// Linux / Unix: Use clock_gettime() with CLOCK_MONOTONIC_RAW
#include <stdio.h>
#include <time.h>
long long get_ticks_ns() {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
return (long long)ts.tv_sec * 1000000000LL + ts.tv_nsec;
}
int main() {
long long start = get_ticks_ns();
// Do some work
for (volatile int i = 0; i < 1000000; i++);
long long end = get_ticks_ns();
long long elapsed_ns = end - start;
double elapsed_us = elapsed_ns / 1000.0;
double elapsed_ms = elapsed_ns / 1000000.0;
double elapsed_s = elapsed_ns / 1000000000.0;
printf("Elapsed ticks (ns): %lld\n", elapsed_ns);
printf("Elapsed microseconds: %.3f\n", elapsed_us);
printf("Elapsed milliseconds: %.3f\n", elapsed_ms);
printf("Elapsed seconds: %.9f\n", elapsed_s);
// Frequency = ticks per second
long long frequency = 1000000000LL;
printf("Timer frequency: %lld Hz\n", frequency);
return 0;
}
/*
run:
Elapsed ticks (ns): 522641
Elapsed microseconds: 522.641
Elapsed milliseconds: 0.523
Elapsed seconds: 0.000522641
Timer frequency: 1000000000 Hz
*/
