ios获取内存信息

#import <sys/types.h>
#import <sys/sysctl.h>
#import <mach/host_info.h>
#import <mach/mach_host.h>
#import <mach/task_info.h>
#import <mach/task.h>

-(void) logMemoryInfo {
    
    
    int mib[6];
    mib[0] = CTL_HW;
    mib[1] = HW_PAGESIZE;
    
    int pagesize;
    size_t length;
    length = sizeof (pagesize);
    if (sysctl (mib, 2, &pagesize, &length, NULL, 0) < 0)
    {
        fprintf (stderr, "getting page size");
    }
    
    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)
    {
        fprintf (stderr, "Failed to get VM statistics.");
    }
    task_basic_info_64_data_t info;
    unsigned size = sizeof (info);
    task_info (mach_task_self (), TASK_BASIC_INFO_64, (task_info_t) &info, &size);
    
    double unit = 1024 * 1024;
    double total = (vmstat.wire_count + vmstat.active_count + vmstat.inactive_count + vmstat.free_count) * pagesize / unit;
    double wired = vmstat.wire_count * pagesize / unit;
    double active = vmstat.active_count * pagesize / unit;
    double inactive = vmstat.inactive_count * pagesize / unit;
    double free = vmstat.free_count * pagesize / unit;
    double resident = info.resident_size / unit;
    NSLog(@"===================================================");
    NSLog(@"Total:%.2lfMb", total);
    NSLog(@"Wired:%.2lfMb", wired);
    NSLog(@"Active:%.2lfMb", active);
    NSLog(@"Inactive:%.2lfMb", inactive);
    NSLog(@"Free:%.2lfMb", free);
    NSLog(@"Resident:%.2lfMb", resident);
}