版本记录

版本号	时间
V1.0	2020.06.24 星期三

前言

很多时候我们做APP，不是完成相关的功能就行，很多时候需要我们不断的进行优化，特别对于像淘宝和微信等巨型app来说，如果没有优化，那会是什么样的结果，一定会有很多人“脱坑”，又何谈发展啊。感兴趣的可以看一下上一篇。
1. iOS性能优化（一）
2. iOS性能优化（二）
3. iOS性能优化（三）
4. iOS性能优化（四） —— 内存优化之泄露及其检测（一）

CPU数目

首先要引入相关的头文件

#import <UIKit/UIKit.h>
#include <sys/sysctl.h>
#include <mach/mach.h>
#include <mach/task_info.h>

下面就是简单的源码了

+ (uint64_t)cpuNumber
{
    return [NSProcessInfo processInfo].activeProcessorCount;
}

app使用的CPU数

+ (uint64_t)appCPUUsage
{
    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(), MACH_TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }
    
    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;
    
    // get threads in the task
    kr = task_threads(mach_task_self(), &thread_list, &thread_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }
    
    long total_time     = 0;
    long total_userTime = 0;
    CGFloat total_cpu   = 0;
    int j;
    
    // for each thread
    for (j = 0; j < (int)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 -1;
        }
        
        basic_info_th = (thread_basic_info_t)thinfo;
        
        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {
            total_time     = total_time + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;
            total_userTime = total_userTime + basic_info_th->user_time.microseconds + basic_info_th->system_time.microseconds;
            total_cpu      = total_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100;
        }
    }
    
    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    
    return total_cpu;
}

总共使用的CPU数

+ (uint64_t)totleCPUUsage {
    kern_return_t kr;
    mach_msg_type_number_t count;
    static host_cpu_load_info_data_t previous_info = {0, 0, 0, 0};
    host_cpu_load_info_data_t info;
    
    count = HOST_CPU_LOAD_INFO_COUNT;
    
    kr = host_statistics(mach_host_self(), HOST_CPU_LOAD_INFO, (host_info_t)&info, &count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }
    
    natural_t user   = info.cpu_ticks[CPU_STATE_USER] - previous_info.cpu_ticks[CPU_STATE_USER];
    natural_t nice   = info.cpu_ticks[CPU_STATE_NICE] - previous_info.cpu_ticks[CPU_STATE_NICE];
    natural_t system = info.cpu_ticks[CPU_STATE_SYSTEM] - previous_info.cpu_ticks[CPU_STATE_SYSTEM];
    natural_t idle   = info.cpu_ticks[CPU_STATE_IDLE] - previous_info.cpu_ticks[CPU_STATE_IDLE];
    natural_t total  = user + nice + system + idle;
    previous_info    = info;
    
    CGFloat useage = (user + nice + system) * 100.0 / total;
    return useage * [self cpuNumber];
}

app内存使用

+ (uint64_t)appMemoryUsage {
    int64_t memory = 0;
    task_vm_info_data_t vmInfo;
    mach_msg_type_number_t count = TASK_VM_INFO_COUNT;
    kern_return_t kernelReturn = task_info(mach_task_self(), TASK_VM_INFO, (task_info_t) &vmInfo, &count);
    if(kernelReturn == KERN_SUCCESS) {
        memory = (int64_t) vmInfo.phys_footprint;
    }
    return memory;
}

总的内存使用

+ (uint64_t)totleMemoryUsage {
    size_t length = 0;
    int mib[6] = {0};
    
    int pagesize = 0;
    mib[0] = CTL_HW;
    mib[1] = HW_PAGESIZE;
    length = sizeof(pagesize);
    if (sysctl(mib, 2, &pagesize, &length, NULL, 0) < 0) {
        return 0;
    }
    
    mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
    vm_statistics_data_t vmstat;
    
    if (host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vmstat, &count) != KERN_SUCCESS) {
        return 0;
    }
    
    int wireMem = vmstat.wire_count * pagesize;
    int activeMem = vmstat.active_count * pagesize;
    
    uint64_t memory = wireMem + activeMem;
    
    return memory;
}

释放的内存

+ (uint64_t)freeMemoryUsage
{
    vm_statistics64_data_t vmStats;
    mach_msg_type_number_t infoCount = HOST_VM_INFO_COUNT;
    kern_return_t kernReturn = host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vmStats, &infoCount);
    
    if (kernReturn != KERN_SUCCESS) {
        return NSNotFound;
    }
    uint64_t memory = vm_page_size * (vmStats.free_count + vmStats.inactive_count);
    
    return memory;
}