iOS-Monitor-Platform 发现获取cpu频率的函数iOS上并不能正常工作

size_t size = sizeof(int);
int results = 0;
int mib[2] = {CTL_HW, HW_CPU_FREQ};
int status = sysctl(mib, 2, &results, &size, NULL, 0);
NSString *cpuFrequency = [NSString stringWithFormat:@"%d", results];
return cpuFrequency;

这段代码但是macos能够返回

Nov 10 '17 01:11 iamqk

@iamqk 我这边测试了下，使用上述方式在 iOS 上确实拿不到 CPU 频率，而拿不到的主要是因为通过 sysctl 系统调用在 MacOS 和 iOS 平台上的获取系统信息的底层实现是通过内核变量的 MIB（管理信息库）来访问导出的内核变量，但是出于安全性的考虑，MIB 有些内核变量在这几个版本的 iOS 上禁止访问这些内核变量，比如你上面提到的 HW_CPU_FREQ 就是其中之一，类似的还有 cpufrequency_max 和 cpufrequency_min，但是网上还有很多代码是通过这种方式在较老版本上成功获取到，包括我文章提到手淘上也用这种方式，应该都是遗留代码。那还有什么其他方式获取 CPU 主频呢？其实可以通过两种方式。第一种方式比较简单，是采取硬编码的方式，在 App 中建立一张 CPU 主频的映射表，然后根据用户的机型去这张映射表中找出即可。

单位为 MHZ
static const NSUInteger CPUFrequencyTable[] = {
    [iPhone_1G]         = 412,
    [iPhone_3G]         = 620,
    [iPhone_3GS]        = 600,
    [iPhone_4]          = 800,
    [iPhone_4_Verizon]  = 800,
    [iPhone_4S]         = 800,
    [iPhone_5_GSM]      = 1300,
    [iPhone_5_CDMA]     = 1300,
    [iPhone_5C]         = 1000,
    [iPhone_5S]         = 1300,
    [iPhone_6]          = 1400,
    [iPhone_6_Plus]     = 1400,
    [iPhone_6S]         = 1850,
    [iPhone_6S_Plus]    = 1850,
    [iPod_Touch_1G]     = 400,
    [iPod_Touch_2G]     = 533,
    [iPod_Touch_3G]     = 600,
    [iPod_Touch_4G]     = 800,
    [iPod_Touch_5]      = 1000,
    [iPad_1]            = 1000,
    [iPad_2_CDMA]       = 1000,
    [iPad_2_GSM]        = 1000,
    [iPad_2_WiFi]       = 1000,
    [iPad_3_WiFi]       = 1000,
    [iPad_3_GSM]        = 1000,
    [iPad_3_CDMA]       = 1000,
    [iPad_4_WiFi]       = 1400,
    [iPad_4_GSM]        = 1400,
    [iPad_4_CDMA]       = 1400,
    [iPad_Air]          = 1400,
    [iPad_Air_Cellular] = 1400,
    [iPad_Air_2]        = 1500,
    [iPad_Air_2_Cellular] = 1500,
    [iPad_Pro]          = 2260,
    [iPad_Mini_WiFi]    = 1000,
    [iPad_Mini_GSM]     = 1000,
    [iPad_Mini_CDMA]    = 1000,
    [iPad_Mini_2]       = 1300,
    [iPad_Mini_2_Cellular] = 1300,
    [iPad_Mini_3]       = 1300,
    [iPad_Mini_3_Cellular] = 1300,
    [iUnknown]          = 0
};

第二种方式是自己通过运算来得出 CPU 的时钟频率

extern int freqTest(int cycles);

static double GetCPUFrequency(void)
{
    volatile NSTimeInterval times[500];
    
    int sum = 0;
    
    for(int i = 0; i < 500; i++)
    {
        times[i] = [[NSProcessInfo processInfo] systemUptime];
        sum += freqTest(10000);
        times[i] = [[NSProcessInfo processInfo] systemUptime] - times[i];
    }
    
