function::gettimeofday_ns - Linux

Overview

function::gettimeofday_ns fetches the current time accurate to nanoseconds. It’s primarily utilized for precise timing measurements in applications that require high temporal resolution.

Syntax

int gettimeofday_ns(struct timespec *ts);

Parameters:

  • ts: Pointer to a timespec structure to store the time results.

Options/Flags

None.

Examples

Get current time accurately.

#include <time.h>

struct timespec ts;
gettimeofday_ns(&ts);

printf("Current time: %lld seconds, %ld nanoseconds\n", (long long)ts.tv_sec, ts.tv_nsec);

Measure execution time of a function.

struct timespec start, end;
gettimeofday_ns(&start);

// Function execution...

gettimeofday_ns(&end);

double elapsed = (end.tv_sec - start.tv_sec) + (end.tv_nsec - start.tv_nsec) * 1e-9;
printf("Function execution time: %.6f seconds\n", elapsed);

Common Issues

  • Invalid pointer: Ensure ts is a valid pointer to a timespec structure.

Integration

With clock_gettime():

struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
printf("Current time: %lld seconds, %ld nanoseconds\n", (long long)ts.tv_sec, ts.tv_nsec);

With nanosleep():

struct timespec sleep_time = {0, 500000000}; // 500 ms
nanosleep(&sleep_time, NULL);

Related Commands

  • clock_gettime()
  • nanosleep()
  • time()