Get detailed iOS CPU usage with different states - ios

Question

How to get CPU usage with different states in IOS for example
1.Idle
2.Running a user space
3.Running the kernel/system
The CPU usage example such as this provide total CPU usage only like below.How can I check the different states within the usage?
Any help?
A general usage example available mostly is like below :
- (NSString *)cpuUsage
{
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 #"NA";
}
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 #"NA";
}
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 nil;
}
basic_info_th = (thread_basic_info_t)thinfo;
if (!(basic_info_th->flags & TH_FLAGS_IDLE))
{
//This is 0
tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;
//This is 0
tot_usec = tot_usec + basic_info_th->system_time.microseconds + basic_info_th->system_time.microseconds;
//This is total
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);
return [NSString stringWithFormat:#"%.2f",tot_cpu];
}
Edit
I did try the sample mentioned .here but the kernel/system reading always return 0 on actual device.
Is it correct? I am not sure.

Answer 1

Try this Objective-C class;
Get current App CPU usage SystemMonitor.cpuUsage()
Get total CPU usage SystemMonitor.usage()
SystemMonitor.h
#ifndef SystemMonitor_h
#define SystemMonitor_h
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
typedef struct {
unsigned int system;
unsigned int user;
unsigned int nice;
unsigned int idle;
} CPUUsage;
#interface SystemMonitor: NSObject
+ (CPUUsage)cpuUsage;
+ (CGFloat)appCpuUsage;
#end
#endif /* SystemMonitor_h */
SystemMonitor.m
#import <Foundation/Foundation.h>
#import "SystemMonitor.h"
#import <sys/sysctl.h>
#import <mach/mach.h>
#import <sys/stat.h>
#implementation SystemMonitor
+ (CPUUsage)cpuUsage {
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;
CPUUsage usage = {0, 0, 0, 1};
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 usage;
}
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;
usage.user = user;
usage.system = system;
usage.nice = nice;
usage.idle = idle;
//return (user + nice + system) * 100.0 / total;
return usage;
}
static NSUInteger const kMaxPercent = 100;
+ (CGFloat)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 * kMaxPercent;
}
}
kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
assert(kr == KERN_SUCCESS);
return total_cpu;
}
#end