sg_get_cpu_stats_diff_between(3)

NAME

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

SYNOPSIS

FC#include <statgrab.h>F[0]

FCsg_cpu_percents *sg_get_cpu_percentsF[0] FC(size_t *entries);F[0]

FCsg_cpu_percents *sg_get_cpu_percents_ofF[0] FC(sg_cpu_percent_source cps, size_t *entries);F[0]

FCsg_cpu_percents *sg_get_cpu_percents_rF[0] FC(const sg_cpu_stats *whereof, size_t *entries);F[0]

FCvoid sg_free_cpu_percentsF[0] FC(sg_cpu_percents *data);F[0]

FCsg_cpu_stats *sg_get_cpu_statsF[0] FC(size_t *entries);F[0]

FCsg_cpu_stats *sg_get_cpu_stats_diffF[0] FC(size_t *entries);F[0]

FCsg_cpu_stats *sg_get_cpu_stats_rF[0] FC(size_t *entries);F[0]

FCsg_cpu_stats *sg_get_cpu_stats_diff_betweenF[0] FC(const sg_cpu_stats *cpu_now, const sg_cpu_stats *cpu_last, size_t *entries);F[0]

FCsg_error sg_free_cpu_statsF[0] FC(sg_cpu_stats *data);F[0]

DESCRIPTION

These are the categories of data delivered by the cpu stats module: FCsg_get_cpu_statsF[0]() and FCsg_get_cpu_stats_rF[0]() deliver native cpu counters since the machine has been started, FCsg_get_cpu_stats_diffF[0]() and FCsg_get_cpu_stats_diff_betweenF[0]() deliver native cpu counters between two FCsg_get_cpu_statsF[0]() calls and FCsg_get_cpu_percents_ofF[0]() and FCsg_get_cpu_percents_rF[0]() deliver correlated relative cpu counters (where total is 100%).

API Shortcut

function	returns	data owner
sg_get_cpu_stats	FCsg_cpu_statsF[0] *	libstatgrab (thread local)
sg_get_cpu_stats_r	FCsg_cpu_statsF[0] *	caller
sg_get_cpu_stats_diff	FCsg_cpu_statsF[0] *	libstatgrab (thread local)
sg_get_cpu_stats_diff_between	FCsg_cpu_statsF[0] *	caller
sg_get_cpu_percents_of	FCsg_cpu_percentsF[0] *	libstatgrab (thread local)
sg_get_cpu_percents_r	FCsg_cpu_percentsF[0] *	caller

The FCsg_cpu_statsF[0] buffer received from FCsg_get_cpu_stats_rF[0]() and the FCsg_get_cpu_stats_diff_betweenF[0]() as well as the FCsg_cpu_percentsF[0] buffer received from FCsg_get_cpu_percents_rF[0]() must be freed using FCsg_free_cpu_statsF[0]() or the FCsg_free_cpu_percentsF[0](), 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 FCsysconf(_SC_CLK_TCK)F[0].

RETURN VALUES

There are two structures returned by the CPU statistics functions.

FC
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;
    F[0]

FC
typedef struct {
        double user;
        double kernel;
        double idle;
        double iowait;
        double swap;
        double nice;
        time_t time_taken;
} sg_cpu_percents;
    F[0]

FCuserF[0] FCkernelF[0] FCidleF[0] FCiowaitF[0] FCswapF[0] FCniceF[0] FCtotalF[0]: The different CPU states.

FCcontext_switchesF[0] FCvoluntary_context_switchesF[0] FCinvoluntary_context_switchesF[0] FCsyscallsF[0] FCinterruptsF[0] FCsoft_interruptsF[0]: The different program actions on CPU.

FCsystimeF[0] FCtime_takenF[0]: The time taken in seconds since the last call of the function, or the system time.

WEBSITE

⟨https://libstatgrab.org/⟩