page_size / unit);
    NSLog(@"Active Memory: %f", vm_active * page_size / unit);
    NSLog(@"Inactive Memory: %f", vm_inactive * page_size / unit);
    NSLog(@"Free Memory: %f", vm_free * page_size / unit);
}

1、关于Ram大小，用HW_MEMSIZE计算得到1000MB，是准确的

2、关于page size，上面提供了三种方法

其中方法一、二在64位机器上返回了16384，只有第三种方法返回了4096

http://stackoverflow.com/questions/21552747/strange-behavior-on-64bit-ios-devices-when-retrieving-vm-statistics/33574804#33574804

这篇文章提出了此疑问，但是没有特别明确的解释

我认为page size应该是4096，用VM Tracker运行，截图如下：

 

以第一项_LINKEDIT为例，13692*4096/1024/1024=53.48M，与Vitual Size吻合

3、关于vm_total、vm_wire、vm_active、vm_inactive、vm_free这几个值

其中一组运行结果如下：

Page size is 4096 bytes
Ram size is 1000.000000 MB
2015-11-22 20:59:41.191 CompSDKDemo[1602:410503] Total Memory: 777.519531
2015-11-22 20:59:41.191 CompSDKDemo[1602:410503] Wired Memory: 205.484375
2015-11-22 20:59:41.192 CompSDKDemo[1602:410503] Active Memory: 374.941406
2015-11-22 20:59:41.192 CompSDKDemo[1602:410503] Inactive Memory: 175.710938
2015-11-22 20:59:41.192 CompSDKDemo[1602:410503] Free Memory: 21.382812

可以看到，Total Memory不是1000MB，这个如何解释呢？

a. 1000M应该是实际的RAM大小，而Total Memory，应该是Virtual Memory，两者是否一回事，有待商榷？

b. 从APP Store上下了一个System Monitor，如下：

可以看到，Wired、Active、Inactive的值都对得上，唯独Free的值对不上

不负责任的猜测，他的Free是通过1000M减其它三项得到的

Source Code : Get Hardware Info of iPhone

http://blog.sina.com.cn/s/blog_4a04a3c90100r9gn.html

How to determine CPU and memory consumption from inside a process? 

http://stackoverflow.com/questions/63166/how-to-determine-cpu-and-memory-consumption-from-inside-a-process

总结下来，关于内存的有两个问题：

1. active、inactive、wired、free加起来不等于1000M

　　这个可以先放一放，我们可以先不用管这部分

2. 当前app消耗的内存，目前的算法与 Debug Gauges的值有偏差，与GT吻合

　　不过发现点击页面增长的值和发回释放的值，与Debug Gauges基本一致，因此可以使用

关于CPU，上面算法给出的值符合要求，可以使用；

接下来是：耗电量、网速、帧率

2015.11.23

耗电量，目前没有找到合适的工具

有两种获取电池电量信息的方法

方法一：

这个方法需要导入 IOKit 库，但是不知从什么时候开始，iOS系统不允许用户导入库

http://www.cocoachina.com/bbs/read.php?tid=268692

这篇文章提供了野路子方法，但是实施起来颇为不便，考虑到要做sdk，不适合

CFTypeRef blob = IOPSCopyPowerSourcesInfo();
CFArrayRef sources = IOPSCopyPowerSourcesList(blob);

方法二：

[UIDevice currentDevice].batteryLevel

据说精度达到1%

找到一篇文章，提供了三种方法

iOS开发之runtime精准获取电池电量

http://www.jianshu.com/p/11c1afdf5415

网络流量

https://github.com/QbsuranAlang/GetNetworkFlow/blob/master/GetNetworkFlow/GetNetworkFlow/ViewController.m

2015.11.24

经测试，mach方法获取的内存值与top命令拿到的RSS、VSS是一致的