Support for mocking Process.clock_gettime via Timecop

[chrisbutcher]

It would be great to be able to freeze and travel time returned by this method.

https://ruby-doc.org/core-2.4.2/Process.html#method-c-clock_gettime

More on monotonic clocks: https://www.softwariness.com/articles/monotonic-clocks-windows-and-posix/

[evan-stripe]

(It'd be helpful if this worked on CLOCK_REALTIME as well as CLOCK_MONOTONIC - we're moving some particularly performance-sensitive code to use Process.clock_gettime(Process::CLOCK_REALTIME) instead of Time.now to avoid an object allocation)

[joshuacronemeyer]

i've got to spend some time with @wishdev's PR, play around with it and do some tests but think this will be a nice new feature to have in our next release.

[adfoster-r7]

This functionality would be great to add, and it looks like there's a PR to deliver it as well - let me know if there's anything we can do to help here 👍

[joshuacronemeyer]

thanks @adfoster-r7 this slipped off my radar. The PR never had passing tests. I haven't played with it either to see how it works.

[ecerulm]

This was closed as completed but still it's not implemented as of timecop 0.9.8 . I checked with

  def test_process_clock_gettime_fail
    time1 = Time.now
    Timecop.freeze(time1) do
      time2 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
      sleep 1
      time3 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
      assert_equal time2, time3
    end
  end

The time obtained via Process.clock_gettime is not influenced by timecop.

@joshuacronemeyer , is this issue closed because it's decided that timecop will never support Process.clock_gettime?

Can I suggest to mention README.md in the homepage directly that Process.clock_gettime is out of the scope?

It provides a unified method to mock Time.now, Date.today, and DateTime.now in a single call (NOTE: Process.clock_gettime is not mocked by timecop)

[joshuacronemeyer]

@ecerulm thanks for checking in on this. I just closed this because it was old and nobody was working on it. Not because we're not open to this functionality.

I don't know much about it. I see we had this PR that was here before I started working on the project: #258

I think we just need somebody to champion a properly tested, working PR.