os.uptime returns float instead of integer

[davedodo]

Version

v14.18.3

Platform

Linux 5.4.0 #1 SMP Thu Apr 22 16:18:59 MSK 2021 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

os

What steps will reproduce the bug?

I just upgraded from Node.js 12 to 14 (on Ubuntu via nodesource repository) and found that require("os").uptime() now returns a float and no longer an integer as the documentation states. Tested on Ubuntu 18.04 on VirtualBox and Ubuntu 20.04 on a Virtuozzo container. So this is either a bug or the documentation needs an update.

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior?

os.uptime should return an integer.

What do you see instead?

os.uptime returns a number that is not an integer.

Additional information

No response

[richardlau]

Some history #12291.

[lal12]

Yes I've noticed this too. There was a change in libuv (libuv/libuv@77a2394) which now reads /proc/uptime instead of using clock_gettime(CLOCK_MONOTONIC and /proc/uptime contains a fractional output. So either this behavior should be changed or the docs should be adjusted to say that it is a fractional number on some systems. I would prefer fractional seconds, since a math.floor is easily doable and a higher precision might be useful sometimes.

[lal12]

I created an additional issue for this in libuv libuv/libuv#3447

[davedodo]

@lal12 You are correct. Funny, this change is related to bug report #36244 I filed in 2020 because clock_gettime doesn't work properly inside OpenVZ/Virtuozzo containers. Fractional seconds are cool, but it would be a breaking change. 🤔

[lal12]

It depends a bit on how you define a breaking change, there is no datatype change so nothing what totally breaks. But yeah it can lead to strange behavior if someone relies on an integer. I found this issue since some number formatting code of ours relied on integers.

However for quite a while windows has returned fractionals in this API, which also was changed.

[lal12]

libuv already returned fractional uptime for some architecture, just did a PR there to return fractions on win. So changing this to round down would be a "breaking" change too, especially since some versions are already released with this behavior. I really think updating the docs accordingly is best.

I can do a PR if wished for.

[santigimeno]

This should be fixed as #42340 has landed