    NSTimeInterval time = times[0];
    for(int i = 1; i < 500; i++)
    {
        if(time > times[i])
            time = times[i];
    }
    
    double freq = 1300000.0 / time;
    return freq;
}

其中 freqTest 这个函数是用汇编写的，在工程加入一个文件 cpuFreq.s，后缀 s 代表这个文件是一个汇编文件，文件的代码如下：

.text
.align 4
.globl _freqTest    

_freqTest:

    push    {r4-r11, lr}

freqTest_LOOP:

    // loop 1
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 2
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 3
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 4
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 5
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 6
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 7
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 8
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 9
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    // loop 10
    add     r2, r2, r1
    add     r3, r3, r2
    add     r4, r4, r3
    add     r5, r5, r4
    add     r6, r6, r5
    add     r7, r7, r6
    add     r8, r8, r7
    add     r9, r9, r8
    add     r10, r10, r9
    add     r11, r11, r10
    add     r12, r12, r11
    add     r14, r14, r12
    add     r1, r1, r14

    subs    r0, r0, #1
    bne     freqTest_LOOP
    pop     {r4-r11, pc}

当然这个汇编文件只支持 armv7 和 armv7s，也就是 32 位 Arch，64位汇编指令没给出，如果你使用的是 64 位机器调试，记得将 build archive architecture only 设置为 NO，否则会编译不通过，如下图：我这边用一台 iPhone 6 测试了这种方法获得 CPU 频率，结果为 1391614727.725209 HZ，大约也就是 1400 MHZ，和上面那张表中主频一致。

Nov 25 '17 15:11 aozhimin

@iamqk 这个 issue 也可以佐证 HW_CPU_FREQ 这个接口已经不行了

Nov 25 '17 15:11 aozhimin

@aozhimin 谢谢你的帮助

Nov 26 '17 02:11 iamqk

@iamqk 不客气，希望上面答案能帮助到你！

Nov 26 '17 03:11 aozhimin

@aozhimin 我今天调了一下，改动了一些上面汇编的代码，发现arm64也能正常测试cpu频率了

.text
.text
.align 4
.globl _freqTest

_freqTest:

STP x4, x5, [sp, #16 * 0]
STP x6, x7, [sp, #16 * 1]
STP x8, x9, [sp, #16 * 2]
STP x10, x11, [sp, #16 * 3]

freqTest_LOOP:

// loop 1
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 2
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 3
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 4
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 5
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 6
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 7
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 8
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 9
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 10
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

subs    x0, x0, #1
bne     freqTest_LOOP

RET

Nov 27 '17 03:11 iamqk

@iamqk , 好的，赞👍

Nov 27 '17 05:11 aozhimin

请问楼主可以给个小demo 本人小白最近最这个比较感兴趣想研究下

Feb 07 '18 02:02 BestZedXiao

@BestZedXiao 完整功能还是只是 CPU 的 Demo？完整功能的我还在整理当中……

Feb 22 '18 02:02 aozhimin

麻烦楼主给个测试cpu的 demo 不太懂汇编怎么弄谢谢非常感谢我邮箱 [email protected]
好人天天开心希望楼主早日看到能够给我发一个急等！再次感谢

Feb 22 '18 09:02 BestZedXiao

@BestZedXiao 好的，我今天晚上把 Demo 发到你的邮箱……

Feb 23 '18 02:02 aozhimin

@19kka 好的，64位的汇编可以参考 @iamqk 上面给的，我还没来得及试，应该没什么问题。

Feb 23 '18 08:02 aozhimin

@BestZedXiao Demo 好了，开了个 Repo，你 clone 下来，在真机运行即可。

Feb 23 '18 10:02 aozhimin

已经收到测试可用也跟其他几款对比下基本吻合谢谢啦像大佬学习也祝天天开心

Feb 23 '18 10:02 BestZedXiao

@19kka 层主发了个demo 我试了下提供的32的汇编是没有问题但是我用64位的贴上去发现clang无法通过如果你测试没问题可以发个测试64位的demo我吗确实很菜对汇编也不懂邮箱 [email protected] 谢谢啦

