Other Alias
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_rSYNOPSIS
#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);
DESCRIPTION
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).
RETURN VALUES
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;
- user kernel idle iowait swap nice total
- The different CPU states.
- context_switches voluntary_context_switches involuntary_context_switches syscalls interrupts soft_interrupts
- The different program actions on CPU.
- systime time_taken
- The time taken in seconds since the last call of the function, or the system time.