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 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 threadsbasic_info=(task_basic_info_t)tinfo;//get threads in the taskkr = task_threads(mach_task_self(), &thread_list, &thread_count);if(kr !=KERN_SUCCESS) {return;
}if(thread_count >0)
stat_thread+=thread_count;longtot_sec =0;longtot_usec =0;floattot_cpu =0;intj;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 threadkr= vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count *sizeof(thread_t));
assert(kr==KERN_SUCCESS);
NSLog(@"CPU Usage: %f \n", 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 Sizeintmib[2];intpage_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: 4096if( host_page_size(mach_host_self(), &page_size)!=KERN_SUCCESS ){
perror("Failed to get page size");
}
printf("Page size is %d bytes\n", page_size);//Get Memory Sizemib[0] =CTL_HW;
mib[1] =HW_MEMSIZE;longram;
len=sizeof(ram);if(sysctl(mib,2, &ram, &len, NULL,0)) {
perror("Failed to get ram size");
}
printf("Ram size is %f MB\n", 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!");
}doublevm_total = vm_stats.wire_count + vm_stats.active_count + vm_stats.inactive_count +vm_stats.free_count;doublevm_wire =vm_stats.wire_count;doublevm_active =vm_stats.active_count;doublevm_inactive =vm_stats.inactive_count;doublevm_free =vm_stats.free_count;doubleunit = (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 sizeis4096bytes
Ram sizeis1000.000000MB2015-11-2220:59:41.191CompSDKDemo[1602:410503] Total Memory:777.5195312015-11-2220:59:41.191CompSDKDemo[1602:410503] Wired Memory:205.4843752015-11-2220:59:41.192CompSDKDemo[1602:410503] Active Memory:374.9414062015-11-2220:59:41.192CompSDKDemo[1602:410503] Inactive Memory:175.7109382015-11-2220:59:41.192CompSDKDemo[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
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