Feb 23 '18 10:02 BestZedXiao

@BestZedXiao 客气了，互相学习，64 位的你将 Demo 中 cpuFreq.s 的汇编代码替换成下面的试试。

.text
.text
.align 4
.globl _freqTest

_freqTest:

STP x4, x5, [sp, #16 * 0]
STP x6, x7, [sp, #16 * 1]
STP x8, x9, [sp, #16 * 2]
STP x10, x11, [sp, #16 * 3]

freqTest_LOOP:

// loop 1
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 2
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 3
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 4
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 5
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 6
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 7
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 8
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 9
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

// loop 10
add     x2, x2, x1
add     x3, x3, x2
add     x4, x4, x3
add     x5, x5, x4
add     x6, x6, x5
add     x7, x7, x6
add     x8, x8, x7
add     x9, x9, x8
add     x10, x10, x9
add     x11, x11, x10
add     x12, x12, x11
add     x14, x14, x12
add     x1, x1, x14

subs    x0, x0, #1
bne     freqTest_LOOP

RET

Feb 23 '18 11:02 aozhimin

我试了呀通不过

Feb 23 '18 12:02 BestZedXiao

@BestZedXiao 我 Demo 更新到 arm64 了，你 pull 下来试试，除了替换 asm 代码，build settings 里面要移除 armv7 armv7s 这两个 32 位架构。

Feb 24 '18 02:02 aozhimin

哦好的谢谢啦测试可以用呢再次感谢

Feb 24 '18 02:02 BestZedXiao

能给我也发一份吗，参考参考另外如果是获取系统的进程有思路吗, sysctl 这个函数也不能获取了邮箱：[email protected] 谢谢

Mar 03 '18 06:03 chestysh

@chestysh https://github.com/aozhimin/iOS-CPUDemo 你要获取系统进程列表，还是系统进程占用的资源？

Mar 06 '18 02:03 aozhimin

大佬我又发现了一个新的问题在debug模式下测试没问题然而release环境下测得值是无穷大的请问这是怎么回事呀？

Mar 09 '18 10:03 BestZedXiao

@BestZedXiao 好的，我这边看是否能重现这个问题

Mar 12 '18 02:03 aozhimin

@iamqk 请问如何做到这个测试的汇编能同时支持arm64和armV7 armV7S

Mar 13 '18 06:03 waiwaib

@waiwaib 分开编译 lipo合成.a

Mar 14 '18 02:03 iamqk

@iamqk 昨天我自己想到这么做了..😀~ 谢谢老哥

Mar 14 '18 03:03 waiwaib

@waiwaib 大佬请教下你在release 环境测试会出现问题么 debug没问题

Mar 14 '18 03:03 BestZedXiao

@BestZedXiao 不会,可以正常 Archive.

Mar 14 '18 03:03 waiwaib

@waiwaib 不是我是说你在release环境跑过吗打包没问题但是测得数据有问题

Mar 14 '18 03:03 BestZedXiao

想要获取系统所有进程列表，有办法解决吗，在高系统版本不好处理

2018-03-14 11:16 GMT+08:00 BestZedXiao [email protected]:

@waiwaib https://github.com/waiwaib 不是我是说你在release环境跑过吗打包没问题但是测得数据有问题

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Mar 14 '18 06:03 chestysh

能否解释下为什么是用：double freq = 1300000.0 / time;来计算CPU频率呢？我知道了，汇编中用了130条add指令，而每次执行10000次，所以1300000除以耗时即得频率了

Mar 15 '18 05:03 thameslu

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发现获取cpu频率的函数iOS上并不能正常工作

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