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MC-2523

Redstone loops get broken timings.

https://www.youtube.com/watch?v=PmXkJIC0Agc

A redstone loop, consisting of 3 repeaters and two torches, acting as a timing loop, will get locked into a stable state, or get an altered timing.

First seen in 125 multiplayer (very common); never happened in 125 single player.

Still happens – much less frequently – in 142.

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Bug is still present in 13w05b
Looks like redstone torches still receive random block updates.
In multiplayer, though, the issue probably lies in block update limit which can get part of your redstone updates postponed to the nex tick.

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Confirmed.

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Sorry. Was in 145; will recheck 147, but not expecting any difference.

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Ahh – someone else has tested this for me 🙂

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I haven't seen any mention of this in the release notes for the snapshots, and I do not have an easy way to test this right now. (BTW: I love that 5 torch dual-loop!). Is this still active, or has it been fixed yet?

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Still present in 13w10b.

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Still present in 1.5 pre-release.
http://youtu.be/aR2Kz2N05SM

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Still in 152.
I have not yet tested in 16x.

CubeTheThird

Is this still a concern in the current Minecraft version 1.6.4 / Launcher version 1.2.5 ? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

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Whoops, yes. Still present in 164.
Will retest in 174 "real soon now" 🙂

galaxy_2alex

Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

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It is probably the same as MC-56541 which ZipKrowd members Kabo and Panda have provided a fix for,

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Unlikely to be the same, but might point to something similar.

I looked, and their list of classes does not include the repeater. Maybe what is being seen has the same issue as that.

To clarify: There is an attachment that shows a loop of just redstone torches; that is easy to show the timing error, and is almost certainly the issue that they found (that random block updates interfere with time sensitive scheduled updates – I agree that the call for a scheduled update should not be the same as the call for a random update). But what I originally found this in, and showed in the video I linked, had repeaters and was not just going into timing error, but steady state – including an "impossible" to get to but stable once obtained state.

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Hmm, need to retest in 1.7.10 ...

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Ok, tested in 1.7.9.

Actually rebuilt both circuits in a new world.

The pure torch loop fails fairly quickly. The torch and repeater loop takes longer to fail, but still fails.

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The problem effects torches which are part of the loop!
Also the image is of loops only consisting of torches.

Random update is for dealing with burned out torches, but the timing fault may result in torches remaining permanently on, which never gets fixed.

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Oh. My video in the original post showed my original circuit – a little more complicated. Basically, an R/S Nor latch, with 3 repeaters at length 4 – two on one side of the circuit, and one on the other side. A "doorbell" button that fed into the circuit, and noteblocks (plus a redstone torch) as outputs.

Gave a nice, "stable" doorbell while playing single player. It actually worked properly in 125 single player. That was the last time that complicated redstone circuits worked without timing issues – heck, instant wire worked across unloaded chunks.

That it worked in 125 single player, and broke in 125 multiplayer, is why I suspect that random block updates is not the only issue, even if it fixed other issues. 125 single player would still have had random updates and scheduled updates.

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Actually, there is something else.

If the issue was that a torch getting a random update would turn on and stay on, then I would probably be seeing a different failure pattern.

The "fail" state is always the impossible state. The circuit should exist in either the "off" state, or the "loop" state – the "on, stable" state should never happen.

The "fail" state is always the "on, stable" state – it never fails into the off state. If I'm understanding what you said about the torches getting random updates and going bad, them 1 out of three failures should be into the off state.

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Is this still an issue in 14w26b? I've recently committed a fix that removes random updates from redstone devices.

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My computer is in the shop right now so I can't test. Should be back by monday.

(Motherboard failure under warranty)

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AAarrrggh.

I cannot find that test world! I have checked every save I can find.

galaxy_2alex

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.

Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been deliviered.

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No response for over a year.

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(Unassigned)

Confirmed

Minecraft 1.4.2, Snapshot 13w05b, Snapshot 13w10b, Minecraft 1.5, Minecraft 1.5.2, Minecraft 1.6.4, Minecraft 1.7.9

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