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gotimeclock

Get monotonic time, same as CLOCK_MONOTONIC

How can I get the monotonic time from boot in nanoseconds in Go? I need the same value that the following C code would return:

static unsigned long get_nsecs(void)
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);
    return ts.tv_sec * 1000000000UL + ts.tv_nsec;
}

The functions in the time package seem to return the current time and/or date.

Solution

  • Use Go with cgo.

    Use unsigned long long to guarantee a 64-bit integer value for nanoseconds. For example, on Windows, unsigned long is a 32-bit integer value.

    monotonic.go:

    package main

import "fmt"

/*
#include <time.h>
static unsigned long long get_nsecs(void)
{
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    return (unsigned long long)ts.tv_sec * 1000000000UL + ts.tv_nsec;
}
*/
import "C"

func main() {
    monotonic := uint64(C.get_nsecs())
    fmt.Println(monotonic)
}

    $ go run monotonic.go
10675342462493
$