Man page - sg_get_cpu_percents(3)

Packages contas this manual

Manual

sg_get_cpu_stats(3) sg_get_cpu_stats(3)

sg_get_cpu_stats, sg_get_cpu_stats_r, sg_get_cpu_stats_diff, sg_get_cpu_stats_diff_between, sg_get_cpu_percents, sg_get_cpu_percents_of, sg_get_cpu_percents_r, sg_free_cpu_stats - get cpu usage

#include <statgrab.h>


sg_cpu_percents *sg_get_cpu_percents
(size_t *entries);


sg_cpu_percents *sg_get_cpu_percents_of
(sg_cpu_percent_source cps, size_t *entries);


sg_cpu_percents *sg_get_cpu_percents_r
(const sg_cpu_stats *whereof, size_t *entries);


void sg_free_cpu_percents
(sg_cpu_percents *data);


sg_cpu_stats *sg_get_cpu_stats
(size_t *entries);


sg_cpu_stats *sg_get_cpu_stats_diff
(size_t *entries);


sg_cpu_stats *sg_get_cpu_stats_r
(size_t *entries);


sg_cpu_stats *sg_get_cpu_stats_diff_between
(const sg_cpu_stats *cpu_now, const sg_cpu_stats *cpu_last, size_t *entries);


sg_error sg_free_cpu_stats
(sg_cpu_stats *data);

These are the categories of data delivered by the cpu stats module: sg_get_cpu_stats() and sg_get_cpu_stats_r() deliver native cpu counters since the machine has been started, sg_get_cpu_stats_diff() and sg_get_cpu_stats_diff_between() deliver native cpu counters between two sg_get_cpu_stats() calls and sg_get_cpu_percents_of() and sg_get_cpu_percents_r() deliver correlated relative cpu counters (where total is 100%).

API Shortcut

function returns data owner
sg_get_cpu_stats sg_cpu_stats * libstatgrab (thread local)
sg_get_cpu_stats_r sg_cpu_stats * caller
sg_get_cpu_stats_diff sg_cpu_stats * libstatgrab (thread local)
sg_get_cpu_stats_diff_between sg_cpu_stats * caller
sg_get_cpu_percents_of sg_cpu_percents * libstatgrab (thread local)
sg_get_cpu_percents_r sg_cpu_percents * caller

The sg_cpu_stats buffer received from sg_get_cpu_stats_r() and the sg_get_cpu_stats_diff_between() as well as the sg_cpu_percents buffer received from sg_get_cpu_percents_r() must be freed using sg_free_cpu_stats() or the sg_free_cpu_percents(), respectively, when not needed any more. The caller is responsible for doing it.

The value stored (the "ticks") will vary between operating systems. For example Solaris has a total of 100 per second, while Linux has substantially more. Also, different operating systems store different information - you won't find nice cpu on Solaris for example.

Modern systems shall provide information about the clock tick resolution by invoking sysconf(_SC_CLK_TCK).

There are two structures returned by the CPU statistics functions.

typedef struct {


        unsigned long long user;


        unsigned long long kernel;


        unsigned long long idle;


        unsigned long long iowait;


        unsigned long long swap;


        unsigned long long nice;


        unsigned long long total;


        unsigned long long context_switches;


        unsigned long long voluntary_context_switches;


        unsigned long long involuntary_context_switches;


        unsigned long long syscalls;


        unsigned long long interrupts;


        unsigned long long soft_interrupts;


        time_t systime;
} sg_cpu_stats;


    

typedef struct {


        double user;


        double kernel;


        double idle;


        double iowait;


        double swap;


        double nice;


        time_t time_taken;
} sg_cpu_percents;
The different CPU states.
The different program actions on CPU.
The time taken in seconds since the last call of the function, or the system time.

statgrab(3)

⟨https://libstatgrab.org/⟩

2019-03-08 libstatgrab